From a1a43d16f56a8dff1a97f1958d1b995b490eaff3 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:13:54 +0530
Subject: [PATCH 01/30] Add ls subcommand

---
 src/main/Main.hs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/main/Main.hs b/src/main/Main.hs
index 928b5ab645..0cc9563f30 100644
--- a/src/main/Main.hs
+++ b/src/main/Main.hs
@@ -71,6 +71,7 @@ import           Stack.Fetch
 import           Stack.FileWatch
 import           Stack.Ghci
 import           Stack.Hoogle
+import           Stack.Ls
 import qualified Stack.IDE as IDE
 import qualified Stack.Image as Image
 import           Stack.Init
@@ -285,6 +286,10 @@ commandLineHandler currentDir progName isInterpreter = complicatedOptions
                     "Print out handy path information"
                     pathCmd
                     Stack.Path.pathParser
+        addCommand' "ls"
+                    "List latest Stackage snapshots"
+                    lsCmd
+                    lsParser
         addCommand' "unpack"
                     "Unpack one or more packages locally"
                     unpackCmd

From 8bec20e8115f8b63dec16bbaf3af46ad1a4cab6b Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:14:03 +0530
Subject: [PATCH 02/30] Implement the module implementing the relevant features

---
 src/Stack/Ls.hs | 181 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 src/Stack/Ls.hs

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
new file mode 100644
index 0000000000..0e5bb9e709
--- /dev/null
+++ b/src/Stack/Ls.hs
@@ -0,0 +1,181 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+
+module Stack.Ls where
+
+import Control.Exception (Exception)
+import Control.Monad.Catch (MonadThrow)
+import Control.Monad.IO.Class (MonadIO, liftIO)
+import Control.Monad.Reader (MonadReader)
+import Data.Aeson
+import qualified Data.Aeson.Types as A
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.List as L
+import Data.Monoid
+import Data.Text
+import qualified Data.Text.IO as T
+import Data.Typeable (Typeable)
+import qualified Data.Vector as V
+import Network.HTTP.Simple
+       (Request, Response, addRequestHeader, getResponseBody, httpJSON,
+        httpJSONEither, httpLbs, parseRequest)
+import Network.HTTP.Types.Header (hAccept)
+import qualified Options.Applicative as OA
+import Path
+import Stack.Runners (withBuildConfig)
+import Stack.Types.Config
+import System.Directory (listDirectory)
+
+data LsView
+    = Local
+    | Remote
+    deriving (Show, Eq, Ord)
+
+data SnapshotType
+    = LtsAndNightly
+    | Lts
+    | Nightly
+    deriving (Show, Eq, Ord)
+
+data LsCmdOpts = LsCmdOpts
+    { lsView :: LsView
+    , lsLtsSnapView :: Bool
+    , lsNightlySnapView :: Bool
+    } deriving (Eq, Show, Ord)
+
+data Snapshot = Snapshot
+    { snapId :: Text
+    , snapTitle :: Text
+    , snapTime :: Text
+    } deriving (Show, Eq, Ord)
+
+data SnapshotData = SnapshotData
+    { snapTotalCounts :: Integer
+    , snaps :: [[Snapshot]]
+    } deriving (Show, Eq, Ord)
+
+toSnapshot :: [Value] -> Snapshot
+toSnapshot ((String sid):(String stitle):(String stime):[]) =
+    Snapshot {snapId = sid, snapTitle = stitle, snapTime = stime}
+toSnapshot _ = undefined
+
+data LsException =
+    ParseFailure Request
+                 (Response ())
+    deriving (Show, Typeable)
+
+instance Exception LsException
+
+parseSnapshot :: Value -> A.Parser Snapshot
+parseSnapshot =
+    A.withArray "array of snapshot" (\val -> return $ toSnapshot (V.toList val))
+
+instance FromJSON Snapshot where
+    parseJSON o@(Array _) = parseSnapshot o
+    parseJSON _ = mempty
+
+instance FromJSON SnapshotData where
+    parseJSON (Object s) =
+        SnapshotData <$> s .: "totalCount" <*> s .: "snapshots"
+    parseJSON _ = mempty
+
+displaySnap :: Snapshot -> IO ()
+displaySnap snapshot = do
+    T.putStrLn $ "Resolver name: " <> snapId snapshot
+    T.putStrLn $ snapTitle snapshot
+    putStrLn ""
+    putStrLn ""
+
+displayTime :: Snapshot -> IO ()
+displayTime snapshot = do
+    T.putStrLn $ snapTime snapshot
+    putStrLn ""
+
+displaySingleSnap :: [Snapshot] -> IO ()
+displaySingleSnap snapshots =
+    case snapshots of
+        [] -> return ()
+        (x:xs) -> do
+            displayTime x
+            displaySnap x
+            mapM_ displaySnap xs
+
+displaySnapshotData :: SnapshotData -> IO ()
+displaySnapshotData sdata =
+    case (L.reverse $ snaps sdata) of
+        [] -> return ()
+        xs -> mapM_ displaySingleSnap xs
+
+filterSnapshotData :: SnapshotData -> SnapshotType -> SnapshotData
+filterSnapshotData sdata stype = sdata {snaps = filterSnapData}
+  where
+    snapdata = snaps sdata
+    filterSnapData =
+        case stype of
+            Lts ->
+                L.map
+                    (\s -> L.filter (\x -> isPrefixOf "lts" (snapId x)) s)
+                    snapdata
+            Nightly ->
+                L.map
+                    (\s -> L.filter (\x -> isPrefixOf "nightly" (snapId x)) s)
+                    snapdata
+
+displayLocalSnapshot :: [String] -> IO ()
+displayLocalSnapshot xs = mapM_ putStrLn xs
+
+handleLocal ::
+       (MonadIO m, MonadThrow m, MonadReader env m, HasEnvConfig env)
+    => LsCmdOpts
+    -> m ()
+handleLocal lsOpts = do
+    (instRoot :: Path Abs Dir) <- installationRootDeps
+    let snapRootDir = parent $ parent $ instRoot
+    snapData <- liftIO $ listDirectory $ toFilePath snapRootDir
+    case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
+        (True, False) ->
+            liftIO $
+            displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
+        (False, True) ->
+            liftIO $
+            displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
+        _ -> liftIO $ displayLocalSnapshot snapData
+
+lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
+lsCmd lsOpts go =
+    case (lsView lsOpts) of
+        Local -> withBuildConfig go (handleLocal lsOpts)
+        Remote -> do
+            req <- parseRequest "http://localhost:3000/snapshots"
+            let req' = addRequestHeader hAccept "application/json" req
+            result <- httpJSON req'
+            let snapData = getResponseBody result
+            case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
+                (True, False) ->
+                    liftIO $
+                    displaySnapshotData $ filterSnapshotData snapData Lts
+                (False, True) ->
+                    liftIO $
+                    displaySnapshotData $ filterSnapshotData snapData Nightly
+                _ -> liftIO $ displaySnapshotData snapData
+
+lsParser :: OA.Parser LsCmdOpts
+lsParser =
+    LsCmdOpts <$> (OA.hsubparser (lsViewLocalCmd <> lsViewRemoteCmd)) <*>
+    (OA.switch
+         ((OA.long "lts") <> (OA.short 'l') <> OA.help ("Just show lts view"))) <*>
+    (OA.switch
+         ((OA.long "nightly") <> (OA.short 'n') <>
+          OA.help ("Just show nightly view")))
+
+lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
+lsViewLocalCmd =
+    OA.command
+        "local"
+        (OA.info (pure Local) (OA.progDesc "View it in your local system"))
+
+lsViewRemoteCmd :: OA.Mod OA.CommandFields LsView
+lsViewRemoteCmd =
+    OA.command
+        "remote"
+        (OA.info (pure Remote) (OA.progDesc "View remote snapshot"))

From 7d87e8726f2e36a4dcae0ffe726d05abf64c3c83 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:14:14 +0530
Subject: [PATCH 03/30] Expose the module

---
 stack.cabal | 1 +
 1 file changed, 1 insertion(+)

diff --git a/stack.cabal b/stack.cabal
index c4ea24f123..b4378a288a 100644
--- a/stack.cabal
+++ b/stack.cabal
@@ -114,6 +114,7 @@ library
                      Stack.IDE
                      Stack.Image
                      Stack.Init
+                     Stack.Ls
                      Stack.New
                      Stack.Nix
                      Stack.Options.BenchParser

From e7910e5e9d67c6847884ef43fe5df50b04ef9a21 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:15:16 +0530
Subject: [PATCH 04/30] Code cleanup

---
 src/Stack/Ls.hs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 0e5bb9e709..4533024f7e 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -9,7 +9,6 @@ import Control.Monad.IO.Class (MonadIO, liftIO)
 import Control.Monad.Reader (MonadReader)
 import Data.Aeson
 import qualified Data.Aeson.Types as A
-import qualified Data.ByteString.Lazy as BL
 import qualified Data.List as L
 import Data.Monoid
 import Data.Text
@@ -18,7 +17,7 @@ import Data.Typeable (Typeable)
 import qualified Data.Vector as V
 import Network.HTTP.Simple
        (Request, Response, addRequestHeader, getResponseBody, httpJSON,
-        httpJSONEither, httpLbs, parseRequest)
+        parseRequest)
 import Network.HTTP.Types.Header (hAccept)
 import qualified Options.Applicative as OA
 import Path
@@ -32,8 +31,7 @@ data LsView
     deriving (Show, Eq, Ord)
 
 data SnapshotType
-    = LtsAndNightly
-    | Lts
+    = Lts
     | Nightly
     deriving (Show, Eq, Ord)
 

From c8d4badea3d26cfa2b2b2d0c60970946ecaa2f2a Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:28:34 +0530
Subject: [PATCH 05/30] More cleanup and some formatting done

---
 src/Stack/Ls.hs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 4533024f7e..3e5d175001 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -23,6 +23,7 @@ import qualified Options.Applicative as OA
 import Path
 import Stack.Runners (withBuildConfig)
 import Stack.Types.Config
+import System.Console.ANSI
 import System.Directory (listDirectory)
 
 data LsView
@@ -82,11 +83,12 @@ displaySnap snapshot = do
     T.putStrLn $ "Resolver name: " <> snapId snapshot
     T.putStrLn $ snapTitle snapshot
     putStrLn ""
-    putStrLn ""
 
 displayTime :: Snapshot -> IO ()
 displayTime snapshot = do
+    setSGR [SetColor Foreground Dull Green]
     T.putStrLn $ snapTime snapshot
+    setSGR [Reset]
     putStrLn ""
 
 displaySingleSnap :: [Snapshot] -> IO ()
@@ -129,7 +131,8 @@ handleLocal ::
 handleLocal lsOpts = do
     (instRoot :: Path Abs Dir) <- installationRootDeps
     let snapRootDir = parent $ parent $ instRoot
-    snapData <- liftIO $ listDirectory $ toFilePath snapRootDir
+    snapData' <- liftIO $ listDirectory $ toFilePath snapRootDir
+    let snapData = L.sort snapData'
     case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
         (True, False) ->
             liftIO $

From 91b0dab9bf23a0ba82a2a4133500186c1712622e Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:31:17 +0530
Subject: [PATCH 06/30] Handle exception scenario

---
 src/Stack/Ls.hs | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 3e5d175001..ee1049433c 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -4,6 +4,7 @@
 module Stack.Ls where
 
 import Control.Exception (Exception)
+import Control.Exception.Safe (impureThrow)
 import Control.Monad.Catch (MonadThrow)
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Control.Monad.Reader (MonadReader)
@@ -16,8 +17,7 @@ import qualified Data.Text.IO as T
 import Data.Typeable (Typeable)
 import qualified Data.Vector as V
 import Network.HTTP.Simple
-       (Request, Response, addRequestHeader, getResponseBody, httpJSON,
-        parseRequest)
+       (addRequestHeader, getResponseBody, httpJSON, parseRequest)
 import Network.HTTP.Types.Header (hAccept)
 import qualified Options.Applicative as OA
 import Path
@@ -56,11 +56,10 @@ data SnapshotData = SnapshotData
 toSnapshot :: [Value] -> Snapshot
 toSnapshot ((String sid):(String stitle):(String stime):[]) =
     Snapshot {snapId = sid, snapTitle = stitle, snapTime = stime}
-toSnapshot _ = undefined
+toSnapshot val = impureThrow $ ParseFailure val
 
 data LsException =
-    ParseFailure Request
-                 (Response ())
+    ParseFailure [Value]
     deriving (Show, Typeable)
 
 instance Exception LsException

From 3e3ce5fb83d1a839a71630533fbcbb4248664896 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 18:36:30 +0530
Subject: [PATCH 07/30] Update to the stackage server url

---
 src/Stack/Ls.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index ee1049433c..39b12b16b1 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -146,7 +146,7 @@ lsCmd lsOpts go =
     case (lsView lsOpts) of
         Local -> withBuildConfig go (handleLocal lsOpts)
         Remote -> do
-            req <- parseRequest "http://localhost:3000/snapshots"
+            req <- parseRequest "https://www.stackage.org/snapshots"
             let req' = addRequestHeader hAccept "application/json" req
             result <- httpJSON req'
             let snapData = getResponseBody result

From e4b400cb9c6f630f8254fb640c21c04943f0673e Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 19:27:50 +0530
Subject: [PATCH 08/30] Improve help messages

---
 src/Stack/Ls.hs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 39b12b16b1..8b52f9a22e 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -163,16 +163,17 @@ lsParser :: OA.Parser LsCmdOpts
 lsParser =
     LsCmdOpts <$> (OA.hsubparser (lsViewLocalCmd <> lsViewRemoteCmd)) <*>
     (OA.switch
-         ((OA.long "lts") <> (OA.short 'l') <> OA.help ("Just show lts view"))) <*>
+         ((OA.long "lts") <> (OA.short 'l') <>
+          OA.help ("Only show lts snapshots"))) <*>
     (OA.switch
          ((OA.long "nightly") <> (OA.short 'n') <>
-          OA.help ("Just show nightly view")))
+          OA.help ("Only show nightly snapshots")))
 
 lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
 lsViewLocalCmd =
     OA.command
         "local"
-        (OA.info (pure Local) (OA.progDesc "View it in your local system"))
+        (OA.info (pure Local) (OA.progDesc "View local snapshot"))
 
 lsViewRemoteCmd :: OA.Mod OA.CommandFields LsView
 lsViewRemoteCmd =

From 9e50072f90ad24ce05c3877e3c76ebc749a75d8e Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 19:30:26 +0530
Subject: [PATCH 09/30] Update Changelog

---
 ChangeLog.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index f5415505b9..a2d4829ca6 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -15,6 +15,8 @@ Behavior changes:
 
 Other enhancements:
 
+* A new sub command `ls` has been introduced to stack to view
+  local and remote snapshots present in the system.
 * `stack setup` allow to control options passed to ghcjs-boot with
   `--ghcjs-boot-options` (one word at a time) and `--[no-]ghcjs-boot-clean`
 * Updates to store-0.4.1, which has improved performance and better error

From 579828695a468e1ed33e4a30810321c82d51ed34 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 22:44:22 +0530
Subject: [PATCH 10/30] Try fixing build error in stack-7.10 yaml environment

---
 stack-7.10.yaml | 1 +
 stack.cabal     | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/stack-7.10.yaml b/stack-7.10.yaml
index 40b1b8966c..d314a503f8 100644
--- a/stack-7.10.yaml
+++ b/stack-7.10.yaml
@@ -38,3 +38,4 @@ extra-deps:
 - hackage-security-0.5.2.2
 - echo-0.1.3
 - mintty-0.1.1
+- directory-1.3.0.0
diff --git a/stack.cabal b/stack.cabal
index b4378a288a..fb3fc8eef0 100644
--- a/stack.cabal
+++ b/stack.cabal
@@ -207,7 +207,7 @@ library
                    , containers >= 0.5.5.1
                    , cryptonite >= 0.19 && < 0.22
                    , cryptonite-conduit >= 0.1 && < 0.3
-                   , directory >= 1.2.1.0 && < 1.4
+                   , directory >= 1.2.5.0 && < 1.4
                    , echo >= 0.1.3 && < 0.2
                    , either
                    , errors < 2.2

From bcb7f750220fefb5ce74ea0fdef5d1e29631de60 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Fri, 7 Jul 2017 22:59:34 +0530
Subject: [PATCH 11/30] Lower constraint because of process dependency

See this for more information:
https://travis-ci.org/commercialhaskell/stack/jobs/251237747
---
 stack-7.10.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stack-7.10.yaml b/stack-7.10.yaml
index d314a503f8..c773688813 100644
--- a/stack-7.10.yaml
+++ b/stack-7.10.yaml
@@ -38,4 +38,4 @@ extra-deps:
 - hackage-security-0.5.2.2
 - echo-0.1.3
 - mintty-0.1.1
-- directory-1.3.0.0
+- directory-1.2.5.1

From 0e14de96c9d77c68ffdf08db6ae1ce16ae1808b9 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sat, 8 Jul 2017 02:30:49 +0530
Subject: [PATCH 12/30] Hlint style fixes

Have to do this to avoid travis CI failures
---
 src/Stack/Ls.hs | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 8b52f9a22e..3dfe21a566 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -54,7 +54,7 @@ data SnapshotData = SnapshotData
     } deriving (Show, Eq, Ord)
 
 toSnapshot :: [Value] -> Snapshot
-toSnapshot ((String sid):(String stitle):(String stime):[]) =
+toSnapshot [String sid, String stitle, String stime] =
     Snapshot {snapId = sid, snapTitle = stitle, snapTime = stime}
 toSnapshot val = impureThrow $ ParseFailure val
 
@@ -101,7 +101,7 @@ displaySingleSnap snapshots =
 
 displaySnapshotData :: SnapshotData -> IO ()
 displaySnapshotData sdata =
-    case (L.reverse $ snaps sdata) of
+    case L.reverse $ snaps sdata of
         [] -> return ()
         xs -> mapM_ displaySingleSnap xs
 
@@ -113,11 +113,11 @@ filterSnapshotData sdata stype = sdata {snaps = filterSnapData}
         case stype of
             Lts ->
                 L.map
-                    (\s -> L.filter (\x -> isPrefixOf "lts" (snapId x)) s)
+                    (\s -> L.filter (\x -> "lts" `isPrefixOf` snapId x) s)
                     snapdata
             Nightly ->
                 L.map
-                    (\s -> L.filter (\x -> isPrefixOf "nightly" (snapId x)) s)
+                    (\s -> L.filter (\x -> "nightly" `isPrefixOf` snapId x) s)
                     snapdata
 
 displayLocalSnapshot :: [String] -> IO ()
@@ -129,7 +129,7 @@ handleLocal ::
     -> m ()
 handleLocal lsOpts = do
     (instRoot :: Path Abs Dir) <- installationRootDeps
-    let snapRootDir = parent $ parent $ instRoot
+    let snapRootDir = parent $ parent instRoot
     snapData' <- liftIO $ listDirectory $ toFilePath snapRootDir
     let snapData = L.sort snapData'
     case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
@@ -143,7 +143,7 @@ handleLocal lsOpts = do
 
 lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
 lsCmd lsOpts go =
-    case (lsView lsOpts) of
+    case lsView lsOpts of
         Local -> withBuildConfig go (handleLocal lsOpts)
         Remote -> do
             req <- parseRequest "https://www.stackage.org/snapshots"
@@ -161,13 +161,13 @@ lsCmd lsOpts go =
 
 lsParser :: OA.Parser LsCmdOpts
 lsParser =
-    LsCmdOpts <$> (OA.hsubparser (lsViewLocalCmd <> lsViewRemoteCmd)) <*>
-    (OA.switch
-         ((OA.long "lts") <> (OA.short 'l') <>
-          OA.help ("Only show lts snapshots"))) <*>
-    (OA.switch
-         ((OA.long "nightly") <> (OA.short 'n') <>
-          OA.help ("Only show nightly snapshots")))
+    LsCmdOpts <$> OA.hsubparser (lsViewLocalCmd <> lsViewRemoteCmd) <*>
+    OA.switch
+         (OA.long "lts" <> OA.short 'l' <>
+          OA.help "Only show lts snapshots") <*>
+    OA.switch
+         (OA.long "nightly" <> OA.short 'n' <>
+          OA.help "Only show nightly snapshots")
 
 lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
 lsViewLocalCmd =

From 9947d9ee49712cbc6a240c82e970c8849115968c Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sat, 8 Jul 2017 02:33:49 +0530
Subject: [PATCH 13/30] Only export lsCmd and lsParser

---
 src/Stack/Ls.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 3dfe21a566..8de3d8dbbb 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
-module Stack.Ls where
+module Stack.Ls (lsCmd, lsParser) where
 
 import Control.Exception (Exception)
 import Control.Exception.Safe (impureThrow)

From ef9aa32100775449050c200a7b7297eaeebb3de5 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sat, 8 Jul 2017 02:44:08 +0530
Subject: [PATCH 14/30] Fix another hlint failure

https://travis-ci.org/commercialhaskell/stack/jobs/251311494#L251
---
 src/Stack/Ls.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 8de3d8dbbb..4c15920295 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -58,7 +58,7 @@ toSnapshot [String sid, String stitle, String stime] =
     Snapshot {snapId = sid, snapTitle = stitle, snapTime = stime}
 toSnapshot val = impureThrow $ ParseFailure val
 
-data LsException =
+newtype LsException =
     ParseFailure [Value]
     deriving (Show, Typeable)
 

From d51783229752b98b0d0cd300a59efb06ed00f876 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sat, 8 Jul 2017 03:41:12 +0530
Subject: [PATCH 15/30] Add no warn for unused-top-binds

---
 src/Stack/Ls.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 4c15920295..53c8c5d7dd 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -1,3 +1,4 @@
+{-# OPTIONS_GHC -fno-warn-unused-top-binds #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 

From fa7fb8b885b83d72abb3f1677f741b57792d3dcd Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sat, 8 Jul 2017 04:32:47 +0530
Subject: [PATCH 16/30] Fix warning at the code level itself

---
 src/Stack/Ls.hs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 53c8c5d7dd..8471330d61 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -1,4 +1,3 @@
-{-# OPTIONS_GHC -fno-warn-unused-top-binds #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
@@ -50,7 +49,7 @@ data Snapshot = Snapshot
     } deriving (Show, Eq, Ord)
 
 data SnapshotData = SnapshotData
-    { snapTotalCounts :: Integer
+    { _snapTotalCounts :: Integer
     , snaps :: [[Snapshot]]
     } deriving (Show, Eq, Ord)
 

From 99edd1b44307e9c183f8df19014c7cbd1589680c Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sat, 8 Jul 2017 17:55:44 +0530
Subject: [PATCH 17/30] Also add tls setting add stackage is https

---
 src/Stack/Ls.hs | 55 ++++++++++++++++++++++++++++---------------------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 8471330d61..633732e826 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -1,7 +1,10 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
-module Stack.Ls (lsCmd, lsParser) where
+module Stack.Ls
+  ( lsCmd
+  , lsParser
+  ) where
 
 import Control.Exception (Exception)
 import Control.Exception.Safe (impureThrow)
@@ -17,7 +20,8 @@ import qualified Data.Text.IO as T
 import Data.Typeable (Typeable)
 import qualified Data.Vector as V
 import Network.HTTP.Simple
-       (addRequestHeader, getResponseBody, httpJSON, parseRequest)
+       (addRequestHeader, getResponseBody, httpJSON, parseRequest,
+        setRequestManager)
 import Network.HTTP.Types.Header (hAccept)
 import qualified Options.Applicative as OA
 import Path
@@ -25,6 +29,7 @@ import Stack.Runners (withBuildConfig)
 import Stack.Types.Config
 import System.Console.ANSI
 import System.Directory (listDirectory)
+import Network.HTTP.Client.TLS (getGlobalManager)
 
 data LsView
     = Local
@@ -55,7 +60,11 @@ data SnapshotData = SnapshotData
 
 toSnapshot :: [Value] -> Snapshot
 toSnapshot [String sid, String stitle, String stime] =
-    Snapshot {snapId = sid, snapTitle = stitle, snapTime = stime}
+    Snapshot
+    { snapId = sid
+    , snapTitle = stitle
+    , snapTime = stime
+    }
 toSnapshot val = impureThrow $ ParseFailure val
 
 newtype LsException =
@@ -106,15 +115,16 @@ displaySnapshotData sdata =
         xs -> mapM_ displaySingleSnap xs
 
 filterSnapshotData :: SnapshotData -> SnapshotType -> SnapshotData
-filterSnapshotData sdata stype = sdata {snaps = filterSnapData}
+filterSnapshotData sdata stype =
+    sdata
+    { snaps = filterSnapData
+    }
   where
     snapdata = snaps sdata
     filterSnapData =
         case stype of
             Lts ->
-                L.map
-                    (\s -> L.filter (\x -> "lts" `isPrefixOf` snapId x) s)
-                    snapdata
+                L.map (\s -> L.filter (\x -> "lts" `isPrefixOf` snapId x) s) snapdata
             Nightly ->
                 L.map
                     (\s -> L.filter (\x -> "nightly" `isPrefixOf` snapId x) s)
@@ -123,10 +133,9 @@ filterSnapshotData sdata stype = sdata {snaps = filterSnapData}
 displayLocalSnapshot :: [String] -> IO ()
 displayLocalSnapshot xs = mapM_ putStrLn xs
 
-handleLocal ::
-       (MonadIO m, MonadThrow m, MonadReader env m, HasEnvConfig env)
-    => LsCmdOpts
-    -> m ()
+handleLocal
+    :: (MonadIO m, MonadThrow m, MonadReader env m, HasEnvConfig env)
+    => LsCmdOpts -> m ()
 handleLocal lsOpts = do
     (instRoot :: Path Abs Dir) <- installationRootDeps
     let snapRootDir = parent $ parent instRoot
@@ -134,11 +143,9 @@ handleLocal lsOpts = do
     let snapData = L.sort snapData'
     case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
         (True, False) ->
-            liftIO $
-            displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
+            liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
         (False, True) ->
-            liftIO $
-            displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
+            liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
         _ -> liftIO $ displayLocalSnapshot snapData
 
 lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
@@ -147,27 +154,27 @@ lsCmd lsOpts go =
         Local -> withBuildConfig go (handleLocal lsOpts)
         Remote -> do
             req <- parseRequest "https://www.stackage.org/snapshots"
-            let req' = addRequestHeader hAccept "application/json" req
+            mgr <- getGlobalManager
+            let req' =
+                    setRequestManager mgr $
+                    addRequestHeader hAccept "application/json" req
             result <- httpJSON req'
             let snapData = getResponseBody result
             case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
                 (True, False) ->
-                    liftIO $
-                    displaySnapshotData $ filterSnapshotData snapData Lts
+                    liftIO $ displaySnapshotData $ filterSnapshotData snapData Lts
                 (False, True) ->
-                    liftIO $
-                    displaySnapshotData $ filterSnapshotData snapData Nightly
+                    liftIO $ displaySnapshotData $ filterSnapshotData snapData Nightly
                 _ -> liftIO $ displaySnapshotData snapData
 
 lsParser :: OA.Parser LsCmdOpts
 lsParser =
     LsCmdOpts <$> OA.hsubparser (lsViewLocalCmd <> lsViewRemoteCmd) <*>
     OA.switch
-         (OA.long "lts" <> OA.short 'l' <>
-          OA.help "Only show lts snapshots") <*>
+        (OA.long "lts" <> OA.short 'l' <> OA.help "Only show lts snapshots") <*>
     OA.switch
-         (OA.long "nightly" <> OA.short 'n' <>
-          OA.help "Only show nightly snapshots")
+        (OA.long "nightly" <> OA.short 'n' <>
+         OA.help "Only show nightly snapshots")
 
 lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
 lsViewLocalCmd =

From 1c92ae5906a5be6b8d5f82c7937018e7db31c79d Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 12 Nov 2017 20:30:13 +0530
Subject: [PATCH 18/30] Have working code based on the feedback.

---
 src/Stack/Ls.hs | 131 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 97 insertions(+), 34 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 633732e826..6b4225d506 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
 module Stack.Ls
@@ -6,8 +7,7 @@ module Stack.Ls
   , lsParser
   ) where
 
-import Control.Exception (Exception)
-import Control.Exception.Safe (impureThrow)
+import Control.Exception (Exception, throw)
 import Control.Monad.Catch (MonadThrow)
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Control.Monad.Reader (MonadReader)
@@ -41,12 +41,46 @@ data SnapshotType
     | Nightly
     deriving (Show, Eq, Ord)
 
+data LsCmds = LsSnapshot SnapshotOpts deriving (Eq, Show, Ord)
+
+data SnapshotOpts = SnapshotOpts {
+      soptViewType :: LsView
+    , soptLtsSnapView :: Bool      
+    , soptNightlySnapView :: Bool
+} deriving (Eq, Show, Ord)
+
 data LsCmdOpts = LsCmdOpts
-    { lsView :: LsView
-    , lsLtsSnapView :: Bool
-    , lsNightlySnapView :: Bool
+    { lsView :: LsCmds
     } deriving (Eq, Show, Ord)
 
+lsParser :: OA.Parser LsCmdOpts
+lsParser = LsCmdOpts <$> OA.hsubparser lsSnapCmd
+
+lsCmdOptsParser :: OA.Parser LsCmds
+lsCmdOptsParser = fmap LsSnapshot lsViewSnapCmd
+
+lsViewSnapCmd :: OA.Parser SnapshotOpts
+lsViewSnapCmd = SnapshotOpts <$> OA.hsubparser (lsViewRemoteCmd <> lsViewLocalCmd) <*> OA.switch (OA.long "some-flag" <> OA.help "Set the flag") <*> OA.switch (OA.long "ome-flag" <> OA.help "Set the flag")
+
+lsSnapCmd :: OA.Mod OA.CommandFields LsCmds
+lsSnapCmd = OA.command "snapshots" (OA.info lsCmdOptsParser (OA.progDesc "View local snapshot"))
+
+
+
+-- <*>
+--     OA.switch
+--         (OA.long "lts" <> OA.short 'l' <> OA.help "Only show lts snapshots") <*>
+--     OA.switch
+--         (OA.long "nightly" <> OA.short 'n' <>
+--          OA.help "Only show nightly snapshots") <*>
+--     OA.option
+--         OA.auto
+--         (OA.long "package" <> OA.help "Show packages list" <> OA.short 'p' <>
+--          OA.value Nothing <>
+--          OA.metavar "RESOLVER")
+
+
+
 data Snapshot = Snapshot
     { snapId :: Text
     , snapTitle :: Text
@@ -58,6 +92,48 @@ data SnapshotData = SnapshotData
     , snaps :: [[Snapshot]]
     } deriving (Show, Eq, Ord)
 
+instance FromJSON Snapshot where
+    parseJSON o@(Array _) = parseSnapshot o
+    parseJSON _ = mempty
+
+instance FromJSON SnapshotData where
+    parseJSON (Object s) =
+        SnapshotData <$> s .: "totalCount" <*> s .: "snapshots"
+    parseJSON _ = mempty
+
+data Package = Package
+    { pkgSynopsis :: Text
+    , pkgVersion :: Text
+    , pkgName :: Text
+    , _pkgCore :: Bool
+    } deriving (Show, Eq, Ord)
+
+data PackageSnapshot = PackageSnapshot
+    { pkgSnapName :: Text
+    , pkgSnapCreated :: Text
+    , pkgSnapGhc :: Text
+    } deriving (Show, Eq, Ord)
+
+instance FromJSON PackageSnapshot where
+    parseJSON (Object s) =
+        PackageSnapshot <$> s .: "name" <*> s .: "created" <*> s .: "ghc"
+    parseJSON _ = mempty
+
+instance FromJSON Package where
+    parseJSON (Object s) =
+        Package <$> s .: "synopsis" <*> s .: "version" <*> s .: "name" <*>
+        s .: "isCore"
+    parseJSON _ = mempty
+
+data Packages = Packages
+    { pkgPackages :: [Package]
+    , pkgSnapshot :: PackageSnapshot
+    } deriving (Show, Eq, Ord)
+
+instance FromJSON Packages where
+    parseJSON (Object s) = Packages <$> s .: "packages" <*> s .: "snapshot"
+    parseJSON _ = mempty
+
 toSnapshot :: [Value] -> Snapshot
 toSnapshot [String sid, String stitle, String stime] =
     Snapshot
@@ -65,7 +141,7 @@ toSnapshot [String sid, String stitle, String stime] =
     , snapTitle = stitle
     , snapTime = stime
     }
-toSnapshot val = impureThrow $ ParseFailure val
+toSnapshot val = throw $ ParseFailure val
 
 newtype LsException =
     ParseFailure [Value]
@@ -77,15 +153,6 @@ parseSnapshot :: Value -> A.Parser Snapshot
 parseSnapshot =
     A.withArray "array of snapshot" (\val -> return $ toSnapshot (V.toList val))
 
-instance FromJSON Snapshot where
-    parseJSON o@(Array _) = parseSnapshot o
-    parseJSON _ = mempty
-
-instance FromJSON SnapshotData where
-    parseJSON (Object s) =
-        SnapshotData <$> s .: "totalCount" <*> s .: "snapshots"
-    parseJSON _ = mempty
-
 displaySnap :: Snapshot -> IO ()
 displaySnap snapshot = do
     T.putStrLn $ "Resolver name: " <> snapId snapshot
@@ -141,46 +208,42 @@ handleLocal lsOpts = do
     let snapRootDir = parent $ parent instRoot
     snapData' <- liftIO $ listDirectory $ toFilePath snapRootDir
     let snapData = L.sort snapData'
-    case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
-        (True, False) ->
-            liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
-        (False, True) ->
-            liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
-        _ -> liftIO $ displayLocalSnapshot snapData
+    case (lsView lsOpts) of
+      LsSnapshot SnapshotOpts{..} -> 
+          case (soptLtsSnapView, soptNightlySnapView) of
+            (True, False) ->
+                liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
+            (False, True) ->
+                liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
+            _ -> liftIO $ displayLocalSnapshot snapData
 
 lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
-lsCmd lsOpts go =
+lsCmd lsOpts go = do
     case lsView lsOpts of
+      LsSnapshot SnapshotOpts{..} -> case soptViewType of
         Local -> withBuildConfig go (handleLocal lsOpts)
         Remote -> do
-            req <- parseRequest "https://www.stackage.org/snapshots"
+            req <- parseRequest urlInfo
             mgr <- getGlobalManager
             let req' =
                     setRequestManager mgr $
                     addRequestHeader hAccept "application/json" req
             result <- httpJSON req'
             let snapData = getResponseBody result
-            case (lsLtsSnapView lsOpts, lsNightlySnapView lsOpts) of
+            case (soptLtsSnapView, soptNightlySnapView) of
                 (True, False) ->
                     liftIO $ displaySnapshotData $ filterSnapshotData snapData Lts
                 (False, True) ->
                     liftIO $ displaySnapshotData $ filterSnapshotData snapData Nightly
                 _ -> liftIO $ displaySnapshotData snapData
-
-lsParser :: OA.Parser LsCmdOpts
-lsParser =
-    LsCmdOpts <$> OA.hsubparser (lsViewLocalCmd <> lsViewRemoteCmd) <*>
-    OA.switch
-        (OA.long "lts" <> OA.short 'l' <> OA.help "Only show lts snapshots") <*>
-    OA.switch
-        (OA.long "nightly" <> OA.short 'n' <>
-         OA.help "Only show nightly snapshots")
+  where
+    urlInfo = "https://www.stackage.org/snapshots"
 
 lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
 lsViewLocalCmd =
     OA.command
         "local"
-        (OA.info (pure Local) (OA.progDesc "View local snapshot"))
+        (OA.info (pure Remote) (OA.progDesc "View local snapshot"))
 
 lsViewRemoteCmd :: OA.Mod OA.CommandFields LsView
 lsViewRemoteCmd =

From 7c0e5671fd5cd15f19dfeb84b21e7391f54c3f24 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 12 Nov 2017 20:30:35 +0530
Subject: [PATCH 19/30] Expose Stack.Ls

---
 package.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/package.yaml b/package.yaml
index 207a3104a9..3fee454b2c 100644
--- a/package.yaml
+++ b/package.yaml
@@ -181,6 +181,7 @@ library:
   - Stack.IDE
   - Stack.Image
   - Stack.Init
+  - Stack.Ls
   - Stack.New
   - Stack.Nix
   - Stack.Options.BenchParser

From 1dea318280d40c5497947711090229b2fde5a7c0 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 12 Nov 2017 20:39:17 +0530
Subject: [PATCH 20/30] Cleanup code

---
 src/Stack/Ls.hs | 127 ++++++++++++++++++------------------------------
 1 file changed, 47 insertions(+), 80 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 6b4225d506..78978d5d49 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -41,13 +41,15 @@ data SnapshotType
     | Nightly
     deriving (Show, Eq, Ord)
 
-data LsCmds = LsSnapshot SnapshotOpts deriving (Eq, Show, Ord)
+data LsCmds =
+    LsSnapshot SnapshotOpts
+    deriving (Eq, Show, Ord)
 
-data SnapshotOpts = SnapshotOpts {
-      soptViewType :: LsView
-    , soptLtsSnapView :: Bool      
+data SnapshotOpts = SnapshotOpts
+    { soptViewType :: LsView
+    , soptLtsSnapView :: Bool
     , soptNightlySnapView :: Bool
-} deriving (Eq, Show, Ord)
+    } deriving (Eq, Show, Ord)
 
 data LsCmdOpts = LsCmdOpts
     { lsView :: LsCmds
@@ -60,26 +62,19 @@ lsCmdOptsParser :: OA.Parser LsCmds
 lsCmdOptsParser = fmap LsSnapshot lsViewSnapCmd
 
 lsViewSnapCmd :: OA.Parser SnapshotOpts
-lsViewSnapCmd = SnapshotOpts <$> OA.hsubparser (lsViewRemoteCmd <> lsViewLocalCmd) <*> OA.switch (OA.long "some-flag" <> OA.help "Set the flag") <*> OA.switch (OA.long "ome-flag" <> OA.help "Set the flag")
+lsViewSnapCmd =
+    SnapshotOpts <$> OA.hsubparser (lsViewRemoteCmd <> lsViewLocalCmd) <*>
+    OA.switch
+        (OA.long "lts" <> OA.short 'l' <> OA.help "Only show lts snapshots") <*>
+    OA.switch
+        (OA.long "nightly" <> OA.short 'n' <>
+         OA.help "Only show nightly snapshots")
 
 lsSnapCmd :: OA.Mod OA.CommandFields LsCmds
-lsSnapCmd = OA.command "snapshots" (OA.info lsCmdOptsParser (OA.progDesc "View local snapshot"))
-
-
-
--- <*>
---     OA.switch
---         (OA.long "lts" <> OA.short 'l' <> OA.help "Only show lts snapshots") <*>
---     OA.switch
---         (OA.long "nightly" <> OA.short 'n' <>
---          OA.help "Only show nightly snapshots") <*>
---     OA.option
---         OA.auto
---         (OA.long "package" <> OA.help "Show packages list" <> OA.short 'p' <>
---          OA.value Nothing <>
---          OA.metavar "RESOLVER")
-
-
+lsSnapCmd =
+    OA.command
+        "snapshots"
+        (OA.info lsCmdOptsParser (OA.progDesc "View local snapshot"))
 
 data Snapshot = Snapshot
     { snapId :: Text
@@ -101,39 +96,6 @@ instance FromJSON SnapshotData where
         SnapshotData <$> s .: "totalCount" <*> s .: "snapshots"
     parseJSON _ = mempty
 
-data Package = Package
-    { pkgSynopsis :: Text
-    , pkgVersion :: Text
-    , pkgName :: Text
-    , _pkgCore :: Bool
-    } deriving (Show, Eq, Ord)
-
-data PackageSnapshot = PackageSnapshot
-    { pkgSnapName :: Text
-    , pkgSnapCreated :: Text
-    , pkgSnapGhc :: Text
-    } deriving (Show, Eq, Ord)
-
-instance FromJSON PackageSnapshot where
-    parseJSON (Object s) =
-        PackageSnapshot <$> s .: "name" <*> s .: "created" <*> s .: "ghc"
-    parseJSON _ = mempty
-
-instance FromJSON Package where
-    parseJSON (Object s) =
-        Package <$> s .: "synopsis" <*> s .: "version" <*> s .: "name" <*>
-        s .: "isCore"
-    parseJSON _ = mempty
-
-data Packages = Packages
-    { pkgPackages :: [Package]
-    , pkgSnapshot :: PackageSnapshot
-    } deriving (Show, Eq, Ord)
-
-instance FromJSON Packages where
-    parseJSON (Object s) = Packages <$> s .: "packages" <*> s .: "snapshot"
-    parseJSON _ = mempty
-
 toSnapshot :: [Value] -> Snapshot
 toSnapshot [String sid, String stitle, String stime] =
     Snapshot
@@ -209,33 +171,38 @@ handleLocal lsOpts = do
     snapData' <- liftIO $ listDirectory $ toFilePath snapRootDir
     let snapData = L.sort snapData'
     case (lsView lsOpts) of
-      LsSnapshot SnapshotOpts{..} -> 
-          case (soptLtsSnapView, soptNightlySnapView) of
-            (True, False) ->
-                liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
-            (False, True) ->
-                liftIO $ displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
-            _ -> liftIO $ displayLocalSnapshot snapData
+        LsSnapshot SnapshotOpts {..} ->
+            case (soptLtsSnapView, soptNightlySnapView) of
+                (True, False) ->
+                    liftIO $
+                    displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
+                (False, True) ->
+                    liftIO $
+                    displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
+                _ -> liftIO $ displayLocalSnapshot snapData
 
 lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
 lsCmd lsOpts go = do
     case lsView lsOpts of
-      LsSnapshot SnapshotOpts{..} -> case soptViewType of
-        Local -> withBuildConfig go (handleLocal lsOpts)
-        Remote -> do
-            req <- parseRequest urlInfo
-            mgr <- getGlobalManager
-            let req' =
-                    setRequestManager mgr $
-                    addRequestHeader hAccept "application/json" req
-            result <- httpJSON req'
-            let snapData = getResponseBody result
-            case (soptLtsSnapView, soptNightlySnapView) of
-                (True, False) ->
-                    liftIO $ displaySnapshotData $ filterSnapshotData snapData Lts
-                (False, True) ->
-                    liftIO $ displaySnapshotData $ filterSnapshotData snapData Nightly
-                _ -> liftIO $ displaySnapshotData snapData
+        LsSnapshot SnapshotOpts {..} ->
+            case soptViewType of
+                Local -> withBuildConfig go (handleLocal lsOpts)
+                Remote -> do
+                    req <- parseRequest urlInfo
+                    mgr <- getGlobalManager
+                    let req' =
+                            setRequestManager mgr $
+                            addRequestHeader hAccept "application/json" req
+                    result <- httpJSON req'
+                    let snapData = getResponseBody result
+                    case (soptLtsSnapView, soptNightlySnapView) of
+                        (True, False) ->
+                            liftIO $
+                            displaySnapshotData $ filterSnapshotData snapData Lts
+                        (False, True) ->
+                            liftIO $
+                            displaySnapshotData $ filterSnapshotData snapData Nightly
+                        _ -> liftIO $ displaySnapshotData snapData
   where
     urlInfo = "https://www.stackage.org/snapshots"
 
@@ -243,7 +210,7 @@ lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
 lsViewLocalCmd =
     OA.command
         "local"
-        (OA.info (pure Remote) (OA.progDesc "View local snapshot"))
+        (OA.info (pure Local) (OA.progDesc "View local snapshot"))
 
 lsViewRemoteCmd :: OA.Mod OA.CommandFields LsView
 lsViewRemoteCmd =

From 0eb4078bfd4bc95c65d470cd4f1af5da81487f19 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 12 Nov 2017 21:46:27 +0530
Subject: [PATCH 21/30] Use pager implementation

---
 src/Stack/Ls.hs | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 78978d5d49..e7ca9147d5 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -12,10 +12,13 @@ import Control.Monad.Catch (MonadThrow)
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Control.Monad.Reader (MonadReader)
 import Data.Aeson
+import Data.ByteString.Lazy.Char8 (ByteString, pack, intercalate)
+import qualified Data.ByteString.Lazy.Char8 as BC
 import qualified Data.Aeson.Types as A
 import qualified Data.List as L
 import Data.Monoid
-import Data.Text
+import Data.Text hiding (pack, intercalate)
+import qualified Data.Text as T
 import qualified Data.Text.IO as T
 import Data.Typeable (Typeable)
 import qualified Data.Vector as V
@@ -28,6 +31,7 @@ import Path
 import Stack.Runners (withBuildConfig)
 import Stack.Types.Config
 import System.Console.ANSI
+import System.Process.PagerEditor
 import System.Directory (listDirectory)
 import Network.HTTP.Client.TLS (getGlobalManager)
 
@@ -121,6 +125,15 @@ displaySnap snapshot = do
     T.putStrLn $ snapTitle snapshot
     putStrLn ""
 
+displayTime' :: Snapshot -> [ByteString]
+displayTime' Snapshot {..} = [pack $ T.unpack snapTime]
+
+displaySnap' :: Snapshot -> [ByteString]
+displaySnap' Snapshot {..} =
+    [ "Resolver name: " <> (pack $ T.unpack snapId)
+    , "\n" <> pack (T.unpack snapTitle) <> "\n\n"
+    ]
+
 displayTime :: Snapshot -> IO ()
 displayTime snapshot = do
     setSGR [SetColor Foreground Dull Green]
@@ -137,11 +150,23 @@ displaySingleSnap snapshots =
             displaySnap x
             mapM_ displaySnap xs
 
+displaySingleSnap' :: [Snapshot] -> ByteString
+displaySingleSnap' snapshots =
+    case snapshots of
+        [] -> mempty
+        (x:xs) ->
+            let snaps =
+                    displayTime' x <> ["\n\n"] <> displaySnap' x <>
+                    (L.concatMap displaySnap' xs)
+            in BC.concat snaps
+
 displaySnapshotData :: SnapshotData -> IO ()
 displaySnapshotData sdata =
     case L.reverse $ snaps sdata of
         [] -> return ()
-        xs -> mapM_ displaySingleSnap xs
+        xs ->
+            let snaps = BC.concat $ L.map displaySingleSnap' xs
+            in pageByteString snaps
 
 filterSnapshotData :: SnapshotData -> SnapshotType -> SnapshotData
 filterSnapshotData sdata stype =
@@ -160,7 +185,10 @@ filterSnapshotData sdata stype =
                     snapdata
 
 displayLocalSnapshot :: [String] -> IO ()
-displayLocalSnapshot xs = mapM_ putStrLn xs
+displayLocalSnapshot xs = pageByteString $ localSnaptoByteString xs
+
+localSnaptoByteString :: [String] -> ByteString
+localSnaptoByteString xs = intercalate "\n" $ L.map pack xs
 
 handleLocal
     :: (MonadIO m, MonadThrow m, MonadReader env m, HasEnvConfig env)

From fef24431c21b88be91b6b0a4845189472cafe5c0 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 12 Nov 2017 21:49:18 +0530
Subject: [PATCH 22/30] Remove dead code and do cleanup

---
 src/Stack/Ls.hs | 40 ++++++++--------------------------------
 1 file changed, 8 insertions(+), 32 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index e7ca9147d5..6560d5456d 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -19,7 +19,6 @@ import qualified Data.List as L
 import Data.Monoid
 import Data.Text hiding (pack, intercalate)
 import qualified Data.Text as T
-import qualified Data.Text.IO as T
 import Data.Typeable (Typeable)
 import qualified Data.Vector as V
 import Network.HTTP.Simple
@@ -30,7 +29,6 @@ import qualified Options.Applicative as OA
 import Path
 import Stack.Runners (withBuildConfig)
 import Stack.Types.Config
-import System.Console.ANSI
 import System.Process.PagerEditor
 import System.Directory (listDirectory)
 import Network.HTTP.Client.TLS (getGlobalManager)
@@ -119,45 +117,23 @@ parseSnapshot :: Value -> A.Parser Snapshot
 parseSnapshot =
     A.withArray "array of snapshot" (\val -> return $ toSnapshot (V.toList val))
 
-displaySnap :: Snapshot -> IO ()
-displaySnap snapshot = do
-    T.putStrLn $ "Resolver name: " <> snapId snapshot
-    T.putStrLn $ snapTitle snapshot
-    putStrLn ""
+displayTime :: Snapshot -> [ByteString]
+displayTime Snapshot {..} = [pack $ T.unpack snapTime]
 
-displayTime' :: Snapshot -> [ByteString]
-displayTime' Snapshot {..} = [pack $ T.unpack snapTime]
-
-displaySnap' :: Snapshot -> [ByteString]
-displaySnap' Snapshot {..} =
+displaySnap :: Snapshot -> [ByteString]
+displaySnap Snapshot {..} =
     [ "Resolver name: " <> (pack $ T.unpack snapId)
     , "\n" <> pack (T.unpack snapTitle) <> "\n\n"
     ]
 
-displayTime :: Snapshot -> IO ()
-displayTime snapshot = do
-    setSGR [SetColor Foreground Dull Green]
-    T.putStrLn $ snapTime snapshot
-    setSGR [Reset]
-    putStrLn ""
-
-displaySingleSnap :: [Snapshot] -> IO ()
+displaySingleSnap :: [Snapshot] -> ByteString
 displaySingleSnap snapshots =
-    case snapshots of
-        [] -> return ()
-        (x:xs) -> do
-            displayTime x
-            displaySnap x
-            mapM_ displaySnap xs
-
-displaySingleSnap' :: [Snapshot] -> ByteString
-displaySingleSnap' snapshots =
     case snapshots of
         [] -> mempty
         (x:xs) ->
             let snaps =
-                    displayTime' x <> ["\n\n"] <> displaySnap' x <>
-                    (L.concatMap displaySnap' xs)
+                    displayTime x <> ["\n\n"] <> displaySnap x <>
+                    (L.concatMap displaySnap xs)
             in BC.concat snaps
 
 displaySnapshotData :: SnapshotData -> IO ()
@@ -165,7 +141,7 @@ displaySnapshotData sdata =
     case L.reverse $ snaps sdata of
         [] -> return ()
         xs ->
-            let snaps = BC.concat $ L.map displaySingleSnap' xs
+            let snaps = BC.concat $ L.map displaySingleSnap xs
             in pageByteString snaps
 
 filterSnapshotData :: SnapshotData -> SnapshotType -> SnapshotData

From 28f11ffd7820b1eb8bb249dd909d782cccc04523 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 12 Nov 2017 22:20:39 +0530
Subject: [PATCH 23/30] Change help message

---
 src/main/Main.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/Main.hs b/src/main/Main.hs
index 17105c91d9..c1b06201eb 100644
--- a/src/main/Main.hs
+++ b/src/main/Main.hs
@@ -293,7 +293,7 @@ commandLineHandler currentDir progName isInterpreter = complicatedOptions
                     pathCmd
                     Stack.Path.pathParser
         addCommand' "ls"
-                    "List latest Stackage snapshots"
+                    "List command. (Supports snapshots)"
                     lsCmd
                     lsParser
         addCommand' "unpack"

From 5cd1db7749ff1f666d943974b63f25a55255f3c3 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Sun, 19 Nov 2017 19:26:32 +0530
Subject: [PATCH 24/30] Fix hlint style issues

---
 src/Stack/Ls.hs | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 6560d5456d..e0f88d82a2 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -114,15 +114,14 @@ newtype LsException =
 instance Exception LsException
 
 parseSnapshot :: Value -> A.Parser Snapshot
-parseSnapshot =
-    A.withArray "array of snapshot" (\val -> return $ toSnapshot (V.toList val))
+parseSnapshot = A.withArray "array of snapshot" (return . toSnapshot . V.toList)
 
 displayTime :: Snapshot -> [ByteString]
 displayTime Snapshot {..} = [pack $ T.unpack snapTime]
 
 displaySnap :: Snapshot -> [ByteString]
 displaySnap Snapshot {..} =
-    [ "Resolver name: " <> (pack $ T.unpack snapId)
+    [ "Resolver name: " <> pack (T.unpack snapId)
     , "\n" <> pack (T.unpack snapTitle) <> "\n\n"
     ]
 
@@ -133,7 +132,7 @@ displaySingleSnap snapshots =
         (x:xs) ->
             let snaps =
                     displayTime x <> ["\n\n"] <> displaySnap x <>
-                    (L.concatMap displaySnap xs)
+                    L.concatMap displaySnap xs
             in BC.concat snaps
 
 displaySnapshotData :: SnapshotData -> IO ()
@@ -153,12 +152,9 @@ filterSnapshotData sdata stype =
     snapdata = snaps sdata
     filterSnapData =
         case stype of
-            Lts ->
-                L.map (\s -> L.filter (\x -> "lts" `isPrefixOf` snapId x) s) snapdata
+            Lts -> L.map (L.filter (\x -> "lts" `isPrefixOf` snapId x)) snapdata
             Nightly ->
-                L.map
-                    (\s -> L.filter (\x -> "nightly" `isPrefixOf` snapId x) s)
-                    snapdata
+                L.map (L.filter (\x -> "nightly" `isPrefixOf` snapId x)) snapdata
 
 displayLocalSnapshot :: [String] -> IO ()
 displayLocalSnapshot xs = pageByteString $ localSnaptoByteString xs
@@ -174,7 +170,7 @@ handleLocal lsOpts = do
     let snapRootDir = parent $ parent instRoot
     snapData' <- liftIO $ listDirectory $ toFilePath snapRootDir
     let snapData = L.sort snapData'
-    case (lsView lsOpts) of
+    case lsView lsOpts of
         LsSnapshot SnapshotOpts {..} ->
             case (soptLtsSnapView, soptNightlySnapView) of
                 (True, False) ->
@@ -186,7 +182,7 @@ handleLocal lsOpts = do
                 _ -> liftIO $ displayLocalSnapshot snapData
 
 lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
-lsCmd lsOpts go = do
+lsCmd lsOpts go =
     case lsView lsOpts of
         LsSnapshot SnapshotOpts {..} ->
             case soptViewType of

From d412dbb05f5356a25431c340aec47c49adc03d18 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Mon, 18 Dec 2017 00:20:12 +0530
Subject: [PATCH 25/30] By default, use Local snapshot if none specified

---
 src/Stack/Ls.hs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index e0f88d82a2..90f51e9b72 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -26,6 +26,7 @@ import Network.HTTP.Simple
         setRequestManager)
 import Network.HTTP.Types.Header (hAccept)
 import qualified Options.Applicative as OA
+import Options.Applicative ((<|>))
 import Path
 import Stack.Runners (withBuildConfig)
 import Stack.Types.Config
@@ -58,14 +59,15 @@ data LsCmdOpts = LsCmdOpts
     } deriving (Eq, Show, Ord)
 
 lsParser :: OA.Parser LsCmdOpts
-lsParser = LsCmdOpts <$> OA.hsubparser lsSnapCmd
+lsParser = LsCmdOpts <$> (OA.hsubparser lsSnapCmd)
 
 lsCmdOptsParser :: OA.Parser LsCmds
 lsCmdOptsParser = fmap LsSnapshot lsViewSnapCmd
 
 lsViewSnapCmd :: OA.Parser SnapshotOpts
 lsViewSnapCmd =
-    SnapshotOpts <$> OA.hsubparser (lsViewRemoteCmd <> lsViewLocalCmd) <*>
+    SnapshotOpts <$>
+    (OA.hsubparser (lsViewRemoteCmd <> lsViewLocalCmd) <|> pure Local) <*>
     OA.switch
         (OA.long "lts" <> OA.short 'l' <> OA.help "Only show lts snapshots") <*>
     OA.switch

From 19d880b23898060c3564daf08c456751fceced20 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Mon, 18 Dec 2017 01:39:58 +0530
Subject: [PATCH 26/30] Add pageText to stream Text via pager

---
 src/System/Process/PagerEditor.hs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/System/Process/PagerEditor.hs b/src/System/Process/PagerEditor.hs
index 37f2bb515e..f3031bd068 100644
--- a/src/System/Process/PagerEditor.hs
+++ b/src/System/Process/PagerEditor.hs
@@ -7,6 +7,7 @@ module System.Process.PagerEditor
   (-- * Pager
    pageWriter
   ,pageByteString
+  ,pageText
   ,pageBuilder
   ,pageFile
   ,pageString
@@ -29,6 +30,7 @@ import System.FilePath ((</>))
 import System.Process (createProcess,shell,proc,waitForProcess,StdStream (CreatePipe)
                       ,CreateProcess(std_in, close_fds, delegate_ctlc))
 import System.IO (hClose,hPutStr,readFile,stdout)
+import qualified Data.Text.IO as T
 
 -- | Run pager, providing a function that writes to the pager's input.
 pageWriter :: (Handle -> IO ()) -> IO ()
@@ -55,6 +57,10 @@ pageWriter writer =
 pageByteString :: ByteString -> IO ()
 pageByteString = pageWriter . flip hPut
 
+-- | Run pager to display a 'Text'
+pageText :: Text -> IO ()
+pageText = pageWriter . flip T.hPutStr
+
 -- | Run pager to display a ByteString-Builder.
 pageBuilder :: Builder -> IO ()
 pageBuilder = pageWriter . flip hPutBuilder

From 1f8d99b706273196a1c94285a1aad66087dc74ac Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Mon, 18 Dec 2017 01:40:28 +0530
Subject: [PATCH 27/30] More changes to ls sub-command

Now the interface is similar to previous commands but we have done
some minor changes:

If a user gives just `stack ls snapshots`, then by default we show the
local snapshots available.

Also based on @mgsloan's input, I don't always use pager now. Also a
new convienence API has been added to `PagerEditor.hs` which exports a
function `pageText`. We use that in our module to pass `Text` content
to pager. (We were using ByteString previously).
---
 src/Stack/Ls.hs | 99 +++++++++++++++++++++++++++++--------------------
 1 file changed, 58 insertions(+), 41 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 90f51e9b72..5da6a06fc5 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -12,13 +12,13 @@ import Control.Monad.Catch (MonadThrow)
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Control.Monad.Reader (MonadReader)
 import Data.Aeson
-import Data.ByteString.Lazy.Char8 (ByteString, pack, intercalate)
-import qualified Data.ByteString.Lazy.Char8 as BC
+import Stack.Types.Runner
 import qualified Data.Aeson.Types as A
 import qualified Data.List as L
 import Data.Monoid
 import Data.Text hiding (pack, intercalate)
 import qualified Data.Text as T
+import qualified Data.Text.IO as T
 import Data.Typeable (Typeable)
 import qualified Data.Vector as V
 import Network.HTTP.Simple
@@ -30,7 +30,7 @@ import Options.Applicative ((<|>))
 import Path
 import Stack.Runners (withBuildConfig)
 import Stack.Types.Config
-import System.Process.PagerEditor
+import System.Process.PagerEditor (pageText)
 import System.Directory (listDirectory)
 import Network.HTTP.Client.TLS (getGlobalManager)
 
@@ -78,7 +78,9 @@ lsSnapCmd :: OA.Mod OA.CommandFields LsCmds
 lsSnapCmd =
     OA.command
         "snapshots"
-        (OA.info lsCmdOptsParser (OA.progDesc "View local snapshot"))
+        (OA.info
+             lsCmdOptsParser
+             (OA.progDesc "View local snapshot (default option)"))
 
 data Snapshot = Snapshot
     { snapId :: Text
@@ -118,16 +120,14 @@ instance Exception LsException
 parseSnapshot :: Value -> A.Parser Snapshot
 parseSnapshot = A.withArray "array of snapshot" (return . toSnapshot . V.toList)
 
-displayTime :: Snapshot -> [ByteString]
-displayTime Snapshot {..} = [pack $ T.unpack snapTime]
+displayTime :: Snapshot -> [Text]
+displayTime Snapshot {..} = [snapTime]
 
-displaySnap :: Snapshot -> [ByteString]
+displaySnap :: Snapshot -> [Text]
 displaySnap Snapshot {..} =
-    [ "Resolver name: " <> pack (T.unpack snapId)
-    , "\n" <> pack (T.unpack snapTitle) <> "\n\n"
-    ]
+    ["Resolver name: " <> snapId, "\n" <> snapTitle <> "\n\n"]
 
-displaySingleSnap :: [Snapshot] -> ByteString
+displaySingleSnap :: [Snapshot] -> Text
 displaySingleSnap snapshots =
     case snapshots of
         [] -> mempty
@@ -135,15 +135,19 @@ displaySingleSnap snapshots =
             let snaps =
                     displayTime x <> ["\n\n"] <> displaySnap x <>
                     L.concatMap displaySnap xs
-            in BC.concat snaps
+            in T.concat snaps
 
-displaySnapshotData :: SnapshotData -> IO ()
-displaySnapshotData sdata =
+renderData :: Bool -> Text -> IO ()
+renderData True content = pageText content
+renderData False content = T.putStr content
+
+displaySnapshotData :: Bool -> SnapshotData -> IO ()
+displaySnapshotData term sdata =
     case L.reverse $ snaps sdata of
         [] -> return ()
         xs ->
-            let snaps = BC.concat $ L.map displaySingleSnap xs
-            in pageByteString snaps
+            let snaps = T.concat $ L.map displaySingleSnap xs
+            in renderData term snaps
 
 filterSnapshotData :: SnapshotData -> SnapshotType -> SnapshotData
 filterSnapshotData sdata stype =
@@ -158,17 +162,18 @@ filterSnapshotData sdata stype =
             Nightly ->
                 L.map (L.filter (\x -> "nightly" `isPrefixOf` snapId x)) snapdata
 
-displayLocalSnapshot :: [String] -> IO ()
-displayLocalSnapshot xs = pageByteString $ localSnaptoByteString xs
+displayLocalSnapshot :: Bool -> [String] -> IO ()
+displayLocalSnapshot term xs = renderData term (localSnaptoText xs)
 
-localSnaptoByteString :: [String] -> ByteString
-localSnaptoByteString xs = intercalate "\n" $ L.map pack xs
+localSnaptoText :: [String] -> Text
+localSnaptoText xs = T.intercalate "\n" $ L.map T.pack xs
 
 handleLocal
     :: (MonadIO m, MonadThrow m, MonadReader env m, HasEnvConfig env)
     => LsCmdOpts -> m ()
 handleLocal lsOpts = do
     (instRoot :: Path Abs Dir) <- installationRootDeps
+    isStdoutTerminal <- view terminalL
     let snapRootDir = parent $ parent instRoot
     snapData' <- liftIO $ listDirectory $ toFilePath snapRootDir
     let snapData = L.sort snapData'
@@ -177,11 +182,40 @@ handleLocal lsOpts = do
             case (soptLtsSnapView, soptNightlySnapView) of
                 (True, False) ->
                     liftIO $
-                    displayLocalSnapshot $ L.filter (L.isPrefixOf "lts") snapData
+                    displayLocalSnapshot isStdoutTerminal $
+                    L.filter (L.isPrefixOf "lts") snapData
                 (False, True) ->
                     liftIO $
-                    displayLocalSnapshot $ L.filter (L.isPrefixOf "night") snapData
-                _ -> liftIO $ displayLocalSnapshot snapData
+                    displayLocalSnapshot isStdoutTerminal $
+                    L.filter (L.isPrefixOf "night") snapData
+                _ -> liftIO $ displayLocalSnapshot isStdoutTerminal snapData
+
+handleRemote
+    :: (MonadIO m, MonadThrow m, MonadReader env m, HasEnvConfig env)
+    => LsCmdOpts -> m ()
+handleRemote lsOpts = do
+    req <- liftIO $ parseRequest urlInfo
+    mgr <- liftIO $ getGlobalManager
+    isStdoutTerminal <- view terminalL
+    let req' =
+            setRequestManager mgr $
+            addRequestHeader hAccept "application/json" req
+    result <- httpJSON req'
+    let snapData = getResponseBody result
+    case lsView lsOpts of
+        LsSnapshot SnapshotOpts {..} ->
+            case (soptLtsSnapView, soptNightlySnapView) of
+                (True, False) ->
+                    liftIO $
+                    displaySnapshotData isStdoutTerminal $
+                    filterSnapshotData snapData Lts
+                (False, True) ->
+                    liftIO $
+                    displaySnapshotData isStdoutTerminal $
+                    filterSnapshotData snapData Nightly
+                _ -> liftIO $ displaySnapshotData isStdoutTerminal snapData
+  where
+    urlInfo = "https://www.stackage.org/snapshots"
 
 lsCmd :: LsCmdOpts -> GlobalOpts -> IO ()
 lsCmd lsOpts go =
@@ -189,24 +223,7 @@ lsCmd lsOpts go =
         LsSnapshot SnapshotOpts {..} ->
             case soptViewType of
                 Local -> withBuildConfig go (handleLocal lsOpts)
-                Remote -> do
-                    req <- parseRequest urlInfo
-                    mgr <- getGlobalManager
-                    let req' =
-                            setRequestManager mgr $
-                            addRequestHeader hAccept "application/json" req
-                    result <- httpJSON req'
-                    let snapData = getResponseBody result
-                    case (soptLtsSnapView, soptNightlySnapView) of
-                        (True, False) ->
-                            liftIO $
-                            displaySnapshotData $ filterSnapshotData snapData Lts
-                        (False, True) ->
-                            liftIO $
-                            displaySnapshotData $ filterSnapshotData snapData Nightly
-                        _ -> liftIO $ displaySnapshotData snapData
-  where
-    urlInfo = "https://www.stackage.org/snapshots"
+                Remote -> withBuildConfig go (handleRemote lsOpts)
 
 lsViewLocalCmd :: OA.Mod OA.CommandFields LsView
 lsViewLocalCmd =

From b29dbed842e4871a3d39e023d08c4eda133c815a Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Mon, 18 Dec 2017 02:58:11 +0530
Subject: [PATCH 28/30] Update changelog

---
 ChangeLog.md | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index fb6d019713..f69cac9623 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -10,6 +10,12 @@ Behaviour changes:
 
 Other enhancements:
 
+* A new sub command `ls` has been introduced to stack to view
+  local and remote snapshots present in the system. Use `stack ls
+  snapshots --help` to get more details about it.
+* `pageText` function introduced in `System.Process.PagerEditor`
+   module.
+
 Bug fixes:
 
 * For versions of Cabal before 1.24, ensure that the dependencies of
@@ -252,8 +258,6 @@ Behavior changes:
 
 Other enhancements:
 
-* A new sub command `ls` has been introduced to stack to view
-  local and remote snapshots present in the system.
 * `stack setup` allow to control options passed to ghcjs-boot with
   `--ghcjs-boot-options` (one word at a time) and `--[no-]ghcjs-boot-clean`
 * `stack setup` now accepts a `--install-cabal VERSION` option which

From 16e5b253c5896843ad72699a799f725308784e98 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Mon, 18 Dec 2017 02:58:24 +0530
Subject: [PATCH 29/30] Fix hlint style issues

---
 src/Stack/Ls.hs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Stack/Ls.hs b/src/Stack/Ls.hs
index 5da6a06fc5..024f0ae06a 100644
--- a/src/Stack/Ls.hs
+++ b/src/Stack/Ls.hs
@@ -44,7 +44,7 @@ data SnapshotType
     | Nightly
     deriving (Show, Eq, Ord)
 
-data LsCmds =
+newtype LsCmds =
     LsSnapshot SnapshotOpts
     deriving (Eq, Show, Ord)
 
@@ -54,12 +54,12 @@ data SnapshotOpts = SnapshotOpts
     , soptNightlySnapView :: Bool
     } deriving (Eq, Show, Ord)
 
-data LsCmdOpts = LsCmdOpts
+newtype LsCmdOpts = LsCmdOpts
     { lsView :: LsCmds
     } deriving (Eq, Show, Ord)
 
 lsParser :: OA.Parser LsCmdOpts
-lsParser = LsCmdOpts <$> (OA.hsubparser lsSnapCmd)
+lsParser = LsCmdOpts <$> OA.hsubparser lsSnapCmd
 
 lsCmdOptsParser :: OA.Parser LsCmds
 lsCmdOptsParser = fmap LsSnapshot lsViewSnapCmd
@@ -195,7 +195,7 @@ handleRemote
     => LsCmdOpts -> m ()
 handleRemote lsOpts = do
     req <- liftIO $ parseRequest urlInfo
-    mgr <- liftIO $ getGlobalManager
+    mgr <- liftIO getGlobalManager
     isStdoutTerminal <- view terminalL
     let req' =
             setRequestManager mgr $

From 947cbc8e647f169cd65dbd50d945960883f335c6 Mon Sep 17 00:00:00 2001
From: Sibi Prabakaran <sibi@psibi.in>
Date: Mon, 18 Dec 2017 05:54:33 +0530
Subject: [PATCH 30/30] Remove API change from changelog

---
 ChangeLog.md | 2 --
 1 file changed, 2 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index f69cac9623..3224a2927f 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -13,8 +13,6 @@ Other enhancements:
 * A new sub command `ls` has been introduced to stack to view
   local and remote snapshots present in the system. Use `stack ls
   snapshots --help` to get more details about it.
-* `pageText` function introduced in `System.Process.PagerEditor`
-   module.
 
 Bug fixes: