cli.sh

#!/usr/bin/env bash
set -euo pipefail

###############################################################################
# cli.sh — Coin Smith: PSBT transaction builder CLI
#
# Usage:
#   ./cli.sh <fixture.json>
#
# Workflow:
#   1. Read the fixture JSON (UTXOs, payments, change template, fee rate)
#   2. Select coins (inputs) to fund the payments
#   3. Compute fee, change, and construct outputs
#   4. Build an unsigned PSBT (BIP-174)
#   5. Write JSON report to out/<fixture_name>.json
#   6. Exit 0 on success, 1 on error
#
# On error, writes { "ok": false, "error": { "code": "...", "message": "..." } }
# to the output file and exits 1.
###############################################################################

error_json() {
  local code="$1"
  local message="$2"
  printf '{"ok":false,"error":{"code":"%s","message":"%s"}}\n' "$code" "$message"
}

if [[ $# -lt 1 ]]; then
  mkdir -p out
  error_json "INVALID_ARGS" "Usage: cli.sh <fixture.json>" > out/invalid_args.json
  echo "Error: No fixture file provided" >&2
  exit 1
fi

FIXTURE="$1"

# Create output directory
mkdir -p out

# Derive output filename from fixture basename
FIXTURE_NAME="$(basename "$FIXTURE")"
OUTPUT_FILE="out/$FIXTURE_NAME"

if [[ ! -f "$FIXTURE" ]]; then
  error_json "FILE_NOT_FOUND" "Fixture file not found: $FIXTURE" > "$OUTPUT_FILE"
  echo "Error: Fixture file not found: $FIXTURE" >&2
  exit 1
fi

# Run prebuilt release binary generated by setup.sh.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CLI_BIN="$SCRIPT_DIR/coin-smith/target/release/cli"

if [[ ! -x "$CLI_BIN" ]]; then
  error_json "BINARY_NOT_FOUND" "Missing CLI binary at coin-smith/target/release/cli. Run ./setup.sh first." > "$OUTPUT_FILE"
  echo "Error: Missing CLI binary. Run ./setup.sh first." >&2
  exit 1
fi

"$CLI_BIN" "$FIXTURE"