Close #82, Implement chain scan request

BlockchainGateway/bc-gateway-ports/bc-chain-proxy/pom.xml

@@ -51,6 +51,10 @@
             <artifactId>bc-gateway-core</artifactId>
             <version>${bc-gateway.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webflux</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

BlockchainGateway/bc-gateway-ports/bc-chain-proxy/src/main/kotlin/co.nilin.opex.port.bcgateway.chainproxy/impl/ChainEndpointProxyImpl.kt

@@ -1,12 +1,80 @@
 package co.nilin.opex.port.bcgateway.chainproxy.impl
 
 import co.nilin.opex.bcgateway.core.model.ChainSyncRecord
+import co.nilin.opex.bcgateway.core.model.Deposit
 import co.nilin.opex.bcgateway.core.model.Endpoint
 import co.nilin.opex.bcgateway.core.spi.ChainEndpointProxy
-import org.springframework.stereotype.Component
+import kotlinx.coroutines.reactive.awaitFirstOrElse
+import org.springframework.core.ParameterizedTypeReference
+import org.springframework.web.reactive.function.client.WebClient
+import org.springframework.web.reactive.function.client.WebClientResponseException
+import reactor.core.publisher.Mono
+import java.math.BigDecimal
+import java.net.URI
+import java.time.LocalDateTime
+
+inline fun <reified T : Any> typeRef(): ParameterizedTypeReference<T> = object : ParameterizedTypeReference<T>() {}
+
+class ChainEndpointProxyImpl(
+    private val chain: String,
+    private val endpoints: List<Endpoint>,
+    private val webClient: WebClient
+) :
+    ChainEndpointProxy {
+    data class TransfersRequest(
+        val startBlock: Long?,
+        val endBlock: Long?,
+        val addresses: List<String>?
+    )
+
+    data class Transfer(
+        var txHash: String,
+        var from: String,
+        var to: String,
+        var isTokenTransfer: Boolean,
+        var token: String? = null,
+        var amount: BigDecimal
+    )
+
+    private suspend fun requestTransferList(baseUrl: String, request: TransfersRequest): List<Deposit> {
+        return webClient.post()
+            .uri(URI.create("$baseUrl/transfers"))
+            .header("Content-Type", "application/json")
+            .body(Mono.just(request), TransfersRequest::class.java)
+            .retrieve()
+            .onStatus({ t -> t.isError }, { it.createException() })
+            .bodyToFlux(typeRef<Transfer>())
+            .log().map { Deposit(null, it.to, null, it.amount, chain, it.isTokenTransfer, it.token) }
+            .collectList()
+            .awaitFirstOrElse { emptyList() }
+    }
+
+    private suspend fun roundRobin(i: Int, request: TransfersRequest): ChainSyncRecord {
+        return try {
+            val deposits =
+                requestTransferList(
+                    endpoints[i].url,
+                    request
+                )
+            ChainSyncRecord(chain, LocalDateTime.now(), endpoints[i], request.endBlock, true, null, deposits)
+        } catch (error: WebClientResponseException) {
+            if (i < endpoints.size - 1) {
+                roundRobin(i + 1, request)
+            } else {
+                ChainSyncRecord(
+                    chain,
+                    LocalDateTime.now(),
+                    endpoints[i],
+                    request.endBlock,
+                    false,
+                    error.message,
+                    emptyList()
+                )
+            }
+        }
+    }
 
-class ChainEndpointProxyImpl(private val endpoints: List<Endpoint>) : ChainEndpointProxy {
     override suspend fun syncTransfers(filter: ChainEndpointProxy.DepositFilter): ChainSyncRecord {
-        TODO("Not yet implemented")
+        return roundRobin(0, TransfersRequest(filter.startBlock, filter.endBlock, filter.tokenAddresses))
     }
 }

BlockchainGateway/bc-gateway-ports/bc-persister-postgres/src/main/kotlin/co/nilin/opex/port/bcgateway/postgres/impl/ChainEndpointProxyFinderImpl.kt

@@ -8,11 +8,13 @@ import co.nilin.opex.port.bcgateway.postgres.dao.ChainRepository
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.toList
 import org.springframework.stereotype.Component
+import org.springframework.web.reactive.function.client.WebClient
 
 @Component
-class ChainEndpointProxyFinderImpl(private val chainRepository: ChainRepository) : ChainEndpointProxyFinder {
+class ChainEndpointProxyFinderImpl(private val chainRepository: ChainRepository, private val webClient: WebClient) :
+    ChainEndpointProxyFinder {
     override suspend fun findChainEndpointProxy(chainName: String): ChainEndpointProxy {
         val endpoints = chainRepository.findEndpointsByName(chainName).map { Endpoint(it.url) }.toList()
-        return ChainEndpointProxyImpl(endpoints)
+        return ChainEndpointProxyImpl(chainName, endpoints,webClient)
     }
 }