[#1045] Implement FetchUTXOsAction

- draft of the fetching

[#1045] Implement FetchUTXOsAction

- updated the way Actions communicate data back to the CBP
- used this mechanism to pass result of utxos fetch so it's passed to the SDKSynchronizer as an Event

Sources/ZcashLightClientKit/Block/Actions/Action.swift

@@ -53,7 +53,7 @@ protocol Action {
     // Each action updates context accordingly. It should at least set new state. Reason for this is that action can return different states for
     // different conditions. And action is the thing that knows these conditions.
 
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext
 
     // Should be called on each existing action when processor wants to stop. Some actions may do it's own background work.
     func stop() async

Sources/ZcashLightClientKit/Block/Actions/ChecksBeforeSyncAction.swift

@@ -12,7 +12,7 @@ class ChecksBeforeSyncAction {
 }
 
 extension ChecksBeforeSyncAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // clear any present cached state if needed.
         // this checks if there was a sync in progress that was
         // interrupted abruptly and cache was not able to be cleared

Sources/ZcashLightClientKit/Block/Actions/ClearAlreadyScannedBlocksAction.swift

@@ -12,7 +12,7 @@ class ClearAlreadyScannedBlocksAction {
 }
 
 extension ClearAlreadyScannedBlocksAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // clear storage but delete only blocks that were already scanned, when doing parallel download all blocks can't be deleted
 
         await context.update(state: .enhance)

Sources/ZcashLightClientKit/Block/Actions/ClearCacheAction.swift

@@ -12,7 +12,7 @@ class ClearCacheAction {
 }
 
 extension ClearCacheAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // clear storage
         await context.update(state: .finished)
         return context

Sources/ZcashLightClientKit/Block/Actions/ComputeSyncRangesAction.swift

@@ -12,7 +12,7 @@ class ComputeSyncRangesAction {
 }
 
 extension ComputeSyncRangesAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // call internalSyncProgress and compute sync ranges and store them in context
         // if there is nothing sync just switch to finished state
 

Sources/ZcashLightClientKit/Block/Actions/DownloadAction.swift

@@ -24,7 +24,7 @@ class DownloadAction {
 }
 
 extension DownloadAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         guard let downloadRange = await context.syncRanges.downloadAndScanRange else {
             return await update(context: context)
         }

Sources/ZcashLightClientKit/Block/Actions/EnhanceAction.swift

@@ -12,7 +12,7 @@ class EnhanceAction {
 }
 
 extension EnhanceAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // Use `BlockEnhancer` to enhance blocks.
         // This action is executed on each downloaded and scanned batch (typically each 100 blocks). But we want to run enhancement each 1000 blocks.
         // This action can use `InternalSyncProgress` and last scanned height to compute when it should do work.

Sources/ZcashLightClientKit/Block/Actions/FetchUTXOsAction.swift

@@ -8,13 +8,18 @@
 import Foundation
 
 class FetchUTXOsAction {
-    init(container: DIContainer) { }
+    let utxoFetcher: UTXOFetcher
+    init(container: DIContainer) {
+        utxoFetcher = container.resolve(UTXOFetcher.self)
+    }
 }
 
 extension FetchUTXOsAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
-        // Use `UTXOFetcher` to fetch UTXOs.
-        
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
+        if let range = await context.syncRanges.fetchUTXORange {
+            let result = try await utxoFetcher.fetch(at: range)
+            await didUpdate(.storedUTXOs(result))
+        }
         await context.update(state: .handleSaplingParams)
         return context
     }

Sources/ZcashLightClientKit/Block/Actions/MigrateLegacyCacheDBAction.swift

@@ -27,7 +27,7 @@ class MigrateLegacyCacheDBAction {
 }
 
 extension MigrateLegacyCacheDBAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         guard let legacyCacheDbURL = config.cacheDbURL else {
             return await updateState(context)
         }

Sources/ZcashLightClientKit/Block/Actions/SaplingParamsAction.swift

@@ -12,7 +12,7 @@ class SaplingParamsAction {
 }
 
 extension SaplingParamsAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // Download files with sapling params.
 
         await context.update(state: .scanDownloaded)

Sources/ZcashLightClientKit/Block/Actions/ScanAction.swift

@@ -12,7 +12,7 @@ class ScanAction {
 }
 
 extension ScanAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         // Scan in range latestScannedHeight...latestScannedHeight+batchSize.
 
         await context.update(state: .clearAlreadyScannedBlocks)

Sources/ZcashLightClientKit/Block/Actions/ScanDownloadedButUnscannedAction.swift

@@ -12,7 +12,7 @@ class ScanDownloadedButUnscannedAction {
 }
 
 extension ScanDownloadedButUnscannedAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
 //        if let range = ranges.downloadedButUnscannedRange {
 //            logger.debug("Starting scan with downloaded but not scanned blocks with range: \(range.lowerBound)...\(range.upperBound)")
 //            try await blockScanner.scanBlocks(at: range, totalProgressRange: totalProgressRange) { [weak self] lastScannedHeight in

Sources/ZcashLightClientKit/Block/Actions/ValidateAction.swift

@@ -15,7 +15,7 @@ class ValidateAction {
 }
 
 extension ValidateAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         try await validator.validate()
         await context.update(state: .scan)
         return context

Sources/ZcashLightClientKit/Block/Actions/ValidateServerAction.swift

@@ -20,7 +20,7 @@ class ValidateServerAction {
 }
 
 extension ValidateServerAction: Action {
-    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProgress) async -> Void) async throws -> ActionContext {
+    func run(with context: ActionContext, didUpdate: @escaping (CompactBlockProcessorNG.Event) async -> Void) async throws -> ActionContext {
         let info = try await service.getInfo()
         let localNetwork = config.network
         let saplingActivation = config.saplingActivation

Sources/ZcashLightClientKit/Block/CompactBlockProcessorNG.swift

@@ -341,8 +341,8 @@ extension CompactBlockProcessorNG {
                 }
 
                 // Execute action.
-                context = try await action.run(with: context) { [weak self] progress in
-                    await self?.update(progress: progress)
+                context = try await action.run(with: context) { [weak self] event in
+                    await self?.send(event: event)
                 }
 
                 await didFinishAction()