Refactor TargetSourcesHandler logic

Author: rockbruno

Sources/SourceKitBazelBSP/RequestHandlers/TargetSourcesHandler.swift

@@ -0,0 +1,99 @@
+// Copyright (c) 2025 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import BuildServerProtocol
+import Foundation
+import LanguageServerProtocol
+
+/// Handles the `buildTarget/sources` request.
+///
+/// Returns the sources for the provided target based on previously gathered information.
+final class TargetSourcesHandler {
+
+    private let initializedConfig: InitializedServerConfig
+    private let targetStore: BazelTargetStore
+
+    init(
+        initializedConfig: InitializedServerConfig,
+        targetStore: BazelTargetStore,
+    ) {
+        self.initializedConfig = initializedConfig
+        self.targetStore = targetStore
+    }
+
+    func buildTargetSources(
+        _ request: BuildTargetSourcesRequest,
+        _ id: RequestID
+    ) throws -> BuildTargetSourcesResponse {
+        let targets = request.targets
+        logger.info("Fetching sources for \(targets.count, privacy: .public) targets")
+
+        var srcs: [SourcesItem] = []
+        for target in targets {
+            let targetSrcs = try targetStore.bazelTargetSrcs(forBSPURI: target.uri)
+            let sources = convertToSourceItems(targetSrcs)
+            srcs.append(
+                SourcesItem(
+                    target: target,
+                    sources: sources
+                )
+            )
+        }
+
+        let count = srcs.reduce(0) { $0 + $1.sources.count }
+
+        logger.info(
+            "Returning \(srcs.count, privacy: .public) source specs (\(count, privacy: .public) total source entries)"
+        )
+
+        return BuildTargetSourcesResponse(items: srcs)
+    }
+
+    func convertToSourceItems(_ targetSrcs: [URI]) -> [SourceItem] {
+        var result: [SourceItem] = []
+        for src in targetSrcs {
+            let kind: SourceKitSourceItemKind
+            if src.stringValue.hasSuffix("h") {
+                kind = .header
+            } else {
+                kind = .source
+            }
+            let language: Language
+            if src.stringValue.hasSuffix("swift") {
+                language = .swift
+            } else {
+                language = .objective_c
+            }
+            result.append(
+                SourceItem(
+                    uri: src,
+                    kind: .file,
+                    generated: false,  // FIXME: Need to handle this properly
+                    dataKind: .sourceKit,
+                    data: SourceKitSourceItemData(
+                        language: language,
+                        kind: kind,
+                        outputPath: nil  // FIXME: Related to the same flag on initialize?
+                    ).encodeToLSPAny()
+                )
+            )
+        }
+        return result
+    }
+}