feat(git): show changed files and content in commit diff

Update GitOperations to list changed files, their statuses, and file contents for each commit diff, including deleted files and raw diff output.

Author: phodal

mpp-core/src/wasmJsMain/kotlin/cc/unitmesh/agent/platform/GitOperations.wasmJs.kt

@@ -203,21 +203,74 @@ actual class GitOperations actual constructor(private val projectPath: String) {
         val module = lg2Module ?: return null
 
         return try {
+            // Step 1: Get list of changed files using diff --name-status
             commandOutputBuffer.clear()
-            val exitCode = module.callMain(jsArrayOf("show", commitHash)).await<JsNumber>().toInt()
+            var exitCode = module.callMain(jsArrayOf("diff", "--name-status", "$commitHash^", commitHash)).await<JsNumber>().toInt()
 
             if (exitCode != 0) {
-                WasmConsole.warn("git show failed with exit code: $exitCode")
+                WasmConsole.warn("git diff --name-status failed with exit code: $exitCode")
                 return null
             }
 
-            val diff = commandOutputBuffer.joinToString("\n")
-            // TODO: Parse diff to extract file changes, additions, and deletions
+            val changedFiles = commandOutputBuffer
+                .filter { it.isNotBlank() }
+                .mapNotNull { line ->
+                    // Format: "M\tfilename" or "A\tfilename" or "D\tfilename"
+                    val parts = line.split("\t", limit = 2)
+                    if (parts.size == 2) {
+                        Pair(parts[0], parts[1]) // (status, filename)
+                    } else null
+                }
+
+            // Step 2: Get the actual diff for context
+            commandOutputBuffer.clear()
+            exitCode = module.callMain(jsArrayOf("diff", "$commitHash^", commitHash)).await<JsNumber>().toInt()
+            val diffContent = if (exitCode == 0) {
+                commandOutputBuffer.joinToString("\n")
+            } else {
+                ""
+            }
+
+            // Step 3: For each modified/added file, read its full content
+            val filesWithContent = buildString {
+                for ((status, filename) in changedFiles) {
+                    appendLine("=" .repeat(80))
+                    appendLine("File: $filename (Status: $status)")
+                    appendLine("=" .repeat(80))
+                    
+                    when (status) {
+                        "D" -> {
+                            appendLine("[File Deleted]")
+                        }
+                        "A", "M" -> {
+                            // Try to read the file content from current working directory
+                            val content = try {
+                                val fileData = module.FS.readFile(filename).toIntArray()
+                                val bytes = fileData.map { it.toByte() }.toByteArray()
+                                bytes.decodeToString()
+                            } catch (e: Throwable) {
+                                "[Unable to read file: ${e.message}]"
+                            }
+                            appendLine(content)
+                        }
+                    }
+                    appendLine()
+                }
+                
+                // Also include the diff for reference
+                if (diffContent.isNotBlank()) {
+                    appendLine("=" .repeat(80))
+                    appendLine("Git Diff Output:")
+                    appendLine("=" .repeat(80))
+                    appendLine(diffContent)
+                }
+            }
+
             GitDiffInfo(
-                files = emptyList(),
-                totalAdditions = 0,
-                totalDeletions = 0,
-                originDiff = diff
+                files = changedFiles.map { it.second },
+                totalAdditions = 0, // Could be parsed from diff output if needed
+                totalDeletions = 0, // Could be parsed from diff output if needed
+                originDiff = filesWithContent
             )
         } catch (e: Throwable) {
             WasmConsole.error("Failed to get commit diff: ${e.message}")