1 files changed, 372 insertions, 0 deletions
diff --git a/internal/llm/tools/patch.go b/internal/llm/tools/patch.go
new file mode 100644
index 000000000..7e20e378e
--- /dev/null
+++ b/internal/llm/tools/patch.go
@@ -0,0 +1,372 @@
+package tools
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/kujtimiihoxha/opencode/internal/config"
+	"github.com/kujtimiihoxha/opencode/internal/diff"
+	"github.com/kujtimiihoxha/opencode/internal/history"
+	"github.com/kujtimiihoxha/opencode/internal/logging"
+	"github.com/kujtimiihoxha/opencode/internal/lsp"
+	"github.com/kujtimiihoxha/opencode/internal/permission"
+)
+
+type PatchParams struct {
+	PatchText string `json:"patch_text"`
+}
+
+type PatchResponseMetadata struct {
+	FilesChanged []string `json:"files_changed"`
+	Additions    int      `json:"additions"`
+	Removals     int      `json:"removals"`
+}
+
+type patchTool struct {
+	lspClients  map[string]*lsp.Client
+	permissions permission.Service
+	files       history.Service
+}
+
+const (
+	PatchToolName    = "patch"
+	patchDescription = `Applies a patch to multiple files in one operation. This tool is useful for making coordinated changes across multiple files.
+
+The patch text must follow this format:
+*** Begin Patch
+*** Update File: /path/to/file
+@@ Context line (unique within the file)
+ Line to keep
+-Line to remove
++Line to add
+ Line to keep
+*** Add File: /path/to/new/file
++Content of the new file
++More content
+*** Delete File: /path/to/file/to/delete
+*** End Patch
+
+Before using this tool:
+1. Use the FileRead tool to understand the files' contents and context
+2. Verify all file paths are correct (use the LS tool)
+
+CRITICAL REQUIREMENTS FOR USING THIS TOOL:
+
+1. UNIQUENESS: Context lines MUST uniquely identify the specific sections you want to change
+2. PRECISION: All whitespace, indentation, and surrounding code must match exactly
+3. VALIDATION: Ensure edits result in idiomatic, correct code
+4. PATHS: Always use absolute file paths (starting with /)
+
+The tool will apply all changes in a single atomic operation.`
+)
+
+func NewPatchTool(lspClients map[string]*lsp.Client, permissions permission.Service, files history.Service) BaseTool {
+	return &patchTool{
+		lspClients:  lspClients,
+		permissions: permissions,
+		files:       files,
+	}
+}
+
+func (p *patchTool) Info() ToolInfo {
+	return ToolInfo{
+		Name:        PatchToolName,
+		Description: patchDescription,
+		Parameters: map[string]any{
+			"patch_text": map[string]any{
+				"type":        "string",
+				"description": "The full patch text that describes all changes to be made",
+			},
+		},
+		Required: []string{"patch_text"},
+	}
+}
+
+func (p *patchTool) Run(ctx context.Context, call ToolCall) (ToolResponse, error) {
+	var params PatchParams
+	if err := json.Unmarshal([]byte(call.Input), &params); err != nil {
+		return NewTextErrorResponse("invalid parameters"), nil
+	}
+
+	if params.PatchText == "" {
+		return NewTextErrorResponse("patch_text is required"), nil
+	}
+
+	// Identify all files needed for the patch and verify they've been read
+	filesToRead := diff.IdentifyFilesNeeded(params.PatchText)
+	for _, filePath := range filesToRead {
+		absPath := filePath
+		if !filepath.IsAbs(absPath) {
+			wd := config.WorkingDirectory()
+			absPath = filepath.Join(wd, absPath)
+		}
+
+		if getLastReadTime(absPath).IsZero() {
+			return NewTextErrorResponse(fmt.Sprintf("you must read the file %s before patching it. Use the FileRead tool first", filePath)), nil
+		}
+
+		fileInfo, err := os.Stat(absPath)
+		if err != nil {
+			if os.IsNotExist(err) {
+				return NewTextErrorResponse(fmt.Sprintf("file not found: %s", absPath)), nil
+			}
+			return ToolResponse{}, fmt.Errorf("failed to access file: %w", err)
+		}
+
+		if fileInfo.IsDir() {
+			return NewTextErrorResponse(fmt.Sprintf("path is a directory, not a file: %s", absPath)), nil
+		}
+
+		modTime := fileInfo.ModTime()
+		lastRead := getLastReadTime(absPath)
+		if modTime.After(lastRead) {
+			return NewTextErrorResponse(
+				fmt.Sprintf("file %s has been modified since it was last read (mod time: %s, last read: %s)",
+					absPath, modTime.Format(time.RFC3339), lastRead.Format(time.RFC3339),
+				)), nil
+		}
+	}
+
+	// Check for new files to ensure they don't already exist
+	filesToAdd := diff.IdentifyFilesAdded(params.PatchText)
+	for _, filePath := range filesToAdd {
+		absPath := filePath
+		if !filepath.IsAbs(absPath) {
+			wd := config.WorkingDirectory()
+			absPath = filepath.Join(wd, absPath)
+		}
+
+		_, err := os.Stat(absPath)
+		if err == nil {
+			return NewTextErrorResponse(fmt.Sprintf("file already exists and cannot be added: %s", absPath)), nil
+		} else if !os.IsNotExist(err) {
+			return ToolResponse{}, fmt.Errorf("failed to check file: %w", err)
+		}
+	}
+
+	// Load all required files
+	currentFiles := make(map[string]string)
+	for _, filePath := range filesToRead {
+		absPath := filePath
+		if !filepath.IsAbs(absPath) {
+			wd := config.WorkingDirectory()
+			absPath = filepath.Join(wd, absPath)
+		}
+
+		content, err := os.ReadFile(absPath)
+		if err != nil {
+			return ToolResponse{}, fmt.Errorf("failed to read file %s: %w", absPath, err)
+		}
+		currentFiles[filePath] = string(content)
+	}
+
+	// Process the patch
+	patch, fuzz, err := diff.TextToPatch(params.PatchText, currentFiles)
+	if err != nil {
+		return NewTextErrorResponse(fmt.Sprintf("failed to parse patch: %s", err)), nil
+	}
+
+	if fuzz > 3 {
+		return NewTextErrorResponse(fmt.Sprintf("patch contains fuzzy matches (fuzz level: %d). Please make your context lines more precise", fuzz)), nil
+	}
+
+	// Convert patch to commit
+	commit, err := diff.PatchToCommit(patch, currentFiles)
+	if err != nil {
+		return NewTextErrorResponse(fmt.Sprintf("failed to create commit from patch: %s", err)), nil
+	}
+
+	// Get session ID and message ID
+	sessionID, messageID := GetContextValues(ctx)
+	if sessionID == "" || messageID == "" {
+		return ToolResponse{}, fmt.Errorf("session ID and message ID are required for creating a patch")
+	}
+
+	// Request permission for all changes
+	for path, change := range commit.Changes {
+		switch change.Type {
+		case diff.ActionAdd:
+			dir := filepath.Dir(path)
+			patchDiff, _, _ := diff.GenerateDiff("", *change.NewContent, path)
+			p := p.permissions.Request(
+				permission.CreatePermissionRequest{
+					SessionID:   sessionID,
+					Path:        dir,
+					ToolName:    PatchToolName,
+					Action:      "create",
+					Description: fmt.Sprintf("Create file %s", path),
+					Params: EditPermissionsParams{
+						FilePath: path,
+						Diff:     patchDiff,
+					},
+				},
+			)
+			if !p {
+				return ToolResponse{}, permission.ErrorPermissionDenied
+			}
+		case diff.ActionUpdate:
+			currentContent := ""
+			if change.OldContent != nil {
+				currentContent = *change.OldContent
+			}
+			newContent := ""
+			if change.NewContent != nil {
+				newContent = *change.NewContent
+			}
+			patchDiff, _, _ := diff.GenerateDiff(currentContent, newContent, path)
+			dir := filepath.Dir(path)
+			p := p.permissions.Request(
+				permission.CreatePermissionRequest{
+					SessionID:   sessionID,
+					Path:        dir,
+					ToolName:    PatchToolName,
+					Action:      "update",
+					Description: fmt.Sprintf("Update file %s", path),
+					Params: EditPermissionsParams{
+						FilePath: path,
+						Diff:     patchDiff,
+					},
+				},
+			)
+			if !p {
+				return ToolResponse{}, permission.ErrorPermissionDenied
+			}
+		case diff.ActionDelete:
+			dir := filepath.Dir(path)
+			patchDiff, _, _ := diff.GenerateDiff(*change.OldContent, "", path)
+			p := p.permissions.Request(
+				permission.CreatePermissionRequest{
+					SessionID:   sessionID,
+					Path:        dir,
+					ToolName:    PatchToolName,
+					Action:      "delete",
+					Description: fmt.Sprintf("Delete file %s", path),
+					Params: EditPermissionsParams{
+						FilePath: path,
+						Diff:     patchDiff,
+					},
+				},
+			)
+			if !p {
+				return ToolResponse{}, permission.ErrorPermissionDenied
+			}
+		}
+	}
+
+	// Apply the changes to the filesystem
+	err = diff.ApplyCommit(commit, func(path string, content string) error {
+		absPath := path
+		if !filepath.IsAbs(absPath) {
+			wd := config.WorkingDirectory()
+			absPath = filepath.Join(wd, absPath)
+		}
+
+		// Create parent directories if needed
+		dir := filepath.Dir(absPath)
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			return fmt.Errorf("failed to create parent directories for %s: %w", absPath, err)
+		}
+
+		return os.WriteFile(absPath, []byte(content), 0o644)
+	}, func(path string) error {
+		absPath := path
+		if !filepath.IsAbs(absPath) {
+			wd := config.WorkingDirectory()
+			absPath = filepath.Join(wd, absPath)
+		}
+		return os.Remove(absPath)
+	})
+	if err != nil {
+		return NewTextErrorResponse(fmt.Sprintf("failed to apply patch: %s", err)), nil
+	}
+
+	// Update file history for all modified files
+	changedFiles := []string{}
+	totalAdditions := 0
+	totalRemovals := 0
+
+	for path, change := range commit.Changes {
+		absPath := path
+		if !filepath.IsAbs(absPath) {
+			wd := config.WorkingDirectory()
+			absPath = filepath.Join(wd, absPath)
+		}
+		changedFiles = append(changedFiles, absPath)
+
+		oldContent := ""
+		if change.OldContent != nil {
+			oldContent = *change.OldContent
+		}
+
+		newContent := ""
+		if change.NewContent != nil {
+			newContent = *change.NewContent
+		}
+
+		// Calculate diff statistics
+		_, additions, removals := diff.GenerateDiff(oldContent, newContent, path)
+		totalAdditions += additions
+		totalRemovals += removals
+
+		// Update history
+		file, err := p.files.GetByPathAndSession(ctx, absPath, sessionID)
+		if err != nil && change.Type != diff.ActionAdd {
+			// If not adding a file, create history entry for existing file
+			_, err = p.files.Create(ctx, sessionID, absPath, oldContent)
+			if err != nil {
+				logging.Debug("Error creating file history", "error", err)
+			}
+		}
+
+		if err == nil && change.Type != diff.ActionAdd && file.Content != oldContent {
+			// User manually changed content, store intermediate version
+			_, err = p.files.CreateVersion(ctx, sessionID, absPath, oldContent)
+			if err != nil {
+				logging.Debug("Error creating file history version", "error", err)
+			}
+		}
+
+		// Store new version
+		if change.Type == diff.ActionDelete {
+			_, err = p.files.CreateVersion(ctx, sessionID, absPath, "")
+		} else {
+			_, err = p.files.CreateVersion(ctx, sessionID, absPath, newContent)
+		}
+		if err != nil {
+			logging.Debug("Error creating file history version", "error", err)
+		}
+
+		// Record file operations
+		recordFileWrite(absPath)
+		recordFileRead(absPath)
+	}
+
+	// Run LSP diagnostics on all changed files
+	for _, filePath := range changedFiles {
+		waitForLspDiagnostics(ctx, filePath, p.lspClients)
+	}
+
+	result := fmt.Sprintf("Patch applied successfully. %d files changed, %d additions, %d removals",
+		len(changedFiles), totalAdditions, totalRemovals)
+
+	diagnosticsText := ""
+	for _, filePath := range changedFiles {
+		diagnosticsText += getDiagnostics(filePath, p.lspClients)
+	}
+
+	if diagnosticsText != "" {
+		result += "\n\nDiagnostics:\n" + diagnosticsText
+	}
+
+	return WithResponseMetadata(
+		NewTextResponse(result),
+		PatchResponseMetadata{
+			FilesChanged: changedFiles,
+			Additions:    totalAdditions,
+			Removals:     totalRemovals,
+		}), nil
+}