package tools

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

// EditFileTool edits a file by replacing old_text with new_text.
// The old_text must exist exactly in the file.
type EditFileTool struct {
	allowedDir string // Optional directory restriction for security
}

// NewEditFileTool creates a new EditFileTool with optional directory restriction.
func NewEditFileTool(allowedDir string) *EditFileTool {
	return &EditFileTool{
		allowedDir: allowedDir,
	}
}

func (t *EditFileTool) Name() string {
	return "edit_file"
}

func (t *EditFileTool) Description() string {
	return "Edit a file by replacing old_text with new_text. The old_text must exist exactly in the file."
}

func (t *EditFileTool) Parameters() map[string]interface{} {
	return map[string]interface{}{
		"type": "object",
		"properties": map[string]interface{}{
			"path": map[string]interface{}{
				"type":        "string",
				"description": "The file path to edit",
			},
			"old_text": map[string]interface{}{
				"type":        "string",
				"description": "The exact text to find and replace",
			},
			"new_text": map[string]interface{}{
				"type":        "string",
				"description": "The text to replace with",
			},
		},
		"required": []string{"path", "old_text", "new_text"},
	}
}

func (t *EditFileTool) Execute(ctx context.Context, args map[string]interface{}) (string, error) {
	path, ok := args["path"].(string)
	if !ok {
		return "", fmt.Errorf("path is required")
	}

	oldText, ok := args["old_text"].(string)
	if !ok {
		return "", fmt.Errorf("old_text is required")
	}

	newText, ok := args["new_text"].(string)
	if !ok {
		return "", fmt.Errorf("new_text is required")
	}

	// Resolve path and enforce directory restriction if configured
	resolvedPath := path
	if filepath.IsAbs(path) {
		resolvedPath = filepath.Clean(path)
	} else {
		abs, err := filepath.Abs(path)
		if err != nil {
			return "", fmt.Errorf("failed to resolve path: %w", err)
		}
		resolvedPath = abs
	}

	// Check directory restriction
	if t.allowedDir != "" {
		allowedAbs, err := filepath.Abs(t.allowedDir)
		if err != nil {
			return "", fmt.Errorf("failed to resolve allowed directory: %w", err)
		}
		if !strings.HasPrefix(resolvedPath, allowedAbs) {
			return "", fmt.Errorf("path %s is outside allowed directory %s", path, t.allowedDir)
		}
	}

	if _, err := os.Stat(resolvedPath); os.IsNotExist(err) {
		return "", fmt.Errorf("file not found: %s", path)
	}

	content, err := os.ReadFile(resolvedPath)
	if err != nil {
		return "", fmt.Errorf("failed to read file: %w", err)
	}

	contentStr := string(content)

	if !strings.Contains(contentStr, oldText) {
		return "", fmt.Errorf("old_text not found in file. Make sure it matches exactly")
	}

	count := strings.Count(contentStr, oldText)
	if count > 1 {
		return "", fmt.Errorf("old_text appears %d times. Please provide more context to make it unique", count)
	}

	newContent := strings.Replace(contentStr, oldText, newText, 1)

	if err := os.WriteFile(resolvedPath, []byte(newContent), 0644); err != nil {
		return "", fmt.Errorf("failed to write file: %w", err)
	}

	return fmt.Sprintf("Successfully edited %s", path), nil
}

type AppendFileTool struct{}

func NewAppendFileTool() *AppendFileTool {
	return &AppendFileTool{}
}

func (t *AppendFileTool) Name() string {
	return "append_file"
}

func (t *AppendFileTool) Description() string {
	return "Append content to the end of a file"
}

func (t *AppendFileTool) Parameters() map[string]interface{} {
	return map[string]interface{}{
		"type": "object",
		"properties": map[string]interface{}{
			"path": map[string]interface{}{
				"type":        "string",
				"description": "The file path to append to",
			},
			"content": map[string]interface{}{
				"type":        "string",
				"description": "The content to append",
			},
		},
		"required": []string{"path", "content"},
	}
}

func (t *AppendFileTool) Execute(ctx context.Context, args map[string]interface{}) (string, error) {
	path, ok := args["path"].(string)
	if !ok {
		return "", fmt.Errorf("path is required")
	}

	content, ok := args["content"].(string)
	if !ok {
		return "", fmt.Errorf("content is required")
	}

	filePath := filepath.Clean(path)

	f, err := os.OpenFile(filePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return "", fmt.Errorf("failed to open file: %w", err)
	}
	defer f.Close()

	if _, err := f.WriteString(content); err != nil {
		return "", fmt.Errorf("failed to append to file: %w", err)
	}

	return fmt.Sprintf("Successfully appended to %s", path), nil
}