package handlers

import (
	"archive/zip"
	"bufio"
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"io"
	"mime"
	"os"
	"os/exec"
	"path/filepath"
	"sort"
	"strings"
	"time"

	"git.elijahkuntz.com/Elijah/drive/config"
	"git.elijahkuntz.com/Elijah/drive/database"
	"git.elijahkuntz.com/Elijah/drive/workers"
	"github.com/gofiber/fiber/v2"
	"github.com/cespare/xxhash/v2"
)

type FSHandler struct {
	DB     *database.DB
	Config *config.Config
}

type FileInfo struct {
	Name      string    `json:"name"`
	Path      string    `json:"path"`
	IsDir     bool      `json:"is_dir"`
	Size      int64     `json:"size"`
	MimeType  string    `json:"mime_type"`
	IsPinned  bool      `json:"is_pinned"`
	IsTrashed bool                   `json:"is_trashed"`
	ModTime   time.Time              `json:"mod_time"`
	Checksum  string                 `json:"checksum,omitempty"`
	Metadata  map[string]interface{} `json:"metadata,omitempty"`
}

type FolderNode struct {
	Name     string        `json:"name"`
	Path     string        `json:"path"`
	Children []*FolderNode `json:"children"`
}

// ListDirectory returns the contents of a directory.
// GET /api/files/*
func (h *FSHandler) ListDirectory(c *fiber.Ctx) error {
	resolvedPath := c.Locals("resolvedPath").(string)

	info, err := os.Stat(resolvedPath)
	if err != nil {
		if os.IsNotExist(err) {
			return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "path not found"})
		}
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to stat path"})
	}

	// If it's a file, return its info directly
	if !info.IsDir() {
		return h.getFileInfo(c, resolvedPath)
	}

	entries, err := os.ReadDir(resolvedPath)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to read directory"})
	}

	relativePath := c.Locals("relativePath").(string)
	files := make([]FileInfo, 0, len(entries))

	for _, entry := range entries {
		// Skip hidden system directories
		if entry.Name() == ".versions" || entry.Name() == ".trash" || entry.Name() == ".backups" {
			continue
		}

		entryInfo, err := entry.Info()
		if err != nil {
			continue
		}

		entryPath := filepath.Join(relativePath, entry.Name())
		mimeType := ""
		if !entry.IsDir() {
			mimeType = mime.TypeByExtension(filepath.Ext(entry.Name()))
		}

		fi := FileInfo{
			Name:    entry.Name(),
			Path:    filepath.ToSlash(entryPath),
			IsDir:   entry.IsDir(),
			Size:    entryInfo.Size(),
			MimeType: mimeType,
			ModTime: entryInfo.ModTime(),
		}

		// Enrich with DB metadata (pinned status, etc.)
		var isPinned, isTrashed int
		var checksum sql.NullString
		err = h.DB.QueryRow(
			"SELECT is_pinned, is_trashed, checksum FROM files WHERE path = ?",
			filepath.ToSlash(entryPath),
		).Scan(&isPinned, &isTrashed, &checksum)
		if err == nil {
			fi.IsPinned = isPinned == 1
			fi.IsTrashed = isTrashed == 1
			if checksum.Valid {
				fi.Checksum = checksum.String
			}
		}

		// Don't show trashed items in normal listings
		if fi.IsTrashed {
			continue
		}

		files = append(files, fi)
	}

	// Sort: directories first, then alphabetically
	sort.Slice(files, func(i, j int) bool {
		if files[i].IsDir != files[j].IsDir {
			return files[i].IsDir
		}
		return strings.ToLower(files[i].Name) < strings.ToLower(files[j].Name)
	})

	return c.JSON(fiber.Map{
		"path":  filepath.ToSlash(relativePath),
		"files": files,
		"count": len(files),
	})
}

// GetFolderTree returns a hierarchical tree of all folders.
// GET /api/files/folders-tree
func (h *FSHandler) GetFolderTree(c *fiber.Ctx) error {
	rootPath := h.Config.StorageDir
	
	root := &FolderNode{
		Name:     "Home",
		Path:     ".",
		Children: make([]*FolderNode, 0),
	}

	nodeMap := make(map[string]*FolderNode)
	nodeMap["."] = root

	filepath.WalkDir(rootPath, func(path string, d os.DirEntry, err error) error {
		if err != nil {
			return nil
		}
		if !d.IsDir() {
			return nil
		}
		
		relPath, err := filepath.Rel(rootPath, path)
		if err != nil || relPath == "." || relPath == "" {
			return nil
		}

		base := filepath.Base(relPath)
		if strings.HasPrefix(base, ".") {
			return filepath.SkipDir
		}

		cleanPath := filepath.ToSlash(relPath)
		parentPath := filepath.ToSlash(filepath.Dir(relPath))
		
		node := &FolderNode{
			Name:     d.Name(),
			Path:     cleanPath,
			Children: make([]*FolderNode, 0),
		}
		nodeMap[cleanPath] = node

		if parentNode, exists := nodeMap[parentPath]; exists {
			parentNode.Children = append(parentNode.Children, node)
		}

		return nil
	})

	var sortNode func(node *FolderNode)
	sortNode = func(node *FolderNode) {
		sort.Slice(node.Children, func(i, j int) bool {
			return strings.ToLower(node.Children[i].Name) < strings.ToLower(node.Children[j].Name)
		})
		for _, child := range node.Children {
			sortNode(child)
		}
	}
	sortNode(root)

	return c.JSON(root)
}

func (h *FSHandler) getFileInfo(c *fiber.Ctx, absPath string) error {
	info, err := os.Stat(absPath)
	if err != nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "file not found"})
	}

	relativePath := c.Locals("relativePath").(string)

	fi := FileInfo{
		Name:     info.Name(),
		Path:     filepath.ToSlash(relativePath),
		IsDir:    info.IsDir(),
		Size:     info.Size(),
		MimeType: mime.TypeByExtension(filepath.Ext(info.Name())),
		ModTime:  info.ModTime(),
	}

	var isPinned int
	var checksum sql.NullString
	err = h.DB.QueryRow(
		"SELECT is_pinned, checksum FROM files WHERE path = ?",
		filepath.ToSlash(relativePath),
	).Scan(&isPinned, &checksum)
	if err == nil {
		fi.IsPinned = isPinned == 1
		if checksum.Valid {
			fi.Checksum = checksum.String
		}
	}

	return c.JSON(fi)
}

// GetExtendedFileInfo gets recursive size and file count for info modal
// GET /api/files/info/*
func (h *FSHandler) GetExtendedFileInfo(c *fiber.Ctx) error {
	resolvedPath := c.Locals("resolvedPath").(string)
	relativePath := c.Locals("relativePath").(string)

	info, err := os.Stat(resolvedPath)
	if err != nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "file not found"})
	}

	fi := FileInfo{
		Name:     info.Name(),
		Path:     filepath.ToSlash(relativePath),
		IsDir:    info.IsDir(),
		Size:     info.Size(),
		MimeType: mime.TypeByExtension(filepath.Ext(info.Name())),
		ModTime:  info.ModTime(),
	}

	var isPinned int
	var isTrashed int
	var checksum sql.NullString
	var createdAt string
	err = h.DB.QueryRow(
		"SELECT is_pinned, is_trashed, checksum, created_at FROM files WHERE path = ?",
		filepath.ToSlash(relativePath),
	).Scan(&isPinned, &isTrashed, &checksum, &createdAt)
	
	if err == nil {
		fi.IsPinned = isPinned == 1
		fi.IsTrashed = isTrashed == 1
		if checksum.Valid {
			fi.Checksum = checksum.String
		}
	}

	fileCount := 0
	if fi.IsDir {
		var totalSize int64 = 0
		filepath.Walk(resolvedPath, func(p string, i os.FileInfo, err error) error {
			if err != nil {
				return nil
			}
			if !i.IsDir() {
				totalSize += i.Size()
				fileCount++
			}
			return nil
		})
		fi.Size = totalSize
		return c.JSON(fiber.Map{
			"info":       fi,
			"file_count": fileCount,
			"created_at": createdAt,
		})
	}

	// For files, attempt to get media metadata
	cat := categorizeFile(filepath.Ext(info.Name()))
	if cat == "images" || cat == "videos" || cat == "audio" {
		ext := strings.ToLower(filepath.Ext(info.Name()))
		validExts := map[string]bool{
			".jpg": true, ".jpeg": true, ".png": true, ".gif": true, ".webp": true,
			".mp4": true, ".mov": true, ".webm": true, ".mkv": true,
			".mp3": true, ".wav": true, ".flac": true, ".m4a": true,
		}
		if validExts[ext] {
			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
			defer cancel()
			cmd := exec.CommandContext(ctx, "exiftool", "-json", "--", resolvedPath)
			output, err := cmd.Output()
			if err == nil {
				var meta []map[string]interface{}
				if err := json.Unmarshal(output, &meta); err == nil && len(meta) > 0 {
					fi.Metadata = meta[0]
				}
			}
		}
	}

	return c.JSON(fiber.Map{
		"info":       fi,
		"file_count": fileCount,
		"created_at": createdAt,
	})
}

// CreateFolder creates a new directory.
// POST /api/files/mkdir
func (h *FSHandler) CreateFolder(c *fiber.Ctx) error {
	var body struct {
		Path string `json:"path"`
	}
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid request body"})
	}

	if body.Path == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "path is required"})
	}

	parentDir := filepath.Dir(body.Path)
	folderName := filepath.Base(body.Path)

	parentFullPath, err := resolveSafe(h.Config.StorageDir, parentDir)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	uniqueName := GetUniquePath(parentFullPath, folderName)
	fullPath := filepath.Join(parentFullPath, uniqueName)
	cleanPath := filepath.ToSlash(filepath.Join(parentDir, uniqueName))
	
	// Remove any prefix like "." if cleanPath was "." and it got joined.
	// filepath.ToSlash cleans the path.
	if cleanPath == "." {
		// Just for safety, but base shouldn't be empty
	}

	if err := os.MkdirAll(fullPath, 0755); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to create folder"})
	}

	// Record in DB
	h.DB.Exec(
		"INSERT OR IGNORE INTO files (path, name, is_dir) VALUES (?, ?, 1)",
		cleanPath, uniqueName,
	)

	h.DB.AddAuditLog("folder_created", cleanPath, c.IP())

	return c.Status(fiber.StatusCreated).JSON(fiber.Map{
		"message": "folder created",
		"path":    cleanPath,
	})
}

// Rename renames a file or folder.
// POST /api/files/rename
func (h *FSHandler) Rename(c *fiber.Ctx) error {
	var body struct {
		OldPath string `json:"old_path"`
		NewName string `json:"new_name"`
	}
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid request body"})
	}

	oldFull, err := resolveSafe(h.Config.StorageDir, body.OldPath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	parentDir := filepath.Dir(oldFull)
	uniqueName := GetUniquePath(parentDir, body.NewName)
	newPath := filepath.Join(filepath.Dir(body.OldPath), uniqueName)
	
	newFull, err := resolveSafe(h.Config.StorageDir, newPath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	if err := os.Rename(oldFull, newFull); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to rename"})
	}
	
	// Update body.NewName to reflect the actual unique name used
	body.NewName = uniqueName

	// Update DB
	h.DB.Exec(
		"UPDATE files SET path = ?, name = ?, updated_at = CURRENT_TIMESTAMP WHERE path = ?",
		filepath.ToSlash(newPath), body.NewName, filepath.ToSlash(body.OldPath),
	)

	h.DB.AddAuditLog("renamed", fmt.Sprintf("%s -> %s", body.OldPath, newPath), c.IP())

	return c.JSON(fiber.Map{"message": "renamed successfully", "new_path": filepath.ToSlash(newPath)})
}

type MoveRequest struct {
	SourcePath string `json:"source_path"`
	DestPath   string `json:"dest_path"`
	Resolution string `json:"resolution"` // "overwrite", "rename", "skip"
}

// Move moves a file or folder to a new location.
// POST /api/files/move
func (h *FSHandler) Move(c *fiber.Ctx) error {
	var body MoveRequest
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid request body"})
	}

	srcFull, err := resolveSafe(h.Config.StorageDir, body.SourcePath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	dstFull, err := resolveSafe(h.Config.StorageDir, body.DestPath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	if srcFull == dstFull || filepath.Dir(srcFull) == dstFull {
		return c.JSON(fiber.Map{"message": "moved successfully"})
	}

	// If destination is a directory, move into it
	if info, err := os.Stat(dstFull); err == nil && info.IsDir() {
		uniqueName := GetUniquePath(dstFull, filepath.Base(srcFull))
		dstFull = filepath.Join(dstFull, uniqueName)
		body.DestPath = filepath.Join(body.DestPath, uniqueName)
	} else if err == nil {
		if body.Resolution == "skip" {
			return c.JSON(fiber.Map{"message": "skipped"})
		}
		if body.Resolution != "overwrite" {
			parentDir := filepath.Dir(dstFull)
			uniqueName := GetUniquePath(parentDir, filepath.Base(dstFull))
			dstFull = filepath.Join(parentDir, uniqueName)
			body.DestPath = filepath.Join(filepath.Dir(body.DestPath), uniqueName)
		} else {
			safeRemovePath(h.Config.StorageDir, dstFull)
		}
	}

	if err := os.Rename(srcFull, dstFull); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to move"})
	}

	h.DB.Exec(
		"UPDATE files SET path = ?, updated_at = CURRENT_TIMESTAMP WHERE path = ?",
		filepath.ToSlash(body.DestPath), filepath.ToSlash(body.SourcePath),
	)

	h.DB.AddAuditLog("moved", fmt.Sprintf("%s -> %s", body.SourcePath, body.DestPath), c.IP())

	return c.JSON(fiber.Map{"message": "moved successfully"})
}

type CopyRequest struct {
	SourcePath string `json:"source_path"`
	DestPath   string `json:"dest_path"`
	Resolution string `json:"resolution"` // "overwrite", "rename", "skip"
}

// Copy copies a file or folder.
// POST /api/files/copy
func (h *FSHandler) Copy(c *fiber.Ctx) error {
	var body CopyRequest
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid request body"})
	}

	srcFull, err := resolveSafe(h.Config.StorageDir, body.SourcePath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	dstFull, err := resolveSafe(h.Config.StorageDir, body.DestPath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	info, err := os.Stat(srcFull)
	if err != nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "source not found"})
	}

	// Handle conflict
	finalDst := dstFull
	if _, err := os.Stat(dstFull); err == nil {
		if body.Resolution == "skip" {
			return c.JSON(fiber.Map{"message": "skipped"})
		}
		if body.Resolution != "overwrite" {
			parentDir := filepath.Dir(dstFull)
			uniqueName := GetUniquePath(parentDir, filepath.Base(dstFull))
			finalDst = filepath.Join(parentDir, uniqueName)
		} else {
			safeRemovePath(h.Config.StorageDir, dstFull)
		}
	}

	if info.IsDir() {
		if err := copyDir(srcFull, finalDst); err != nil {
			return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to copy directory"})
		}
	} else {
		if err := copyFile(srcFull, finalDst); err != nil {
			return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to copy file"})
		}
	}

	h.DB.AddAuditLog("copied", fmt.Sprintf("%s -> %s", body.SourcePath, body.DestPath), c.IP())

	return c.JSON(fiber.Map{"message": "copied successfully"})
}

// Delete soft-deletes a file (moves to trash).
// DELETE /api/files/*
func (h *FSHandler) Delete(c *fiber.Ctx) error {
	resolvedPath := c.Locals("resolvedPath").(string)
	relativePath := c.Locals("relativePath").(string)

	// Generate unique suffix for the trash path to prevent collisions
	trashSuffix := fmt.Sprintf("_%d", time.Now().UnixNano())
	trashName := filepath.Base(relativePath) + trashSuffix
	trashDir := filepath.Dir(relativePath)
	if trashDir == "." {
		trashDir = ""
	}
	trashedRelativePath := filepath.Join(trashDir, trashName)
	trashPath := filepath.Join(h.Config.TrashDir, trashedRelativePath)

	// Check if permanent
	isPermanent := c.Query("permanent") == "true"
	if isPermanent {
		// Ensure we don't delete the root
		if resolvedPath == h.Config.StorageDir && relativePath == "." {
			return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "cannot permanently delete root"})
		}
		
		// Remove both potential locations to be safe
		safeRemovePath(h.Config.StorageDir, resolvedPath)
		if relativePath != "." {
			safeRemovePath(h.Config.TrashDir, trashPath)
		}
		
		cleanPath := filepath.ToSlash(relativePath)
		h.DB.Exec(`DELETE FROM files WHERE path = ? OR path LIKE ?`, cleanPath, cleanPath+"/%")
		h.DB.AddAuditLog("permanently_deleted", cleanPath, c.IP())
		return c.JSON(fiber.Map{"message": "permanently deleted"})
	}

	// For soft-delete, file must exist in regular storage
	if _, err := os.Stat(resolvedPath); os.IsNotExist(err) {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "file not found"})
	}

	if err := os.MkdirAll(filepath.Dir(trashPath), 0755); err != nil {
		fmt.Printf("MkdirAll error: %v\n", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to prepare trash"})
	}

	info, err := os.Stat(resolvedPath)
	isDir := 0
	size := int64(0)
	if err == nil {
		if info.IsDir() {
			isDir = 1
		}
		size = info.Size()
	}

	if err := os.Rename(resolvedPath, trashPath); err != nil {
		fmt.Printf("Rename error %s -> %s: %v. Attempting copy & delete fallback...\n", resolvedPath, trashPath, err)
		if isDir == 1 {
			if err := copyDir(resolvedPath, trashPath); err != nil {
				return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to move directory to trash"})
			}
		} else {
			if err := copyFile(resolvedPath, trashPath); err != nil {
				return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to move file to trash"})
			}
		}
		safeRemovePath(h.Config.StorageDir, resolvedPath)
	}

	// Update DB
	cleanPath := filepath.ToSlash(relativePath)
	cleanTrashPath := filepath.ToSlash(trashedRelativePath)

	h.DB.Exec(
		`UPDATE files SET is_trashed = 1, trashed_at = CURRENT_TIMESTAMP, original_path = ?, is_dir = ?, size = ?, path = ? WHERE path = ?`,
		cleanPath, isDir, size, cleanTrashPath, cleanPath,
	)

	if isDir == 1 {
		h.DB.Exec(
			`UPDATE files SET path = REPLACE(path, ?, ?) WHERE path LIKE ?`,
			cleanPath+"/", cleanTrashPath+"/", cleanPath+"/%",
		)
	}

	// Also insert if not tracked
	h.DB.Exec(
		`INSERT OR IGNORE INTO files (path, name, is_trashed, trashed_at, original_path, is_dir, size) VALUES (?, ?, 1, CURRENT_TIMESTAMP, ?, ?, ?)`,
		cleanTrashPath, filepath.Base(cleanTrashPath), cleanPath, isDir, size,
	)

	h.DB.AddAuditLog("deleted", cleanTrashPath, c.IP())

	return c.JSON(fiber.Map{"message": "moved to trash"})
}

// ListTrash lists all trashed items.
// GET /api/trash
func (h *FSHandler) ListTrash(c *fiber.Ctx) error {
	rows, err := h.DB.Query(
		"SELECT path, name, is_dir, size, original_path, trashed_at FROM files WHERE is_trashed = 1 ORDER BY trashed_at DESC",
	)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "database error"})
	}
	defer rows.Close()

	type TrashItem struct {
		Path         string    `json:"path"`
		Name         string    `json:"name"`
		IsDir        bool      `json:"is_dir"`
		Size         int64     `json:"size"`
		OriginalPath string    `json:"original_path"`
		TrashedAt    time.Time `json:"trashed_at"`
	}

	items := []TrashItem{}
	for rows.Next() {
		var item TrashItem
		var isDir int
		var trashedAt sql.NullTime
		if err := rows.Scan(&item.Path, &item.Name, &isDir, &item.Size, &item.OriginalPath, &trashedAt); err != nil {
			continue
		}
		item.IsDir = isDir == 1
		if trashedAt.Valid {
			item.TrashedAt = trashedAt.Time
		}
		items = append(items, item)
	}

	return c.JSON(fiber.Map{"items": items, "count": len(items)})
}

// RestoreFromTrash restores a file from the trash.
// POST /api/trash/restore
func (h *FSHandler) RestoreFromTrash(c *fiber.Ctx) error {
	var body struct {
		Path string `json:"path"`
	}
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid request body"})
	}

	// Get original path from DB
	var originalPath string
	err := h.DB.QueryRow(
		"SELECT original_path FROM files WHERE path = ? AND is_trashed = 1",
		body.Path,
	).Scan(&originalPath)
	if err != nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "item not found in trash"})
	}

	trashPath := filepath.Join(h.Config.TrashDir, filepath.FromSlash(body.Path))
	destFull := filepath.Join(h.Config.StorageDir, filepath.FromSlash(originalPath))

	// Check if originalPath already exists, assign new name if so
	if _, err := os.Stat(destFull); err == nil {
		uniqueName := GetUniquePath(filepath.Dir(destFull), filepath.Base(destFull))
		originalPath = filepath.ToSlash(filepath.Join(filepath.Dir(originalPath), uniqueName))
		destFull = filepath.Join(filepath.Dir(destFull), uniqueName)
	}

	// Ensure parent directory exists
	if err := os.MkdirAll(filepath.Dir(destFull), 0755); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to prepare restore location"})
	}

	if err := os.Rename(trashPath, destFull); err != nil {
		if err := copyFile(trashPath, destFull); err != nil {
			return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to restore file"})
		}
		safeRemovePath(h.Config.TrashDir, trashPath)
	}

	h.DB.Exec("UPDATE files SET path = ?, name = ?, is_trashed = 0, trashed_at = NULL WHERE path = ?", originalPath, filepath.Base(originalPath), body.Path)
	
	var isDir int
	h.DB.QueryRow("SELECT is_dir FROM files WHERE path = ?", originalPath).Scan(&isDir)
	if isDir == 1 {
		h.DB.Exec(
			`UPDATE files SET path = REPLACE(path, ?, ?) WHERE path LIKE ?`,
			body.Path+"/", originalPath+"/", body.Path+"/%",
		)
	}

	h.DB.AddAuditLog("restored", originalPath, c.IP())

	h.DB.AddAuditLog("restored", fmt.Sprintf("Restored '%s' from trash", originalPath), c.IP())

	return c.JSON(fiber.Map{"message": "restored successfully", "path": originalPath})
}

// EmptyTrash permanently deletes all trashed items.
// DELETE /api/trash
func (h *FSHandler) EmptyTrash(c *fiber.Ctx) error {
	if err := safeRemovePath(h.Config.TrashDir, h.Config.TrashDir); err != nil {
		// safeRemovePath blocks deleting the root directory, so we just clear its contents instead
		entries, err := os.ReadDir(h.Config.TrashDir)
		if err == nil {
			for _, e := range entries {
				os.RemoveAll(filepath.Join(h.Config.TrashDir, e.Name()))
			}
		}
	}

	h.DB.Exec("DELETE FROM files WHERE is_trashed = 1")
	h.DB.AddAuditLog("emptied_trash", "User emptied trash", c.IP())
	return c.JSON(fiber.Map{"message": "trash emptied"})
}

// DownloadFolder creates and streams a ZIP archive of a folder.
// GET /api/files/download-folder?path=...
func (h *FSHandler) DownloadFolder(c *fiber.Ctx) error {
	folderPath := c.Query("path")
	if folderPath == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "path is required"})
	}

	fullPath, err := resolveSafe(h.Config.StorageDir, folderPath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	info, err := os.Stat(fullPath)
	if err != nil || !info.IsDir() {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "folder not found"})
	}

	c.Set("Content-Type", "application/zip")
	c.Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s.zip\"", filepath.Base(fullPath)))

	c.Context().SetBodyStreamWriter(func(w *bufio.Writer) {
		zipWriter := zip.NewWriter(w)
		defer zipWriter.Close()

		filepath.Walk(fullPath, func(path string, info os.FileInfo, err error) error {
			if err != nil {
				return err
			}
			if path == fullPath {
				return nil
			}

			relPath, err := filepath.Rel(fullPath, path)
			if err != nil {
				return err
			}

			if info.IsDir() {
				// add directory entry
				relPath += "/"
				_, err = zipWriter.Create(relPath)
				return err
			}

			// add file entry
			zipFile, err := zipWriter.Create(relPath)
			if err != nil {
				return err
			}

			fsFile, err := os.Open(path)
			if err != nil {
				return err
			}
			defer fsFile.Close()

			_, err = io.Copy(zipFile, fsFile)
			return err
		})
	})

	return nil
}

// DownloadBulk creates and streams a ZIP archive of multiple selected items.
// POST /api/files/download-bulk
func (h *FSHandler) DownloadBulk(c *fiber.Ctx) error {
	var body struct {
		Paths []string `json:"paths" form:"paths"`
	}
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid payload"})
	}

	if len(body.Paths) == 0 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "no paths provided"})
	}

	c.Set("Content-Type", "application/zip")
	c.Set("Content-Disposition", "attachment; filename=\"download.zip\"")

	c.Context().SetBodyStreamWriter(func(w *bufio.Writer) {
		zipWriter := zip.NewWriter(w)
		defer zipWriter.Close()

		for _, p := range body.Paths {
			fullPath, err := resolveSafe(h.Config.StorageDir, p)
			if err != nil {
				continue
			}

			info, err := os.Stat(fullPath)
			if err != nil {
				continue
			}

			if info.IsDir() {
				filepath.Walk(fullPath, func(path string, walkInfo os.FileInfo, err error) error {
					if err != nil {
						return err
					}
					
					// Make it relative to the parent of the chosen directory
					relPath, err := filepath.Rel(filepath.Dir(fullPath), path)
					if err != nil {
						return err
					}

					if walkInfo.IsDir() {
						relPath += "/"
						_, _ = zipWriter.Create(relPath)
						return nil
					}

					zipFile, err := zipWriter.Create(relPath)
					if err != nil {
						return err
					}

					fsFile, err := os.Open(path)
					if err != nil {
						return err
					}
					defer fsFile.Close()

					_, _ = io.Copy(zipFile, fsFile)
					return nil
				})
			} else {
				zipFile, err := zipWriter.Create(info.Name())
				if err != nil {
					continue
				}

				fsFile, err := os.Open(fullPath)
				if err != nil {
					continue
				}

				_, _ = io.Copy(zipFile, fsFile)
				fsFile.Close()
			}
		}
	})

	return nil
}

// TogglePin pins or unpins a file/folder.
// POST /api/files/pin
func (h *FSHandler) TogglePin(c *fiber.Ctx) error {
	var body struct {
		Path string `json:"path"`
	}
	if err := c.BodyParser(&body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid request body"})
	}

	cleanPath := filepath.ToSlash(body.Path)

	// Ensure the file record exists
	h.DB.Exec(
		"INSERT OR IGNORE INTO files (path, name) VALUES (?, ?)",
		cleanPath, filepath.Base(cleanPath),
	)

	// Toggle pin
	_, err := h.DB.Exec(
		"UPDATE files SET is_pinned = CASE WHEN is_pinned = 1 THEN 0 ELSE 1 END WHERE path = ?",
		cleanPath,
	)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to toggle pin"})
	}

	var isPinned int
	h.DB.QueryRow("SELECT is_pinned FROM files WHERE path = ?", cleanPath).Scan(&isPinned)

	return c.JSON(fiber.Map{"pinned": isPinned == 1, "path": cleanPath})
}

// ListPinned returns all pinned items.
// GET /api/files/pinned
func (h *FSHandler) ListPinned(c *fiber.Ctx) error {
	rows, err := h.DB.Query(
		"SELECT path, name, is_dir, size, mime_type FROM files WHERE is_pinned = 1 AND is_trashed = 0",
	)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "database error"})
	}
	defer rows.Close()

	items := []FileInfo{}
	for rows.Next() {
		var fi FileInfo
		var isDir int
		if err := rows.Scan(&fi.Path, &fi.Name, &isDir, &fi.Size, &fi.MimeType); err != nil {
			continue
		}
		fi.IsDir = isDir == 1
		fi.IsPinned = true
		items = append(items, fi)
	}

	return c.JSON(fiber.Map{"items": items, "count": len(items)})
}

// Search performs an FTS5 full-text search on file names and paths.
// GET /api/search?q=query
func (h *FSHandler) Search(c *fiber.Ctx) error {
	query := c.Query("q", "")
	if query == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "query parameter 'q' is required"})
	}

	// Sanitize FTS5 query to prevent syntax errors
	words := strings.Fields(query)
	var safeWords []string
	for _, w := range words {
		// Keep only alphanumeric characters
		var clean strings.Builder
		for _, r := range w {
			if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') {
				clean.WriteRune(r)
			}
		}
		if clean.Len() > 0 {
			safeWords = append(safeWords, clean.String()+"*")
		}
	}
	
	ftsQuery := strings.Join(safeWords, " AND ")
	if ftsQuery == "" {
		return c.JSON(fiber.Map{"items": []FileInfo{}, "count": 0})
	}

	rows, err := h.DB.Query(`
		SELECT f.path, f.name, f.is_dir, f.size, f.mime_type, f.is_pinned, f.checksum
		FROM files f
		JOIN files_fts fts ON f.id = fts.rowid
		WHERE files_fts MATCH ? AND f.is_trashed = 0
		ORDER BY rank
		LIMIT 50
	`, ftsQuery)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "search failed"})
	}
	defer rows.Close()

	results := []FileInfo{}
	for rows.Next() {
		var fi FileInfo
		var isDir, isPinned int
		var checksum sql.NullString
		if err := rows.Scan(&fi.Path, &fi.Name, &isDir, &fi.Size, &fi.MimeType, &isPinned, &checksum); err != nil {
			continue
		}
		fi.IsDir = isDir == 1
		fi.IsPinned = isPinned == 1
		fi.Checksum = checksum.String
		results = append(results, fi)
	}

	return c.JSON(fiber.Map{"results": results, "count": len(results)})
}

// Download serves a file with full HTTP Range Request support.
// GET /api/files/download/*
func (h *FSHandler) Download(c *fiber.Ctx) error {
	resolvedPath := c.Locals("resolvedPath").(string)

	info, err := os.Stat(resolvedPath)
	if err != nil || info.IsDir() {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "file not found"})
	}

	// Verify checksum on download if stored
	relativePath := c.Locals("relativePath").(string)
	var storedChecksum string
	h.DB.QueryRow("SELECT checksum FROM files WHERE path = ?", filepath.ToSlash(relativePath)).Scan(&storedChecksum)

	// Set appropriate headers for range requests
	c.Set("Accept-Ranges", "bytes")
	c.Set("Content-Type", mime.TypeByExtension(filepath.Ext(resolvedPath)))

	// Use Fiber's built-in SendFile which supports Range requests
	return c.SendFile(resolvedPath)
}

// Upload handles file upload and generates an XXHash checksum.
// POST /api/files/upload
func (h *FSHandler) Upload(c *fiber.Ctx) error {
	destPath := c.FormValue("path", "")
	if destPath == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "destination path is required"})
	}

	file, err := c.FormFile("file")
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "file is required"})
	}

	fullDest, err := resolveSafe(h.Config.StorageDir, destPath)
	if err != nil {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": err.Error()})
	}

	// If destination is a directory, save into it
	if info, err := os.Stat(fullDest); err == nil && info.IsDir() {
		uniqueName := GetUniquePath(fullDest, file.Filename)
		fullDest = filepath.Join(fullDest, uniqueName)
		destPath = filepath.Join(destPath, uniqueName)
	}

	// Ensure parent directory exists
	if err := os.MkdirAll(filepath.Dir(fullDest), 0755); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to create directory"})
	}

	// Save the file
	if err := c.SaveFile(file, fullDest); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "failed to save file"})
	}

	// Generate XXHash checksum
	checksum, err := generateChecksum(fullDest)
	if err != nil {
		// File saved but checksum failed — log but don't fail the upload
		fmt.Printf("Warning: checksum generation failed for %s: %v\n", destPath, err)
	}

	cleanPath := filepath.ToSlash(destPath)
	mimeType := mime.TypeByExtension(filepath.Ext(file.Filename))

	// Upsert file record
	h.DB.Exec(`
		INSERT INTO files (path, name, size, mime_type, checksum)
		VALUES (?, ?, ?, ?, ?)
		ON CONFLICT(path) DO UPDATE SET
			size = excluded.size,
			mime_type = excluded.mime_type,
			checksum = excluded.checksum,
			updated_at = CURRENT_TIMESTAMP
	`, cleanPath, file.Filename, file.Size, mimeType, checksum)

	h.DB.AddAuditLog("uploaded", fmt.Sprintf("%s (%d bytes)", cleanPath, file.Size), c.IP())

	// Queue thumbnail generation
	if workers.Instance != nil {
		workers.Instance.Enqueue(workers.ThumbnailJob{
			FilePath: fullDest,
			Checksum: checksum,
			MimeType: mimeType,
		})
	}

	return c.Status(fiber.StatusCreated).JSON(fiber.Map{
		"message":  "uploaded successfully",
		"path":     cleanPath,
		"checksum": checksum,
		"size":     file.Size,
	})
}

// StorageDashboard returns storage usage broken down by file type.
// GET /api/storage/dashboard
func (h *FSHandler) StorageDashboard(c *fiber.Ctx) error {
	type CategoryUsage struct {
		Category string `json:"category"`
		Size     int64  `json:"size"`
		Count    int    `json:"count"`
	}

	// Walk the storage directory to compute real usage
	categories := map[string]*CategoryUsage{
		"images":    {Category: "images"},
		"videos":    {Category: "videos"},
		"audio":     {Category: "audio"},
		"documents": {Category: "documents"},
		"archives":  {Category: "archives"},
		"other":     {Category: "other"},
	}

	var totalSize int64

	filepath.Walk(h.Config.StorageDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() {
			return nil
		}
		// Skip system dirs
		rel, _ := filepath.Rel(h.Config.StorageDir, path)
		if strings.HasPrefix(rel, ".trash") || strings.HasPrefix(rel, ".versions") || strings.HasPrefix(rel, ".backups") {
			return nil
		}

		ext := strings.ToLower(filepath.Ext(info.Name()))
		cat := categorizeFile(ext)
		categories[cat].Size += info.Size()
		categories[cat].Count++
		totalSize += info.Size()
		return nil
	})

	result := make([]CategoryUsage, 0, len(categories))
	for _, cat := range categories {
		if cat.Count > 0 {
			result = append(result, *cat)
		}
	}

	return c.JSON(fiber.Map{
		"total_size":  totalSize,
		"categories":  result,
	})
}

// --- Helper functions ---

func generateChecksum(filePath string) (string, error) {
	f, err := os.Open(filePath)
	if err != nil {
		return "", err
	}
	defer f.Close()

	h := xxhash.New()
	if _, err := io.Copy(h, f); err != nil {
		return "", err
	}

	return fmt.Sprintf("%016x", h.Sum64()), nil
}

func copyFile(src, dst string) error {
	if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
		return err
	}

	sourceFile, err := os.Open(src)
	if err != nil {
		return err
	}
	defer sourceFile.Close()

	destFile, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer destFile.Close()

	_, err = io.Copy(destFile, sourceFile)
	return err
}

func copyDir(src, dst string) error {
	return filepath.Walk(src, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		rel, _ := filepath.Rel(src, path)
		target := filepath.Join(dst, rel)

		if info.IsDir() {
			return os.MkdirAll(target, info.Mode())
		}

		return copyFile(path, target)
	})
}

func categorizeFile(ext string) string {
	switch ext {
	case ".jpg", ".jpeg", ".png", ".gif", ".bmp", ".svg", ".webp", ".ico", ".tiff":
		return "images"
	case ".mp4", ".mkv", ".avi", ".mov", ".wmv", ".flv", ".webm", ".m4v":
		return "videos"
	case ".mp3", ".wav", ".flac", ".aac", ".ogg", ".wma", ".m4a":
		return "audio"
	case ".pdf", ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx", ".txt", ".md", ".csv":
		return "documents"
	case ".zip", ".tar", ".gz", ".rar", ".7z", ".bz2":
		return "archives"
	default:
		return "other"
	}
}

// ServeThumbnail serves a generated thumbnail image.
// GET /api/files/thumbnail/:checksum
func (h *FSHandler) ServeThumbnail(c *fiber.Ctx) error {
	checksum := c.Params("checksum")
	if checksum == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "missing checksum"})
	}

	// Sanitize checksum: should only contain hex characters to prevent path traversal
	isHex := true
	for _, char := range checksum {
		if !((char >= '0' && char <= '9') || (char >= 'a' && char <= 'f') || (char >= 'A' && char <= 'F')) {
			isHex = false
			break
		}
	}
	if !isHex {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid checksum format"})
	}

	thumbPath := filepath.Join(h.Config.ThumbnailDir, checksum+".jpg")
	
	if _, err := os.Stat(thumbPath); os.IsNotExist(err) {
		return c.SendStatus(fiber.StatusNotFound)
	}

	// Set caching headers for thumbnails (they don't change because checksums are immutable)
	c.Set("Cache-Control", "public, max-age=31536000, immutable")
	
	return c.SendFile(thumbPath)
}

type CheckConflictsRequest struct {
	DestPath string   `json:"dest_path"`
	Files    []string `json:"files"`
}

// CheckConflicts checks if files exist in the destination.
// POST /api/files/check-conflicts
func (h *FSHandler) CheckConflicts(c *fiber.Ctx) error {
	var req CheckConflictsRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid body"})
	}

	destFull, err := resolveSafe(h.Config.StorageDir, req.DestPath)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid path"})
	}

	conflicts := []string{}
	for _, file := range req.Files {
		filePath := filepath.Join(destFull, file)
		if _, err := os.Stat(filePath); err == nil {
			conflicts = append(conflicts, file)
		}
	}

	return c.JSON(fiber.Map{"conflicts": conflicts})
}

// safeRemovePath ensures we never delete a base directory.
func safeRemovePath(baseDir, targetAbsPath string) error {
	cleanBase := filepath.Clean(baseDir)
	cleanTarget := filepath.Clean(targetAbsPath)
	if cleanTarget == cleanBase || cleanTarget == "." || cleanTarget == "/" {
		return fmt.Errorf("cannot remove base directory %s", baseDir)
	}
	// Ensure it's inside the baseDir
	if !strings.HasPrefix(cleanTarget, cleanBase+string(os.PathSeparator)) {
		return fmt.Errorf("path escapes base directory")
	}
	return os.RemoveAll(cleanTarget)
}