//go:generate go get github.com/jteeuwen/go-bindata
//go:generate go install github.com/jteeuwen/go-bindata/go-bindata
//go:generate go-bindata -debug -pkg filemanager -prefix "assets" -o binary.go assets/...
// TODO: remove debug from the comment

// Package filemanager provides middleware for managing files in a directory
// when directory path is requested instead of a specific file. Based on browse
// middleware.
package filemanager

import (
	"mime"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"github.com/mholt/caddy/caddyhttp/httpserver"
)

const assetsURL = "/_filemanagerinternal"

// FileManager is an http.Handler that can show a file listing when
// directories in the given paths are specified.
type FileManager struct {
	Next    httpserver.Handler
	Configs []Config
}

// ServeHTTP determines if the request is for this plugin, and if all prerequisites are met.
func (f FileManager) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
	var (
		c      *Config
		fi     *FileInfo
		code   int
		err    error
		assets bool
	)

	for i := range f.Configs {
		if httpserver.Path(r.URL.Path).Matches(f.Configs[i].BaseURL) {
			c = &f.Configs[i]
			assets = httpserver.Path(r.URL.Path).Matches(c.BaseURL + assetsURL)

			if r.Method != http.MethodPost && !assets {
				fi, code, err = GetFileInfo(r.URL, c)
				if err != nil {
					return code, err
				}

				if fi.IsDir && !strings.HasSuffix(r.URL.Path, "/") {
					http.Redirect(w, r, r.URL.Path+"/", http.StatusTemporaryRedirect)
					return 0, nil
				}
			}

			// Route the request depending on the HTTP Method
			switch r.Method {
			case http.MethodGet:
				// Read and show directory or file
				if assets {
					return ServeAssets(w, r, c)
				}

			/* 	if file.Info.IsDir() {
				return f.ServeListing(w, r, file.File, c)
			}
			return f.ServeSingleFile(w, r, file, c) */
			case http.MethodPost:
				// Create new file or directory

				return http.StatusOK, nil
			case http.MethodDelete:
				// Delete a file or a directory
				return fi.Delete()
			case http.MethodPut:
				// Update/Modify a directory or file

				return http.StatusOK, nil
			case http.MethodPatch:
				// Rename a file or directory

				return http.StatusOK, nil
			default:
				return http.StatusNotImplemented, nil
			}
		}
	}

	return f.Next.ServeHTTP(w, r)
}

// ErrorToHTTPCode gets the respective HTTP code for an error
func ErrorToHTTPCode(err error) int {
	switch {
	case os.IsPermission(err):
		return http.StatusForbidden
	case os.IsExist(err):
		return http.StatusGone
	default:
		return http.StatusInternalServerError
	}
}

// ServeAssets provides the needed assets for the front-end
func ServeAssets(w http.ResponseWriter, r *http.Request, c *Config) (int, error) {
	// gets the filename to be used with Assets function
	filename := strings.Replace(r.URL.Path, c.BaseURL+assetsURL, "public", 1)
	file, err := Asset(filename)
	if err != nil {
		return http.StatusNotFound, nil
	}

	// Get the file extension and its mimetype
	extension := filepath.Ext(filename)
	mediatype := mime.TypeByExtension(extension)

	// Write the header with the Content-Type and write the file
	// content to the buffer
	w.Header().Set("Content-Type", mediatype)
	w.Write(file)
	return 200, nil
}