package fs

import (
	"context"
	"strings"

	sr "tildegit.org/tjp/sliderule"
	"tildegit.org/tjp/sliderule/gopher"
	"tildegit.org/tjp/sliderule/gopher/gophermap"
)

// GopherFileHandler builds a handler which serves up files from a file system.
//
// It only serves responses for paths which correspond to files, not directories.
func GopherFileHandler(fsroot, urlroot string, settings *gophermap.FileSystemSettings) sr.Handler {
	handler := fileHandler(gopher.ServerProtocol, fsroot, urlroot)
	return gophermap.ExtendMiddleware(fsroot, urlroot, settings)(handler)
}

// GopherDirectoryDefault serves up default files for directory path requests.
//
// If any of the supported filenames are found in the requested directory, the
// contents of that file is returned as the gopher response.
//
// It returns nil for any paths which don't correspond to a directory.
func GopherDirectoryDefault(fsroot, urlroot string, settings *gophermap.FileSystemSettings) sr.Handler {
	if settings == nil {
		return sr.HandlerFunc(func(_ context.Context, _ *sr.Request) *sr.Response { return nil })
	}

	handler := directoryDefault(gopher.ServerProtocol, fsroot, urlroot, false, settings.DirMaps...)
	return gophermap.ExtendMiddleware(fsroot, urlroot, settings)(handler)
}

// GopherDirectoryListing produces a listing of the contents of any requested directories.
//
// It returns nil for any paths which don't correspond to a filesystem directory.
func GopherDirectoryListing(fsroot, urlroot string, settings *gophermap.FileSystemSettings) sr.Handler {
	fsroot = strings.TrimRight(fsroot, "/")

	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
		if !strings.HasPrefix(request.Path, urlroot) {
			return nil
		}

		dpath, _ := rebasePath(fsroot, urlroot, request)

		if isPrivate(dpath) {
			return nil
		}
		if isd, err := isDir(dpath); err != nil {
			return gopher.Error(err).Response()
		} else if !isd {
			return nil
		}

		if settings == nil {
			settings = &gophermap.FileSystemSettings{}
		}
		doc, err := gophermap.ListDir(dpath, request.URL, *settings)
		if err != nil {
			return gopher.Error(err).Response()
		}

		return doc.Response()
	})
}