package tree

import (
	"context"
	"fmt"
	"io"
	"os"
	"path"
	"path/filepath"
	"strings"
	"time"

	"github.com/a8m/tree"
	"github.com/pkg/errors"
	"github.com/rclone/rclone/cmd"
	"github.com/rclone/rclone/fs"
	"github.com/rclone/rclone/fs/config/flags"
	"github.com/rclone/rclone/fs/dirtree"
	"github.com/rclone/rclone/fs/log"
	"github.com/rclone/rclone/fs/walk"
	"github.com/spf13/cobra"
)

var (
	opts        tree.Options
	outFileName string
	noReport    bool
	sort        string
)

func init() {
	cmd.Root.AddCommand(commandDefinition)
	cmdFlags := commandDefinition.Flags()
	// List
	flags.BoolVarP(cmdFlags, &opts.All, "all", "a", false, "All files are listed (list . files too).")
	flags.BoolVarP(cmdFlags, &opts.DirsOnly, "dirs-only", "d", false, "List directories only.")
	flags.BoolVarP(cmdFlags, &opts.FullPath, "full-path", "", false, "Print the full path prefix for each file.")
	//flags.BoolVarP(cmdFlags, &opts.IgnoreCase, "ignore-case", "", false, "Ignore case when pattern matching.")
	flags.BoolVarP(cmdFlags, &noReport, "noreport", "", false, "Turn off file/directory count at end of tree listing.")
	// flags.BoolVarP(cmdFlags, &opts.FollowLink, "follow", "l", false, "Follow symbolic links like directories.")
	flags.IntVarP(cmdFlags, &opts.DeepLevel, "level", "", 0, "Descend only level directories deep.")
	// flags.StringVarP(cmdFlags, &opts.Pattern, "pattern", "P", "", "List only those files that match the pattern given.")
	// flags.StringVarP(cmdFlags, &opts.IPattern, "exclude", "", "", "Do not list files that match the given pattern.")
	flags.StringVarP(cmdFlags, &outFileName, "output", "o", "", "Output to file instead of stdout.")
	// Files
	flags.BoolVarP(cmdFlags, &opts.ByteSize, "size", "s", false, "Print the size in bytes of each file.")
	flags.BoolVarP(cmdFlags, &opts.FileMode, "protections", "p", false, "Print the protections for each file.")
	// flags.BoolVarP(cmdFlags, &opts.ShowUid, "uid", "", false, "Displays file owner or UID number.")
	// flags.BoolVarP(cmdFlags, &opts.ShowGid, "gid", "", false, "Displays file group owner or GID number.")
	flags.BoolVarP(cmdFlags, &opts.Quotes, "quote", "Q", false, "Quote filenames with double quotes.")
	flags.BoolVarP(cmdFlags, &opts.LastMod, "modtime", "D", false, "Print the date of last modification.")
	// flags.BoolVarP(cmdFlags, &opts.Inodes, "inodes", "", false, "Print inode number of each file.")
	// flags.BoolVarP(cmdFlags, &opts.Device, "device", "", false, "Print device ID number to which each file belongs.")
	// Sort
	flags.BoolVarP(cmdFlags, &opts.NoSort, "unsorted", "U", false, "Leave files unsorted.")
	flags.BoolVarP(cmdFlags, &opts.VerSort, "version", "", false, "Sort files alphanumerically by version.")
	flags.BoolVarP(cmdFlags, &opts.ModSort, "sort-modtime", "t", false, "Sort files by last modification time.")
	flags.BoolVarP(cmdFlags, &opts.CTimeSort, "sort-ctime", "", false, "Sort files by last status change time.")
	flags.BoolVarP(cmdFlags, &opts.ReverSort, "sort-reverse", "r", false, "Reverse the order of the sort.")
	flags.BoolVarP(cmdFlags, &opts.DirSort, "dirsfirst", "", false, "List directories before files (-U disables).")
	flags.StringVarP(cmdFlags, &sort, "sort", "", "", "Select sort: name,version,size,mtime,ctime.")
	// Graphics
	flags.BoolVarP(cmdFlags, &opts.NoIndent, "noindent", "", false, "Don't print indentation lines.")
	flags.BoolVarP(cmdFlags, &opts.Colorize, "color", "C", false, "Turn colorization on always.")
}

var commandDefinition = &cobra.Command{
	Use:   "tree remote:path",
	Short: `List the contents of the remote in a tree like fashion.`,
	Long: `
rclone tree lists the contents of a remote in a similar way to the
unix tree command.

For example

    $ rclone tree remote:path
    /
    ├── file1
    ├── file2
    ├── file3
    └── subdir
        ├── file4
        └── file5
    
    1 directories, 5 files

You can use any of the filtering options with the tree command (e.g.
--include and --exclude).  You can also use --fast-list.

The tree command has many options for controlling the listing which
are compatible with the tree command.  Note that not all of them have
short options as they conflict with rclone's short options.
`,
	RunE: func(command *cobra.Command, args []string) error {
		cmd.CheckArgs(1, 1, command, args)
		fsrc := cmd.NewFsSrc(args)
		outFile := os.Stdout
		if outFileName != "" {
			var err error
			outFile, err = os.Create(outFileName)
			if err != nil {
				return errors.Errorf("failed to create output file: %v", err)
			}
		}
		opts.VerSort = opts.VerSort || sort == "version"
		opts.ModSort = opts.ModSort || sort == "mtime"
		opts.CTimeSort = opts.CTimeSort || sort == "ctime"
		opts.NameSort = sort == "name"
		opts.SizeSort = sort == "size"
		ci := fs.GetConfig(context.Background())
		opts.UnitSize = ci.HumanReadable
		if opts.DeepLevel == 0 {
			opts.DeepLevel = ci.MaxDepth
		}
		cmd.Run(false, false, command, func() error {
			return Tree(fsrc, outFile, &opts)
		})
		return nil
	},
}

// Tree lists fsrc to outFile using the Options passed in
func Tree(fsrc fs.Fs, outFile io.Writer, opts *tree.Options) error {
	dirs, err := walk.NewDirTree(context.Background(), fsrc, "", false, opts.DeepLevel)
	if err != nil {
		return err
	}
	opts.Fs = NewFs(dirs)
	opts.OutFile = outFile
	inf := tree.New("/")
	var nd, nf int
	if d, f := inf.Visit(opts); f != 0 {
		nd, nf = nd+d, nf+f
	}
	inf.Print(opts)
	// Print footer report
	if !noReport {
		footer := fmt.Sprintf("\n%d directories", nd)
		if !opts.DirsOnly {
			footer += fmt.Sprintf(", %d files", nf)
		}
		_, _ = fmt.Fprintln(outFile, footer)
	}
	return nil
}

// FileInfo maps an fs.DirEntry into an os.FileInfo
type FileInfo struct {
	entry fs.DirEntry
}

// Name is base name of the file
func (to *FileInfo) Name() string {
	return path.Base(to.entry.Remote())
}

// Size in bytes for regular files; system-dependent for others
func (to *FileInfo) Size() int64 {
	return to.entry.Size()
}

// Mode is file mode bits
func (to *FileInfo) Mode() os.FileMode {
	if to.IsDir() {
		return os.FileMode(0777)
	}
	return os.FileMode(0666)
}

// ModTime is modification time
func (to *FileInfo) ModTime() time.Time {
	return to.entry.ModTime(context.Background())
}

// IsDir is abbreviation for Mode().IsDir()
func (to *FileInfo) IsDir() bool {
	_, ok := to.entry.(fs.Directory)
	return ok
}

// Sys is underlying data source (can return nil)
func (to *FileInfo) Sys() interface{} {
	return nil
}

// String returns the full path
func (to *FileInfo) String() string {
	return to.entry.Remote()
}

// Fs maps an fs.Fs into a tree.Fs
type Fs dirtree.DirTree

// NewFs creates a new tree
func NewFs(dirs dirtree.DirTree) Fs {
	return Fs(dirs)
}

// Stat returns info about the file
func (dirs Fs) Stat(filePath string) (fi os.FileInfo, err error) {
	defer log.Trace(nil, "filePath=%q", filePath)("fi=%+v, err=%v", &fi, &err)
	filePath = filepath.ToSlash(filePath)
	filePath = strings.TrimLeft(filePath, "/")
	if filePath == "" {
		return &FileInfo{fs.NewDir("", time.Now())}, nil
	}
	_, entry := dirtree.DirTree(dirs).Find(filePath)
	if entry == nil {
		return nil, errors.Errorf("Couldn't find %q in directory cache", filePath)
	}
	return &FileInfo{entry}, nil
}

// ReadDir returns info about the directory and fills up the directory cache
func (dirs Fs) ReadDir(dir string) (names []string, err error) {
	defer log.Trace(nil, "dir=%s", dir)("names=%+v, err=%v", &names, &err)
	dir = filepath.ToSlash(dir)
	dir = strings.TrimLeft(dir, "/")
	entries, ok := dirs[dir]
	if !ok {
		return nil, errors.Errorf("Couldn't find directory %q", dir)
	}
	for _, entry := range entries {
		names = append(names, path.Base(entry.Remote()))
	}
	return
}

// check interfaces
var (
	_ tree.Fs     = (*Fs)(nil)
	_ os.FileInfo = (*FileInfo)(nil)
)