package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"os/signal"
	"path/filepath"
	"strings"
	"sync"
	"syscall"
	"time"

	"git.milar.in/milarin/buildinfo"
	"github.com/fatih/color"
)

var (
	Current Entry
	Root    Entry

	ColorRed   = color.New(color.FgRed)
	ColorBlue  = color.New(color.FgBlue)
	ColorGreen = color.New(color.FgGreen)

	IconTheme = flag.String("i", "unicode", "icon theme (currently supported: default, unicode, nerd)")

	ShowVersion = flag.Bool("v", false, "show version and exit")
)

// FIXME sometimes sorting not applied after removing items
// TODO pwd command showing Current entry path and Root entry path in filesystem
// TODO arrow up -> last command (`stty -raw` necessary?). even better: rlwrap impl (see tsoding noq)
// TODO config file with preferred icon theme or read best icon theme from terminfo somehow
// TODO on exit: show deleted files in recursive tree (only deleted files and their parent directories)
// TODO autocomplete on TAB (see arrow up issue: raw necessary?)
func main() {
	flag.Parse()

	if *ShowVersion {
		buildinfo.Print(buildinfo.Options{})
		return
	}

	rootPath := flag.Arg(0)

	mounts, err := Mounts()
	if err != nil {
		fmt.Fprintln(os.Stderr, "Mount points could not be read! All mount points will be calculated as well")
	}

	if abs, err := filepath.Abs(rootPath); err == nil {
		rootPath = abs
	} else {
		panic(err)
	}

	root, err := NewEntry(rootPath)
	if err != nil {
		panic(err)
	}

	start := time.Now()
	ScanEntryLive(root, mounts)
	fmt.Println(Translate("Scanning took %s", time.Since(start)))
	fmt.Println()

	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
	go func() {
		for range c {
			fmt.Println()
			showError("Use command 'exit' for exiting properly")
			fmt.Print("> ")
		}
	}()

	Root = root
	Current = root

	s := bufio.NewScanner(os.Stdin)
	showCurrentDir := true
	for {
		if showCurrentDir {
			fmt.Println(Current.StringRecursive(1))
		}

		fmt.Print("> ")

		s.Scan()
		input := s.Text()
		showCurrentDir = handleInput(input)
	}
}

func handleInput(input string) bool {
	cmd := strings.Split(strings.TrimSpace(input), " ")
	switch cmd[0] {
	case "ls":
		ls(cmd[1:])
		return false
	case "cd":
		cd(cmd[1:])
	case "rm":
		rm(cmd[1:], true)
	case "urm":
		rm(cmd[1:], false)
	case "exit":
		exit()
	case "help":
		help(cmd[1:])
	}

	return true
}

func showError(str string, args ...interface{}) {
	fmt.Println()
	ColorRed.Println(Translate(str, args...))
	fmt.Println()
}

func entryByPath(path string) Entry {
	if !strings.HasPrefix(path, Root.Path()) {
		return nil
	}

	path = strings.TrimPrefix(path, Root.Path())
	if path == "/" || path == "" {
		return Root
	} else {
		path = strings.TrimPrefix(path, "/")
	}

	return Root.Entry(path)
}

func getEntriesForPath(path string) []Entry {
	path = filepath.Clean(path)

	if filepath.IsAbs(path) {
		path = filepath.Join(Root.Path(), path)
	} else {
		path = filepath.Join(Current.Path(), path)
	}

	paths, err := filepath.Glob(path)
	if err != nil {
		panic(err)
	}

	entries := make([]Entry, 0, len(paths))
	for _, path := range paths {
		if entry := entryByPath(path); entry != nil {
			entries = append(entries, entry)
		}
	}

	return entries
}

func ScanEntryLive(entry Entry, mounts map[string]struct{}) {
	ch := make(chan string, 10)

	wg := new(sync.WaitGroup)

	// TODO cap string size to terminal width
	//width, _, _ := terminal.GetSize(int(os.Stdin.Fd()))

	wg.Add(1)
	go func(ch <-chan string) {
		defer wg.Done()
		for path := range ch {
			os.Stdout.Write([]byte{'\r'})
			clearEOL()
			fmt.Print(Translate("Scanning ") + path)
		}

		os.Stdout.Write([]byte{'\r'})
		clearEOL()
	}(ch)

	entry.Scan(ch, mounts)
	close(ch)
	wg.Wait()
}

func removeMarkedEntries(entry Entry) {
	if entry.RemovalMark() {
		err := os.RemoveAll(entry.Path())
		if err != nil {
			ColorRed.Println(Translate("Could not delete '%s': %s", entry.Path(), err.Error()))
		}
	} else {
		for _, entry := range entry.Entries() {
			removeMarkedEntries(entry)
		}
	}
}