package main

import (
	"flag"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
)

var dryrun bool
var execCmd string

func main() {
	args := os.Args[1:]
	if len(args) == 0 {
		fmt.Println("No action specified")
		return
	}

	flag.BoolVar(&dryrun, "n", false, "Show what would have been done.")
	flag.StringVar(&execCmd, "exec", "", "Run commant on matching file.")
	flag.Parse()

	fmt.Println(execCmd)
	fmt.Println(dryrun)

	switch flag.Arg(0) {
	case "normalize":
		fallthrough
	case "n":
		filepath.Walk(".", normalize)
	case "removesuffix":
		fallthrough
	case "rs":
		suffix := args[1]
		filepath.Walk(".", removeSuffix(suffix))
		removeSuffix(suffix)
		break
	case "unpack":
		fallthrough
	case "up":
		filepath.Walk(".", unpack)
	default:
		fmt.Println("Invalid action specified")
		return
	}
}

func skipDir(filename string) (bool, error) {
	if filename == "." || filename == ".." {
		return true, nil
	}

	if filename == "Bin" {
		return true, filepath.SkipDir
	}

	return false, nil
}

func removeSuffix(suffix string) filepath.WalkFunc {
	return func(p string, f os.FileInfo, err error) error {
		filename := f.Name()
		if skip, err := skipDir(filename); skip {
			return err
		}

		element := newMediaElement(p)
		fmt.Println(element.Path())

		dir := filepath.Dir(p)
		ext := filepath.Ext(filename)
		filenameNoExt := trimSuffix(filename, ext)
		filenameNoSuff := trimSuffix(filenameNoExt, suffix)
		if filenameNoSuff != filenameNoExt {
			newFilename := filenameNoSuff + ext

			err := os.Rename(filepath.Join(dir, filename), filepath.Join(dir, newFilename))
			if err != nil {
				fmt.Printf("Could not rename %s: %v\n", filename, err)
			} else {
				fmt.Println("Renamed " + filename + " to " + newFilename)
			}
		}

		return nil
	}
}

func normalize(p string, f os.FileInfo, err error) error {
	filename := f.Name()
	if skip, err := skipDir(filename); skip {
		return err
	}

	element := newMediaElement(p)
	newPath := element.Path()
	if newPath != p {
		if dryrun {
			fmt.Printf("Would move %s to %s\n", p, newPath)
		} else {
			os.Rename(p, newPath)
			fmt.Printf("%s => %s\n", p, newPath)
		}
	}

	return nil
}

func unpack(p string, f os.FileInfo, err error) error {
	filename := f.Name()
	if skip, err := skipDir(filename); skip {
		return err
	}

	ext := filepath.Ext(filename)
	ext = strings.ToLower(ext)
	if ext != ".rar" {
		return nil
	}

	cmd := exec.Command(execCmd, p)
	filename = trimSuffix(filename, ext)
	ext = filepath.Ext(filename)
	if ext == "" {
		fmt.Println(p)
		err := cmd.Run()
		if err != nil {
			fmt.Printf("Error executing: %v\n", err)
		}
		fmt.Println(p)
		return nil
	}

	if strings.HasPrefix(ext, ".part") {
		ext = ext[5:]
		part, err := strconv.Atoi(ext)
		if err == nil && part == 1 {
			fmt.Println(p)
			err := cmd.Run()
			if err != nil {
				fmt.Printf("Error executing: %v\n", err)
			}
			fmt.Println(p)
			return nil
		}
	}
	return nil
}