package main

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
)

var (
	KEEP_SRT bool = false
)

func scan_dir(dir string) ([]string, error) {
	var r []string = []string{}
	ls, err := os.ReadDir(dir)
	if err != nil {
		return nil, err
	}
	for _, elem := range ls {
		if elem.IsDir() {
			rs, err := scan_dir(filepath.Join(dir, elem.Name()))
			if err != nil {
				return nil, err
			}
			for _, e := range rs {
				r = append(r, filepath.Join(elem.Name(), e))
			}
		} else {
			if strings.HasSuffix(elem.Name(), ".srt") {
				if !KEEP_SRT {
					continue
				}
				r = append(r, elem.Name())
				continue
			}
			if strings.HasSuffix(elem.Name(), ".info") || strings.HasSuffix(elem.Name(), ".txt") {
				continue
			}
			r = append(r, elem.Name())
		}
	}
	return r, nil
}

func is_empty(dir string) bool {
	ls, err := os.ReadDir(dir)
	if err != nil {
		return false
	}
	for _, elem := range ls {
		if elem.IsDir() {
			return is_empty(filepath.Join(dir, elem.Name()))
		}
		if strings.HasSuffix(elem.Name(), ".srt") {
			if !KEEP_SRT {
				continue
			}
			return false
		}
		if strings.HasSuffix(elem.Name(), ".info") || strings.HasSuffix(elem.Name(), ".txt") {
			continue
		}
		return false
	}
	return true
}

func scan_for_dirs(dir string) ([]string, error) {
	var r []string = []string{}
	ls, err := os.ReadDir(dir)
	if err != nil {
		return nil, err
	}
	for _, elem := range ls {
		if elem.IsDir() && is_empty(filepath.Join(dir, elem.Name())) {
			r = append(r, filepath.Join(dir, elem.Name()))
		}
	}
	return r, nil
}

func main() {
	var REMOVE bool = true
	// Keeps
	if len(os.Args) != 1 {
		for idx, arg := range os.Args {
			if idx == 0 { // Skip program name
				continue
			}
			switch strings.ToLower(arg) {
			case "srt":
				KEEP_SRT = true
			case "norm", "no-rm", "no-remove":
				REMOVE = false
			case "help", "h", "?":
				fmt.Println("--- Help ---")
				fmt.Println("undir will move 1 or more files from a directory, then delete the directory.")
				fmt.Println("")
				fmt.Println("Commands:")
				fmt.Println("")
				fmt.Println(" srt                        undir will move *.srt files")
				fmt.Println(" norm, no-rm, no-remove     undir will NOT remove directories or files")
				fmt.Println(" help, h, ?                 Prints this help screen and exits (code 0, success)")
				fmt.Println("")
				fmt.Println("Example Usage:")
				fmt.Println("")
				fmt.Println("undir                       Standard run of undir, will move any file NOT *.info or *.srt")
				fmt.Println("undir srt                   Run undir but move *.srt files")
				fmt.Println("undir no-rm                 Run undir but do NOT remove directories or files, simply copy them")
				fmt.Println("undir srt norm              Run undir but move *.srt files, also do NOT remove directories or files, simply copy them")
				fmt.Println("undir ?                     Prints this help screen and exits (code 0, success)")
				os.Exit(0)
			}
		}
		if KEEP_SRT {
			fmt.Println("Keeping .srt's")
		}
		if !REMOVE {
			fmt.Println("No Remove Mode")
		}
	}
	actions, err := scan_dir(".")
	if err != nil {
		fmt.Println("Err:", err)
		return
	}
	fmt.Println("Found:", len(actions))
	for idx, a := range actions {
		fmt.Println(a)
		out, err := os.Create(filepath.Base(a))
		if err != nil {
			fmt.Println("Err (Create out):", err)
			continue
		}
		in, err := os.Open(a)
		if err != nil {
			out.Close()
			fmt.Println("RM", filepath.Base(a))
			err1 := os.Remove(filepath.Base(a))
			if err1 != nil {
				fmt.Println("Err (Cleanup):", err1)
			}
			fmt.Println("Err (Open in):", err)
			continue
		}
		_, err = io.Copy(out, in)
		if err != nil {
			in.Close()
			out.Close()
			fmt.Println("RM", filepath.Base(a))
			err1 := os.Remove(filepath.Base(a))
			if err1 != nil {
				fmt.Println("Err (Cleanup):", err1)
			}
			fmt.Println("Err (Copy in -> out):", err)
			continue
		}
		if idx+1 < len(actions) {
			fmt.Println("End?")
			if REMOVE {
				fmt.Println("RM", filepath.Dir(a))
				err = os.RemoveAll(filepath.Dir(a))
				if err != nil {
					fmt.Println("Err (Remove):", err)
				}
				var can_clean bool = true
				for _, next := range actions[idx+1:] {
					if filepath.Dir(next) == filepath.Dir(a) {
						can_clean = false
					}
				}
				if can_clean {
					new_scan, err := scan_for_dirs(".")
					if err != nil {
						fmt.Println("Err (Rescan):", err)
						continue
					}
					if len(new_scan) != 0 {
						for _, elem := range new_scan {
							fmt.Println("RM", elem)
							err = os.RemoveAll(elem)
							if err != nil {
								fmt.Println("Err (Remove):", err)
							}
						}
					}
				}
			}
			continue
		}
		var can_clean bool = true
		for _, next := range actions[idx+1:] {
			if filepath.Dir(next) == filepath.Dir(a) {
				can_clean = false
			}
		}
		if can_clean && REMOVE {
			fmt.Println("RM", filepath.Dir(a))
			err = os.RemoveAll(filepath.Dir(a))
			if err != nil {
				fmt.Println("Err (Remove):", err)
				continue
			}
			new_scan, err := scan_for_dirs(".")
			if err != nil {
				fmt.Println("Err (Rescan):", err)
				continue
			}
			if len(new_scan) != 0 {
				for _, elem := range new_scan {
					fmt.Println("RM", elem)
					err = os.RemoveAll(elem)
					if err != nil {
						fmt.Println("Err (Remove):", err)
					}
				}
			}
		}
	}
}