package process

import (
	"fmt"
	"os"
	"strings"

	"github.com/akamensky/argparse"
	"github.com/rs/zerolog/log"
	"gitlab.com/ChaotiCryptidz/musicutil/types"
	"gitlab.com/ChaotiCryptidz/musicutil/utils"
	"gitlab.com/ChaotiCryptidz/musicutil/utils/ascii_reduce"
	"gitlab.com/ChaotiCryptidz/musicutil/utils/tag_cache"
)

type ProcessCommandArgs struct {
	Source *string
	DryRun *bool
}

func RegisterProcessCommand(parser *argparse.Parser) (*argparse.Command, *ProcessCommandArgs) {
	cmd := parser.NewCommand("process", "")

	arguments := &ProcessCommandArgs{}
	arguments.Source = cmd.String("s", "src", &argparse.Options{
		Required: true,
		Validate: func(args []string) error {
			fileInfo, err := os.Stat(args[0])
			if err != nil {
				return fmt.Errorf("Source does not exist")
			}

			if !fileInfo.IsDir() {
				return fmt.Errorf("Source is not a directory")
			}

			return nil
		},
	})

	arguments.DryRun = cmd.Flag("", "dry-run", &argparse.Options{})

	return cmd, arguments
}

type ProcessCommand struct {
	Args     *ProcessCommandArgs
	Files    []*types.File
	TagCache *tag_cache.TagCache
}

func NewProcessCommand(args *ProcessCommandArgs) *ProcessCommand {
	return &ProcessCommand{
		Args:  args,
		Files: make([]*types.File, 0),
	}
}

func (c *ProcessCommand) Run() {
	log.Info().Str("dir", *c.Args.Source).Msg("Processing")

	c.TagCache = tag_cache.NewTagCache(*c.Args.Source)
	defer c.TagCache.Close()
	c.scan_for_music()
	c.load_tag_information()
	c.rename_files()
}

func (c *ProcessCommand) scan_for_music() {
	log.Info().Msg("Scanning For Music")
	files, err := utils.ScanForMusic(*c.Args.Source)
	if err != nil {
		panic(err)
	}

	c.Files = files
}

func (c *ProcessCommand) load_tag_information() {
	log.Info().Msg("Load Tag Information")

	for _, file := range c.Files {
		if cached_tags, ok := c.TagCache.IsCached(file); !ok {
			log.Info().Str("file", file.JoinFilename()).Msg("Loading Tags")

			tags, err := utils.ExtractTags(file)
			if err != nil {
				panic(err)
			}
			file.Tags = tags
			c.TagCache.AddToCache(file, tags)
		} else {
			log.Info().Str("file", file.JoinFilename()).Msg("Loading Tags From Cache")
			file.Tags = cached_tags
		}
	}
}

// returns the new file so if renamed,
// any step after it is ran can operate on file
// if dry run then returns orig file without changed filename
func (c *ProcessCommand) rename_file(file *types.File) *types.File {
	title := file.Tags.Title
	artist := file.Tags.Artist

	replace_char := "_"

	// Step 1: Remove Newlines
	title = strings.ReplaceAll(title, "\n", "")
	artist = strings.ReplaceAll(artist, "\n", "")

	// Step 2: Strip ASCII
	title = ascii_reduce.Reduce(title, replace_char)
	artist = ascii_reduce.Reduce(artist, replace_char)

	// Step 3: Remove File Seperators
	title = strings.ReplaceAll(title, "\\", replace_char)
	title = strings.ReplaceAll(title, "/", replace_char)
	artist = strings.ReplaceAll(artist, "\\", replace_char)
	artist = strings.ReplaceAll(artist, "/", replace_char)

	// Step 4: Join Filename
	filename := fmt.Sprintf("%s - %s", artist, title)

	if filename == file.Filename {
		return file
	}

	// Step 5: Make new File with filename set
	new_file := file.DeepCopy()
	if !*c.Args.DryRun {
		new_file.Filename = filename
	}

	// Step 6: Rename File
	log.Info().
		Str("old", file.Filename).
		Str("new", filename).
		Msg("Renaming File")

	if !*c.Args.DryRun {
		if _, err := os.Stat(new_file.JoinPathTo()); err == nil {
			log.Fatal().
				Str("old", file.JoinFilename()).
				Str("new", new_file.JoinFilename()).
				Msg("Refusing to rename files, please retag to be distinct")
		}

		err := os.Rename(file.JoinPathTo(), new_file.JoinPathTo())
		if err != nil {
			log.Fatal().Err(err).Msg("Failed to rename file")
		}
	}

	return new_file
}

func (c *ProcessCommand) rename_files() {
	log.Info().Msg("Renaming Files")

	for _, file := range c.Files {
		c.rename_file(file)
	}

}