package ctrladmin

import (
	"bufio"
	"fmt"
	"mime/multipart"
	"strings"

	"github.com/jinzhu/gorm"
	"github.com/pkg/errors"

	"senan.xyz/g/gonic/db"
)

func playlistParseLine(c *Controller, path string) (int, error) {
	if strings.HasPrefix(path, "#") || strings.TrimSpace(path) == "" {
		return 0, nil
	}
	var track db.Track
	query := c.DB.Raw(`
		SELECT tracks.id FROM TRACKS
		JOIN albums ON tracks.album_id=albums.id
		WHERE (? || '/' || albums.left_path || albums.right_path || '/' || tracks.filename)=?`,
		c.MusicPath, path)
	err := query.First(&track).Error
	switch {
	case gorm.IsRecordNotFoundError(err):
		return 0, fmt.Errorf("couldn't match track %q", path)
	case err != nil:
		return 0, errors.Wrap(err, "while matching")
	default:
		return track.ID, nil
	}
}

func playlistParseUpload(c *Controller, userID int, header *multipart.FileHeader) ([]string, bool) {
	file, err := header.Open()
	if err != nil {
		return []string{fmt.Sprintf("couldn't open file %q", header.Filename)}, false
	}
	playlistName := strings.TrimSuffix(header.Filename, ".m3u8")
	if playlistName == "" {
		return []string{fmt.Sprintf("invalid filename %q", header.Filename)}, false
	}
	contentType := header.Header.Get("Content-Type")
	if !(contentType == "audio/x-mpegurl" || contentType == "application/octet-stream") {
		return []string{fmt.Sprintf("invalid content-type %q", contentType)}, false
	}
	var trackIDs []int
	var errors []string
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		trackID, err := playlistParseLine(c, scanner.Text())
		if err != nil {
			// trim length of error to not overflow cookie flash
			errors = append(errors, fmt.Sprintf("%.100s", err.Error()))
		}
		if trackID != 0 {
			trackIDs = append(trackIDs, trackID)
		}
	}
	if err := scanner.Err(); err != nil {
		return []string{fmt.Sprintf("iterating playlist file: %v", err)}, true
	}
	playlist := &db.Playlist{}
	c.DB.FirstOrCreate(playlist, db.Playlist{
		Name:   playlistName,
		UserID: userID,
	})
	playlist.SetItems(trackIDs)
	c.DB.Save(playlist)
	return errors, true
}