/*
Copyright © 2024 Philipp Wolfer <phw@uploadedlobster.com>

Scotty is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later version.

Scotty is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
Scotty. If not, see <https://www.gnu.org/licenses/>.
*/

package similarity

import (
	"regexp"
	"strings"

	"github.com/agnivade/levenshtein"
	"go.uploadedlobster.com/scotty/internal/util"
	"golang.org/x/text/unicode/norm"
)

// Returns the Levensthein distance between s1 and s2 relative to the length of
// the longer string.
// Unicode normalization on the strings is performed.
func Similarity(s1 string, s2 string) float64 {
	s1 = norm.NFKC.String(s1)
	s2 = norm.NFKC.String(s2)
	l1 := len([]rune(s1))
	l2 := len([]rune(s2))
	maxLen := util.Max(l1, l2)
	// Empty strings always compare full equal
	if maxLen == 0 {
		return 1.0
	}
	dist := levenshtein.ComputeDistance(s1, s2)
	// fmt.Printf("%v (%v) ~ %v (%v) = %v\n", s1, l1, s2, l2, dist)
	return 1.0 - (float64(dist) / float64(maxLen))
}

var reExtraTitleInfo = regexp.MustCompile(`\([^)]+\)$`)
var reMultiSpace = regexp.MustCompile(`\s+`)

// Normalizes a track or release title.
func NormalizeTitle(s string) string {
	s = strings.TrimSpace(s)
	s = strings.ToLower(s)
	s = reExtraTitleInfo.ReplaceAllString(s, "")
	s = reMultiSpace.ReplaceAllString(s, " ")
	return s
}