// Package detector provides music link detection in text.
package detector

import (
	"regexp"

	"musiclink/internal/services"
)

// pattern matches music service URLs.
// We use a combined pattern since the idonthavespotify API handles all services.
var pattern = regexp.MustCompile(
	`https?://(?:` +
		`(?:open\.)?spotify\.com/(?:track|album|artist|playlist)/[a-zA-Z0-9]+|` +
		`spoti\.fi/[a-zA-Z0-9]+|` +
		`(?:www\.)?(?:youtube\.com/watch\?v=|youtu\.be/|music\.youtube\.com/watch\?v=)[a-zA-Z0-9_-]{11}|` +
		`(?:music\.)?apple\.com/[a-z]{2}/(?:album|artist|playlist|song)/[^\s]+|` +
		`(?:www\.)?deezer\.com/(?:[a-z]{2}/)?(?:track|album|artist|playlist)/\d+|` +
		`(?:www\.)?soundcloud\.com/[a-zA-Z0-9_-]+/[a-zA-Z0-9_-]+|` +
		`(?:www\.)?tidal\.com/(?:browse/)?(?:track|album|artist|playlist)/\d+|` +
		`[a-zA-Z0-9_-]+\.bandcamp\.com/(?:track|album)/[a-zA-Z0-9_-]+` +
		`)`,
)

// Detector finds music links in text.
type Detector struct{}

// New creates a new Detector.
func New() *Detector {
	return &Detector{}
}

// Detect finds all music links in the given text.
func (d *Detector) Detect(text string) []services.DetectedLink {
	matches := pattern.FindAllString(text, -1)
	if len(matches) == 0 {
		return nil
	}

	links := make([]services.DetectedLink, len(matches))
	for i, match := range matches {
		links[i] = services.DetectedLink{
			URL:      match,
			RawMatch: match,
		}
	}

	return links
}