package subsonic

import (
	"database/sql"

	"git.noroutes.net/NoRoutes/vibetunes/internal/database"
)

func init() {
	register("search", handleSearch)
	register("search2", handleSearch2)
	register("search3", handleSearch3)
}

type searchMatches struct {
	Artists []*database.Artist
	Albums  []*database.Album
	Songs   []*database.Song
}

// runSearch performs a simple substring, case-insensitive match against
// artist/album/song names, with independent offset/count for each
// category as the protocol requires. VibeSonic's libraries are small
// enough (self-hosted, not a streaming catalog) that a LIKE scan is
// plenty fast; there's no need for SQLite FTS's added complexity here.
func runSearch(db *sql.DB, query string, artistOffset, artistCount, albumOffset, albumCount, songOffset, songCount int) (searchMatches, error) {
	var m searchMatches
	if query == "" {
		return m, nil
	}
	like := "%" + query + "%"

	artistRows, err := db.Query(`SELECT DISTINCT a.id FROM artists a JOIN album_artists aa ON aa.artist_id = a.id
		WHERE a.name LIKE ? COLLATE NOCASE ORDER BY a.name COLLATE NOCASE LIMIT ? OFFSET ?`, like, artistCount, artistOffset)
	if err != nil {
		return m, err
	}
	for artistRows.Next() {
		var id string
		if err := artistRows.Scan(&id); err == nil {
			if a, err := database.GetArtist(db, id); err == nil {
				m.Artists = append(m.Artists, a)
			}
		}
	}
	artistRows.Close()

	albumRows, err := db.Query(`SELECT id FROM albums WHERE title LIKE ? COLLATE NOCASE ORDER BY title COLLATE NOCASE LIMIT ? OFFSET ?`, like, albumCount, albumOffset)
	if err != nil {
		return m, err
	}
	for albumRows.Next() {
		var id string
		if err := albumRows.Scan(&id); err == nil {
			if a, err := database.GetAlbum(db, id); err == nil {
				m.Albums = append(m.Albums, a)
			}
		}
	}
	albumRows.Close()

	songRows, err := db.Query(`SELECT id FROM songs WHERE title LIKE ? COLLATE NOCASE ORDER BY title COLLATE NOCASE LIMIT ? OFFSET ?`, like, songCount, songOffset)
	if err != nil {
		return m, err
	}
	for songRows.Next() {
		var id string
		if err := songRows.Scan(&id); err == nil {
			if s, err := database.GetSong(db, id); err == nil {
				m.Songs = append(m.Songs, s)
			}
		}
	}
	songRows.Close()

	return m, nil
}

// handleSearch implements the original, deprecated (since 1.4.0, but
// still required) flat search: a single "any" query with one offset/
// count, results as Child, regardless of type.
func handleSearch(rc *Context) *apiError {
	any, aerr := rc.Params.Required("any")
	if aerr != nil {
		return aerr
	}
	db := rc.Server.DB
	offset := rc.Params.Int("offset", 0)
	count := rc.Params.Int("count", 20)

	m, err := runSearch(db, any, offset, count, offset, count, offset, count)
	if err != nil {
		return newError(ErrGeneric, err.Error())
	}
	out := &SearchResult{Offset: offset}
	for _, a := range m.Artists {
		out.Match = append(out.Match, Child{ID: a.ID, IsDir: true, Title: a.Name})
	}
	for _, a := range m.Albums {
		out.Match = append(out.Match, childFromAlbum(db, a, rc.User.ID))
	}
	for _, s := range m.Songs {
		mf, merr := database.GetMediaFile(db, s.MediaFileID)
		if merr != nil {
			continue
		}
		out.Match = append(out.Match, childFromSong(db, s, mf, albumOfSong(db, s), rc.User.ID))
	}
	out.TotalHits = len(out.Match)
	rc.Response = newResponse()
	rc.Response.SearchResult = out
	return nil
}

func handleSearch2(rc *Context) *apiError {
	query, aerr := rc.Params.Required("query")
	if aerr != nil {
		return aerr
	}
	db := rc.Server.DB
	m, err := runSearch(db, query,
		rc.Params.Int("artistOffset", 0), rc.Params.Int("artistCount", 20),
		rc.Params.Int("albumOffset", 0), rc.Params.Int("albumCount", 20),
		rc.Params.Int("songOffset", 0), rc.Params.Int("songCount", 20))
	if err != nil {
		return newError(ErrGeneric, err.Error())
	}
	out := &SearchResult2{}
	for _, a := range m.Artists {
		out.Artist = append(out.Artist, Artist{ID: a.ID, Name: a.Name})
	}
	for _, a := range m.Albums {
		out.Album = append(out.Album, childFromAlbum(db, a, rc.User.ID))
	}
	for _, s := range m.Songs {
		mf, merr := database.GetMediaFile(db, s.MediaFileID)
		if merr != nil {
			continue
		}
		out.Song = append(out.Song, childFromSong(db, s, mf, albumOfSong(db, s), rc.User.ID))
	}
	rc.Response = newResponse()
	rc.Response.SearchResult2 = out
	return nil
}

func handleSearch3(rc *Context) *apiError {
	query, aerr := rc.Params.Required("query")
	if aerr != nil {
		return aerr
	}
	db := rc.Server.DB
	m, err := runSearch(db, query,
		rc.Params.Int("artistOffset", 0), rc.Params.Int("artistCount", 20),
		rc.Params.Int("albumOffset", 0), rc.Params.Int("albumCount", 20),
		rc.Params.Int("songOffset", 0), rc.Params.Int("songCount", 20))
	if err != nil {
		return newError(ErrGeneric, err.Error())
	}
	out := &SearchResult3{}
	for _, a := range m.Artists {
		out.Artist = append(out.Artist, artistToID3(db, a, rc.User.ID))
	}
	for _, a := range m.Albums {
		out.Album = append(out.Album, albumToID3(db, a, rc.User.ID))
	}
	for _, s := range m.Songs {
		mf, merr := database.GetMediaFile(db, s.MediaFileID)
		if merr != nil {
			continue
		}
		out.Song = append(out.Song, childFromSong(db, s, mf, albumOfSong(db, s), rc.User.ID))
	}
	rc.Response = newResponse()
	rc.Response.SearchResult3 = out
	return nil
}