use std::future::Future;

use crate::error::DataResult;
use crate::types::{
    ArtistInfo, ArtistSearchResult, DiscographyEntry, LyricsResult, PopularTrack, RecordingDetails,
    RecordingMatch, ReleaseGroupEntry, ReleaseMatch, ReleaseTrack, SimilarArtist,
};

/// Trait for metadata lookup backends. MusicBrainz is the default implementation;
/// others (Last.fm, Discogs, etc.) can be added later.
pub trait MetadataFetcher: Send + Sync {
    fn search_recording(
        &self,
        artist: &str,
        title: &str,
    ) -> impl Future<Output = DataResult<Vec<RecordingMatch>>> + Send;

    fn search_release(
        &self,
        artist: &str,
        album: &str,
    ) -> impl Future<Output = DataResult<Vec<ReleaseMatch>>> + Send;

    fn get_recording(
        &self,
        mbid: &str,
    ) -> impl Future<Output = DataResult<RecordingDetails>> + Send;

    fn search_artist(
        &self,
        query: &str,
        limit: u32,
    ) -> impl Future<Output = DataResult<Vec<ArtistSearchResult>>> + Send;

    fn get_artist_releases(
        &self,
        artist_mbid: &str,
        limit: u32,
    ) -> impl Future<Output = DataResult<Vec<DiscographyEntry>>> + Send;

    fn get_release_tracks(
        &self,
        release_mbid: &str,
    ) -> impl Future<Output = DataResult<Vec<ReleaseTrack>>> + Send;

    /// Get deduplicated release groups (albums, EPs, singles) for an artist.
    fn get_artist_release_groups(
        &self,
        artist_mbid: &str,
    ) -> impl Future<Output = DataResult<Vec<ReleaseGroupEntry>>> + Send;

    /// Resolve a release-group MBID to a concrete release MBID (first release in the group).
    fn resolve_release_from_group(
        &self,
        release_group_mbid: &str,
    ) -> impl Future<Output = DataResult<String>> + Send;
}

/// Fetches artist image URLs from an external source.
pub trait ArtistImageFetcher: Send + Sync {
    /// Thumbnail/profile image for the artist.
    fn get_artist_image(
        &self,
        artist_info: &ArtistInfo,
    ) -> impl Future<Output = DataResult<Option<String>>> + Send;

    /// Wide banner/background image for the artist (e.g., 1920x1080).
    /// Returns None by default — providers that don't support banners need not implement this.
    fn get_artist_banner(
        &self,
        artist_info: &ArtistInfo,
    ) -> impl Future<Output = DataResult<Option<String>>> + Send {
        let _ = artist_info;
        async { Ok(None) }
    }
}

/// Fetches an artist biography from an external source.
pub trait ArtistBioFetcher: Send + Sync {
    fn get_artist_bio(
        &self,
        artist_info: &ArtistInfo,
    ) -> impl Future<Output = DataResult<Option<String>>> + Send;
}

/// Fetches song lyrics from an external source.
pub trait LyricsFetcher: Send + Sync {
    fn get_lyrics(
        &self,
        artist: &str,
        title: &str,
    ) -> impl Future<Output = DataResult<LyricsResult>> + Send;
}

/// Fetches similar artists and top tracks from an external source (e.g. Last.fm).
pub trait SimilarArtistFetcher: Send + Sync {
    fn get_similar_artists(
        &self,
        artist_name: &str,
        mbid: Option<&str>,
    ) -> impl Future<Output = DataResult<Vec<SimilarArtist>>> + Send;

    fn get_top_tracks(
        &self,
        artist_name: &str,
        mbid: Option<&str>,
    ) -> impl Future<Output = DataResult<Vec<PopularTrack>>> + Send;
}

/// Fetches cover art URLs for releases.
pub trait CoverArtFetcher: Send + Sync {
    fn get_cover_art_url(&self, release_id: &str) -> Option<String>;
}