use crate::{
    auth_urls,
    clients::{
        convert_result,
        pagination::{paginate, paginate_with_ctx, Paginator},
    },
    http::{BaseHttpClient, Form, Headers, HttpClient, Query},
    join_ids,
    model::*,
    sync::Mutex,
    util::build_map,
    ClientError, ClientResult, Config, Credentials, Token,
};

use std::{collections::HashMap, fmt, ops::Not, sync::Arc};

use chrono::Utc;
use maybe_async::maybe_async;
use serde_json::Value;

/// This trait implements the basic endpoints from the Spotify API that may be
/// accessed without user authorization, including parts of the authentication
/// flow that are shared, and the endpoints.
#[cfg_attr(target_arch = "wasm32", maybe_async(?Send))]
#[cfg_attr(not(target_arch = "wasm32"), maybe_async)]
pub trait BaseClient
where
    Self: Send + Sync + Default + Clone + fmt::Debug,
{
    fn get_config(&self) -> &Config;
    fn get_http(&self) -> &HttpClient;
    fn get_creds(&self) -> &Credentials;

    /// Note that the token is wrapped by a `Mutex` in order to allow interior
    /// mutability. This is required so that the entire client doesn't have to
    /// be mutable (the token is accessed to from every endpoint).
    fn get_token(&self) -> Arc<Mutex<Option<Token>>>;

    /// Returns the absolute URL for an endpoint in the API.
    fn api_url(&self, url: &str) -> String {
        let mut base = self.get_config().api_base_url.clone();
        if !base.ends_with('/') {
            base.push('/');
        }
        base + url
    }

    /// Returns the absolute URL for an authentication step in the API.
    fn auth_url(&self, url: &str) -> String {
        let mut base = self.get_config().auth_base_url.clone();
        if !base.ends_with('/') {
            base.push('/');
        }
        base + url
    }

    /// Refetch the current access token given a refresh token.
    async fn refetch_token(&self) -> ClientResult<Option<Token>>;

    /// Re-authenticate the client automatically if it's configured to do so,
    /// which uses the refresh token to obtain a new access token.
    async fn auto_reauth(&self) -> ClientResult<()> {
        if !self.get_config().token_refreshing {
            return Ok(());
        }

        // NOTE: It's important to not leave the token locked, or else a
        // deadlock when calling `refresh_token` will occur.
        let should_reauth = self
            .get_token()
            .lock()
            .await
            .unwrap()
            .as_ref()
            .map_or(false, Token::is_expired);

        if should_reauth {
            self.refresh_token().await
        } else {
            Ok(())
        }
    }

    /// Refreshes the current access token given a refresh token. The obtained
    /// token will be saved internally.
    async fn refresh_token(&self) -> ClientResult<()> {
        let token = self.refetch_token().await?;
        *self.get_token().lock().await.unwrap() = token;
        self.write_token_cache().await
    }

    /// The headers required for authenticated requests to the API.
    ///
    /// Since this is accessed by authenticated requests always, it's where the
    /// automatic reauthentication takes place, if enabled.
    #[doc(hidden)]
    async fn auth_headers(&self) -> ClientResult<Headers> {
        self.auto_reauth().await?;

        Ok(self
            .get_token()
            .lock()
            .await
            .unwrap()
            .as_ref()
            .ok_or(ClientError::InvalidToken)?
            .auth_headers())
    }

    // HTTP-related methods for the Spotify client. They wrap up the basic HTTP
    // client with its specific usage for endpoints or authentication.

    /// Convenience method to send GET requests related to an endpoint in the
    /// API.
    #[doc(hidden)]
    #[inline]
    async fn api_get(&self, url: &str, payload: &Query<'_>) -> ClientResult<String> {
        let url = self.api_url(url);
        let headers = self.auth_headers().await?;
        Ok(self.get_http().get(&url, Some(&headers), payload).await?)
    }

    /// Convenience method to send POST requests related to an endpoint in the
    /// API.
    #[doc(hidden)]
    #[inline]
    async fn api_post(&self, url: &str, payload: &Value) -> ClientResult<String> {
        let url = self.api_url(url);
        let headers = self.auth_headers().await?;
        Ok(self.get_http().post(&url, Some(&headers), payload).await?)
    }

    /// Convenience method to send PUT requests related to an endpoint in the
    /// API.
    #[doc(hidden)]
    #[inline]
    async fn api_put(&self, url: &str, payload: &Value) -> ClientResult<String> {
        let url = self.api_url(url);
        let headers = self.auth_headers().await?;
        Ok(self.get_http().put(&url, Some(&headers), payload).await?)
    }

    /// Convenience method to send DELETE requests related to an endpoint in the
    /// API.
    #[doc(hidden)]
    #[inline]
    async fn api_delete(&self, url: &str, payload: &Value) -> ClientResult<String> {
        let url = self.api_url(url);
        let headers = self.auth_headers().await?;
        Ok(self
            .get_http()
            .delete(&url, Some(&headers), payload)
            .await?)
    }

    /// Convenience method to send POST requests related to the authentication
    /// process.
    #[doc(hidden)]
    #[inline]
    async fn auth_post(
        &self,
        url: &str,
        headers: Option<&Headers>,
        payload: &Form<'_>,
    ) -> ClientResult<String> {
        let url = self.auth_url(url);
        Ok(self.get_http().post_form(&url, headers, payload).await?)
    }

    /// Updates the cache file at the internal cache path.
    ///
    /// This should be used whenever it's possible to, even if the cached token
    /// isn't configured, because this will already check `Config::token_cached`
    /// and do nothing in that case already.
    async fn write_token_cache(&self) -> ClientResult<()> {
        if !self.get_config().token_cached {
            log::info!("Token cache write ignored (not configured)");
            return Ok(());
        }

        log::info!("Writing token cache");
        if let Some(tok) = self.get_token().lock().await.unwrap().as_ref() {
            tok.write_cache(&self.get_config().cache_path)?;
        }

        Ok(())
    }

    /// Sends a request to Spotify for an access token.
    async fn fetch_access_token(
        &self,
        payload: &Form<'_>,
        headers: Option<&Headers>,
    ) -> ClientResult<Token> {
        let response = self.auth_post(auth_urls::TOKEN, headers, payload).await?;

        let mut tok = serde_json::from_str::<Token>(&response)?;
        tok.expires_at = Utc::now().checked_add_signed(tok.expires_in);
        Ok(tok)
    }

    /// Returns a single track given the track's ID, URI or URL.
    ///
    /// Parameters:
    /// - track_id - a spotify URI, URL or ID
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-track)
    async fn track(
        &self,
        track_id: TrackId<'_>,
        market: Option<Market>,
    ) -> ClientResult<FullTrack> {
        let params = build_map([("market", market.map(Into::into))]);

        let url = format!("tracks/{}", track_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Returns a list of tracks given a list of track IDs, URIs, or URLs.
    ///
    /// Parameters:
    /// - track_ids - a list of spotify URIs, URLs or IDs
    /// - market - an ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-several-tracks)
    async fn tracks<'a>(
        &self,
        track_ids: impl IntoIterator<Item = TrackId<'a>> + Send + 'a,
        market: Option<Market>,
    ) -> ClientResult<Vec<FullTrack>> {
        let ids = join_ids(track_ids);
        let params = build_map([("market", market.map(Into::into))]);

        let url = format!("tracks/?ids={ids}");
        let result = self.api_get(&url, &params).await?;
        convert_result::<FullTracks>(&result).map(|x| x.tracks)
    }

    /// Returns a single artist given the artist's ID, URI or URL.
    ///
    /// Parameters:
    /// - artist_id - an artist ID, URI or URL
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-artist)
    async fn artist(&self, artist_id: ArtistId<'_>) -> ClientResult<FullArtist> {
        let url = format!("artists/{}", artist_id.id());
        let result = self.api_get(&url, &Query::new()).await?;
        convert_result(&result)
    }

    /// Returns a list of artists given the artist IDs, URIs, or URLs.
    ///
    /// Parameters:
    /// - artist_ids - a list of artist IDs, URIs or URLs
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-multiple-artists)
    async fn artists<'a>(
        &self,
        artist_ids: impl IntoIterator<Item = ArtistId<'a>> + Send + 'a,
    ) -> ClientResult<Vec<FullArtist>> {
        let ids = join_ids(artist_ids);
        let url = format!("artists/?ids={ids}");
        let result = self.api_get(&url, &Query::new()).await?;

        convert_result::<FullArtists>(&result).map(|x| x.artists)
    }

    /// Get Spotify catalog information about an artist's albums.
    ///
    /// Parameters:
    /// - artist_id - the artist ID, URI or URL
    /// - include_groups -  a list of album type like 'album', 'single' that will be used to filter response. if not supplied, all album types will be returned.
    /// - market - limit the response to one particular country.
    /// - limit  - the number of albums to return
    /// - offset - the index of the first album to return
    ///
    /// See [`Self::artist_albums_manual`] for a manually paginated version of
    /// this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-artists-albums)
    fn artist_albums<'a>(
        &'a self,
        artist_id: ArtistId<'a>,
        include_groups: impl IntoIterator<Item = AlbumType> + Send + Copy + 'a,
        market: Option<Market>,
    ) -> Paginator<'_, ClientResult<SimplifiedAlbum>> {
        paginate_with_ctx(
            (self, artist_id),
            move |(slf, artist_id), limit, offset| {
                slf.artist_albums_manual(
                    artist_id.as_ref(),
                    include_groups,
                    market,
                    Some(limit),
                    Some(offset),
                )
            },
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::artist_albums`].
    async fn artist_albums_manual<'a>(
        &self,
        artist_id: ArtistId<'_>,
        include_groups: impl IntoIterator<Item = AlbumType> + Send + 'a,
        market: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<SimplifiedAlbum>> {
        let limit = limit.map(|x| x.to_string());
        let offset = offset.map(|x| x.to_string());
        let include_groups_vec = include_groups
            .into_iter()
            .map(|t| t.into())
            .collect::<Vec<&'static str>>();
        let include_groups_opt = include_groups_vec
            .is_empty()
            .not()
            .then_some(include_groups_vec)
            .map(|t| t.join(","));

        let params = build_map([
            ("include_groups", include_groups_opt.as_deref()),
            ("market", market.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let url = format!("artists/{}/albums", artist_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Get Spotify catalog information about an artist's top 10 tracks by
    /// country.
    ///
    /// Parameters:
    /// - artist_id - the artist ID, URI or URL
    /// - market - limit the response to one particular country.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-artists-top-tracks)
    async fn artist_top_tracks(
        &self,
        artist_id: ArtistId<'_>,
        market: Option<Market>,
    ) -> ClientResult<Vec<FullTrack>> {
        let params = build_map([("market", market.map(Into::into))]);

        let url = format!("artists/{}/top-tracks", artist_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result::<FullTracks>(&result).map(|x| x.tracks)
    }

    /// Get Spotify catalog information about artists similar to an identified
    /// artist. Similarity is based on analysis of the Spotify community's
    /// listening history.
    ///
    /// Parameters:
    /// - artist_id - the artist ID, URI or URL
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-artists-related-artists)
    async fn artist_related_artists(
        &self,
        artist_id: ArtistId<'_>,
    ) -> ClientResult<Vec<FullArtist>> {
        let url = format!("artists/{}/related-artists", artist_id.id());
        let result = self.api_get(&url, &Query::new()).await?;
        convert_result::<FullArtists>(&result).map(|x| x.artists)
    }

    /// Returns a single album given the album's ID, URIs or URL.
    ///
    /// Parameters:
    /// - album_id - the album ID, URI or URL
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-album)
    async fn album(
        &self,
        album_id: AlbumId<'_>,
        market: Option<Market>,
    ) -> ClientResult<FullAlbum> {
        let params = build_map([("market", market.map(Into::into))]);

        let url = format!("albums/{}", album_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Returns a list of albums given the album IDs, URIs, or URLs.
    ///
    /// Parameters:
    /// - albums_ids - a list of album IDs, URIs or URLs
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-multiple-albums)
    async fn albums<'a>(
        &self,
        album_ids: impl IntoIterator<Item = AlbumId<'a>> + Send + 'a,
        market: Option<Market>,
    ) -> ClientResult<Vec<FullAlbum>> {
        let params = build_map([("market", market.map(Into::into))]);

        let ids = join_ids(album_ids);
        let url = format!("albums/?ids={ids}");
        let result = self.api_get(&url, &params).await?;
        convert_result::<FullAlbums>(&result).map(|x| x.albums)
    }

    /// Search for an Item. Get Spotify catalog information about artists,
    /// albums, tracks or playlists that match a keyword string.
    ///
    /// Parameters:
    /// - q - the search query
    /// - limit  - the number of items to return
    /// - offset - the index of the first item to return
    /// - type - the type of item to return. One of 'artist', 'album', 'track',
    ///  'playlist', 'show' or 'episode'
    /// - market - An ISO 3166-1 alpha-2 country code or the string from_token.
    /// - include_external: Optional.Possible values: audio. If
    ///   include_external=audio is specified the response will include any
    ///   relevant audio content that is hosted externally.  
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/search)
    async fn search(
        &self,
        q: &str,
        _type: SearchType,
        market: Option<Market>,
        include_external: Option<IncludeExternal>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<SearchResult> {
        let limit = limit.map(|s| s.to_string());
        let offset = offset.map(|s| s.to_string());
        let params = build_map([
            ("q", Some(q)),
            ("type", Some(_type.into())),
            ("market", market.map(Into::into)),
            ("include_external", include_external.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let result = self.api_get("search", &params).await?;
        convert_result(&result)
    }

    /// Get Spotify catalog information about an album's tracks.
    ///
    /// Parameters:
    /// - album_id - the album ID, URI or URL
    /// - limit  - the number of items to return
    /// - offset - the index of the first item to return
    ///
    /// See [`Self::album_track_manual`] for a manually paginated version of
    /// this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-albums-tracks)
    fn album_track<'a>(
        &'a self,
        album_id: AlbumId<'a>,
        market: Option<Market>,
    ) -> Paginator<'_, ClientResult<SimplifiedTrack>> {
        paginate_with_ctx(
            (self, album_id),
            move |(slf, album_id), limit, offset| {
                slf.album_track_manual(album_id.as_ref(), market, Some(limit), Some(offset))
            },
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::album_track`].
    async fn album_track_manual(
        &self,
        album_id: AlbumId<'_>,
        market: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<SimplifiedTrack>> {
        let limit = limit.map(|s| s.to_string());
        let offset = offset.map(|s| s.to_string());
        let params = build_map([
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
            ("market", market.map(Into::into)),
        ]);

        let url = format!("albums/{}/tracks", album_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Gets basic profile information about a Spotify User.
    ///
    /// Parameters:
    /// - user - the id of the usr
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-users-profile)
    async fn user(&self, user_id: UserId<'_>) -> ClientResult<PublicUser> {
        let url = format!("users/{}", user_id.id());
        let result = self.api_get(&url, &Query::new()).await?;
        convert_result(&result)
    }

    /// Get full details about Spotify playlist.
    ///
    /// Parameters:
    /// - playlist_id - the id of the playlist
    /// - market - an ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-playlist)
    async fn playlist(
        &self,
        playlist_id: PlaylistId<'_>,
        fields: Option<&str>,
        market: Option<Market>,
    ) -> ClientResult<FullPlaylist> {
        let params = build_map([("fields", fields), ("market", market.map(Into::into))]);

        let url = format!("playlists/{}", playlist_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Gets playlist of a user.
    ///
    /// Parameters:
    /// - user_id - the id of the user
    /// - playlist_id - the id of the playlist
    /// - fields - which fields to return
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-list-users-playlists)
    async fn user_playlist(
        &self,
        user_id: UserId<'_>,
        playlist_id: Option<PlaylistId<'_>>,
        fields: Option<&str>,
    ) -> ClientResult<FullPlaylist> {
        let params = build_map([("fields", fields)]);

        let url = match playlist_id {
            Some(playlist_id) => format!("users/{}/playlists/{}", user_id.id(), playlist_id.id()),
            None => format!("users/{}/starred", user_id.id()),
        };
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Check to see if the given users are following the given playlist.
    ///
    /// Parameters:
    /// - playlist_id - the id of the playlist
    /// - user_ids - the ids of the users that you want to check to see if they
    ///   follow the playlist. Maximum: 5 ids.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/check-if-user-follows-playlist)
    async fn playlist_check_follow(
        &self,
        playlist_id: PlaylistId<'_>,
        user_ids: &[UserId<'_>],
    ) -> ClientResult<Vec<bool>> {
        debug_assert!(
            user_ids.len() <= 5,
            "The maximum length of user ids is limited to 5 :-)"
        );
        let url = format!(
            "playlists/{}/followers/contains?ids={}",
            playlist_id.id(),
            user_ids.iter().map(Id::id).collect::<Vec<_>>().join(","),
        );
        let result = self.api_get(&url, &Query::new()).await?;
        convert_result(&result)
    }

    /// Get Spotify catalog information for a single show identified by its unique Spotify ID.
    ///
    /// Path Parameters:
    /// - id: The Spotify ID for the show.
    ///
    /// Query Parameters
    /// - market(Optional): An ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-a-show)
    async fn get_a_show(&self, id: ShowId<'_>, market: Option<Market>) -> ClientResult<FullShow> {
        let params = build_map([("market", market.map(Into::into))]);

        let url = format!("shows/{}", id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Get Spotify catalog information for multiple shows based on their
    /// Spotify IDs.
    ///
    /// Query Parameters
    /// - ids(Required) A comma-separated list of the Spotify IDs for the shows. Maximum: 50 IDs.
    /// - market(Optional) An ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-multiple-shows)
    async fn get_several_shows<'a>(
        &self,
        ids: impl IntoIterator<Item = ShowId<'a>> + Send + 'a,
        market: Option<Market>,
    ) -> ClientResult<Vec<SimplifiedShow>> {
        let ids = join_ids(ids);
        let params = build_map([("ids", Some(&ids)), ("market", market.map(Into::into))]);

        let result = self.api_get("shows", &params).await?;
        convert_result::<SeversalSimplifiedShows>(&result).map(|x| x.shows)
    }

    /// Get Spotify catalog information about an show’s episodes. Optional
    /// parameters can be used to limit the number of episodes returned.
    ///
    /// Path Parameters
    /// - id: The Spotify ID for the show.
    ///
    /// Query Parameters
    /// - limit: Optional. The maximum number of episodes to return. Default: 20. Minimum: 1. Maximum: 50.
    /// - offset: Optional. The index of the first episode to return. Default: 0 (the first object). Use with limit to get the next set of episodes.
    /// - market: Optional. An ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// See [`Self::get_shows_episodes_manual`] for a manually paginated version
    /// of this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-a-shows-episodes)
    fn get_shows_episodes<'a>(
        &'a self,
        id: ShowId<'a>,
        market: Option<Market>,
    ) -> Paginator<'_, ClientResult<SimplifiedEpisode>> {
        paginate_with_ctx(
            (self, id),
            move |(slf, id), limit, offset| {
                slf.get_shows_episodes_manual(id.as_ref(), market, Some(limit), Some(offset))
            },
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::get_shows_episodes`].
    async fn get_shows_episodes_manual(
        &self,
        id: ShowId<'_>,
        market: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<SimplifiedEpisode>> {
        let limit = limit.map(|x| x.to_string());
        let offset = offset.map(|x| x.to_string());
        let params = build_map([
            ("market", market.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let url = format!("shows/{}/episodes", id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Get Spotify catalog information for a single episode identified by its unique Spotify ID.
    ///
    /// Path Parameters
    /// - id: The Spotify ID for the episode.
    ///
    /// Query Parameters
    /// - market: Optional. An ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-an-episode)
    async fn get_an_episode(
        &self,
        id: EpisodeId<'_>,
        market: Option<Market>,
    ) -> ClientResult<FullEpisode> {
        let url = format!("episodes/{}", id.id());
        let params = build_map([("market", market.map(Into::into))]);

        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Get Spotify catalog information for multiple episodes based on their Spotify IDs.
    ///
    /// Query Parameters
    /// - ids: Required. A comma-separated list of the Spotify IDs for the episodes. Maximum: 50 IDs.
    /// - market: Optional. An ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-multiple-episodes)
    async fn get_several_episodes<'a>(
        &self,
        ids: impl IntoIterator<Item = EpisodeId<'a>> + Send + 'a,
        market: Option<Market>,
    ) -> ClientResult<Vec<FullEpisode>> {
        let ids = join_ids(ids);
        let params = build_map([("ids", Some(&ids)), ("market", market.map(Into::into))]);

        let result = self.api_get("episodes", &params).await?;
        convert_result::<EpisodesPayload>(&result).map(|x| x.episodes)
    }

    /// Get audio features for a track
    ///
    /// Parameters:
    /// - track - track URI, URL or ID
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-audio-features)
    async fn track_features(&self, track_id: TrackId<'_>) -> ClientResult<AudioFeatures> {
        let url = format!("audio-features/{}", track_id.id());
        let result = self.api_get(&url, &Query::new()).await?;
        convert_result(&result)
    }

    /// Get Audio Features for Several Tracks
    ///
    /// Parameters:
    /// - tracks a list of track URIs, URLs or IDs
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-several-audio-features)
    async fn tracks_features<'a>(
        &self,
        track_ids: impl IntoIterator<Item = TrackId<'a>> + Send + 'a,
    ) -> ClientResult<Option<Vec<AudioFeatures>>> {
        let url = format!("audio-features/?ids={}", join_ids(track_ids));

        let result = self.api_get(&url, &Query::new()).await?;
        if result.is_empty() {
            Ok(None)
        } else if let Some(payload) = convert_result::<Option<AudioFeaturesPayload>>(&result)? {
            let audio_features = payload.audio_features.into_iter().flatten().collect();
            Ok(Some(audio_features))
        } else {
            Ok(None)
        }
    }

    /// Get Audio Analysis for a Track
    ///
    /// Parameters:
    /// - track_id - a track URI, URL or ID
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-audio-analysis)
    async fn track_analysis(&self, track_id: TrackId<'_>) -> ClientResult<AudioAnalysis> {
        let url = format!("audio-analysis/{}", track_id.id());
        let result = self.api_get(&url, &Query::new()).await?;
        convert_result(&result)
    }

    /// Get a list of new album releases featured in Spotify
    ///
    /// Parameters:
    /// - country - An ISO 3166-1 alpha-2 country code or string from_token.
    /// - locale - The desired language, consisting of an ISO 639 language code
    ///   and an ISO 3166-1 alpha-2 country code, joined by an underscore.
    /// - limit - The maximum number of items to return. Default: 20.
    ///   Minimum: 1. Maximum: 50
    /// - offset - The index of the first item to return. Default: 0 (the first
    ///   object). Use with limit to get the next set of items.
    ///
    /// See [`Self::categories_manual`] for a manually paginated version of
    /// this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-categories)
    fn categories<'a>(
        &'a self,
        locale: Option<&'a str>,
        country: Option<Market>,
    ) -> Paginator<'_, ClientResult<Category>> {
        paginate(
            move |limit, offset| self.categories_manual(locale, country, Some(limit), Some(offset)),
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::categories`].
    async fn categories_manual(
        &self,
        locale: Option<&str>,
        country: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<Category>> {
        let limit = limit.map(|x| x.to_string());
        let offset = offset.map(|x| x.to_string());
        let params = build_map([
            ("locale", locale),
            ("country", country.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);
        let result = self.api_get("browse/categories", &params).await?;
        convert_result::<PageCategory>(&result).map(|x| x.categories)
    }

    /// Get a list of playlists in a category in Spotify
    ///
    /// Parameters:
    /// - category_id - The category id to get playlists from.
    /// - country - An ISO 3166-1 alpha-2 country code or the string from_token.
    /// - limit - The maximum number of items to return. Default: 20.
    ///   Minimum: 1. Maximum: 50
    /// - offset - The index of the first item to return. Default: 0 (the first
    ///   object). Use with limit to get the next set of items.
    ///
    /// See [`Self::category_playlists_manual`] for a manually paginated version
    /// of this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-a-categories-playlists)
    fn category_playlists<'a>(
        &'a self,
        category_id: &'a str,
        country: Option<Market>,
    ) -> Paginator<'_, ClientResult<SimplifiedPlaylist>> {
        paginate(
            move |limit, offset| {
                self.category_playlists_manual(category_id, country, Some(limit), Some(offset))
            },
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::category_playlists`].
    async fn category_playlists_manual(
        &self,
        category_id: &str,
        country: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<SimplifiedPlaylist>> {
        let limit = limit.map(|x| x.to_string());
        let offset = offset.map(|x| x.to_string());
        let params = build_map([
            ("country", country.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let url = format!("browse/categories/{category_id}/playlists");
        let result = self.api_get(&url, &params).await?;
        convert_result::<CategoryPlaylists>(&result).map(|x| x.playlists)
    }

    /// Get a list of Spotify featured playlists.
    ///
    /// Parameters:
    /// - locale - The desired language, consisting of a lowercase ISO 639
    ///   language code and an uppercase ISO 3166-1 alpha-2 country code,
    ///   joined by an underscore.
    /// - country - An ISO 3166-1 alpha-2 country code or the string from_token.
    /// - timestamp - A timestamp in ISO 8601 format: yyyy-MM-ddTHH:mm:ss. Use
    ///   this parameter to specify the user's local time to get results
    ///   tailored for that specific date and time in the day
    /// - limit - The maximum number of items to return. Default: 20.
    ///   Minimum: 1. Maximum: 50
    /// - offset - The index of the first item to return. Default: 0
    ///   (the first object). Use with limit to get the next set of
    ///   items.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-featured-playlists)
    async fn featured_playlists(
        &self,
        locale: Option<&str>,
        country: Option<Market>,
        timestamp: Option<chrono::DateTime<chrono::Utc>>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<FeaturedPlaylists> {
        let limit = limit.map(|x| x.to_string());
        let offset = offset.map(|x| x.to_string());
        let timestamp = timestamp.map(|x| x.to_rfc3339());
        let params = build_map([
            ("locale", locale),
            ("country", country.map(Into::into)),
            ("timestamp", timestamp.as_deref()),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let result = self.api_get("browse/featured-playlists", &params).await?;
        convert_result(&result)
    }

    /// Get a list of new album releases featured in Spotify.
    ///
    /// Parameters:
    /// - country - An ISO 3166-1 alpha-2 country code or string from_token.
    /// - limit - The maximum number of items to return. Default: 20.
    ///   Minimum: 1. Maximum: 50
    /// - offset - The index of the first item to return. Default: 0 (the first
    ///   object). Use with limit to get the next set of items.
    ///
    /// See [`Self::new_releases_manual`] for a manually paginated version of
    /// this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-new-releases)
    fn new_releases(
        &self,
        country: Option<Market>,
    ) -> Paginator<'_, ClientResult<SimplifiedAlbum>> {
        paginate(
            move |limit, offset| self.new_releases_manual(country, Some(limit), Some(offset)),
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::new_releases`].
    async fn new_releases_manual(
        &self,
        country: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<SimplifiedAlbum>> {
        let limit = limit.map(|x| x.to_string());
        let offset = offset.map(|x| x.to_string());
        let params = build_map([
            ("country", country.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let result = self.api_get("browse/new-releases", &params).await?;
        convert_result::<PageSimplifiedAlbums>(&result).map(|x| x.albums)
    }

    /// Get Recommendations Based on Seeds
    ///
    /// Parameters:
    /// - attributes - restrictions on attributes for the selected tracks, such
    ///   as `min_acousticness` or `target_duration_ms`.
    /// - seed_artists - a list of artist IDs, URIs or URLs
    /// - seed_tracks - a list of artist IDs, URIs or URLs
    /// - seed_genres - a list of genre names. Available genres for
    /// - market - An ISO 3166-1 alpha-2 country code or the string from_token.
    ///   If provided, all results will be playable in this country.
    /// - limit - The maximum number of items to return. Default: 20.
    ///   Minimum: 1. Maximum: 100
    /// - `min/max/target_<attribute>` - For the tuneable track attributes
    ///   listed in the documentation, these values provide filters and
    ///   targeting on results.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-recommendations)
    async fn recommendations<'a>(
        &self,
        attributes: impl IntoIterator<Item = RecommendationsAttribute> + Send + 'a,
        seed_artists: Option<impl IntoIterator<Item = ArtistId<'a>> + Send + 'a>,
        seed_genres: Option<impl IntoIterator<Item = &'a str> + Send + 'a>,
        seed_tracks: Option<impl IntoIterator<Item = TrackId<'a>> + Send + 'a>,
        market: Option<Market>,
        limit: Option<u32>,
    ) -> ClientResult<Recommendations> {
        let seed_artists = seed_artists.map(join_ids);
        let seed_genres = seed_genres.map(|x| x.into_iter().collect::<Vec<_>>().join(","));
        let seed_tracks = seed_tracks.map(join_ids);
        let limit = limit.map(|x| x.to_string());
        let mut params = build_map([
            ("seed_artists", seed_artists.as_deref()),
            ("seed_genres", seed_genres.as_deref()),
            ("seed_tracks", seed_tracks.as_deref()),
            ("market", market.map(Into::into)),
            ("limit", limit.as_deref()),
        ]);

        // First converting the attributes into owned `String`s
        let owned_attributes = attributes
            .into_iter()
            .map(|attr| (<&str>::from(attr).to_owned(), attr.value_string()))
            .collect::<HashMap<_, _>>();
        // Afterwards converting the values into `&str`s; otherwise they
        // wouldn't live long enough
        let borrowed_attributes = owned_attributes
            .iter()
            .map(|(key, value)| (key.as_str(), value.as_str()));
        // And finally adding all of them to the payload
        params.extend(borrowed_attributes);

        let result = self.api_get("recommendations", &params).await?;
        convert_result(&result)
    }

    /// Get full details of the items of a playlist owned by a user.
    ///
    /// Parameters:
    /// - playlist_id - the id of the playlist
    /// - fields - which fields to return
    /// - limit - the maximum number of tracks to return
    /// - offset - the index of the first track to return
    /// - market - an ISO 3166-1 alpha-2 country code or the string from_token.
    ///
    /// See [`Self::playlist_items_manual`] for a manually paginated version of
    /// this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-playlists-tracks)
    fn playlist_items<'a>(
        &'a self,
        playlist_id: PlaylistId<'a>,
        fields: Option<&'a str>,
        market: Option<Market>,
    ) -> Paginator<'_, ClientResult<PlaylistItem>> {
        paginate_with_ctx(
            (self, playlist_id, fields),
            move |(slf, playlist_id, fields), limit, offset| {
                slf.playlist_items_manual(
                    playlist_id.as_ref(),
                    *fields,
                    market,
                    Some(limit),
                    Some(offset),
                )
            },
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::playlist_items`].
    async fn playlist_items_manual(
        &self,
        playlist_id: PlaylistId<'_>,
        fields: Option<&str>,
        market: Option<Market>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<PlaylistItem>> {
        let limit = limit.map(|s| s.to_string());
        let offset = offset.map(|s| s.to_string());
        let params = build_map([
            ("fields", fields),
            ("market", market.map(Into::into)),
            ("limit", limit.as_deref()),
            ("offset", offset.as_deref()),
        ]);

        let url = format!("playlists/{}/tracks", playlist_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }

    /// Gets playlists of a user.
    ///
    /// Parameters:
    /// - user_id - the id of the usr
    /// - limit  - the number of items to return
    /// - offset - the index of the first item to return
    ///
    /// See [`Self::user_playlists_manual`] for a manually paginated version of
    /// this.
    ///
    /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#/operations/get-list-users-playlists)
    fn user_playlists<'a>(
        &'a self,
        user_id: UserId<'a>,
    ) -> Paginator<'_, ClientResult<SimplifiedPlaylist>> {
        paginate_with_ctx(
            (self, user_id),
            move |(slf, user_id), limit, offset| {
                slf.user_playlists_manual(user_id.as_ref(), Some(limit), Some(offset))
            },
            self.get_config().pagination_chunks,
        )
    }

    /// The manually paginated version of [`Self::user_playlists`].
    async fn user_playlists_manual(
        &self,
        user_id: UserId<'_>,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> ClientResult<Page<SimplifiedPlaylist>> {
        let limit = limit.map(|s| s.to_string());
        let offset = offset.map(|s| s.to_string());
        let params = build_map([("limit", limit.as_deref()), ("offset", offset.as_deref())]);

        let url = format!("users/{}/playlists", user_id.id());
        let result = self.api_get(&url, &params).await?;
        convert_result(&result)
    }
}