namespace Webzine.Entity.Fixtures;

using System.Globalization;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text;
using System.Text.Json.Serialization;

using Microsoft.Extensions.Options;

public class SpotifySeederOptions
{
    public string ClientId { get; set; } = string.Empty;

    public string ClientSecret { get; set; } = string.Empty;

    public string Market { get; set; } = "FR";

    public List<string> Genres { get; set; } =
    [
        "rock",
        "pop",
        "jazz",
        "hip hop",
        "electronic",
        "metal",
    ];

    public int ArtistsPerGenre { get; set; } = 4;

    public int AlbumsPerArtist { get; set; } = 2;

    public int TracksPerAlbum { get; set; } = 4;

    public int MaxCommentsPerTrack { get; set; } = 3;
}

public class SeedDataSpotify
{
    private readonly HttpClient httpClient;
    private readonly SpotifySeederOptions options;

    public SeedDataSpotify(HttpClient httpClient, IOptions<SpotifySeederOptions> optionsAccessor)
    {
        this.httpClient = httpClient;
        this.options = optionsAccessor.Value;
    }

    /// <summary>
    ///
    /// </summary>
    /// <param name="cancellationToken"></param>
    /// <returns><placeholder>A <see cref="Task"/> representing the asynchronous operation.</placeholder></returns>
    /// <exception cref="InvalidOperationException"></exception>
    public async Task<SeedDataSet> GenererJeuDeDonneesAsync(CancellationToken cancellationToken = default)
    {
        if (string.IsNullOrWhiteSpace(this.options.ClientId) || string.IsNullOrWhiteSpace(this.options.ClientSecret))
        {
            throw new InvalidOperationException("Renseignez SpotifySeeder:ClientId et SpotifySeeder:ClientSecret.");
        }

        var token = await this.GetTokenAsync(cancellationToken);
        var styles = new Dictionary<string, Style>(StringComparer.OrdinalIgnoreCase);
        var artistes = new List<Artiste>();
        var titres = new List<Titre>();
        var commentaires = new List<Commentaire>();
        var artistIds = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
        int nextArtistId = 1;
        int nextStyleId = 1;
        int nextTitreId = 1;
        int nextCommentaireId = 1;

        foreach (var genre in this.options.Genres.Where(g => !string.IsNullOrWhiteSpace(g)))
        {
            var artistesSpotify = await this.GetAsync<SpotifySearchArtistsResponse>(
                $"https://api.spotify.com/v1/search?q={Uri.EscapeDataString($"genre:\"{genre}\"")}&type=artist&market={this.options.Market}&limit={Math.Clamp(this.options.ArtistsPerGenre, 1, 10)}",
                token,
                cancellationToken);

            foreach (var artisteSpotify in artistesSpotify?.Artists?.Items ??[])
            {
                if (string.IsNullOrWhiteSpace(artisteSpotify.Id) || !artistIds.Add(artisteSpotify.Id))
                {
                    continue;
                }

                var stylesTitre = (artisteSpotify.Genres.Count > 0 ? artisteSpotify.Genres :[genre])
                    .Select(g => this.GetOrCreateStyle(styles, NormalizeGenre(g), ref nextStyleId))
                    .DistinctBy(s => s.IdStyle)
                    .ToList();

                var artiste = new Artiste
                {
                    IdArtiste = nextArtistId++,
                    Nom = Trim(artisteSpotify.Name, 50, "Artiste Spotify"),
                    Biographie = Trim(
                        $"{artisteSpotify.Name} est un artiste present sur Spotify, associe aux styles {string.Join(", ", stylesTitre.Select(s => s.Libelle))}.",
                        4000,
                        "Artiste issu du catalogue Spotify."),
                    Titres = new List<Titre>(),
                };

                artistes.Add(artiste);

                var albums = await this.GetAsync<SpotifyAlbumsResponse>(
                    $"https://api.spotify.com/v1/artists/{artisteSpotify.Id}/albums?include_groups=album,single&market={this.options.Market}",
                    token,
                    cancellationToken);

                foreach (var album in albums?.Items?.GroupBy(a => a.Name, StringComparer.OrdinalIgnoreCase).Select(g => g.First()) ??[])
                {
                    var tracks = await this.GetAsync<SpotifyTracksResponse>(
                        $"https://api.spotify.com/v1/albums/{album.Id}/tracks?market={this.options.Market}&limit={Math.Clamp(this.options.TracksPerAlbum, 1, 10)}",
                        token,
                        cancellationToken);

                    foreach (var track in tracks?.Items ??[])
                    {
                        var titre = new Titre
                        {
                            IdTitre = nextTitreId++,
                            IdArtiste = artiste.IdArtiste,
                            Artiste = artiste,
                            Libelle = Trim(track.Name, 200, "Titre Spotify"),
                            Chronique = Trim(
                                $"{track.Name} est un titre de {artiste.Nom}, issu de l'album {album.Name}. Cette fiche a ete generee depuis Spotify.",
                                4000,
                                "Titre importe depuis Spotify."),
                            DateCreation = DateTime.UtcNow,
                            DateSortie = ParseDate(album.ReleaseDate),
                            Duree = Math.Max(1, track.DurationMs / 1000),
                            UrlJaquette = Trim(album.Images.FirstOrDefault()?.Url, 250, "https://placehold.co/640x640"),
                            UrlEcoute = Trim(track.ExternalUrls?.Spotify ?? $"https://open.spotify.com/track/{track.Id}", 250, string.Empty),
                            NbLectures = Random.Shared.Next(500, 50000),
                            NbLikes = Random.Shared.Next(50, 5000),
                            Album = Trim(album.Name, 200, "Album Spotify"),
                            Commentaires = new List<Commentaire>(),
                            Styles = new List<Style>(stylesTitre),
                        };

                        var commentairesTitre = SeedDataLocal.GenererListeCommentaire(
                            titre,
                            0,
                            Math.Clamp(this.options.MaxCommentsPerTrack, 0, 10),
                            nextCommentaireId);

                        nextCommentaireId += commentairesTitre.Count;

                        titre.Commentaires.AddRange(commentairesTitre);
                        commentaires.AddRange(commentairesTitre);
                        titres.Add(titre);
                        artiste.Titres.Add(titre);

                        foreach (var style in titre.Styles)
                        {
                            style.Titres.Add(titre);
                        }
                    }
                }
            }
        }

        return new SeedDataSet
        {
            Artistes = artistes,
            Styles = styles.Values.OrderBy(s => s.IdStyle).ToList(),
            Titres = titres,
            Commentaires = commentaires,
        };
    }

    private static string NormalizeGenre(string genre)
    {
        var value = string.IsNullOrWhiteSpace(genre) ? "Musique" : genre.Trim().Replace('-', ' ');
        return CultureInfo.InvariantCulture.TextInfo.ToTitleCase(value);
    }

    private static string Trim(string? value, int maxLength, string fallback)
    {
        var result = string.IsNullOrWhiteSpace(value) ? fallback : value.Trim();
        return result.Length > maxLength ? result[..maxLength] : result;
    }

    private static DateTime ParseDate(string? value)
    {
        if (string.IsNullOrWhiteSpace(value))
        {
            return DateTime.UtcNow;
        }

        if (DateTime.TryParse(value, CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal, out var date))
        {
            return DateTime.SpecifyKind(date, DateTimeKind.Utc);
        }

        if (DateTime.TryParseExact(value, "yyyy-MM", CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
        {
            return DateTime.SpecifyKind(date, DateTimeKind.Utc);
        }

        if (DateTime.TryParseExact(value, "yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
        {
            return DateTime.SpecifyKind(date, DateTimeKind.Utc);
        }

        return DateTime.UtcNow;
    }

    private Style GetOrCreateStyle(Dictionary<string, Style> styles, string libelle, ref int nextStyleId)
    {
        if (!styles.TryGetValue(libelle, out var style))
        {
            style = new Style
            {
                IdStyle = nextStyleId++,
                Libelle = Trim(libelle, 50, "Musique"),
                Titres = new List<Titre>(),
            };

            styles.Add(style.Libelle, style);
        }

        return style;
    }

    private async Task<string> GetTokenAsync(CancellationToken cancellationToken)
    {
        using var request = new HttpRequestMessage(HttpMethod.Post, "https://accounts.spotify.com/api/token");
        request.Content = new FormUrlEncodedContent(
        [
            new KeyValuePair<string, string>("grant_type", "client_credentials"),
        ]);

        var basic = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{this.options.ClientId}:{this.options.ClientSecret}"));
        request.Headers.Authorization = new AuthenticationHeaderValue("Basic", basic);

        using var response = await this.httpClient.SendAsync(request, cancellationToken);
        response.EnsureSuccessStatusCode();

        var payload = await response.Content.ReadFromJsonAsync<SpotifyTokenResponse>(cancellationToken: cancellationToken);
        return payload?.AccessToken ?? throw new InvalidOperationException("Token Spotify introuvable.");
    }

    private async Task<T?> GetAsync<T>(string url, string token, CancellationToken cancellationToken)
    {
        using var request = new HttpRequestMessage(HttpMethod.Get, url);
        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);

        using var response = await this.httpClient.SendAsync(request, cancellationToken);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadFromJsonAsync<T>(cancellationToken: cancellationToken);
    }

    private sealed class SpotifyTokenResponse
    {
        [JsonPropertyName("access_token")]
        public string? AccessToken { get; set; }
    }

    private sealed class SpotifySearchArtistsResponse
    {
        [JsonPropertyName("artists")]
        public SpotifyArtistsContainer? Artists { get; set; }
    }

    private sealed class SpotifyArtistsContainer
    {
        [JsonPropertyName("items")]
        public List<SpotifyArtist> Items { get; set; } = new ();
    }

    private sealed class SpotifyArtist
    {
        [JsonPropertyName("id")]
        public string Id { get; set; } = string.Empty;

        [JsonPropertyName("name")]
        public string Name { get; set; } = string.Empty;

        [JsonPropertyName("genres")]
        public List<string> Genres { get; set; } = new ();
    }

    private sealed class SpotifyAlbumsResponse
    {
        [JsonPropertyName("items")]
        public List<SpotifyAlbum> Items { get; set; } = new ();
    }

    private sealed class SpotifyAlbum
    {
        [JsonPropertyName("id")]
        public string Id { get; set; } = string.Empty;

        [JsonPropertyName("name")]
        public string Name { get; set; } = string.Empty;

        [JsonPropertyName("release_date")]
        public string? ReleaseDate { get; set; }

        [JsonPropertyName("images")]
        public List<SpotifyImage> Images { get; set; } = new ();
    }

    private sealed class SpotifyTracksResponse
    {
        [JsonPropertyName("items")]
        public List<SpotifyTrack> Items { get; set; } = new ();
    }

    private sealed class SpotifyTrack
    {
        [JsonPropertyName("id")]
        public string Id { get; set; } = string.Empty;

        [JsonPropertyName("name")]
        public string Name { get; set; } = string.Empty;

        [JsonPropertyName("duration_ms")]
        public int DurationMs { get; set; }

        [JsonPropertyName("external_urls")]
        public SpotifyExternalUrls? ExternalUrls { get; set; }
    }

    private sealed class SpotifyImage
    {
        [JsonPropertyName("url")]
        public string? Url { get; set; }
    }

    private sealed class SpotifyExternalUrls
    {
        [JsonPropertyName("spotify")]
        public string? Spotify { get; set; }
    }
}