using System;
using System.Collections.Generic;
using System.Threading.Tasks;

/// <summary>
/// Brisk SDK 的静态总入口。
/// 初始化完成后，开发者可以通过 <c>Brisk.Auth</c>、<c>Brisk.Leaderboard</c> 等模块直接访问能力。
/// </summary>
public static class Brisk
{
    private static BriskContext s_context;

    static Brisk()
    {
        Auth = new BriskAuthModule();
        Player = new BriskPlayerModule();
        Config = new BriskConfigModule();
        Announcements = new BriskAnnouncementsModule();
        Leaderboard = new BriskLeaderboardModule();
        Archive = new BriskArchiveModule();
        Space = new BriskSpaceModule();
    }

    /// <summary>
    /// SDK 初始化完成后触发。
    /// </summary>
    public static event Action OnInitialized;
    /// <summary>
    /// 登录成功并保存会话后触发。
    /// </summary>
    public static event Action OnLoggedIn;
    /// <summary>
    /// 主动登出并清理本地会话后触发。
    /// </summary>
    public static event Action OnLoggedOut;
    /// <summary>
    /// 发生维护、封禁、强更等严重阻断错误时触发。
    /// </summary>
    public static event Action<BriskBlockingException> OnBlockingError;
    /// <summary>
    /// 登录态失效并清空本地会话时触发。
    /// </summary>
    public static event Action<BriskAuthExpiredException> OnAuthExpired;

    /// <summary>
    /// 认证模块入口。
    /// </summary>
    public static BriskAuthModule Auth { get; }

    /// <summary>
    /// 玩家模块入口。
    /// </summary>
    public static BriskPlayerModule Player { get; }

    /// <summary>
    /// 动态配置模块入口。
    /// </summary>
    public static BriskConfigModule Config { get; }

    /// <summary>
    /// 公告模块入口。
    /// </summary>
    public static BriskAnnouncementsModule Announcements { get; }

    /// <summary>
    /// 排行榜模块入口。
    /// </summary>
    public static BriskLeaderboardModule Leaderboard { get; }

    /// <summary>
    /// 云存档模块入口。
    /// </summary>
    public static BriskArchiveModule Archive { get; }

    /// <summary>
    /// 玩家空间模块入口。
    /// </summary>
    public static BriskSpaceModule Space { get; }

    /// <summary>
    /// 当前 SDK 是否已完成初始化。
    /// </summary>
    public static bool IsInitialized => s_context != null;

    /// <summary>
    /// 当前是否存在可用登录态。
    /// </summary>
    public static bool IsLoggedIn => s_context != null && s_context.Session.HasAccessToken;

    /// <summary>
    /// 当前访问令牌。
    /// </summary>
    public static string AccessToken => s_context != null ? s_context.Session.AccessToken : null;

    /// <summary>
    /// 当前玩家 ID。
    /// </summary>
    public static string PlayerId => s_context != null ? s_context.Session.PlayerId : null;

    /// <summary>
    /// 当前登录身份摘要。
    /// </summary>
    public static BriskIdentity Identity => s_context != null ? s_context.Session.Identity : null;

    /// <summary>
    /// 当前初始化选项。
    /// </summary>
    public static BriskOptions Options => s_context != null ? s_context.Options : null;

    /// <summary>
    /// 初始化阶段获取到的 bootstrap 结果。
    /// </summary>
    public static BriskBootstrapResult Bootstrap => s_context != null ? s_context.Bootstrap : null;

    /// <summary>
    /// 初始化 SDK，并执行 bootstrap 与本地会话恢复。
    /// </summary>
    /// <param name="options">初始化选项。</param>
    public static async Task InitializeAsync(BriskOptions options)
    {
        if (options == null)
        {
            throw new ArgumentNullException(nameof(options));
        }

        options.Validate();
        var context = new BriskContext(options);
        s_context = context;

        try
        {
            await BootstrapAsync(context);
            await RestoreSessionAsync(context);
            OnInitialized?.Invoke();
        }
        catch
        {
            if (context.Bootstrap == null)
            {
                s_context = null;
            }

            throw;
        }
    }

    /// <summary>
    /// 关闭 SDK 并清空当前上下文。
    /// </summary>
    public static void Shutdown()
    {
        s_context = null;
    }

    /// <summary>
    /// 设置严重错误的展示器。
    /// </summary>
    /// <param name="presenter">自定义错误展示器；传入 null 时恢复默认展示器。</param>
    public static void SetErrorPresenter(IBriskErrorPresenter presenter)
    {
        GetRequiredContext().ErrorPresenter = presenter ?? BriskDefaultErrorPresenter.Instance;
    }

    /// <summary>
    /// 设置阻断错误确认后的退出回调。
    /// </summary>
    /// <param name="exitHandler">项目方自定义退出逻辑。</param>
    public static void SetExitHandler(Action exitHandler)
    {
        GetRequiredContext().ExitHandler = exitHandler;
    }

    internal static BriskContext GetRequiredContext()
    {
        if (s_context == null)
        {
            throw new BriskNotInitializedException();
        }

        return s_context;
    }

    internal static void NotifyLoggedIn()
    {
        OnLoggedIn?.Invoke();
    }

    internal static void NotifyLoggedOut()
    {
        OnLoggedOut?.Invoke();
    }

    internal static void NotifyBlockingError(BriskBlockingException exception)
    {
        s_context?.ErrorPresenter?.ShowBlockingError(exception);
        OnBlockingError?.Invoke(exception);
    }

    internal static void NotifyAuthExpired(BriskAuthExpiredException exception)
    {
        s_context?.ErrorPresenter?.ShowAuthExpired(exception);
        OnAuthExpired?.Invoke(exception);
    }

    private static async Task BootstrapAsync(BriskContext context)
    {
        var query = new Dictionary<string, string>
        {
            { "game_key", context.Options.GameKey },
            { "client_version", context.Options.ClientVersion },
            { "device_id", context.Options.DeviceId }
        };

        var bootstrapData = await context.HttpClient.GetDataAsync("/client/bootstrap", query, false);
        var bootstrap = BriskModelMapper.ToBootstrapResult(bootstrapData);
        context.Bootstrap = bootstrap;

        if (bootstrap.MaintenanceMode)
        {
            var message = string.IsNullOrWhiteSpace(bootstrap.MaintenanceMessage)
                ? "Server is under maintenance."
                : bootstrap.MaintenanceMessage;
            var exception = new BriskMaintenanceException(message);
            NotifyBlockingError(exception);
            throw exception;
        }

        if (BriskVersionComparer.IsLessThan(context.Options.ClientVersion, bootstrap.MinClientVersion))
        {
            var exception = new BriskClientUpdateRequiredException("Client version is lower than the minimum supported version.");
            NotifyBlockingError(exception);
            throw exception;
        }
    }

    private static async Task RestoreSessionAsync(BriskContext context)
    {
        var storedSession = await context.TokenStore.LoadAsync();
        if (storedSession == null || string.IsNullOrWhiteSpace(storedSession.AccessToken))
        {
            return;
        }

        context.Session.Update(
            storedSession.AccessToken,
            storedSession.ExpiresAt,
            storedSession.PlayerId,
            storedSession.ProjectAccountId,
            storedSession.LoginProvider,
            storedSession.LoginUserId);

        if (!context.Options.ValidateSessionOnInitialize)
        {
            return;
        }

        try
        {
            var meData = await context.HttpClient.GetDataAsync("/player/me", null, true);
            var me = BriskModelMapper.ToPlayerMe(meData);
            context.Session.Update(
                storedSession.AccessToken,
                storedSession.ExpiresAt,
                me.PlayerId,
                me.ProjectAccountId,
                me.LoginProvider,
                me.LoginUserId);
        }
        catch (BriskAuthExpiredException exception)
        {
            context.Session.Clear();
            await context.TokenStore.ClearAsync();
            NotifyAuthExpired(exception);
        }
        catch (BriskBlockingException exception)
        {
            NotifyBlockingError(exception);
            throw;
        }
    }
}