using System.Collections.Concurrent;
using System.Reflection;
using System.Security.Claims;

namespace Dpz.Core.Auth;

public static class AuthHelper
{
    private static readonly HashSet<string> AllowedPermissionGroups = new(StringComparer.Ordinal)
    {
        "Endpoints",
        "GrantTypes",
        "ResponseTypes",
        "Scopes",
    };

    public static readonly Lazy<Dictionary<string, List<string>>> OpenIddictPermissionCache = new(
        GetPermissionGroups
    );

    private static Dictionary<string, List<string>> GetPermissionGroups()
    {
        const BindingFlags flags =
            BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy;
        var groups = new Dictionary<string, List<string>>(StringComparer.Ordinal);
        foreach (
            var t in typeof(OpenIddict.Abstractions.OpenIddictConstants.Permissions).GetNestedTypes()
        )
        {
            if (!AllowedPermissionGroups.Contains(t.Name))
            {
                continue;
            }
            var values = t.GetFields(flags)
                .Where(f =>
                    f is { IsLiteral: true, IsInitOnly: false } && f.FieldType == typeof(string)
                )
                .Select(f => (string)f.GetRawConstantValue()!)
                .OrderBy(x => x, StringComparer.Ordinal)
                .ToList();
            if (values.Count > 0)
            {
                groups[t.Name] = values;
            }
        }
        return groups;
    }

    private static readonly ConcurrentDictionary<string, string> AuthorizationDescription = new(
        StringComparer.OrdinalIgnoreCase
    );

    private static readonly ConcurrentDictionary<string, string> TokenStatusDescription = new(
        StringComparer.OrdinalIgnoreCase
    );

    private static readonly ConcurrentDictionary<string, string> TokenTypeDescription = new(
        StringComparer.OrdinalIgnoreCase
    );

    static AuthHelper()
    {
        AuthorizationDescription.TryAdd("valid", "有效");
        AuthorizationDescription.TryAdd("revoked", "已撤销");
        AuthorizationDescription.TryAdd("inactive", "禁用");
        AuthorizationDescription.TryAdd("ad-hoc", "临时授权");
        AuthorizationDescription.TryAdd("permanent", "永久授权");

        TokenStatusDescription.TryAdd("valid", "有效");
        TokenStatusDescription.TryAdd("revoked", "已撤销");
        TokenStatusDescription.TryAdd("expired", "已过期");
        TokenStatusDescription.TryAdd("invalid", "无效");
        TokenStatusDescription.TryAdd("inactive", "未激活");
        TokenStatusDescription.TryAdd("used", "已使用");
        TokenStatusDescription.TryAdd("replaced", "已替换");
        TokenStatusDescription.TryAdd("redeemed", "已兑换");

        TokenTypeDescription.TryAdd("access_token", "访问令牌");
        TokenTypeDescription.TryAdd("refresh_token", "刷新令牌");
        TokenTypeDescription.TryAdd("device_code", "设备码");
        TokenTypeDescription.TryAdd("authorization_code", "授权码");
        TokenTypeDescription.TryAdd("id_token", "身份令牌");
        TokenTypeDescription.TryAdd("oidc_principal", "OIDC 主体令牌");
        TokenTypeDescription.TryAdd("reference_token", "引用令牌");
        TokenTypeDescription.TryAdd("personal_access_token", "个人访问令牌");
    }

    public static string GetAuthorizationDescription(string? key)
    {
        if (string.IsNullOrWhiteSpace(key))
        {
            return "-";
        }

        if (AuthorizationDescription.TryGetValue(key, out var value))
        {
            return value;
        }

        return key;
    }

    public static string GetTokenStatusDescription(string? key)
    {
        if (string.IsNullOrWhiteSpace(key))
        {
            return "-";
        }

        var dictKey = TokenStatusDescription.Keys.FirstOrDefault(x =>
            key.EndsWith(x, StringComparison.OrdinalIgnoreCase)
        );
        if (dictKey == null)
        {
            return "-";
        }
        return TokenStatusDescription[dictKey];
    }

    public static string GetTokenTypeDescription(string? key)
    {
        if (string.IsNullOrWhiteSpace(key))
        {
            return "-";
        }

        var dictKey = TokenTypeDescription.Keys.FirstOrDefault(x =>
            key.EndsWith(x, StringComparison.OrdinalIgnoreCase)
        );
        if (dictKey == null)
        {
            return "-";
        }
        return TokenTypeDescription[dictKey];
    }

    extension(ClaimsPrincipal principal)
    {
        /// <summary>
        /// 账号 用户ID
        /// </summary>
        public string? NameIdentifier => principal.FindFirst(ClaimTypes.NameIdentifier)?.Value;
    }
}