using Blazored.LocalStorage;
using Microsoft.AspNetCore.Components.Authorization;
using System.Security.Claims;
using System.Text.Json;

namespace HotelPms.Client.Blazor.Util
{
    public class ApiAuthenticationStateProvider : AuthenticationStateProvider
    {
        public static string? AccessToken { get; set; }

        private readonly ILocalStorageService _localStorage;

        public ApiAuthenticationStateProvider(ILocalStorageService localStorage)
        {
            _localStorage = localStorage;
        }

        public override async Task<AuthenticationState> GetAuthenticationStateAsync()
        {
            var savedToken = await _localStorage.GetItemAsync<string>("authToken");
            EnvironmentSetting.Debug($"GetAuthenticationStateAsync：{savedToken}");

            if (string.IsNullOrWhiteSpace(savedToken))
            {
                return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
            }

            if (string.IsNullOrEmpty(AccessToken))
            {
                EnvironmentSetting.Debug($"初次认证");
                //判断savedToken过期？
                //return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
            }

            //_httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", savedToken);
            AccessToken = savedToken;
            EnvironmentSetting.Debug($"AccessToken：{AccessToken}");

            return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity(ParseClaimsFromJwt(savedToken), "jwt")));
        }

        public void MarkUserAsAuthenticated(string token)
        {
            var authenticatedUser = new ClaimsPrincipal(new ClaimsIdentity(ParseClaimsFromJwt(token), "jwt"));
            var authState = Task.FromResult(new AuthenticationState(authenticatedUser));
            NotifyAuthenticationStateChanged(authState);
        }

        public void MarkUserAsLoggedOut()
        {
            var anonymousUser = new ClaimsPrincipal(new ClaimsIdentity());
            var authState = Task.FromResult(new AuthenticationState(anonymousUser));
            NotifyAuthenticationStateChanged(authState);
        }

        private IEnumerable<Claim> ParseClaimsFromJwt(string jwt)
        {
            var claims = new List<Claim>();
            var payload = jwt.Split('.')[1];
            var jsonBytes = ParseBase64WithoutPadding(payload);
            var keyValuePairs = JsonSerializer.Deserialize<Dictionary<string, object>>(jsonBytes);

            keyValuePairs.TryGetValue(ClaimTypes.Role, out object roles);

            if (roles != null)
            {
                if (roles.ToString().Trim().StartsWith("["))
                {
                    var parsedRoles = JsonSerializer.Deserialize<string[]>(roles.ToString());

                    foreach (var parsedRole in parsedRoles)
                    {
                        EnvironmentSetting.Debug("parsedRole:" + parsedRole);
                        claims.Add(new Claim(ClaimTypes.Role, parsedRole));
                    }
                }
                else
                {
                    EnvironmentSetting.Debug(roles.ToString());
                    claims.Add(new Claim(ClaimTypes.Role, roles.ToString()));
                }

                keyValuePairs.Remove(ClaimTypes.Role);
            }

            claims.AddRange(keyValuePairs.Select(kvp => new Claim(kvp.Key, kvp.Value.ToString())));

            return claims;
        }

        private byte[] ParseBase64WithoutPadding(string base64)
        {
            switch (base64.Length % 4)
            {
                case 2: base64 += "=="; break;
                case 3: base64 += "="; break;
            }
            return Convert.FromBase64String(base64);
        }
    }
}