using System;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using Microsoft.AspNetCore.Http;
using Volo.Abp.MultiTenancy;
using Volo.Abp.Security.Claims;
using Yi.Framework.Rbac.Domain.Shared.Consts;

namespace FoodLabeling.Application.MultiTenancy;

/// <summary>
/// 从 JWT Claim <see cref="TokenTypeConst.TenantId"/> 解析当前租户（泰额版登录写入）
/// </summary>
public class JwtClaimTenantResolveContributor : TenantResolveContributorBase
{
    public const string ContributorName = "JwtClaim";

    public override string Name => ContributorName;

    public override Task ResolveAsync(ITenantResolveContext context)
    {
        var httpContext = (context.ServiceProvider.GetService(typeof(IHttpContextAccessor)) as IHttpContextAccessor)
            ?.HttpContext;
        if (httpContext is null)
        {
            return Task.CompletedTask;
        }

        var tenantClaim = TryGetTenantIdFromPrincipal(httpContext.User)
                          ?? TryGetTenantIdFromAuthorizationHeader(
                              httpContext.Request.Headers.Authorization.ToString());

        if (!string.IsNullOrWhiteSpace(tenantClaim)
            && Guid.TryParse(tenantClaim, out var tenantGuid)
            && tenantGuid != Guid.Empty)
        {
            context.TenantIdOrName = tenantClaim;
        }

        return Task.CompletedTask;
    }

    private static string? TryGetTenantIdFromPrincipal(ClaimsPrincipal? user)
    {
        if (user?.Identity?.IsAuthenticated != true)
        {
            return null;
        }

        return user.FindFirst(TokenTypeConst.TenantId)?.Value
               ?? user.FindFirst(AbpClaimTypes.TenantId)?.Value
               ?? user.Claims.FirstOrDefault(c =>
                   c.Type.EndsWith("tenantId", StringComparison.OrdinalIgnoreCase)
                   || c.Type.Equals("tenantid", StringComparison.OrdinalIgnoreCase))?.Value;
    }

    /// <summary>
    /// 多租户中间件可能早于 JWT Principal 就绪；直接从 Authorization 解析 TenantId Claim。
    /// </summary>
    private static string? TryGetTenantIdFromAuthorizationHeader(string? authorization)
    {
        if (string.IsNullOrWhiteSpace(authorization))
        {
            return null;
        }

        const string bearerPrefix = "Bearer ";
        if (!authorization.StartsWith(bearerPrefix, StringComparison.OrdinalIgnoreCase))
        {
            return null;
        }

        var jwt = authorization[bearerPrefix.Length..].Trim();
        if (string.IsNullOrWhiteSpace(jwt))
        {
            return null;
        }

        try
        {
            var token = new JwtSecurityTokenHandler().ReadJwtToken(jwt);
            return token.Claims.FirstOrDefault(c =>
                       c.Type == TokenTypeConst.TenantId
                       || c.Type == AbpClaimTypes.TenantId
                       || c.Type.EndsWith("tenantId", StringComparison.OrdinalIgnoreCase))
                   ?.Value;
        }
        catch (Exception)
        {
            return null;
        }
    }
}