using FutureMailAPI.Services;
using FutureMailAPI.Models;

namespace FutureMailAPI.Middleware
{
    public class OAuthAuthenticationMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger<OAuthAuthenticationMiddleware> _logger;
        
        public OAuthAuthenticationMiddleware(RequestDelegate next, ILogger<OAuthAuthenticationMiddleware> logger)
        {
            _next = next;
            _logger = logger;
        }
        
        public async Task InvokeAsync(HttpContext context, IOAuthService oauthService)
        {
            // 检查是否需要OAuth认证
            var endpoint = context.GetEndpoint();
            if (endpoint != null)
            {
                // 如果端点标记为AllowAnonymous，则跳过认证
                var allowAnonymousAttribute = endpoint.Metadata.GetMetadata<Microsoft.AspNetCore.Authorization.AllowAnonymousAttribute>();
                if (allowAnonymousAttribute != null)
                {
                    await _next(context);
                    return;
                }
            }
            
            // 检查Authorization头
            var authHeader = context.Request.Headers.Authorization.FirstOrDefault();
            if (authHeader != null && authHeader.StartsWith("Bearer "))
            {
                var token = authHeader.Substring("Bearer ".Length).Trim();
                
                // 验证令牌
                var validationResult = await oauthService.ValidateTokenAsync(token);
                if (validationResult.Success)
                {
                    // 获取访问令牌信息
                    var accessToken = await oauthService.GetAccessTokenAsync(token);
                    if (accessToken != null)
                    {
                        // 将用户信息添加到HttpContext
                        context.Items["UserId"] = accessToken.UserId;
                        context.Items["UserEmail"] = accessToken.User.Email;
                        context.Items["AccessToken"] = accessToken;
                        
                        await _next(context);
                        return;
                    }
                }
            }
            
            // 如果没有有效的令牌，返回401未授权
            context.Response.StatusCode = 401;
            await context.Response.WriteAsync("未授权访问");
        }
    }
}