//
// Copyright (C) 2024 veypi <i@veypi.com>
// 2025-07-24 15:27:31
// Distributed under terms of the MIT license.
//

package oauth

import (
	"github.com/veypi/OneAuth/cfg"
	"github.com/vyes-ai/vigo"
	"gorm.io/gorm"
	"time"
)

// AuthorizeRequest 授权请求参数
type AuthorizeRequest struct {
	ResponseType        string `form:"response_type" binding:"required"`
	ClientID            string `form:"client_id" binding:"required"`
	RedirectURI         string `form:"redirect_uri" binding:"required"`
	Scope               string `form:"scope"`
	State               string `form:"state"`
	CodeChallenge       string `form:"code_challenge"`
	CodeChallengeMethod string `form:"code_challenge_method"`
}

// AuthorizeResponse 授权响应
type AuthorizeResponse struct {
	Code        string `json:"code,omitempty"`
	State       string `json:"state,omitempty"`
	RedirectURI string `json:"redirect_uri"`
	Error       string `json:"error,omitempty"`
	ErrorDesc   string `json:"error_description,omitempty"`
}

// handleAuthorize 处理OAuth授权请求
func handleAuthorize(x *vigo.X) error {
	args := &AuthorizeRequest{}
	if err := x.Parse(args); err != nil {
		return vigo.NewError("参数解析失败").WithError(err).WithCode(400)
	}

	db := cfg.DB()

	// 1. 验证响应类型
	if args.ResponseType != ResponseTypeCode {
		errorURI := BuildErrorRedirectURI(args.RedirectURI, ErrorUnsupportedResponseType, "不支持的响应类型", args.State)
		return x.JSON(&AuthorizeResponse{
			Error:       "unsupported_response_type",
			ErrorDesc:   "不支持的响应类型",
			RedirectURI: errorURI,
		})
	}

	// 2. 验证客户端
	var client OAuthClient
	if err := db.Where("client_id = ? AND is_active = ?", args.ClientID, true).First(&client).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			errorURI := BuildErrorRedirectURI(args.RedirectURI, ErrorInvalidClient, "无效的客户端", args.State)
			return x.JSON(&AuthorizeResponse{
				Error:       "invalid_client",
				ErrorDesc:   "无效的客户端",
				RedirectURI: errorURI,
			})
		}
		return vigo.NewError("数据库查询失败").WithError(err).WithCode(500)
	}

	// 3. 验证重定向URI
	if !client.IsRedirectURIValid(args.RedirectURI) {
		return vigo.NewError("无效的重定向URI").WithCode(400)
	}

	// 4. 验证作用域
	if args.Scope != "" && !client.HasScope(args.Scope) {
		errorURI := BuildErrorRedirectURI(args.RedirectURI, ErrorInvalidScope, "无效的授权范围", args.State)
		return x.JSON(&AuthorizeResponse{
			Error:       "invalid_scope",
			ErrorDesc:   "无效的授权范围",
			RedirectURI: errorURI,
		})
	}

	// TODO: 在实际应用中，这里应该:
	// 1. 检查用户是否已登录
	// 2. 显示授权同意页面
	// 3. 用户同意后生成授权码
	// 为了演示，这里假设用户已登录且同意授权

	// 假设当前用户ID (实际应从session或JWT token中获取)
	userID := "demo-user-id"

	// 5. 生成授权码
	code, err := generateRandomString(32)
	if err != nil {
		errorURI := BuildErrorRedirectURI(args.RedirectURI, ErrorServerError, "授权码生成失败", args.State)
		return x.JSON(&AuthorizeResponse{
			Error:       "server_error",
			ErrorDesc:   "授权码生成失败",
			RedirectURI: errorURI,
		})
	}

	// 6. 创建授权码记录
	authCode := &OAuthAuthorizationCode{
		Code:                code,
		ClientID:            client.ID,
		UserID:              userID,
		RedirectURI:         args.RedirectURI,
		Scope:               args.Scope,
		CodeChallenge:       args.CodeChallenge,
		CodeChallengeMethod: args.CodeChallengeMethod,
		ExpiresAt:           time.Now().Add(DefaultAuthorizationCodeExpiry),
		Used:                false,
	}

	if err := db.Create(authCode).Error; err != nil {
		errorURI := BuildErrorRedirectURI(args.RedirectURI, ErrorServerError, "授权码保存失败", args.State)
		return x.JSON(&AuthorizeResponse{
			Error:       "server_error",
			ErrorDesc:   "授权码保存失败",
			RedirectURI: errorURI,
		})
	}

	// 7. 构建成功重定向URI
	redirectURI := BuildRedirectURI(args.RedirectURI, authCode.Code, args.State)

	return x.JSON(&AuthorizeResponse{
		Code:        authCode.Code,
		State:       args.State,
		RedirectURI: redirectURI,
	})
}