package handler

import (
	"errors"
	"log"
	"net/http"

	"github.com/gin-gonic/gin"

	"wx_service/internal/common/auth/service"
	"wx_service/internal/middleware"
	"wx_service/internal/model"
)

type AuthHandler struct {
	// handler 层通常只做“协议转换”：
	// - 把 HTTP 请求（JSON/header 等）解析成结构体
	// - 调用 service 完成业务逻辑
	// - 把结果/错误转换成统一的 JSON 响应
	authService *service.AuthService
}

func NewAuthHandler(authService *service.AuthService) *AuthHandler {
	return &AuthHandler{
		authService: authService,
	}
}

type weChatLoginRequest struct {
	// binding:"required" 是 Gin 的校验标签：字段缺失或为空会导致 ShouldBindJSON 返回错误
	MiniProgramID uint   `json:"mini_program_id" binding:"required"`
	Code          string `json:"code" binding:"required"`
	NickName      string `json:"nickname"`
	AvatarURL     string `json:"avatar_url"`
	// 使用 *int 可以区分：
	// - nil：前端没传 gender
	// - 非 nil：前端传了具体值（即使是 0）
	Gender *int   `json:"gender"`
	Phone  string `json:"phone"`
}

func (h *AuthHandler) LoginWithWeChat(c *gin.Context) {
	// gin.Context 是每个请求的上下文对象：
	// - c.Request.Context() 是标准库 context，用于把超时/取消信号传递到 DB/HTTP 调用
	// - c.JSON(...) 用于写 JSON 响应
	var req weChatLoginRequest
	// ShouldBindJSON 会从请求体 JSON 反序列化到结构体，并根据 binding 标签做基础校验
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "invalid request payload"))
		return
	}

	// 业务逻辑下沉到 service：这样 handler 更薄、更容易测试
	result, err := h.authService.LoginWithCode(c.Request.Context(), service.LoginRequest{
		MiniProgramID: req.MiniProgramID,
		Code:          req.Code,
		NickName:      req.NickName,
		AvatarURL:     req.AvatarURL,
		Gender:        req.Gender,
		Phone:         req.Phone,
	})
	if err != nil {
		switch {
		case errors.Is(err, service.ErrCodeRequired):
			c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "code is required"))
		case errors.Is(err, service.ErrMiniProgramRequired):
			c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "mini_program_id is required"))
		case errors.Is(err, service.ErrMiniProgramNotFound):
			c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "mini program not found"))
		default:
			var apiErr *service.WeChatError
			if errors.As(err, &apiErr) {
				c.JSON(http.StatusBadGateway, model.Error(http.StatusBadGateway, apiErr.Error()))
				return
			}
			c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "login failed"))
		}
		return
	}

	userPayload := gin.H{
		"id":              result.User.ID,
		"mini_program_id": result.User.MiniProgramID,
		"open_id":         result.User.OpenID,
		"nickname":        result.User.NickName,
		"avatar_url":      result.User.AvatarURL,
		"gender":          result.User.Gender,
		"phone":           result.User.Phone,
	}
	if result.User.UnionID != "" {
		userPayload["union_id"] = result.User.UnionID
	}
	if result.Mode != "" {
		userPayload["mode"] = result.Mode
	}

	miniProgramPayload := gin.H{
		"id":     result.MiniProgram.ID,
		"name":   result.MiniProgram.Name,
		"app_id": result.MiniProgram.AppID,
	}
	if result.MiniProgram.Description != "" {
		miniProgramPayload["description"] = result.MiniProgram.Description
	}

	c.JSON(http.StatusOK, model.Success(gin.H{
		"user":         userPayload,
		"session_key":  result.SessionKey,
		"mini_program": miniProgramPayload,
	}))
}

type devLoginRequest struct {
	MiniProgramID uint `json:"mini_program_id"`
}

// DevLogin 仅在非 release 模式下可用，用于 H5 开发调试。
func (h *AuthHandler) DevLogin(c *gin.Context) {
	if gin.Mode() == gin.ReleaseMode {
		c.JSON(http.StatusNotFound, model.Error(http.StatusNotFound, "not found"))
		return
	}

	var req devLoginRequest
	_ = c.ShouldBindJSON(&req)
	if req.MiniProgramID == 0 {
		req.MiniProgramID = 3
	}

	result, err := h.authService.DevLogin(c.Request.Context(), req.MiniProgramID)
	if err != nil {
		log.Printf("[dev_login] error: %v", err)
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "dev login failed: "+err.Error()))
		return
	}

	c.JSON(http.StatusOK, model.Success(gin.H{
		"user": gin.H{
			"id":              result.User.ID,
			"mini_program_id": result.User.MiniProgramID,
			"open_id":         result.User.OpenID,
			"nickname":        result.User.NickName,
			"avatar_url":      result.User.AvatarURL,
		},
		"session_key": result.SessionKey,
		"mini_program": gin.H{
			"id":   result.MiniProgram.ID,
			"name": result.MiniProgram.Name,
		},
	}))
}

type updateProfileRequest struct {
	Nickname  string `json:"nickname"`
	AvatarURL string `json:"avatar_url"`
}

func (h *AuthHandler) UpdateProfile(c *gin.Context) {
	user := middleware.MustCurrentUser(c)

	var req updateProfileRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "参数错误"))
		return
	}
	if req.Nickname == "" && req.AvatarURL == "" {
		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "请提供昵称或头像"))
		return
	}

	updated, err := h.authService.UpdateProfile(c.Request.Context(), user.ID, req.Nickname, req.AvatarURL)
	if err != nil {
		log.Printf("[update_profile] error: %v", err)
		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "更新失败"))
		return
	}

	c.JSON(http.StatusOK, model.Success(gin.H{
		"id":         updated.ID,
		"nickname":   updated.NickName,
		"avatar_url": updated.AvatarURL,
	}))
}