package controller

import (
	"errors"
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

	pbModeration "github.com/topfans/backend/pkg/proto/moderation"
	modSvc "github.com/topfans/backend/services/moderationService/service"

	"github.com/topfans/backend/gateway/dto"
	"github.com/topfans/backend/gateway/pkg/response"
)

// modSpecErrCode 举报/反馈业务错误码（spec §7,50001-50019）
// 配套 api.js 的 REPORT_ERROR_MSG 映射表使用
const (
	modCodeCategoryInvalid      = 50001 // 举报分类不存在或已停用
	modCodeFeedbackCatInvalid   = 50002 // 反馈分类不存在或已停用
	modCodeTargetNotFound       = 50003 // 目标对象不存在
	modCodeDuplicateReport      = 50004 // 已举报过
	modCodeDescriptionTooLong   = 50005 // 描述过长
	modCodeTooManyEvidence      = 50006 // 证据图超限
	modCodeReportNotFound       = 50007 // 工单不存在
	modCodeReportClaimed        = 50008 // 工单已被他人认领
	modCodeReportClosed         = 50009 // 工单已结案
	modCodeSelfReport           = 50011 // 不能举报自己
	modCodeRateLimited          = 50012 // 提交过于频繁
	modCodeInvalidStateMig      = 50014 // 状态机非法迁移
	modCodeTargetTypeUnsupported = 50016 // target_type 不支持
)

// modErrMapping 错误 → 业务错误码的映射表
// 与 modSpecErrCode 常量集中维护
var modErrMapping = map[error]int{
	modSvc.ErrCategoryInvalid:       modCodeCategoryInvalid,
	modSvc.ErrFeedbackCatInvalid:    modCodeFeedbackCatInvalid,
	modSvc.ErrTargetNotFound:        modCodeTargetNotFound,
	modSvc.ErrDuplicateReport:       modCodeDuplicateReport,
	modSvc.ErrDescriptionTooLong:    modCodeDescriptionTooLong,
	modSvc.ErrTooManyEvidence:       modCodeTooManyEvidence,
	modSvc.ErrReportNotFound:        modCodeReportNotFound,
	modSvc.ErrReportClaimed:         modCodeReportClaimed,
	modSvc.ErrReportClosed:          modCodeReportClosed,
	modSvc.ErrSelfReport:            modCodeSelfReport,
	modSvc.ErrRateLimited:           modCodeRateLimited,
	modSvc.ErrInvalidStateMigration: modCodeInvalidStateMig,
	modSvc.ErrTargetTypeUnsupported: modCodeTargetTypeUnsupported,
}

// modSpecErrMsg 业务错误码 → spec 文案（spec §7 中文版）
// 与 api.js 的 REPORT_ERROR_MSG 同源；后端优先返回这里的中文，前端做兼容兜底
var modSpecErrMsg = map[int]string{
	modCodeCategoryInvalid:       "举报分类不存在或已停用",
	modCodeFeedbackCatInvalid:    "反馈分类不存在或已停用",
	modCodeTargetNotFound:        "目标对象不存在",
	modCodeDuplicateReport:       "您已举报过该对象",
	modCodeDescriptionTooLong:    "描述过长（最多 500 字）",
	modCodeTooManyEvidence:       "证据图超限（最多 5 张）",
	modCodeReportNotFound:        "工单不存在",
	modCodeReportClaimed:         "工单已被他人认领",
	modCodeReportClosed:          "工单已结案，无法再操作",
	modCodeSelfReport:            "不能举报自己",
	modCodeRateLimited:           "提交过于频繁，请稍后再试",
	modCodeInvalidStateMig:       "工单状态不允许此操作",
	modCodeTargetTypeUnsupported: "举报对象类型不支持",
}

// mapModError 把 service 层错误翻译为 (业务错误码, 中文 message)。
// 命中则返回 (code, msg, true)；未命中返回 (500, "", false) 由调用方走 500 兜底
func mapModError(err error) (int, string, bool) {
	if err == nil {
		return 0, "", false
	}
	for target, code := range modErrMapping {
		if errors.Is(err, target) {
			return code, modSpecErrMsg[code], true
		}
	}
	return http.StatusInternalServerError, "", false
}

// ModerationController 举报反馈控制器（spec §5.1 客户端 API）
type ModerationController struct {
	modService pbModeration.ModerationService
}

// NewModerationController 创建举报反馈控制器（service 由 gateway 注入）
func NewModerationController() *ModerationController {
	return &ModerationController{}
}

// SetService 由 gateway 注入
func (ctrl *ModerationController) SetService(svc pbModeration.ModerationService) {
	ctrl.modService = svc
}

// getUserID 从 gin context 提取 user_id（key 由 auth middleware 写入）
func getUserID(c *gin.Context) int64 {
	if v, ok := c.Get("user_id"); ok {
		if id, ok := v.(int64); ok {
			return id
		}
	}
	return 0
}

// GetReportCategories 获取举报分类
func (ctrl *ModerationController) GetReportCategories(c *gin.Context) {
	resp, err := ctrl.modService.GetReportCategories(
		c.Request.Context(), &pbModeration.GetReportCategoriesRequest{},
	)
	if err != nil {
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewReportCategoryList(resp.Categories))
}

// GetFeedbackCategories 获取反馈分类
func (ctrl *ModerationController) GetFeedbackCategories(c *gin.Context) {
	resp, err := ctrl.modService.GetFeedbackCategories(
		c.Request.Context(), &pbModeration.GetFeedbackCategoriesRequest{},
	)
	if err != nil {
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewFeedbackCategoryList(resp.Categories))
}

// SubmitReport 提交举报
func (ctrl *ModerationController) SubmitReport(c *gin.Context) {
	var req dto.SubmitReportRequestDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		response.Error(c, http.StatusBadRequest, "参数错误: "+err.Error())
		return
	}
	userID := getUserID(c)
	resp, err := ctrl.modService.SubmitReport(c.Request.Context(), &pbModeration.SubmitReportRequest{
		ReporterId:   userID,
		TargetType:   req.TargetType,
		TargetId:     req.TargetID,
		CategoryCode: req.CategoryCode,
		Description:  req.Description,
		IsAnonymous:  req.IsAnonymous,
		EvidenceKeys: req.EvidenceKeys,
		ClientIp:     c.ClientIP(),
		DeviceFp:     c.GetHeader("X-Device-Fingerprint"),
	})
	if err != nil {
		if code, msg, ok := mapModError(err); ok {
			response.ErrorWithCode(c, code, msg)
			return
		}
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewSubmitReportResponse(resp))
}

// ListMyReports 我的举报列表
func (ctrl *ModerationController) ListMyReports(c *gin.Context) {
	userID := getUserID(c)
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	resp, err := ctrl.modService.ListMyReports(c.Request.Context(), &pbModeration.ListMyReportsRequest{
		ReporterId: userID,
		Status:     c.Query("status"),
		Page:       int32(page),
		PageSize:   int32(pageSize),
	})
	if err != nil {
		if code, msg, ok := mapModError(err); ok {
			response.ErrorWithCode(c, code, msg)
			return
		}
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewListMyReportsResponse(resp))
}

// GetReportDetail 举报详情
func (ctrl *ModerationController) GetReportDetail(c *gin.Context) {
	userID := getUserID(c)
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, http.StatusBadRequest, "无效的 ID")
		return
	}
	resp, err := ctrl.modService.GetReport(c.Request.Context(), &pbModeration.GetReportRequest{
		ReporterId: userID, Id: id,
	})
	if err != nil {
		if code, msg, ok := mapModError(err); ok {
			response.ErrorWithCode(c, code, msg)
			return
		}
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewGetReportResponse(resp))
}

// SubmitFeedback 提交反馈
func (ctrl *ModerationController) SubmitFeedback(c *gin.Context) {
	var req dto.SubmitFeedbackRequestDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		response.Error(c, http.StatusBadRequest, "参数错误: "+err.Error())
		return
	}
	userID := getUserID(c)
	resp, err := ctrl.modService.SubmitFeedback(c.Request.Context(), &pbModeration.SubmitFeedbackRequest{
		UserId:       userID,
		StarId:       req.StarID,
		CategoryCode: req.CategoryCode,
		Title:        req.Title,
		Content:      req.Content,
		Contact:      req.Contact,
		IsAnonymous:  req.IsAnonymous,
		EvidenceKeys: req.EvidenceKeys,
	})
	if err != nil {
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewSubmitFeedbackResponse(resp))
}

// ListMyFeedbacks 我的反馈列表
func (ctrl *ModerationController) ListMyFeedbacks(c *gin.Context) {
	userID := getUserID(c)
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	resp, err := ctrl.modService.ListMyFeedbacks(c.Request.Context(), &pbModeration.ListMyFeedbacksRequest{
		UserId:   userID,
		Status:   c.Query("status"),
		Page:     int32(page),
		PageSize: int32(pageSize),
	})
	if err != nil {
		if code, msg, ok := mapModError(err); ok {
			response.ErrorWithCode(c, code, msg)
			return
		}
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewListMyFeedbacksResponse(resp))
}

// GetFeedbackDetail 反馈详情
func (ctrl *ModerationController) GetFeedbackDetail(c *gin.Context) {
	userID := getUserID(c)
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, http.StatusBadRequest, "无效的 ID")
		return
	}
	resp, err := ctrl.modService.GetFeedback(c.Request.Context(), &pbModeration.GetFeedbackRequest{
		UserId: userID, Id: id,
	})
	if err != nil {
		if code, msg, ok := mapModError(err); ok {
			response.ErrorWithCode(c, code, msg)
			return
		}
		response.Error(c, http.StatusInternalServerError, err.Error())
		return
	}
	response.Success(c, dto.NewGetFeedbackResponse(resp))
}