package handler

import (
	"strconv"

	"affiliate_dash/internal/middleware"
	"affiliate_dash/internal/pkg/response"
	"affiliate_dash/internal/service"

	"github.com/gin-gonic/gin"
)

const uploadMaxBytes = 5 * 1024 * 1024 // 单张图片最大 5MB

// RechargeHandler 提供积分充值申请（商户侧）与审核入账（管理员侧）能力。
type RechargeHandler struct {
	rechargeSvc *service.RechargeService
}

func NewRechargeHandler(rechargeSvc *service.RechargeService) *RechargeHandler {
	return &RechargeHandler{rechargeSvc: rechargeSvc}
}

type rechargeCreateReq struct {
	AmountCNY int64    `json:"amount_cny" binding:"required"` // 人民币，单位：分
	Vouchers  []string `json:"vouchers" binding:"required"`
	Note      string   `json:"note"`
}

// CreateApplication POST /api/merchant/recharge/applications
func (h *RechargeHandler) CreateApplication(c *gin.Context) {
	var req rechargeCreateReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：amount_cny 与 vouchers 必填")
		return
	}
	app, err := h.rechargeSvc.CreateRecharge(service.CreateRechargeInput{
		MerchantID:  middleware.GetMerchantID(c),
		ActorUserID: middleware.GetUserID(c),
		AmountCNY:   req.AmountCNY,
		Vouchers:    req.Vouchers,
		Note:        req.Note,
	})
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, app)
}

// ListApplications GET /api/merchant/recharge/applications（当前商户）
func (h *RechargeHandler) ListApplications(c *gin.Context) {
	page, size := pageParams(c)
	list, total, err := h.rechargeSvc.ListRechargeApplications(middleware.GetMerchantID(c), page, size, c.Query("status"))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

// AdminListApplications GET /api/platform/recharge/applications（全部商户）
func (h *RechargeHandler) AdminListApplications(c *gin.Context) {
	page, size := pageParams(c)
	list, total, err := h.rechargeSvc.ListAllRechargeApplications(page, size, c.Query("status"))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

type rechargeReviewReq struct {
	Approved   bool   `json:"approved" binding:"required"`
	ReviewNote string `json:"review_note"`
}

// AdminReviewApplication POST /api/platform/recharge/applications/:id/review
// 通过后由后端按 1 元 = 100 积分自动入账到商户钱包，幂等键为申请单号。
func (h *RechargeHandler) AdminReviewApplication(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if id == 0 {
		response.BadRequest(c, "申请 ID 无效")
		return
	}
	var req rechargeReviewReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：approved 必填")
		return
	}
	app, err := h.rechargeSvc.ReviewRecharge(service.ReviewRechargeInput{
		ApplicationID: uint(id),
		Approved:      req.Approved,
		ReviewNote:    req.ReviewNote,
		ActorUserID:   middleware.GetUserID(c),
	})
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	h.rechargeSvc.CheckLowBalanceAndNotify(app.MerchantID)
	response.OK(c, app)
}

// GetAlertConfig GET /api/merchant/recharge/alert-config
func (h *RechargeHandler) GetAlertConfig(c *gin.Context) {
	cfg, err := h.rechargeSvc.GetAlertConfig(middleware.GetMerchantID(c))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, cfg)
}

type alertConfigReq struct {
	Enabled         bool   `json:"enabled"`
	ThresholdPoints int64  `json:"threshold_points"`
	WebhookURL      string `json:"webhook_url"`
}

// SaveAlertConfig PUT /api/merchant/recharge/alert-config
func (h *RechargeHandler) SaveAlertConfig(c *gin.Context) {
	var req alertConfigReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误")
		return
	}
	cfg, err := h.rechargeSvc.SaveAlertConfig(middleware.GetMerchantID(c), service.SaveAlertInput{
		Enabled:         req.Enabled,
		ThresholdPoints: req.ThresholdPoints,
		WebhookURL:      req.WebhookURL,
	})
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, cfg)
}

// Upload POST /api/upload 上传凭证图片（multipart 字段名 file）。
func (h *RechargeHandler) Upload(c *gin.Context) {
	fileHeader, err := c.FormFile("file")
	if err != nil {
		response.BadRequest(c, "请选择要上传的图片")
		return
	}
	file, err := fileHeader.Open()
	if err != nil {
		response.BadRequest(c, "读取上传文件失败")
		return
	}
	defer file.Close()

	url, err := h.rechargeSvc.SaveUploadFile(file, fileHeader.Filename, uploadMaxBytes)
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, gin.H{"url": url})
}