package handler

import (
	"strconv"
	"time"

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

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

// MerchantHandler 提供商户后台与平台管理员的多租户管理能力。
type MerchantHandler struct {
	merchantSvc    *service.MerchantService
	fulfillmentSvc *service.FulfillmentService
	callbackSvc    *service.CallbackService
	deliverySvc    *service.DeliveryService
}

func NewMerchantHandler(merchantSvc *service.MerchantService, fulfillmentSvc *service.FulfillmentService, callbackSvc *service.CallbackService, deliverySvc *service.DeliveryService) *MerchantHandler {
	return &MerchantHandler{
		merchantSvc:    merchantSvc,
		fulfillmentSvc: fulfillmentSvc,
		callbackSvc:    callbackSvc,
		deliverySvc:    deliverySvc,
	}
}

func (h *MerchantHandler) Current(c *gin.Context) {
	merchant, err := h.merchantSvc.GetMerchant(middleware.GetMerchantID(c))
	if err != nil {
		response.NotFound(c, err.Error())
		return
	}
	response.OK(c, gin.H{
		"merchant": merchant,
		"role":     middleware.GetMerchantRole(c),
	})
}

func (h *MerchantHandler) ListProducts(c *gin.Context) {
	page, size := pageParams(c)
	list, total, err := h.merchantSvc.ListMerchantProducts(middleware.GetMerchantID(c), page, size, false)
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

type merchantProductReq struct {
	ProductCode       string `json:"product_code"`
	ProductName       string `json:"product_name"`
	Category          string `json:"category"`
	Description       string `json:"description"`
	Attributes        string `json:"attributes"`
	SKU               string `json:"sku" binding:"required"`
	DisplayName       string `json:"display_name"`
	PriceAmount       int64  `json:"price_amount"`
	CostAmount        int64  `json:"cost_amount"`
	Currency          string `json:"currency"`
	Stock             int64  `json:"stock"`
	Status            string `json:"status"`
	FulfillmentConfig string `json:"fulfillment_config"`
}

func (h *MerchantHandler) CreateProduct(c *gin.Context) {
	var req merchantProductReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：sku 必填")
		return
	}
	product, err := h.merchantSvc.CreateMerchantProduct(middleware.GetMerchantID(c), service.CreateMerchantProductInput{
		ProductCode:       req.ProductCode,
		ProductName:       req.ProductName,
		Category:          req.Category,
		Description:       req.Description,
		Attributes:        req.Attributes,
		SKU:               req.SKU,
		DisplayName:       req.DisplayName,
		PriceAmount:       req.PriceAmount,
		CostAmount:        req.CostAmount,
		Currency:          req.Currency,
		Stock:             req.Stock,
		Status:            req.Status,
		FulfillmentConfig: req.FulfillmentConfig,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, product)
}

type merchantProductUpdateReq struct {
	DisplayName       *string `json:"display_name"`
	PriceAmount       *int64  `json:"price_amount"`
	CostAmount        *int64  `json:"cost_amount"`
	Stock             *int64  `json:"stock"`
	Status            *string `json:"status"`
	FulfillmentConfig *string `json:"fulfillment_config"`
}

func (h *MerchantHandler) UpdateProduct(c *gin.Context) {
	var req merchantProductUpdateReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误")
		return
	}
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if err := h.merchantSvc.UpdateMerchantProduct(middleware.GetMerchantID(c), uint(id), service.UpdateMerchantProductInput{
		DisplayName:       req.DisplayName,
		PriceAmount:       req.PriceAmount,
		CostAmount:        req.CostAmount,
		Stock:             req.Stock,
		Status:            req.Status,
		FulfillmentConfig: req.FulfillmentConfig,
	}, middleware.GetUserID(c)); err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, nil)
}

func (h *MerchantHandler) ListOrders(c *gin.Context) {
	page, size := pageParams(c)
	list, total, err := h.fulfillmentSvc.ListOrders(middleware.GetMerchantID(c), page, size, c.Query("order_status"))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

type merchantTestOrderReq struct {
	SKU            string `json:"sku" binding:"required"`
	BuyerReference string `json:"buyer_reference"`
	Note           string `json:"note"`
	OrderStatus    string `json:"order_status"`
}

func (h *MerchantHandler) CreateTestOrder(c *gin.Context) {
	var req merchantTestOrderReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：sku 必填")
		return
	}
	order, err := h.fulfillmentSvc.CreateTestOrder(service.CreateTestOrderInput{
		MerchantID:     middleware.GetMerchantID(c),
		ActorUserID:    middleware.GetUserID(c),
		SKU:            req.SKU,
		BuyerReference: req.BuyerReference,
		Note:           req.Note,
		OrderStatus:    req.OrderStatus,
	})
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	canShip, cannotShipReason := service.CanFulfill(order)
	response.OK(c, gin.H{
		"order":              order,
		"can_ship":           canShip,
		"cannot_ship_reason": cannotShipReason,
	})
}

func (h *MerchantHandler) GetDeliveryLink(c *gin.Context) {
	link, err := h.deliverySvc.GetOrCreateDeliveryLink(middleware.GetMerchantID(c), c.Param("order_no"), requestBaseURL(c))
	if err != nil {
		writeDeliveryError(c, err)
		return
	}
	response.OK(c, link)
}

func (h *MerchantHandler) RevokeDeliveryLink(c *gin.Context) {
	if err := h.deliverySvc.RevokeDeliveryLink(middleware.GetMerchantID(c), c.Param("order_no")); err != nil {
		writeDeliveryError(c, err)
		return
	}
	response.OK(c, nil)
}

func (h *MerchantHandler) RestoreDeliveryLink(c *gin.Context) {
	link, err := h.deliverySvc.RestoreDeliveryLink(middleware.GetMerchantID(c), c.Param("order_no"), requestBaseURL(c))
	if err != nil {
		writeDeliveryError(c, err)
		return
	}
	response.OK(c, link)
}

func (h *MerchantHandler) GetWallet(c *gin.Context) {
	wallet, err := h.fulfillmentSvc.GetWallet(middleware.GetMerchantID(c))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, wallet)
}

func (h *MerchantHandler) ListWalletLedger(c *gin.Context) {
	page, size := pageParams(c)
	referenceNo := c.Query("reference_no")
	entryType := c.Query("type")
	list, total, err := h.fulfillmentSvc.ListWalletLedger(middleware.GetMerchantID(c), page, size, referenceNo, entryType)
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

// AdminGetWallet 供平台管理员查看指定商户的钱包。
func (h *MerchantHandler) AdminGetWallet(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if id == 0 {
		response.BadRequest(c, "商户 ID 无效")
		return
	}
	wallet, err := h.fulfillmentSvc.GetWallet(uint(id))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, wallet)
}

// AdminListWalletLedger 供平台管理员查看指定商户的积分流水。
func (h *MerchantHandler) AdminListWalletLedger(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if id == 0 {
		response.BadRequest(c, "商户 ID 无效")
		return
	}
	page, size := pageParams(c)
	list, total, err := h.fulfillmentSvc.ListWalletLedger(uint(id), page, size, c.Query("reference_no"), c.Query("type"))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

type walletAdjustReq struct {
	Amount         int64  `json:"amount" binding:"required"`
	IdempotencyKey string `json:"idempotency_key" binding:"required"`
	Note           string `json:"note"`
}

// AdminAdjustWallet 供平台管理员手动调整指定商户的积分，商户侧无任何调账入口。
func (h *MerchantHandler) AdminAdjustWallet(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if id == 0 {
		response.BadRequest(c, "商户 ID 无效")
		return
	}
	var req walletAdjustReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：amount 与 idempotency_key 必填")
		return
	}
	wallet, err := h.fulfillmentSvc.AdjustWallet(service.WalletAdjustInput{
		MerchantID:     uint(id),
		ActorUserID:    middleware.GetUserID(c),
		Amount:         req.Amount,
		IdempotencyKey: req.IdempotencyKey,
		Note:           req.Note,
	})
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, wallet)
}

func (h *MerchantHandler) ListAPIClients(c *gin.Context) {
	clients, err := h.merchantSvc.ListAPIClients(middleware.GetMerchantID(c))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, clients)
}

type apiClientReq struct {
	Name             string `json:"name" binding:"required"`
	Scopes           string `json:"scopes" binding:"required"`
	SignatureVersion string `json:"signature_version"`
	ExpiresAt        string `json:"expires_at"`
}

func (h *MerchantHandler) CreateAPIClient(c *gin.Context) {
	var req apiClientReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：name 与 scopes 必填")
		return
	}
	var expiresAt *time.Time
	if req.ExpiresAt != "" {
		value, err := time.Parse(time.RFC3339, req.ExpiresAt)
		if err != nil {
			response.BadRequest(c, "expires_at 必须是 RFC3339 时间")
			return
		}
		expiresAt = &value
	}
	credential, err := h.merchantSvc.CreateAPIClient(middleware.GetMerchantID(c), service.CreateAPIClientInput{
		Name:             req.Name,
		Scopes:           req.Scopes,
		SignatureVersion: req.SignatureVersion,
		ExpiresAt:        expiresAt,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, credential)
}

type statusReq struct {
	Status string `json:"status" binding:"required"`
}

func (h *MerchantHandler) UpdateAPIClientStatus(c *gin.Context) {
	var req statusReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误")
		return
	}
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if err := h.merchantSvc.UpdateAPIClientStatus(middleware.GetMerchantID(c), uint(id), req.Status, middleware.GetUserID(c)); err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, nil)
}

// DeleteAPIClient DELETE /api/merchant/api-clients/:id
func (h *MerchantHandler) DeleteAPIClient(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if err := h.merchantSvc.DeleteAPIClient(middleware.GetMerchantID(c), uint(id), middleware.GetUserID(c)); err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, nil)
}

func (h *MerchantHandler) ListCallbacks(c *gin.Context) {
	subscription, err := h.callbackSvc.GetSubscription(middleware.GetMerchantID(c))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, subscription)
}

type callbackReq struct {
	Name        string `json:"name"`
	URL         string `json:"url" binding:"required"`
	Events      string `json:"events" binding:"required"`
	Status      string `json:"status"`
	RotateSecret bool   `json:"rotate_secret"`
}

func (h *MerchantHandler) CreateCallback(c *gin.Context) {
	var req callbackReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：url、events 必填")
		return
	}
	credential, err := h.callbackSvc.CreateSubscription(middleware.GetMerchantID(c), service.CreateCallbackInput{
		Name:        req.Name,
		URL:         req.URL,
		Events:      req.Events,
		Status:      req.Status,
		RotateSecret: req.RotateSecret,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, credential)
}

func (h *MerchantHandler) ListMembers(c *gin.Context) {
	members, err := h.merchantSvc.ListMembers(middleware.GetMerchantID(c))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, members)
}

type addMemberReq struct {
	UserID    uint   `json:"user_id" binding:"required"`
	Role      string `json:"role" binding:"required"`
	IsDefault bool   `json:"is_default"`
}

func (h *MerchantHandler) AddCurrentMerchantMember(c *gin.Context) {
	var req addMemberReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：user_id 与 role 必填")
		return
	}
	member, err := h.merchantSvc.AddMember(middleware.GetMerchantID(c), service.AddMemberInput{
		UserID:    req.UserID,
		Role:      req.Role,
		IsDefault: req.IsDefault,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, member)
}

func (h *MerchantHandler) ListPlatformMerchants(c *gin.Context) {
	page, size := pageParams(c)
	list, total, err := h.merchantSvc.ListMerchants(page, size)
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.Page(c, list, total, page, size)
}

// ListProductCatalog 返回自营商户的全部可售商品，作为平台默认商品目录供分配。
func (h *MerchantHandler) ListProductCatalog(c *gin.Context) {
	list, err := h.merchantSvc.ListProductCatalog()
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, list)
}

// ListMerchantProductsByAdmin 供平台管理员查看指定商户的可售商品。
func (h *MerchantHandler) ListMerchantProductsByAdmin(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	list, err := h.merchantSvc.ListMerchantProductsByAdmin(uint(id))
	if err != nil {
		response.ServerError(c, err.Error())
		return
	}
	response.OK(c, list)
}

type assignProductsReq struct {
	CatalogIDs []uint `json:"catalog_ids"`
}

// AssignProducts 按商品目录 ID 批量同步商户的可售商品。
func (h *MerchantHandler) AssignProducts(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	var req assignProductsReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误")
		return
	}
	count, err := h.merchantSvc.AssignProducts(uint(id), service.AssignProductsInput{
		CatalogIDs: req.CatalogIDs,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, gin.H{"assigned": count})
}

type createMerchantReq struct {
	Code           string `json:"code" binding:"required"`
	Name           string `json:"name" binding:"required"`
	ContactName    string `json:"contact_name"`
	ContactInfo    string `json:"contact_info"`
	OwnerUserID    uint   `json:"owner_user_id"`
	OwnerUsername  string `json:"owner_username"`
	OwnerPassword  string `json:"owner_password"`
	OwnerNickname  string `json:"owner_nickname"`
	Features       string `json:"features"`
	FeeType        string `json:"fee_type"`
	FeeRateBP      int64  `json:"fee_rate_bp"`
	FeeFixedAmount int64  `json:"fee_fixed_amount"`
}

func (h *MerchantHandler) CreateMerchant(c *gin.Context) {
	var req createMerchantReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：code、name 必填")
		return
	}
	merchant, err := h.merchantSvc.CreateMerchant(service.CreateMerchantInput{
		Code:           req.Code,
		Name:           req.Name,
		ContactName:    req.ContactName,
		ContactInfo:    req.ContactInfo,
		OwnerUserID:    req.OwnerUserID,
		OwnerUsername:  req.OwnerUsername,
		OwnerPassword:  req.OwnerPassword,
		OwnerNickname:  req.OwnerNickname,
		Features:       req.Features,
		FeeType:        req.FeeType,
		FeeRateBP:      req.FeeRateBP,
		FeeFixedAmount: req.FeeFixedAmount,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, merchant)
}

type updateMerchantSettingsReq struct {
	Name           *string `json:"name"`
	Status         *string `json:"status"`
	ContactName    *string `json:"contact_name"`
	ContactInfo    *string `json:"contact_info"`
	Features       *string `json:"features"`
	FeeType        *string `json:"fee_type"`
	FeeRateBP      *int64  `json:"fee_rate_bp"`
	FeeFixedAmount *int64  `json:"fee_fixed_amount"`
}

func (h *MerchantHandler) UpdateMerchantSettings(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	var req updateMerchantSettingsReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误")
		return
	}
	if err := h.merchantSvc.UpdateMerchantSettings(uint(id), service.UpdateMerchantSettingsInput{
		Name:           req.Name,
		Status:         req.Status,
		ContactName:    req.ContactName,
		ContactInfo:    req.ContactInfo,
		Features:       req.Features,
		FeeType:        req.FeeType,
		FeeRateBP:      req.FeeRateBP,
		FeeFixedAmount: req.FeeFixedAmount,
	}, middleware.GetUserID(c)); err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, nil)
}

func (h *MerchantHandler) AddPlatformMerchantMember(c *gin.Context) {
	var req addMemberReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误：user_id 与 role 必填")
		return
	}
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	member, err := h.merchantSvc.AddMember(uint(id), service.AddMemberInput{
		UserID:    req.UserID,
		Role:      req.Role,
		IsDefault: req.IsDefault,
	}, middleware.GetUserID(c))
	if err != nil {
		response.BadRequest(c, err.Error())
		return
	}
	response.OK(c, member)
}

func pageParams(c *gin.Context) (int, int) {
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))
	return page, size
}