package web

import (
	"fmt"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"cmautobuy/admin/repository"
	"cmautobuy/admin/service"
)

// ShopeeList 渲染蝦皮数据列表页。
//
// **商品级一行**（不是 SKU 级），数据来自 shopee_products 和 shopee_skus
// 聚合联查。列定义见 docs/admin/05-ui-specification.md §4.2、工单 #41。
func (h *Handler) ShopeeList(c *gin.Context) {
	h.renderShopeeList(c, c.Query("q"), c.Query("search_field"), c.Query("status"),
		c.Query("deleted"), c.Query("unlinked"), c.Query("page"), c.Query("msg"))
}

// ShopeeDetail 渲染双击行弹出的那个弹窗的**内容**（不是整页）。
//
// 复用 #18 的弹窗机制：行上写 data-detail-id="{{.GoodsID}}"，
// 前端拿 goods_id 拼到 data-detail-url 后面，以 "id" 作为查询参数名
// （固定写法，见 static/js/app.js「双击行打开详情弹窗」）。
func (h *Handler) ShopeeDetail(c *gin.Context) {
	goodsID := strings.TrimSpace(c.Query("id"))
	if goodsID == "" {
		fail(c, http.StatusBadRequest, "商品编号不对，请刷新页面后重试。")
		return
	}

	detail, err := service.GetShopeeProductDetail(h.db, goodsID)
	if err != nil {
		fail(c, http.StatusInternalServerError, "读取商品详情失败，数据没有被改动。")
		return
	}
	if detail == nil {
		fail(c, http.StatusNotFound, "这个商品不存在，请刷新页面。")
		return
	}

	returnValues := url.Values{}
	if value := strings.TrimSpace(c.Query("q")); value != "" {
		returnValues.Set("q", value)
	}
	returnValues.Set("search_field", service.ParseShopeeSearchField(c.Query("search_field")))
	if value := service.ParseShopeeStatus(c.Query("status")); value != "" {
		returnValues.Set("status", value)
	}
	if currentUser(c).IsAdmin() && c.Query("deleted") == "1" {
		returnValues.Set("deleted", "1")
	}
	if c.Query("unlinked") == "1" {
		returnValues.Set("unlinked", "1")
	}
	returnValues.Set("page", strconv.Itoa(service.ParsePage(c.Query("page"))))
	returnValues.Set("page_size", strconv.Itoa(service.ParsePageSize(c.Query("page_size"))))
	returnValues.Set("open_id", goodsID)
	colorValues := url.Values{"goods_id": {goodsID}, "return_to": {"/shopee?" + returnValues.Encode()}}

	c.HTML(http.StatusOK, "shopee/detail_modal", gin.H{
		"D": detail, "CSRFToken": csrfToken(c),
		"Keyword": c.Query("q"), "SearchField": service.ParseShopeeSearchField(c.Query("search_field")),
		"StatusFilter":    service.ParseShopeeStatus(c.Query("status")),
		"DeletedFilter":   currentUser(c).IsAdmin() && c.Query("deleted") == "1",
		"UnlinkedFilter":  c.Query("unlinked") == "1",
		"CurrentPage":     service.ParsePage(c.Query("page")),
		"CurrentPageSize": service.ParsePageSize(c.Query("page_size")),
		"ColorMappingURL": "/shopee/color-mappings?" + colorValues.Encode(),
	})
}

// renderShopeeList 统一渲染蝦皮列表；数据写入改由商品目录接口负责。
//
// `[必须]` 分页控件用 <a href> 纯 GET 导航，翻页要保留状态、分类、关键词和内部范围，
// 所以这里把归一后的有效值透传回模板去拼下一页的链接（工单 #43、#213）。
func (h *Handler) renderShopeeList(c *gin.Context, keyword, searchFieldRaw, statusRaw, deletedRaw, unlinkedRaw, pageRaw, msg string) {
	filter := repository.ShopeeFilter{
		Keyword:     strings.TrimSpace(keyword),
		SearchField: service.ParseShopeeSearchField(searchFieldRaw),
		Status:      service.ParseShopeeStatus(statusRaw),
		Unlinked:    unlinkedRaw == "1",
	}
	if currentUser(c).IsAdmin() && deletedRaw == "1" {
		filter.Deleted = true
	}
	// 不叫 page：本文件末尾要调用同名的 page(c, ...) 渲染辅助函数，
	// 局部变量会把它遮住导致编译失败。
	pageNum := service.ParsePage(pageRaw)
	pageSize := service.ParsePageSize(c.Query("page_size"))

	result, err := service.ListShopeeProductsWithPageSize(h.db, filter, pageNum, pageSize)
	if err != nil {
		fail(c, http.StatusInternalServerError,
			"读取蝦皮数据失败，数据没有被改动。刷新页面重试；一直失败请把这句话报给维护者。")
		return
	}
	assignableClients, err := service.ListAssignableClients(h.db, currentUser(c), h.onlineThreshold)
	if err != nil {
		fail(c, http.StatusInternalServerError,
			"读取可选客户端失败，数据没有被改动。刷新页面重试。")
		return
	}
	status := msg
	if status == "" {
		status = shopeeStatusLine(filter.Status, result)
	}

	values := url.Values{}
	if filter.Keyword != "" {
		values.Set("q", filter.Keyword)
	}
	values.Set("search_field", filter.SearchField)
	if filter.Status != "" {
		values.Set("status", filter.Status)
	}
	if filter.Deleted {
		values.Set("deleted", "1")
	}
	if filter.Unlinked {
		values.Set("unlinked", "1")
	}
	values.Set("page_size", strconv.Itoa(pageSize))

	c.HTML(http.StatusOK, "shopee/list", page(c, "shopee", "蝦皮数据", gin.H{
		"Keyword":            filter.Keyword,
		"SearchField":        filter.SearchField,
		"SearchFieldOptions": service.ShopeeSearchFieldOptions(),
		"StatusFilter":       filter.Status,
		"StatusOptions":      service.ShopeeStatusOptions(),
		"DeletedFilter":      filter.Deleted,
		"UnlinkedFilter":     filter.Unlinked,
		"Rows":               result.Rows,
		"Status":             status,
		"HasAnyProducts":     result.HasAnyProducts,
		"IsFiltered":         result.IsFiltered,
		"Pagination":         service.NewPaginationView(result.Page, pageSize, result.TotalPages, values.Encode()),
		"CurrentPage":        result.Page,
		"CurrentPageSize":    pageSize,
		"DetailURL":          "/shopee/detail?" + detailValuesForShopee(values, result.Page),
		"AutoOpenDetailID":   strings.TrimSpace(c.Query("open_id")),
		"AssignableClients":  assignableClients,
		"ReturnToEscaped":    url.QueryEscape(c.Request.URL.RequestURI()),
	}))
}

// ShopeeColorMappings 渲染当前蝦皮商品的独立颜色匹配工作区。
func (h *Handler) ShopeeColorMappings(c *gin.Context) {
	h.renderShopeeColorMappings(c, strings.TrimSpace(c.Query("goods_id")),
		safeNext(c.Query("return_to")), nil, c.Query("msg"), "", http.StatusOK)
}

// ShopeeColorMappingsSave 只接收发生变化的颜色键和目标值；所有业务事实都重新从数据库读取。
func (h *Handler) ShopeeColorMappingsSave(c *gin.Context) {
	goodsID := strings.TrimSpace(c.PostForm("goods_id"))
	returnTo := safeNext(c.PostForm("return_to"))
	colorKeys, targets := c.PostFormArray("color_key"), c.PostFormArray("target_value")
	overrides := make(map[string]string, len(colorKeys))
	updates := make([]service.ProductColorMappingUpdate, 0, len(colorKeys))
	if len(colorKeys) != len(targets) {
		h.renderShopeeColorMappings(c, goodsID, returnTo, overrides, "", "提交的颜色行不完整，请刷新后重试。", http.StatusBadRequest)
		return
	}
	for i, key := range colorKeys {
		key = strings.TrimSpace(key)
		overrides[key] = targets[i]
		updates = append(updates, service.ProductColorMappingUpdate{ShopeeColorKey: key, TargetValue: targets[i]})
	}
	changed, err := service.SaveProductColorMappings(h.db, currentUser(c), goodsID,
		c.PostForm("context_version"), updates)
	if err != nil {
		status, message := http.StatusInternalServerError, "保存颜色映射失败，数据库没有改动。请稍后重试。"
		if service.IsValidationError(err) {
			status, message = http.StatusConflict, err.Error()
		}
		h.renderShopeeColorMappings(c, goodsID, returnTo, overrides, "", message, status)
		return
	}
	values := url.Values{"goods_id": {goodsID}, "return_to": {returnTo},
		"msg": {fmt.Sprintf("已保存 %d 条颜色修改", changed)}}
	c.Redirect(http.StatusSeeOther, "/shopee/color-mappings?"+values.Encode())
}

func (h *Handler) renderShopeeColorMappings(c *gin.Context, goodsID, returnTo string, overrides map[string]string, message, alert string, status int) {
	if goodsID == "" {
		fail(c, http.StatusBadRequest, "商品编号不对，请返回蝦皮数据页重新选择。")
		return
	}
	context, err := service.GetProductColorMappingContext(h.db, goodsID)
	if err != nil {
		fail(c, http.StatusInternalServerError, "读取商品颜色匹配数据失败，数据没有被改动。")
		return
	}
	if context == nil {
		fail(c, http.StatusNotFound, "这个蝦皮商品不存在或已删除，请返回列表刷新。")
		return
	}
	view := service.BuildProductColorMappingPageView(context, overrides)
	statusText := service.ProductColorMappingStatusLine(view)
	if message != "" {
		statusText = message + " · " + statusText
	}
	c.HTML(status, "shopee/color_mappings", page(c, "shopee", "颜色匹配", gin.H{
		"V": view, "ReturnTo": safeNext(returnTo), "Message": message, "Alert": alert,
		"Status": statusText, "PageScript": "/static/js/color_mappings.js",
	}))
}

func detailValuesForShopee(values url.Values, pageNum int) string {
	detailValues := url.Values{}
	for key, entries := range values {
		detailValues[key] = append([]string(nil), entries...)
	}
	detailValues.Set("page", strconv.Itoa(pageNum))
	return detailValues.Encode()
}

// shopeeStatusLine 组装底部状态条的默认文案（没有 msg 覆盖时）。
//
// `[必须]` 显示的是筛选后的**全量**总数（result.Total），不是本页行数，
// 筛选时前缀用状态文字（"待补规格：6 个商品"），不筛选时用"共"，
// 见工单 #43。
func shopeeStatusLine(statusFilter string, result *service.ShopeeListResult) string {
	prefix := fmt.Sprintf("共 %d 个商品", result.Total)
	if text := service.ShopeeStatusLabel(statusFilter); text != "" {
		prefix = fmt.Sprintf("%s：%d 个商品", text, result.Total)
	} else if result.IsFiltered {
		prefix = fmt.Sprintf("筛选结果：%d 个商品", result.Total)
	}
	return fmt.Sprintf("%s · 第 %d/%d 页", prefix, result.Page, result.TotalPages)
}

// ShopeeSave 保存蝦皮商品当前关联的 PDD 商品。
func (h *Handler) ShopeeSave(c *gin.Context) {
	goodsID, err := service.AssociateShopeePdd(h.db, c.PostForm("shopee_goods_id"),
		c.PostForm("pdd_url"), c.PostForm("confirm_replace") == "1")
	if err != nil {
		h.shopeeRedirect(c, "PDD 关联未保存："+err.Error()+"。请核对链接后重试。")
		return
	}
	h.shopeeRedirect(c, fmt.Sprintf("已关联 PDD 商品 %s，可继续创建采集任务", goodsID))
}

// ShopeeSpecSave 保存一条现有蝦皮 SKU 的人工颜色、尺码和建议说明。
func (h *Handler) ShopeeSpecSave(c *gin.Context) {
	err := service.UpdateShopeeSKUManual(h.db, currentUser(c), c.PostForm("shopee_goods_id"),
		c.PostForm("sku_record_id"), c.PostForm("color"), c.PostForm("size"),
		c.PostForm("advice"), time.Now())
	if err != nil {
		if service.IsValidationError(err) {
			h.shopeeRedirect(c, "规格未保存："+err.Error())
			return
		}
		fail(c, http.StatusInternalServerError, "保存蝦皮规格失败，数据没有被改动。请刷新页面后重试。")
		return
	}
	h.shopeeRedirect(c, "蝦皮规格已保存，人工字段不会被后续导入覆盖")
}

// ShopeeDelete 批量删除勾选的行。
func (h *Handler) ShopeeDelete(c *gin.Context) {
	count, err := service.DeleteShopeeProducts(h.db, currentUser(c), c.PostFormArray("ids"))
	if err != nil {
		if service.IsValidationError(err) {
			h.shopeeRedirect(c, "删除失败："+err.Error())
			return
		}
		fail(c, http.StatusInternalServerError, "删除蝦皮商品失败，数据没有被改动。")
		return
	}
	h.shopeeRedirect(c, fmt.Sprintf("已将 %d 个蝦皮商品移入已删除，可由管理员恢复", count))
}

// ShopeeRestore 恢复软删除商品及其原有 SKU、PDD 关联。
func (h *Handler) ShopeeRestore(c *gin.Context) {
	count, err := service.RestoreShopeeProducts(h.db, currentUser(c), c.PostFormArray("ids"))
	if err != nil {
		if service.IsValidationError(err) {
			h.shopeeRedirect(c, "恢复失败："+err.Error())
			return
		}
		fail(c, http.StatusInternalServerError, "恢复蝦皮商品失败，数据没有被改动。")
		return
	}
	h.shopeeRedirect(c, fmt.Sprintf("已恢复 %d 个蝦皮商品", count))
}

// ShopeeCollect 发起采集任务。
//
// 入口在编辑弹窗里，紧挨 PDD 链接输入框——不要放到表格每一行，
// 一个商品有 N 个 SKU 行，放行上就是 N 个按钮干同一件事。
//
// 规则：
//   - PDD 链接为空不允许发起；
//   - collect_status 已经是 collecting 的跳过并说明跳过了几个；
//   - 批量采集要**按商品去重**后再建任务。
//
// `[不做]` 本工单（#38）明确不实现这个接口，保持 501。
func (h *Handler) ShopeeCollect(c *gin.Context) {
	result, err := service.CreateShopeePddCollectTaskForUser(h.db, currentUser(c), c.PostForm("shopee_goods_id"))
	if err != nil {
		h.shopeeRedirect(c, "采集任务未创建："+err.Error())
		return
	}
	h.shopeeRedirect(c, service.FormatCollectTaskMessage(result))
}

// ShopeeCollectBatch 为勾选的蝦皮商品按当前 PDD 关联批量创建采集任务。
func (h *Handler) ShopeeCollectBatch(c *gin.Context) {
	ids := c.PostFormArray("ids")
	if len(ids) == 0 {
		h.shopeeRedirect(c, "没有勾选任何蝦皮商品，没有创建任务")
		return
	}
	result, err := service.CreateShopeePddCollectTasksForUser(
		h.db, currentUser(c), ids, c.PostForm("client_id"))
	if err != nil {
		status := http.StatusInternalServerError
		message := "创建采集任务失败，系统没有改动这一批数据。请稍后重试。"
		if service.IsValidationError(err) {
			status = http.StatusBadRequest
			message = err.Error() + "。这一批任务整体没有创建，请重新选择。"
		}
		fail(c, status, message)
		return
	}
	h.shopeeRedirect(c, service.FormatCollectTaskMessage(result))
}

func (h *Handler) shopeeRedirect(c *gin.Context, msg string) {
	params := url.Values{}
	if value := strings.TrimSpace(c.PostForm("q")); value != "" {
		params.Set("q", value)
	}
	params.Set("search_field", service.ParseShopeeSearchField(c.PostForm("search_field")))
	if value := strings.TrimSpace(c.PostForm("status")); value != "" {
		params.Set("status", service.ParseShopeeStatus(value))
	}
	if currentUser(c).IsAdmin() && c.PostForm("deleted") == "1" {
		params.Set("deleted", "1")
	}
	if c.PostForm("unlinked") == "1" {
		params.Set("unlinked", "1")
	}
	if value := strings.TrimSpace(c.PostForm("page")); value != "" {
		params.Set("page", value)
	}
	params.Set("page_size", strconv.Itoa(service.ParsePageSize(c.PostForm("page_size"))))
	if value := strings.TrimSpace(c.PostForm("open_id")); value != "" {
		params.Set("open_id", value)
	}
	if msg != "" {
		params.Set("msg", msg)
	}
	c.Redirect(http.StatusSeeOther, "/shopee?"+params.Encode())
}