package web

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

	"daili/internal/domain"
	"daili/internal/store"
)

type packagesData struct {
	List []store.Package
}

func (s *Server) handlePackages(w http.ResponseWriter, r *http.Request) {
	list, err := s.db.ListPackages(true)
	if err != nil {
		http.Error(w, "读取套餐失败", http.StatusInternalServerError)
		return
	}
	p := s.newPage(r, "套餐", "packages")
	p.D = &packagesData{List: list}
	s.render(w, r, "packages", p)
}

type packageFormData struct {
	Package *store.Package
	IsNew   bool
	Tags    []string
}

func (s *Server) handlePackageNewPage(w http.ResponseWriter, r *http.Request) {
	p := s.newPage(r, "新增套餐", "packages")
	tags, _ := s.db.PackageTags()
	p.D = &packageFormData{
		Package: &store.Package{Unit: domain.UnitDay, DefaultAmount: 30, Color: "#2F5D50"},
		IsNew:   true,
		Tags:    tags,
	}
	s.render(w, r, "package_form", p)
}

func readPackageForm(r *http.Request) *store.Package {
	p := &store.Package{
		Name:          strings.TrimSpace(r.PostFormValue("name")),
		Unit:          strings.TrimSpace(r.PostFormValue("unit")),
		DefaultAmount: 0,
		Color:         strings.TrimSpace(r.PostFormValue("color")),
		Note:          strings.TrimSpace(r.PostFormValue("note")),
		SortOrder:     0,
	}
	if v, err := strconv.Atoi(strings.TrimSpace(r.PostFormValue("default_amount"))); err == nil {
		p.DefaultAmount = v
	}
	if v, err := strconv.Atoi(strings.TrimSpace(r.PostFormValue("sort_order"))); err == nil {
		p.SortOrder = v
	}
	if price := strings.TrimSpace(r.PostFormValue("price")); price != "" {
		if f, err := strconv.ParseFloat(price, 64); err == nil {
			p.PriceCents = int(f*100 + 0.5)
			p.HasPrice = true
		}
	}
	if p.Unit == "" {
		p.Unit = domain.UnitDay
	}
	p.CalendarSeparate = r.PostFormValue("calendar_separate") != ""
	p.Tag = strings.TrimSpace(r.PostFormValue("tag"))
	if p.Unit == "season" {
		p.Season = true
		p.Unit = domain.UnitDay
	}
	if v, err := strconv.Atoi(strings.TrimSpace(r.PostFormValue("default_validity_days"))); err == nil {
		p.DefaultValidityDays = v
	}
	p.SeasonStart = strings.TrimSpace(r.PostFormValue("season_start"))
	p.SeasonEnd = strings.TrimSpace(r.PostFormValue("season_end"))
	return p
}

func validatePackage(p *store.Package) string {
	if p.Season {
		if p.SeasonStart == "" || p.SeasonEnd == "" {
			return "包赛季套餐必须填写赛季开始日和结束日"
		}
		if p.SeasonEnd < p.SeasonStart {
			return "赛季结束日不能早于开始日"
		}
	}
	if p.Name == "" {
		return "套餐名称不能为空"
	}
	if len([]rune(p.Name)) > 32 {
		return "套餐名称最长 32 字"
	}
	if p.Unit != domain.UnitDay && p.Unit != domain.UnitCount {
		return "套餐类型不正确"
	}
	if p.DefaultAmount <= 0 {
		return "默认天数/次数必须大于 0"
	}
	if p.Color == "" || !strings.HasPrefix(p.Color, "#") {
		return "请选择套餐颜色"
	}
	return ""
}

// packageDetailData 套餐详情页数据。
type packageDetailData struct {
	Package    *store.Package
	Customers  []store.Customer
	Subscribed map[int64]bool
	Q          string
	Tags       []string
	Today      string
}

// handlePackageDetail 套餐详情：查看信息 + 勾选客户批量开通。
func (s *Server) handlePackageDetail(w http.ResponseWriter, r *http.Request) {
	id := pathID(r)
	pkg, err := s.db.Package(id)
	if err != nil {
		http.NotFound(w, r)
		return
	}
	today := domain.Today()
	warn := s.warnDays()
	q := strings.TrimSpace(r.URL.Query().Get("q"))
	list, _, err := s.db.ListCustomers(q, 300, 0, domain.Date(today), warn, false)
	if err != nil {
		http.Error(w, "读取客户失败", http.StatusInternalServerError)
		return
	}
	subscribed, err := s.db.SubscribedCustomerIDs(id)
	if err != nil {
		http.Error(w, "读取订阅失败", http.StatusInternalServerError)
		return
	}
	tags, _ := s.db.PackageTags()
	p := s.newPage(r, "套餐详情", "packages")
	p.D = &packageDetailData{Package: pkg, Customers: list, Subscribed: subscribed, Q: q, Tags: tags, Today: domain.Date(today)}
	s.render(w, r, "package_detail", p)
}

// handlePackageBatchSubscribe 给勾选的客户批量开通该套餐。
func (s *Server) handlePackageBatchSubscribe(w http.ResponseWriter, r *http.Request) {
	id := pathID(r)
	pkg, err := s.db.Package(id)
	if err != nil {
		http.NotFound(w, r)
		return
	}
	_ = r.ParseForm()
	back := "/packages/" + itoa(id)
	raw := r.PostForm["customer_ids"]
	if len(raw) == 0 {
		s.redirect(w, r, back, "没有选中任何客户")
		return
	}
	start := strings.TrimSpace(r.PostFormValue("start_date"))
	if start == "" {
		start = domain.Date(domain.Today())
	}
	if _, err := domain.ParseDate(start); err != nil {
		s.redirect(w, r, back, "开始日期格式不正确")
		return
	}
	end := strings.TrimSpace(r.PostFormValue("end_date"))
	days := s.formInt(r, "days", 0)
	count := s.formInt(r, "total_count", 0)
	u := s.currentUser(r)
	var op int64
	if u != nil {
		op = u.ID
	}

	done, skipped, failed := 0, 0, 0
	var lastErr string
	for _, v := range raw {
		cid, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64)
		if err != nil {
			failed++
			continue
		}
		_, err = s.db.CreateSub(store.CreateSubInput{
			CustomerID: cid, PackageID: id, StartDate: start, EndDate: end,
			Days: days, TotalCount: count, OperatorID: op,
		})
		if err != nil {
			if strings.Contains(err.Error(), "已订阅") {
				skipped++
				continue
			}
			failed++
			lastErr = err.Error()
			continue
		}
		done++
	}
	s.logOp(r, "批量开通", "package", id,
		fmt.Sprintf("%s：成功 %d、跳过 %d、失败 %d", pkg.Name, done, skipped, failed))
	msg := fmt.Sprintf("已为 %d 位客户开通「%s」", done, pkg.Name)
	if skipped > 0 {
		msg += fmt.Sprintf("，%d 位已有该套餐已跳过", skipped)
	}
	if failed > 0 {
		msg += fmt.Sprintf("，%d 位失败（%s）", failed, lastErr)
	}
	s.redirect(w, r, back, msg)
}

func (s *Server) handlePackageCreate(w http.ResponseWriter, r *http.Request) {
	pkg := readPackageForm(r)
	p := s.newPage(r, "新增套餐", "packages")
	if msg := validatePackage(pkg); msg != "" {
		tags, _ := s.db.PackageTags()
		p.D = &packageFormData{Package: pkg, IsNew: true, Tags: tags}
		s.fail(w, r, "package_form", msg, p)
		return
	}
	id, err := s.db.CreatePackage(pkg)
	if err != nil {
		tags, _ := s.db.PackageTags()
		p.D = &packageFormData{Package: pkg, IsNew: true, Tags: tags}
		s.fail(w, r, "package_form", "保存失败："+err.Error(), p)
		return
	}
	s.logOp(r, "新增套餐", "package", id, "新增套餐 "+pkg.Name)
	s.redirect(w, r, "/packages", "套餐已创建，现在可以给客户开通了")
}

func (s *Server) handlePackageEditPage(w http.ResponseWriter, r *http.Request) {
	id := pathID(r)
	pkg, err := s.db.Package(id)
	if err != nil {
		http.NotFound(w, r)
		return
	}
	p := s.newPage(r, "编辑套餐", "packages")
	tags, _ := s.db.PackageTags()
	p.D = &packageFormData{Package: pkg, IsNew: false, Tags: tags}
	s.render(w, r, "package_form", p)
}

func (s *Server) handlePackageUpdate(w http.ResponseWriter, r *http.Request) {
	id := pathID(r)
	pkg := readPackageForm(r)
	pkg.ID = id
	p := s.newPage(r, "编辑套餐", "packages")
	if msg := validatePackage(pkg); msg != "" {
		tags, _ := s.db.PackageTags()
		p.D = &packageFormData{Package: pkg, IsNew: false, Tags: tags}
		s.fail(w, r, "package_form", msg, p)
		return
	}
	if err := s.db.UpdatePackage(pkg); err != nil {
		tags, _ := s.db.PackageTags()
		p.D = &packageFormData{Package: pkg, IsNew: false, Tags: tags}
		s.fail(w, r, "package_form", "保存失败："+err.Error(), p)
		return
	}
	s.logOp(r, "编辑套餐", "package", id, "修改套餐 "+pkg.Name)
	s.redirect(w, r, "/packages", "套餐已保存")
}

func (s *Server) handlePackageArchive(w http.ResponseWriter, r *http.Request) {
	id := pathID(r)
	pkg, err := s.db.Package(id)
	if err != nil {
		http.NotFound(w, r)
		return
	}
	archived := !pkg.Archived
	if err := s.db.SetPackageArchived(id, archived); err != nil {
		s.redirect(w, r, "/packages", "操作失败："+err.Error())
		return
	}
	action := "归档套餐"
	msg := "套餐已归档，不再允许新订阅（已有订阅不受影响）"
	if !archived {
		action = "取消归档"
		msg = "套餐已恢复"
	}
	s.logOp(r, action, "package", id, action+" "+pkg.Name)
	s.redirect(w, r, "/packages", msg)
}