package web

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

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

// portalDay 自助查询月历中的一天。
type portalDay struct {
	Date    string
	Day     int
	InMonth bool
	Today   bool
	Total   int
	Done    int
}

// portalSub 自助查询里展示的订阅（隐藏备注、打手、价格）。
type portalSub struct {
	Name      string
	UnitLabel string
	Status    string
	Period    string
	TodayDone bool
}

// portalAsk 同一尾号命中多个客户时要求补姓名。
type portalAsk struct {
	Count int
	Names []string
}

// portalView 查询结果。
type portalView struct {
	Tail       string
	Name       string
	Game       string
	Subs       []portalSub
	Weeks      [][]portalDay
	MonthTitle string
	Prev       string
	Next       string
	TodayTotal int
	TodayDone  int
	AllDone    bool
	ActiveSubs int
	Expiring   string
	TodayPct   int
	Count      int
	Names      []string
}

// handleCustomerPortal 客户自助查询页（公开，无入口链接）。
func (s *Server) handleCustomerPortal(w http.ResponseWriter, r *http.Request) {
	p := s.newPage(r, "排单查询", "")
	q := r.URL.Query()
	tail := strings.TrimSpace(q.Get("tail"))
	name := strings.TrimSpace(q.Get("name"))
	month := strings.TrimSpace(q.Get("cm"))
	p.Query = tail
	if tail == "" {
		s.render(w, r, "portal", p)
		return
	}

	list, err := s.db.CustomersByTail(tail)
	if err != nil {
		p.Error = "读取客户失败，请稍后再试"
		s.render(w, r, "portal", p)
		return
	}
	list = filterActive(list)
	if len(list) == 0 {
		p.Error = "没有找到这个尾号的客户，请核对尾号"
		s.render(w, r, "portal", p)
		return
	}
	if len(list) > 1 {
		if name == "" {
			names := make([]string, 0, len(list))
			for _, c := range list {
				names = append(names, c.Name)
			}
			p.D = &portalAsk{Count: len(list), Names: names}
			s.render(w, r, "portal", p)
			return
		}
		matched := matchByName(list, name)
		if len(matched) == 0 {
			p.Error = "尾号对得上，但姓名不匹配，请再确认一下"
			s.render(w, r, "portal", p)
			return
		}
		if len(matched) > 1 {
			names := make([]string, 0, len(matched))
			for _, c := range matched {
				names = append(names, c.Name)
			}
			p.D = &portalAsk{Count: len(matched), Names: names}
			s.render(w, r, "portal", p)
			return
		}
		list = matched
	}

	c := list[0]
	p.D = s.buildPortal(c, tail, name, month)
	s.render(w, r, "portal", p)
}

func filterActive(list []store.Customer) []store.Customer {
	out := list[:0]
	for _, c := range list {
		if !c.Archived {
			out = append(out, c)
		}
	}
	return out
}

func matchByName(list []store.Customer, name string) []store.Customer {
	needle := strings.ToLower(strings.TrimSpace(name))
	out := make([]store.Customer, 0, len(list))
	for _, c := range list {
		if strings.Contains(strings.ToLower(c.Name), needle) {
			out = append(out, c)
		}
	}
	return out
}

// buildPortal 组装某位客户的排单视图。
func (s *Server) buildPortal(c store.Customer, tail, name, month string) *portalView {
	today := domain.Today()
	todayStr := domain.Date(today)
	first := time.Date(today.Year(), today.Month(), 1, 0, 0, 0, 0, time.UTC)
	if month != "" {
		if t, err := time.Parse("2006-01", month); err == nil {
			first = t
		}
	}
	year, mon := first.Year(), int(first.Month())
	firstDay := time.Date(year, time.Month(mon), 1, 0, 0, 0, 0, time.UTC)
	lastDay := firstDay.AddDate(0, 1, -1)
	start := firstDay.AddDate(0, 0, -((int(firstDay.Weekday()) + 6) % 7))
	end := lastDay.AddDate(0, 0, 6-((int(lastDay.Weekday())+6)%7))

	subs, _ := s.db.SubsByCustomer(c.ID)
	active := make([]store.Subscription, 0, len(subs))
	for _, sub := range subs {
		if sub.Status != domain.StatusClosed {
			active = append(active, sub)
		}
	}

	cov := func(sub store.Subscription, date string) bool {
		if date < sub.StartDate {
			return false
		}
		if sub.EndDate == "" {
			return true
		}
		return date <= sub.EndDate
	}

	// 打卡记录
	cks, _ := s.db.CheckinsBetween(domain.Date(start), domain.Date(end))

	v := &portalView{Tail: c.Tail, Name: c.Name, Game: c.GameName, ActiveSubs: len(active)}
	v.MonthTitle = fmt.Sprintf("%d 年 %d 月", year, mon)
	q := "?tail=" + tail
	if name != "" {
		q += "&name=" + name
	}
	v.Prev = q + "&cm=" + firstDay.AddDate(0, -1, 0).Format("2006-01")
	v.Next = q + "&cm=" + firstDay.AddDate(0, 1, 0).Format("2006-01")

	for _, sub := range active {
		label := "按日"
		if sub.Season {
			label = "包赛季"
		} else if sub.Unit == domain.UnitCount {
			label = "按次"
		}
		period := sub.StartDate
		if sub.EndDate != "" {
			period += " → " + sub.EndDate
		} else {
			period += " 起 · 无有效期"
		}
		ps := portalSub{Name: sub.PackageName, UnitLabel: label, Status: sub.Status, Period: period}
		if m, ok := cks[sub.ID]; ok {
			if ck, ok2 := m[todayStr]; ok2 && ck.Status == "done" {
				ps.TodayDone = true
			}
		}
		v.Subs = append(v.Subs, ps)
		if sub.EndDate != "" && (v.Expiring == "" || sub.EndDate < v.Expiring) {
			v.Expiring = sub.EndDate
		}
	}

	// 月历
	days := int(end.Sub(start).Hours()/24) + 1
	week := make([]portalDay, 0, 7)
	for i := 0; i < days; i++ {
		d := start.AddDate(0, 0, i)
		ds := domain.Date(d)
		pd := portalDay{Date: ds, Day: d.Day(), InMonth: d.Month() == time.Month(mon), Today: ds == todayStr}
		for _, sub := range active {
			if !cov(sub, ds) {
				continue
			}
			pd.Total++
			if m, ok := cks[sub.ID]; ok {
				if ck, ok2 := m[ds]; ok2 && ck.Status == "done" {
					pd.Done++
				}
			}
		}
		if pd.Today {
			v.TodayTotal, v.TodayDone = pd.Total, pd.Done
		}
		week = append(week, pd)
		if len(week) == 7 {
			v.Weeks = append(v.Weeks, week)
			week = make([]portalDay, 0, 7)
		}
	}
	if len(week) > 0 {
		v.Weeks = append(v.Weeks, week)
	}
	v.AllDone = v.TodayTotal > 0 && v.TodayDone >= v.TodayTotal
	if v.TodayTotal > 0 {
		v.TodayPct = v.TodayDone * 100 / v.TodayTotal
	}
	return v
}