package controllers

import (
	"sort"
	"time"

	"server/models"

	beego "github.com/beego/beego/v2/server/web"
)

// =============================================================
// CRM 招投标管理 - 到期提醒（开发计划 4.1）
// =============================================================
//
// 不新增表、不引入定时任务：所有提醒都是「按当前时间实时计算」的，
// 避免定时任务没跑导致状态陈旧。前端在招投标首页拉取近 N 天的待办。
//
// 覆盖四类到期：
//   1. 投标：报名截止 / 投标截止 / 开标时间
//   2. 招标：报名截止 / 投标截止 / 开标时间
//   3. 资质：证书到期
//
// GET /backend/crm/bidding/reminders?days=7
// =============================================================

// BackendCrmBiddingReminderController 招投标到期提醒
type BackendCrmBiddingReminderController struct {
	beego.Controller
}

// biddingReminderItem 一条到期提醒
type biddingReminderItem struct {
	BizType    string `json:"biz_type"`    // bid | tender | qualification
	BizID      uint64 `json:"biz_id"`      // 业务记录ID
	Kind       string `json:"kind"`        // register_end | bid_end | open_bid | expire
	KindName   string `json:"kind_name"`   // 提醒类型名称
	Title      string `json:"title"`       // 记录标题
	DueDate    string `json:"due_date"`    // 到期时间 yyyy-MM-dd HH:mm:ss
	RemainDays int    `json:"remain_days"` // 剩余天数，负值表示已逾期
	Level      string `json:"level"`       // danger(<=1天/已逾期) | warning(<=3天) | info
	OwnerName  string `json:"owner_user_name"`
}

// List GET /backend/crm/bidding/reminders?days=7
func (c *BackendCrmBiddingReminderController) List() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	tid := pipelineTenantID(claims)

	days, _ := c.GetInt("days", 7)
	if days <= 0 || days > 365 {
		days = 7
	}
	now := time.Now()
	deadline := now.AddDate(0, 0, days)

	items := make([]biddingReminderItem, 0, 32)

	// ---------- 投标侧 ----------
	var bids []models.TenantCrmBiddingBid
	_, _ = models.Orm.QueryTable(new(models.TenantCrmBiddingBid)).
		Filter("tenant_id", tid).
		Filter("delete_time__isnull", true).
		Filter("status__in", 0, 1, 2, 3).
		All(&bids)
	for _, b := range bids {
		if !canAccessCrmRecord(claims, b.OwnerUserID, b.CreateUserID) {
			continue
		}
		items = append(items, pickBidReminders(b, now, deadline)...)
	}

	// ---------- 招标侧 ----------
	var tenders []models.TenantCrmBiddingTender
	_, _ = models.Orm.QueryTable(new(models.TenantCrmBiddingTender)).
		Filter("tenant_id", tid).
		Filter("delete_time__isnull", true).
		Filter("status__in", 0, 1, 2, 3, 4, 5).
		All(&tenders)
	for _, t := range tenders {
		if !canAccessCrmRecord(claims, t.OwnerUserID, t.CreateUserID) {
			continue
		}
		items = append(items, pickTenderReminders(t, now, deadline)...)
	}

	// ---------- 资质到期 ----------
	var quals []models.TenantCrmBiddingBidQualification
	_, _ = models.Orm.QueryTable(new(models.TenantCrmBiddingBidQualification)).
		Filter("tenant_id", tid).
		Filter("delete_time__isnull", true).
		All(&quals)
	for _, q := range quals {
		if q.ExpireDate == nil {
			continue
		}
		due := *q.ExpireDate
		// 资质到期包含「已过期」，便于用户发现失效证书
		if due.After(deadline) {
			continue
		}
		items = append(items, biddingReminderItem{
			BizType:    "qualification",
			BizID:      q.ID,
			Kind:       "expire",
			KindName:   "资质到期",
			Title:      q.QualificationName,
			DueDate:    due.Format("2006-01-02"),
			RemainDays: daysBetween(now, due),
			Level:      levelOf(daysBetween(now, due)),
			OwnerName:  q.OwnerUserName,
		})
	}

	// 按到期时间升序：最紧急的排在最前
	sort.SliceStable(items, func(i, j int) bool {
		if items[i].RemainDays != items[j].RemainDays {
			return items[i].RemainDays < items[j].RemainDays
		}
		return items[i].DueDate < items[j].DueDate
	})

	pipelineOk(&c.Controller, map[string]interface{}{
		"list":  items,
		"total": len(items),
		"days":  days,
	})
}

// pickBidReminders 从一条投标记录中挑出落在窗口内的到期项
func pickBidReminders(b models.TenantCrmBiddingBid, now, deadline time.Time) []biddingReminderItem {
	out := make([]biddingReminderItem, 0, 3)
	add := func(kind, kindName string, due *time.Time) {
		if due == nil {
			return
		}
		d := *due
		if d.Before(now) || d.After(deadline) {
			return
		}
		out = append(out, biddingReminderItem{
			BizType:    "bid",
			BizID:      b.ID,
			Kind:       kind,
			KindName:   kindName,
			Title:      b.Title,
			DueDate:    d.Format("2006-01-02 15:04:05"),
			RemainDays: daysBetween(now, d),
			Level:      levelOf(daysBetween(now, d)),
			OwnerName:  b.OwnerUserName,
		})
	}
	add("register_end", "报名截止", b.RegisterEndDate)
	add("bid_end", "投标截止", b.BidEndDate)
	add("open_bid", "开标时间", b.OpenBidDate)
	return out
}

// pickTenderReminders 从一条招标记录中挑出落在窗口内的到期项
func pickTenderReminders(t models.TenantCrmBiddingTender, now, deadline time.Time) []biddingReminderItem {
	out := make([]biddingReminderItem, 0, 3)
	add := func(kind, kindName string, due *time.Time) {
		if due == nil {
			return
		}
		d := *due
		if d.Before(now) || d.After(deadline) {
			return
		}
		out = append(out, biddingReminderItem{
			BizType:    "tender",
			BizID:      t.ID,
			Kind:       kind,
			KindName:   kindName,
			Title:      t.Title,
			DueDate:    d.Format("2006-01-02 15:04:05"),
			RemainDays: daysBetween(now, d),
			Level:      levelOf(daysBetween(now, d)),
			OwnerName:  t.OwnerUserName,
		})
	}
	add("register_end", "报名截止", t.RegisterEndDate)
	add("bid_end", "投标截止", t.BidEndDate)
	add("open_bid", "开标时间", t.OpenBidDate)
	return out
}

// daysBetween 计算今天(0点)到目标时间的剩余天数
func daysBetween(now, target time.Time) int {
	n := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
	t := time.Date(target.Year(), target.Month(), target.Day(), 0, 0, 0, 0, target.Location())
	return int(t.Sub(n).Hours() / 24)
}

// levelOf 剩余天数 -> 提醒等级
func levelOf(days int) string {
	if days <= 1 {
		return "danger"
	}
	if days <= 3 {
		return "warning"
	}
	return "info"
}