package controllers

import (
	"encoding/json"
	"io"
	"regexp"
	"strconv"
	"strings"
	"time"
	"unicode/utf8"

	"server/models"
	"server/pkg/jwtutil"

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

// BackendOaScheduleController OA日程管理（日历待办）。
// 日程数据按 JWT 中的租户与用户双重隔离，仅创建者本人可见与操作。
type BackendOaScheduleController struct {
	beego.Controller
}

func (c *BackendOaScheduleController) oaScheduleClaims() (*jwtutil.Claims, error) {
	auth := c.Ctx.Request.Header.Get("Authorization")
	if auth == "" {
		return nil, orm.ErrNoRows
	}
	parts := strings.SplitN(auth, " ", 2)
	if len(parts) != 2 || parts[0] != "Bearer" {
		return nil, orm.ErrNoRows
	}
	claims, err := jwtutil.ParseToken(parts[1])
	if err != nil {
		return nil, err
	}
	if claims.UserType != "backend" {
		return nil, orm.ErrNoRows
	}
	return claims, nil
}

func (c *BackendOaScheduleController) oasJsonErr(httpStatus, bizCode int, msg string) {
	c.Ctx.Output.SetStatus(httpStatus)
	c.Data["json"] = map[string]interface{}{"code": bizCode, "msg": msg}
	_ = c.ServeJSON()
}

func (c *BackendOaScheduleController) oasOk(data interface{}) {
	c.Data["json"] = map[string]interface{}{"code": 200, "msg": "success", "data": data}
	_ = c.ServeJSON()
}

var (
	oasDatePattern = regexp.MustCompile(`^\d{4}-\d{2}-\d{2}$`)
	oasTimePattern = regexp.MustCompile(`^\d{2}:\d{2}$`)
)

// isValidOaDate 校验 "YYYY-MM-DD" 日期字符串（含真实日历合法性，如 2 月 30 日）。
func isValidOaDate(s string) bool {
	if !oasDatePattern.MatchString(s) {
		return false
	}
	_, err := time.ParseInLocation("2006-01-02", s, time.Local)
	return err == nil
}

// isValidOaTime 校验 "HH:mm" 时间字符串；HH:mm 定长数字串的字典序即时间序。
func isValidOaTime(s string) bool {
	if !oasTimePattern.MatchString(s) {
		return false
	}
	_, err := time.ParseInLocation("15:04", s, time.Local)
	return err == nil
}

// normalizeOaDate 将 ORM 读出的日期值统一为 "YYYY-MM-DD"。
// DSN 开启 parseTime=True 后 DATE 列会被驱动解析为 time.Time，
// 赋给 string 字段后是 Go 默认格式（"2026-08-29 00:00:00 +0800 CST"），取前 10 位。
func normalizeOaDate(s string) string {
	s = strings.TrimSpace(s)
	if len(s) >= 10 {
		return s[:10]
	}
	return s
}

// List GET /backend/oa/schedule/list
// 分页查询当前用户的日程，支持 keyword/status/priority/start_date/end_date 筛选。
// 日历视图传 start_date/end_date 且 pageSize 足够大时一次拉取区间全量数据。
func (c *BackendOaScheduleController) List() {
	claims, err := c.oaScheduleClaims()
	if err != nil {
		c.oasJsonErr(401, 401, "未登录或无权限")
		return
	}

	page, _ := c.GetInt("page", 1)
	pageSize, _ := c.GetInt("pageSize", 20)
	keyword := strings.TrimSpace(c.GetString("keyword"))
	status := strings.TrimSpace(c.GetString("status"))
	priority := strings.TrimSpace(c.GetString("priority"))
	startDate := strings.TrimSpace(c.GetString("start_date"))
	endDate := strings.TrimSpace(c.GetString("end_date"))

	if page < 1 {
		page = 1
	}
	if pageSize < 1 || pageSize > 500 {
		pageSize = 20
	}

	qs := models.Orm.QueryTable(new(models.OaSchedule)).
		Filter("is_deleted", 0).
		Filter("tid", claims.TenantId).
		Filter("user_id", claims.UserID)

	if keyword != "" {
		qs = qs.Filter("title__icontains", keyword)
	}
	if status == "0" || status == "1" {
		statusVal, _ := strconv.Atoi(status)
		qs = qs.Filter("status", int8(statusVal))
	}
	if priority == "0" || priority == "1" || priority == "2" {
		priorityVal, _ := strconv.Atoi(priority)
		qs = qs.Filter("priority", int8(priorityVal))
	}
	if isValidOaDate(startDate) {
		qs = qs.Filter("schedule_date__gte", startDate)
	}
	if isValidOaDate(endDate) {
		qs = qs.Filter("schedule_date__lte", endDate)
	}

	total, _ := qs.Count()

	var list []models.OaSchedule
	_, err = qs.OrderBy("schedule_date", "start_time", "-id").
		Limit(pageSize).Offset((page - 1) * pageSize).
		All(&list)
	if err != nil && err != orm.ErrNoRows {
		c.oasJsonErr(500, 500, "查询失败")
		return
	}
	if list == nil {
		list = []models.OaSchedule{}
	}

	// 统一日期格式，前端日历分组与日期标签均依赖 "YYYY-MM-DD"。
	for i := range list {
		list[i].ScheduleDate = normalizeOaDate(list[i].ScheduleDate)
	}

	c.oasOk(map[string]interface{}{"list": list, "total": total})
}

// Stats GET /backend/oa/schedule/stats
// 返回今日/本周/本月的日程统计与逾期数，供页面顶部统计卡片展示。
func (c *BackendOaScheduleController) Stats() {
	claims, err := c.oaScheduleClaims()
	if err != nil {
		c.oasJsonErr(401, 401, "未登录或无权限")
		return
	}

	now := time.Now()
	today := now.Format("2006-01-02")
	// 本周从周一开始
	weekday := int(now.Weekday())
	if weekday == 0 {
		weekday = 7
	}
	weekStart := now.AddDate(0, 0, -(weekday - 1)).Format("2006-01-02")
	weekEnd := now.AddDate(0, 0, 7-weekday).Format("2006-01-02")
	monthStart := now.Format("2006-01") + "-01"

	base := func() orm.QuerySeter {
		return models.Orm.QueryTable(new(models.OaSchedule)).
			Filter("is_deleted", 0).
			Filter("tid", claims.TenantId).
			Filter("user_id", claims.UserID)
	}

	todayTotal, _ := base().Filter("schedule_date", today).Count()
	todayDone, _ := base().Filter("schedule_date", today).Filter("status", 1).Count()
	weekTotal, _ := base().Filter("schedule_date__gte", weekStart).Filter("schedule_date__lte", weekEnd).Count()
	monthTotal, _ := base().Filter("schedule_date__gte", monthStart).Count()
	monthDone, _ := base().Filter("schedule_date__gte", monthStart).Filter("status", 1).Count()
	overdue, _ := base().Filter("schedule_date__lt", today).Filter("status", 0).Count()

	c.oasOk(map[string]interface{}{
		"today_total": todayTotal,
		"today_done":  todayDone,
		"week_total":  weekTotal,
		"month_total": monthTotal,
		"month_done":  monthDone,
		"overdue":     overdue,
	})
}

type oaSchedulePayload struct {
	Title        string `json:"title"`
	Content      string `json:"content"`
	ScheduleDate string `json:"schedule_date"`
	StartTime    string `json:"start_time"`
	EndTime      string `json:"end_time"`
	AllDay       int8   `json:"all_day"`
	Color        string `json:"color"`
	Priority     int8   `json:"priority"`
}

// parseOaSchedulePayload 读取并校验新建/编辑日程的请求体；校验失败时直接输出错误响应。
func (c *BackendOaScheduleController) parseOaSchedulePayload() (oaSchedulePayload, bool) {
	var payload oaSchedulePayload
	raw, err := io.ReadAll(c.Ctx.Request.Body)
	if err != nil || json.Unmarshal(raw, &payload) != nil {
		c.oasJsonErr(400, 400, "参数错误")
		return payload, false
	}

	payload.Title = strings.TrimSpace(payload.Title)
	if payload.Title == "" {
		c.oasJsonErr(400, 400, "请输入日程标题")
		return payload, false
	}
	if utf8.RuneCountInString(payload.Title) > 80 {
		c.oasJsonErr(400, 400, "日程标题不能超过80字")
		return payload, false
	}
	if !isValidOaDate(payload.ScheduleDate) {
		c.oasJsonErr(400, 400, "日程日期无效")
		return payload, false
	}
	if payload.AllDay != 0 {
		payload.AllDay = 1
		payload.StartTime = ""
		payload.EndTime = ""
	} else {
		if !isValidOaTime(payload.StartTime) {
			c.oasJsonErr(400, 400, "开始时间无效")
			return payload, false
		}
		if payload.EndTime != "" {
			if !isValidOaTime(payload.EndTime) {
				c.oasJsonErr(400, 400, "结束时间无效")
				return payload, false
			}
			if payload.EndTime < payload.StartTime {
				c.oasJsonErr(400, 400, "结束时间不能早于开始时间")
				return payload, false
			}
		}
	}
	if payload.Priority < 0 || payload.Priority > 2 {
		payload.Priority = 0
	}
	payload.Color = strings.TrimSpace(payload.Color)
	if payload.Color == "" {
		payload.Color = "#409EFF"
	}
	return payload, true
}

// Create POST /backend/oa/schedule/create
func (c *BackendOaScheduleController) Create() {
	claims, err := c.oaScheduleClaims()
	if err != nil {
		c.oasJsonErr(401, 401, "未登录或无权限")
		return
	}

	payload, ok := c.parseOaSchedulePayload()
	if !ok {
		return
	}

	now := time.Now()
	item := &models.OaSchedule{
		Tid:          claims.TenantId,
		UserID:       uint64(claims.UserID),
		UserName:     claims.Username,
		Title:        payload.Title,
		Content:      payload.Content,
		ScheduleDate: payload.ScheduleDate,
		StartTime:    payload.StartTime,
		EndTime:      payload.EndTime,
		AllDay:       payload.AllDay,
		Color:        payload.Color,
		Priority:     payload.Priority,
		Status:       0,
		IsDeleted:    0,
		CreateTime:   now,
		UpdateTime:   &now,
	}
	if _, err := models.Orm.Insert(item); err != nil {
		c.oasJsonErr(500, 500, "保存失败")
		return
	}

	c.oasOk(item)
}

// Update POST /backend/oa/schedule/update/:id
func (c *BackendOaScheduleController) Update() {
	claims, err := c.oaScheduleClaims()
	if err != nil {
		c.oasJsonErr(401, 401, "未登录或无权限")
		return
	}

	id, err := strconv.ParseUint(c.Ctx.Input.Param(":id"), 10, 64)
	if err != nil || id == 0 {
		c.oasJsonErr(400, 400, "无效ID")
		return
	}

	payload, ok := c.parseOaSchedulePayload()
	if !ok {
		return
	}

	var item models.OaSchedule
	err = models.Orm.QueryTable(new(models.OaSchedule)).
		Filter("id", id).
		Filter("is_deleted", 0).
		Filter("tid", claims.TenantId).
		Filter("user_id", claims.UserID).
		One(&item)
	if err != nil {
		c.oasJsonErr(404, 404, "日程不存在")
		return
	}

	now := time.Now()
	item.Title = payload.Title
	item.Content = payload.Content
	item.ScheduleDate = payload.ScheduleDate
	item.StartTime = payload.StartTime
	item.EndTime = payload.EndTime
	item.AllDay = payload.AllDay
	item.Color = payload.Color
	item.Priority = payload.Priority
	item.UpdateTime = &now

	if _, err := models.Orm.Update(&item,
		"Title", "Content", "ScheduleDate", "StartTime", "EndTime",
		"AllDay", "Color", "Priority", "UpdateTime"); err != nil {
		c.oasJsonErr(500, 500, "保存失败")
		return
	}

	c.oasOk(item)
}

// Delete DELETE /backend/oa/schedule/delete/:id 软删除日程。
func (c *BackendOaScheduleController) Delete() {
	claims, err := c.oaScheduleClaims()
	if err != nil {
		c.oasJsonErr(401, 401, "未登录或无权限")
		return
	}

	id, err := strconv.ParseUint(c.Ctx.Input.Param(":id"), 10, 64)
	if err != nil || id == 0 {
		c.oasJsonErr(400, 400, "无效ID")
		return
	}

	now := time.Now()
	n, err := models.Orm.QueryTable(new(models.OaSchedule)).
		Filter("id", id).
		Filter("is_deleted", 0).
		Filter("tid", claims.TenantId).
		Filter("user_id", claims.UserID).
		Update(map[string]interface{}{
			"IsDeleted":  int8(1),
			"DeleteTime": now,
			"UpdateTime": now,
		})
	if err != nil || n == 0 {
		c.oasJsonErr(404, 404, "日程不存在或已删除")
		return
	}

	c.oasOk(nil)
}

// FinishSchedule POST /backend/oa/schedule/finish/:id
// 切换完成状态：待办 -> 完成（记录完成时间）；完成 -> 待办（清除完成时间）。
// 注意：方法名不能叫 Finish——Finish 是 beego Controller 的生命周期钩子，
// 同名会导致路由调用后再被框架自动调用一次，toggle 逻辑被执行两遍（状态来回切）。
func (c *BackendOaScheduleController) FinishSchedule() {
	claims, err := c.oaScheduleClaims()
	if err != nil {
		c.oasJsonErr(401, 401, "未登录或无权限")
		return
	}

	id, err := strconv.ParseUint(c.Ctx.Input.Param(":id"), 10, 64)
	if err != nil || id == 0 {
		c.oasJsonErr(400, 400, "无效ID")
		return
	}

	var item models.OaSchedule
	err = models.Orm.QueryTable(new(models.OaSchedule)).
		Filter("id", id).
		Filter("is_deleted", 0).
		Filter("tid", claims.TenantId).
		Filter("user_id", claims.UserID).
		One(&item)
	if err != nil {
		c.oasJsonErr(404, 404, "日程不存在")
		return
	}

	now := time.Now()
	newStatus := int8(1)
	var finishTime *time.Time
	if item.Status == 1 {
		newStatus = 0
	} else {
		finishTime = &now
	}

	item.Status = newStatus
	item.FinishTime = finishTime
	item.UpdateTime = &now

	if _, err := models.Orm.Update(&item, "Status", "FinishTime", "UpdateTime"); err != nil {
		c.oasJsonErr(500, 500, "操作失败")
		return
	}

	c.oasOk(map[string]interface{}{"status": newStatus})
}