// Package handler 按模块实现全部 action，与 backend/api/index.php 一一对应。
package handler

import (
	"bytes"
	"encoding/json"
	"fmt"
	"math/rand"
	"strings"
	"time"
	"unicode/utf16"
	"unicode/utf8"

	"past/internal/httpapi"
	"past/internal/store"
	"past/internal/upload"
)

type M = httpapi.M

// deps 注入的依赖（上传器等）
var up *upload.Uploader

// Register 注册全部 action
func Register(r *httpapi.Router, uploader *upload.Uploader) {
	up = uploader
	r.SetFileStorage(uploader)
	registerUser(r)
	registerCouple(r)
	registerTimeline(r)
	registerAlbum(r)
	registerDiary(r)
	registerSongs(r)
	registerCheckin(r)
	registerPeriod(r)
	registerBg(r)
	registerSite(r)
	registerActivity(r)
	registerSubscribe(r)
	registerPet(r)
	registerAdmin(r)
	registerStorage(r)
	r.Handle("announcement", announcement)
	r.Handle("admin_announcement", adminAnnouncement)
	r.Handle("account_deletion_preview", accountDeletionPreview)
	r.Handle("account_delete", accountDelete)
}

func now() string { return time.Now().Format("2006-01-02 15:04:05") }

// needLoginRecord 对应“从未登录过，或距上次登录超过 5 分钟”
func needLoginRecord(lastLoginAt string) bool {
	if lastLoginAt == "" {
		return true
	}
	t, err := time.ParseInLocation("2006-01-02 15:04:05", lastLoginAt, time.Local)
	return err != nil || time.Since(t) > 300*time.Second
}
func today() string        { return time.Now().Format("2006-01-02") }
func daysAgo(n int) string { return time.Now().AddDate(0, 0, -n).Format("2006-01-02") }

// startOfToday 返回今天 00:00（本地时区）。姨姨每日标记只写「已确认」的日期，
// 未来日期尚未确认经期量，不预先标记为有经期，避免把预估结束日误判为实际经期。
func startOfToday() time.Time {
	now := time.Now()
	return time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
}

// rows 保证列表非 nil（JSON 输出 [] 而非 null）
func rows(r []store.Row) []store.Row {
	if r == nil {
		return []store.Row{}
	}
	return r
}

// generateUserId 对应 generateUserId($db)：520 开头顺序递增，记录在 settings.last_user_id
// generateUserId uses a PostgreSQL sequence; simultaneous registrations cannot collide.
func generateUserId(db store.Querier) (string, error) {
	row, err := db.QueryOne("SELECT nextval('past_user_display_id') AS display_id")
	if err != nil {
		return "", err
	}
	if row == nil {
		return "", fmt.Errorf("用户编号生成失败")
	}
	return row.Str("display_id"), nil
}

// generateCoupleSpaceId 对应 'CP' . str_pad($coupleId, 6, '0', STR_PAD_LEFT)
func generateCoupleSpaceId(coupleID string) string {
	return "CP" + strings.ReplaceAll(coupleID, "-", "")
}

// logActivity 对应 logActivity()，返回 activity id
func logActivity(db store.Querier, coupleID, userID string, actionType, description, detail string) string {
	if coupleID == "" {
		return ""
	}
	id, _ := db.Insert("INSERT INTO activity_log (couple_id, user_id, action_type, description, detail, created_at) VALUES (?, ?, ?, ?, ?, NOW())",
		coupleID, userID, actionType, description, detail)
	return id
}

// coupleUserIds 对应 getCoupleUserIds($coupleId)：返回 [user1_id, user2_id]，无则空
func coupleUserIds(c *httpapi.Ctx, coupleID string) []string {
	if coupleID == "" {
		coupleID = c.CoupleID()
		if coupleID == "" {
			return nil
		}
	}
	row, _ := c.DB.QueryOne("SELECT user1_id, user2_id FROM couples WHERE id = ?", coupleID)
	if row == nil {
		return nil
	}
	return []string{row.Str("user1_id"), row.Str("user2_id")}
}

// partnerUserId 对应 getPartnerUserId($userId)；无则 0
func partnerUserId(db store.Querier, userID string) string {
	u, _ := db.QueryOne("SELECT couple_id FROM users WHERE id = ?", userID)
	if u == nil || u.Str("couple_id") == "" {
		return ""
	}
	cp, _ := db.QueryOne("SELECT user1_id, user2_id FROM couples WHERE id = ?", u.Str("couple_id"))
	if cp == nil {
		return ""
	}
	if cp.Str("user1_id") == userID {
		return cp.Str("user2_id")
	}
	return cp.Str("user1_id")
}

// userOpenId 对应 getUserOpenId($uid)
func userOpenId(db store.Querier, uid string) string {
	if uid == "" {
		return ""
	}
	row, _ := db.QueryOne("SELECT openid FROM users WHERE id = ?", uid)
	if row == nil {
		return ""
	}
	return row.Str("openid")
}

// executeUnbind 对应 executeUnbind($db, $cid)：删除全部情侣数据与文件，仅保留用户资料
func executeUnbind(db store.Querier, cid string) {
	db.Exec("DELETE FROM timeline WHERE couple_id = ?", cid)
	db.Exec("DELETE FROM diaries WHERE couple_id = ?", cid)
	db.Exec("DELETE FROM songs WHERE couple_id = ?", cid)
	db.Exec("DELETE FROM checkin_logs WHERE couple_id = ?", cid)
	db.Exec("DELETE FROM checkins WHERE couple_id = ?", cid)
	albums, _ := db.Query("SELECT id FROM albums WHERE couple_id = ?", cid)
	for _, a := range albums {
		db.Exec("DELETE FROM photos WHERE album_id = ?", a.Str("id"))
	}
	db.Exec("DELETE FROM albums WHERE couple_id = ?", cid)
	db.Exec("DELETE FROM activity_log WHERE couple_id = ?", cid)
	users, _ := db.Query("SELECT id FROM users WHERE couple_id = ?", cid)
	if len(users) > 0 {
		ids := make([]any, 0, len(users))
		for _, u := range users {
			ids = append(ids, u.Str("id"))
		}
		ph := placeholders(len(ids))
		args := append(append([]any{}, ids...), ids...)
		db.Exec("DELETE FROM invitations WHERE from_user_id IN ("+ph+") OR to_user_id IN ("+ph+")", args...)
		db.Exec("DELETE FROM invite_links WHERE user_id IN ("+ph+")", ids...)
	}
	db.Exec("DELETE FROM unbind_requests WHERE couple_id = ?", cid)
	db.Exec("UPDATE users SET couple_id = NULL, updated_at = CURRENT_TIMESTAMP WHERE couple_id = ?", cid)
	db.Exec("DELETE FROM couples WHERE id = ?", cid)
}

// createDefaultAlbums 对应 createDefaultAlbums()
func createDefaultAlbums(db store.Querier, coupleID, userID string) {
	defaults := [][2]string{
		{"日常甜蜜", "我们的小日常"},
		{"旅行记录", "一起走过的风景"},
		{"美食打卡", "一起吃的每一顿饭"},
		{"生活碎片", "生活中的点点滴滴"},
		{"节日纪念", "特别的节日和纪念日"},
		{"自拍合照", "我们的精彩瞬间"},
	}
	for i, d := range defaults {
		db.Exec("INSERT INTO albums (couple_id, title, description, sort_order, created_by) VALUES (?, ?, ?, ?, ?)", coupleID, d[0], d[1], i, userID)
	}
}

func placeholders(n int) string {
	if n <= 0 {
		return ""
	}
	return strings.TrimSuffix(strings.Repeat("?,", n), ",")
}

// resolveLoginLocation 对应 resolveLoginLocation($input, $fallback)
func resolveLoginLocation(c *httpapi.Ctx, fallback string) string {
	raw := strings.TrimSpace(c.InStr("location"))
	if raw == "" {
		raw = strings.TrimSpace(fallback)
	}
	if raw == "" {
		return ""
	}
	if strings.Contains(raw, ",") {
		parts := strings.Split(raw, ",")
		if len(parts) == 2 && isNumeric(strings.TrimSpace(parts[0])) && isNumeric(strings.TrimSpace(parts[1])) {
			lat := store.ToFloat(strings.TrimSpace(parts[0]))
			lng := store.ToFloat(strings.TrimSpace(parts[1]))
			if addr := c.App.Geo.ReverseGeocode(lat, lng); addr != "" {
				return addr
			}
		}
	}
	return raw
}

// isNumeric 对应 PHP is_numeric
func isNumeric(s string) bool {
	if s == "" {
		return false
	}
	var f float64
	_, err := fmt.Sscanf(s, "%g", &f)
	if err != nil {
		return false
	}
	// Sscanf 允许前缀匹配，再严格检查字符集
	for _, ch := range s {
		if !(ch >= '0' && ch <= '9') && ch != '.' && ch != '-' && ch != '+' && ch != 'e' && ch != 'E' {
			return false
		}
	}
	return true
}

// demoData 对应 getDemoData($module)
func demoData(module string) []M {
	ts := now()
	switch module {
	case "timeline":
		return []M{
			{"id": -1, "title": "第一次相遇", "content": "还记得那天阳光正好，你穿着白色的衬衫，在图书馆的角落里安静地看书。", "event_date": daysAgo(30), "location": "图书馆", "images": []any{}, "icon": "❤️", "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -2, "title": "第一次约会", "content": "一起看了场电影，吃了顿美味的晚餐，聊了很多很多。", "event_date": daysAgo(25), "location": "电影院", "images": []any{}, "icon": "🎬", "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -3, "title": "一起做饭", "content": "第一次一起下厨，虽然把厨房弄得一团糟，但很开心。", "event_date": daysAgo(20), "location": "家", "images": []any{}, "icon": "🍳", "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -4, "title": "公园散步", "content": "傍晚在公园散步，夕阳很美，你更美。", "event_date": daysAgo(15), "location": "公园", "images": []any{}, "icon": "🌅", "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -5, "title": "纪念日", "content": "属于我们的特别日子，值得永远铭记。", "event_date": daysAgo(10), "location": "", "images": []any{}, "icon": "🎉", "sort_order": 0, "created_by": 0, "created_at": ts},
		}
	case "album":
		return []M{
			{"id": -1, "title": "甜蜜日常", "description": "记录我们的点点滴滴", "cover": "", "photo_count": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -2, "title": "旅行记忆", "description": "一起走过的风景", "cover": "", "photo_count": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -3, "title": "美食打卡", "description": "一起吃的每一顿饭", "cover": "", "photo_count": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -4, "title": "生活碎片", "description": "生活中的点点滴滴", "cover": "", "photo_count": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -5, "title": "我们的故事", "description": "从开始到现在", "cover": "", "photo_count": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
		}
	case "diary":
		return []M{
			{"id": -1, "title": "初识", "content": "今天在图书馆遇见了你，心跳加速的感觉真好。", "mood": "😊", "weather": "☀️", "diary_date": daysAgo(5), "images": []any{}, "created_by": 0, "created_at": ts},
			{"id": -2, "title": "美好的一天", "content": "和你在一起的时间总是过得太快，期待下次见面。", "mood": "🥰", "weather": "☀️", "diary_date": daysAgo(4), "images": []any{}, "created_by": 0, "created_at": ts},
			{"id": -3, "title": "小确幸", "content": "收到你的消息，一整天的心情都变好了。", "mood": "💕", "weather": "⛅", "diary_date": daysAgo(3), "images": []any{}, "created_by": 0, "created_at": ts},
			{"id": -4, "title": "想念", "content": "今天没有见到你，好想你呀。", "mood": "😔", "weather": "🌧️", "diary_date": daysAgo(2), "images": []any{}, "created_by": 0, "created_at": ts},
			{"id": -5, "title": "期待未来", "content": "想象和你一起的每一个明天，都是那么美好。", "mood": "💖", "weather": "☀️", "diary_date": daysAgo(1), "images": []any{}, "created_by": 0, "created_at": ts},
		}
	case "songs":
		return []M{
			{"id": -1, "song_name": "告白气球", "artist": "周杰伦", "note": "第一次约会时听的歌", "created_by": 0, "created_at": ts},
			{"id": -2, "song_name": "小情歌", "artist": "苏打绿", "note": "你最喜欢的一首歌", "created_by": 0, "created_at": ts},
			{"id": -3, "song_name": "想你的夜", "artist": "关喆", "note": "每次想你的时候都会听", "created_by": 0, "created_at": ts},
			{"id": -4, "song_name": "有点甜", "artist": "汪苏泷", "note": "我们的主题曲", "created_by": 0, "created_at": ts},
			{"id": -5, "song_name": "最美的期待", "artist": "周笔畅", "note": "对未来充满期待", "created_by": 0, "created_at": ts},
		}
	case "checkin":
		return []M{
			{"id": -1, "title": "每天说爱你", "icon": "❤️", "type": "both", "frequency": "daily", "is_completed": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -2, "title": "一起运动", "icon": "🏃", "type": "both", "frequency": "daily", "is_completed": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -3, "title": "早睡打卡", "icon": "🌙", "type": "both", "frequency": "daily", "is_completed": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -4, "title": "喝水提醒", "icon": "💧", "type": "both", "frequency": "daily", "is_completed": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
			{"id": -5, "title": "看书学习", "icon": "📚", "type": "both", "frequency": "daily", "is_completed": 0, "sort_order": 0, "created_by": 0, "created_at": ts},
		}
	}
	return []M{}
}

// inOr 对应 $input['key'] ?? $def（null 也视为未设置）
func inOr(c *httpapi.Ctx, key string, def any) any {
	if v := c.In(key); v != nil {
		return v
	}
	return def
}

// mbTruncate 对应 mb_strlen($s) > n ? mb_substr($s, 0, n) . '...' : $s
func mbTruncate(s string, n int) string {
	r := []rune(s)
	if len(r) > n {
		return string(r[:n]) + "..."
	}
	return s
}

// jsonEncode 对应 PHP json_encode($v) 默认标志（存库用）：转义 "/" 为 "\/"，非 ASCII 转 \uXXXX（含代理对），
// 使 Go 写入的 JSON 字段与 PHP 历史数据字节一致。
func jsonEncode(v any) string {
	if v == nil {
		return "null"
	}
	var buf bytes.Buffer
	enc := json.NewEncoder(&buf)
	enc.SetEscapeHTML(false)
	if err := enc.Encode(v); err != nil {
		return "null"
	}
	return phpEscapeJSON(strings.TrimRight(buf.String(), "\n"))
}

// phpEscapeJSON 把 Go 的 JSON 文本转换成 PHP json_encode 默认输出形式
func phpEscapeJSON(s string) string {
	var sb strings.Builder
	inStr := false
	for i := 0; i < len(s); {
		ch := s[i]
		if !inStr {
			if ch == '"' {
				inStr = true
			}
			sb.WriteByte(ch)
			i++
			continue
		}
		switch {
		case ch == '\\':
			// 已转义序列（Go 产生的 \uXXXX / \" / \\ / \n 等）原样保留
			if i+1 < len(s) {
				sb.WriteByte(ch)
				sb.WriteByte(s[i+1])
				i += 2
			} else {
				sb.WriteByte(ch)
				i++
			}
		case ch == '"':
			inStr = false
			sb.WriteByte(ch)
			i++
		case ch == '/':
			sb.WriteString("\\/")
			i++
		case ch >= 0x80:
			r, size := utf8.DecodeRuneInString(s[i:])
			if r >= 0x10000 {
				r1, r2 := utf16.EncodeRune(r)
				fmt.Fprintf(&sb, "\\u%04x\\u%04x", r1, r2)
			} else {
				fmt.Fprintf(&sb, "\\u%04x", r)
			}
			i += size
		default:
			sb.WriteByte(ch)
			i++
		}
	}
	return sb.String()
}

// jsonDecodeList 对应 json_decode($s, true) ?: []：解析失败或为空返回空数组
func jsonDecodeList(v any) any {
	s := store.ToStr(v)
	if s == "" {
		return []any{}
	}
	var out any
	if err := json.Unmarshal([]byte(s), &out); err != nil || out == nil {
		return []any{}
	}
	switch x := out.(type) {
	case []any:
		if len(x) == 0 {
			return []any{}
		}
	case map[string]any:
		if len(x) == 0 {
			return []any{}
		}
	case bool:
		if !x {
			return []any{}
		}
	case float64:
		if x == 0 {
			return []any{}
		}
	case string:
		if x == "" || x == "0" {
			return []any{}
		}
	}
	return out
}

// countRaw 对应 $stmt->fetch()['cnt'] 原样输出（未经 intval，PHP 8.0 下为字符串）
func countRaw(c *httpapi.Ctx, col, sql string, args ...any) any {
	r, _ := c.DB.QueryOne(sql, args...)
	if r == nil {
		return nil
	}
	return r[col]
}

// randInt 对应 random_int(min, max)
func randInt(min, max int) int { return min + rand.Intn(max-min+1) }

func nullableCoupleID(id string) any {
	if id == "" {
		return nil
	}
	return id
}