package weekstar

import (
	"fmt"
	"sort"
	"strconv"
	"strings"
	"time"

	"chatapp3-golang/internal/model"
)

// buildGiftPayloads 把礼物配置表转换成对外载体。
func buildGiftPayloads(rows []model.WeekStarActivityGiftConfig) []WeekStarGiftConfigPayload {
	sort.Slice(rows, func(i, j int) bool {
		return rows[i].Sort < rows[j].Sort
	})
	result := make([]WeekStarGiftConfigPayload, 0, len(rows))
	for _, row := range rows {
		result = append(result, WeekStarGiftConfigPayload{
			GiftID:    row.GiftID,
			GiftName:  row.GiftName,
			GiftPhoto: row.GiftPhoto,
			GiftCandy: row.GiftCandy,
			Sort:      row.Sort,
		})
	}
	return result
}

// calculateGiftScore 按活动口径计算一笔送礼的金币积分。
func calculateGiftScore(event weekStarGiftEvent) int64 {
	if actual := int64(event.GiftValue.ActualAmount); actual > 0 {
		return actual
	}
	acceptUserSize := int64(countDistinctAcceptUsers(event.Accepts))
	if acceptUserSize <= 0 {
		acceptUserSize = 1
	}
	quantity := int64(event.Quantity)
	if quantity <= 0 {
		quantity = 1
	}
	giftCandy := int64(event.GiftConfig.GiftCandy)
	if giftCandy <= 0 {
		return 0
	}
	return giftCandy * quantity * acceptUserSize
}

// countDistinctAcceptUsers 统计不同收礼用户数。
func countDistinctAcceptUsers(users []weekStarGiftEventUser) int {
	if len(users) == 0 {
		return 0
	}
	set := make(map[int64]struct{}, len(users))
	for _, user := range users {
		if int64(user.AcceptUserID) <= 0 {
			continue
		}
		set[int64(user.AcceptUserID)] = struct{}{}
	}
	return len(set)
}

// containsGiftID 判断礼物是否命中活动指定礼物列表。
func containsGiftID(rows []model.WeekStarActivityGiftConfig, giftID int64) bool {
	for _, row := range rows {
		if row.GiftID == giftID {
			return true
		}
	}
	return false
}

// parseRedisMemberInt64 把 Redis member 统一解析为用户 ID。
func parseRedisMemberInt64(member any) (int64, bool) {
	switch value := member.(type) {
	case string:
		parsed, err := strconv.ParseInt(strings.TrimSpace(value), 10, 64)
		return parsed, err == nil
	case []byte:
		parsed, err := strconv.ParseInt(strings.TrimSpace(string(value)), 10, 64)
		return parsed, err == nil
	case int64:
		return value, true
	case int:
		return int64(value), true
	default:
		return 0, false
	}
}

// parseDateTimeInLocation 按指定时区解析后台传入的时间字符串。
func parseDateTimeInLocation(value string, location *time.Location) (time.Time, error) {
	value = strings.TrimSpace(value)
	if value == "" {
		return time.Time{}, fmt.Errorf("time is required")
	}
	layouts := []string{
		"2006-01-02 15:04:05",
		"2006-01-02T15:04:05",
		time.RFC3339,
		"2006-01-02",
	}
	for _, layout := range layouts {
		if layout == time.RFC3339 {
			if parsed, err := time.Parse(layout, value); err == nil {
				return parsed.In(location), nil
			}
			continue
		}
		if parsed, err := time.ParseInLocation(layout, value, location); err == nil {
			return parsed, nil
		}
	}
	return time.Time{}, fmt.Errorf("unsupported time format: %s", value)
}

// resolveMillisTime 把毫秒时间戳解析为时间，失败时回退默认值。
func resolveMillisTime(raw int64, fallback time.Time) time.Time {
	if raw <= 0 {
		return fallback
	}
	if raw < 1_000_000_000_000 {
		return time.Unix(raw, 0)
	}
	return time.UnixMilli(raw)
}

// normalizePage 规范分页参数，避免非法页码或 pageSize。
func normalizePage(cursor, limit int) (int, int) {
	if cursor <= 0 {
		cursor = 1
	}
	if limit <= 0 {
		limit = 20
	}
	if limit > 100 {
		limit = 100
	}
	return cursor, limit
}

// formatDateTime 把时间格式化成统一展示字符串。
func formatDateTime(t time.Time) string {
	if t.IsZero() {
		return ""
	}
	return t.Format("2006-01-02 15:04:05")
}

// formatPeriodText 把周期起止时间格式化成页面展示文案。
func formatPeriodText(start, end time.Time) string {
	if start.IsZero() || end.IsZero() || !end.After(start) {
		return ""
	}
	return start.Format("2006/01/02") + "-" + end.Format("2006/01/02")
}

// truncateString 截断字符串，避免超出字段长度限制。
func truncateString(value string, limit int) string {
	if limit <= 0 || len(value) <= limit {
		return value
	}
	return value[:limit]
}

// maxTime 返回两个时间中的较大值。
func maxTime(left, right time.Time) time.Time {
	if left.After(right) {
		return left
	}
	return right
}

// minTime 返回两个时间中的较小值。
func minTime(left, right time.Time) time.Time {
	if left.Before(right) {
		return left
	}
	return right
}

// maxInt64 返回两个整数中的较大值。
func maxInt64(left, right int64) int64 {
	if left > right {
		return left
	}
	return right
}

// isDuplicateKeyErr 判断是否是数据库唯一键冲突错误。
func isDuplicateKeyErr(err error) bool {
	if err == nil {
		return false
	}
	message := strings.ToLower(err.Error())
	return strings.Contains(message, "duplicate entry") || strings.Contains(message, "duplicate key")
}

// toWeekStarRewardRecordView 把发奖记录模型转换成后台展示对象。
func toWeekStarRewardRecordView(row model.WeekStarRewardRecord) WeekStarRewardRecordView {
	return WeekStarRewardRecordView{
		ID:              row.ID,
		ConfigID:        row.ConfigID,
		CycleKey:        row.CycleKey,
		UserID:          row.UserID,
		UserAvatar:      row.UserAvatar,
		UserNickname:    row.UserNickname,
		Account:         row.Account,
		CountryCode:     row.CountryCode,
		CountryName:     row.CountryName,
		Rank:            row.Rank,
		RewardGroupID:   row.RewardGroupID,
		RewardGroupName: row.RewardGroupName,
		ScoreGold:       row.ScoreGold,
		Status:          row.Status,
		RetryCount:      row.RetryCount,
		LastError:       row.LastError,
		SentAt:          formatDateTime(pointerTimeValue(row.SentAt)),
		UpdateTime:      formatDateTime(row.UpdateTime),
	}
}

// pointerTimeValue 把可空时间指针转换成非空时间值。
func pointerTimeValue(value *time.Time) time.Time {
	if value == nil {
		return time.Time{}
	}
	return *value
}