package storage

import (
	"context"
	"log/slog"
	"time"
)

func (r *MySQLRepository) StartCleanup(ctx context.Context, logger *slog.Logger) {
	if r.cfg.Dashboard.CleanupInterval <= 0 {
		return
	}
	go func() {
		r.cleanupOnce(ctx, logger)
		ticker := time.NewTicker(r.cfg.Dashboard.CleanupInterval)
		defer ticker.Stop()
		for {
			select {
			case <-ctx.Done():
				return
			case <-ticker.C:
				r.cleanupOnce(ctx, logger)
			}
		}
	}()
}

func (r *MySQLRepository) cleanupOnce(ctx context.Context, logger *slog.Logger) {
	rows, err := r.Cleanup(ctx)
	if err != nil {
		if r.metrics != nil {
			r.metrics.RecordError(err)
		}
		logger.Error("dashboard cleanup failed", "error", err)
		return
	}
	if r.metrics != nil {
		r.metrics.RecordCleanup(rows)
	}
	if rows > 0 {
		logger.Info("dashboard cleanup finished", "rows", rows)
	}
}

func (r *MySQLRepository) Cleanup(ctx context.Context) (int64, error) {
	var total int64
	if r.cfg.Dashboard.DedupRetention > 0 {
		cutoff := time.Now().Add(-r.cfg.Dashboard.DedupRetention)
		rows, err := r.deleteLimit(ctx, `
DELETE FROM dashboard_cdc_event_dedup
WHERE created_at < ?
LIMIT ?`, cutoff, r.cfg.Dashboard.CleanupBatchSize)
		if err != nil {
			return total, err
		}
		total += rows
	}

	if r.cfg.Dashboard.UserMetricDays > 0 {
		cutoffDate := time.Now().AddDate(0, 0, -r.cfg.Dashboard.UserMetricDays).Format("2006-01-02")
		deletes := []struct {
			sql  string
			args []interface{}
		}{
			{
				sql: `
DELETE FROM country_dashboard_daily_user_metric
WHERE stat_date < ?
LIMIT ?`,
				args: []interface{}{cutoffDate, r.cfg.Dashboard.CleanupBatchSize},
			},
			{
				sql: `
DELETE FROM country_dashboard_period_user_metric
WHERE period_type <> 'ALL'
  AND period_end_date IS NOT NULL
  AND period_end_date < ?
LIMIT ?`,
				args: []interface{}{cutoffDate, r.cfg.Dashboard.CleanupBatchSize},
			},
			{
				sql: `
DELETE FROM country_dashboard_game_period_user_metric
WHERE period_type <> 'ALL'
  AND period_end_date IS NOT NULL
  AND period_end_date < ?
LIMIT ?`,
				args: []interface{}{cutoffDate, r.cfg.Dashboard.CleanupBatchSize},
			},
			{
				sql: `
DELETE FROM country_dashboard_recharge_detail
WHERE create_time < ?
LIMIT ?`,
				args: []interface{}{cutoffDate, r.cfg.Dashboard.CleanupBatchSize},
			},
		}
		for _, item := range deletes {
			rows, err := r.execRows(ctx, item.sql, item.args...)
			if err != nil {
				return total, err
			}
			total += rows
		}
	}
	return total, nil
}

func (r *MySQLRepository) deleteLimit(ctx context.Context, query string, args ...interface{}) (int64, error) {
	return r.execRows(ctx, query, args...)
}

func (r *MySQLRepository) execRows(ctx context.Context, query string, args ...interface{}) (int64, error) {
	result, err := r.db.ExecContext(ctx, query, args...)
	if err != nil {
		return 0, err
	}
	return result.RowsAffected()
}