package repository

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"strings"

	"github.com/topfans/backend/services/statisticService/model"
)

// EventRepository events 表操作
type EventRepository struct {
	db     *sql.DB
	schema string
}

// NewEventRepository 构造 EventRepository
func NewEventRepository(db *sql.DB, schema string) *EventRepository {
	return &EventRepository{db: db, schema: schema}
}

// InsertBatch 批量插入事件，event_id 重复时 ON CONFLICT DO NOTHING
// 返回实际插入的行数
func (r *EventRepository) InsertBatch(ctx context.Context, events []*model.Event) (int, error) {
	if len(events) == 0 {
		return 0, nil
	}

	placeholders := make([]string, 0, len(events))
	args := make([]interface{}, 0, len(events)*7)
	for _, e := range events {
		props := e.Properties
		if props == nil {
			props = map[string]string{}
		}
		propsJSON, _ := json.Marshal(props)

		placeholders = append(placeholders, fmt.Sprintf("($%d, $%d, $%d, $%d, $%d, $%d, $%d)",
			len(args)+1, len(args)+2, len(args)+3, len(args)+4, len(args)+5, len(args)+6, len(args)+7))
		args = append(args, e.EventID, e.UserID, e.StarID, e.EventType, e.OccurredAt, e.ReceivedAt, string(propsJSON))
	}

	query := fmt.Sprintf(`
		INSERT INTO %s.events (event_id, user_id, star_id, event_type, occurred_at, received_at, properties)
		VALUES %s
		ON CONFLICT (event_id, received_at) DO NOTHING
	`, r.schema, strings.Join(placeholders, ","))

	res, err := r.db.ExecContext(ctx, query, args...)
	if err != nil {
		return 0, fmt.Errorf("insert events: %w", err)
	}
	n, err := res.RowsAffected()
	if err != nil {
		return 0, fmt.Errorf("rows affected: %w", err)
	}
	return int(n), nil
}