package database

import (
	"base-go-v2/internal/config"
	"database/sql"
	"fmt"
	"time"

	_ "github.com/lib/pq"
)

var DB *sql.DB

var defaultPoolConfig = struct {
	MaxOpenConns    int
	MaxIdleConns    int
	ConnMaxLifetime time.Duration
}{
	MaxOpenConns:    10,
	MaxIdleConns:    5,
	ConnMaxLifetime: 30 * time.Minute,
}

func InitDb() error {
	d := config.Db

	// 构造 DSN
	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
		d.Host, d.Port, d.User, d.Password, d.Dbname)

	db, err := sql.Open("postgres", dsn)
	if err != nil {
		return fmt.Errorf("打开数据库失败: %w", err)
	}

	// 设置连接池（使用默认值，如果用户没传）
	maxOpenConns := d.MaxOpenConns
	if maxOpenConns == 0 {
		maxOpenConns = defaultPoolConfig.MaxOpenConns
	}
	db.SetMaxOpenConns(maxOpenConns)

	maxIdleConns := d.MaxIdleConns
	if maxIdleConns == 0 {
		maxIdleConns = defaultPoolConfig.MaxIdleConns
	}
	db.SetMaxIdleConns(maxIdleConns)

	connMaxLifetime := d.ConnMaxLifetime
	if connMaxLifetime == 0 {
		connMaxLifetime = defaultPoolConfig.ConnMaxLifetime
	}
	db.SetConnMaxLifetime(connMaxLifetime)

	// 测试连接
	if err := db.Ping(); err != nil {
		return fmt.Errorf("数据库连接测试失败: %w", err)
	}

	DB = db
	return nil
}