// Author: simon (ynwdlxm@163.com)
// Date: 2025/9/12 11:02
// Desc: Encapsulation of each connection (description of each client connection)

package connection

import (
	"net"
	"sync"
	"time"

	"github.com/runningwater/go-redis/lib/logger"
	"github.com/runningwater/go-redis/lib/sync/wait"
)

// Connection represents a client connection to the Redis server
type Connection struct {
	conn       net.Conn
	waiting    wait.Wait
	mu         sync.Mutex
	selectedDB int
}

// NewConnection creates a new connection wrapper
func NewConnection(conn net.Conn) *Connection {
	return &Connection{
		conn: conn,
	}
}

// RemoteAddr returns the remote network address
func (c *Connection) RemoteAddr() net.Addr {
	return c.conn.RemoteAddr()
}

// Close closes the connection
func (c *Connection) Close() error {
	timeout := c.waiting.WaitWithTimeout(10 * time.Second)
	if timeout {
		logger.Info("timeout to close connection")
	} else {
		logger.Info("connection closed")
	}
	err := c.conn.Close()
	return err
}

// Write writes data to the connection
func (c *Connection) Write(bytes []byte) error {
	if len(bytes) == 0 {
		return nil
	}
	logger.InfoC("write to client: ", string(bytes))
	c.mu.Lock()
	c.waiting.Add(1)
	defer func() {
		c.waiting.Done()
		c.mu.Unlock()
	}()
	_, err := c.conn.Write(bytes)
	return err
}

// GetDBIndex returns the currently selected database index
func (c *Connection) GetDBIndex() int {
	return c.selectedDB
}

// SelectDB selects a database
func (c *Connection) SelectDB(dbNum int) {
	c.selectedDB = dbNum
}