package reconnect

import (
	"context"
	"sync"

	amqp "github.com/rabbitmq/amqp091-go"
)

// RabbitMQClientConfig RabbitMQ客户端配置
type RabbitMQClientConfig struct {
	// URL RabbitMQ连接URL
	URL string
	// Config amqp配置
	Config *amqp.Config
	// ReconnectConfig 重连配置
	ReconnectConfig Config
}

// RabbitMQClient 带重连功能的RabbitMQ客户端
type RabbitMQClient struct {
	config  RabbitMQClientConfig
	conn    *amqp.Connection
	manager *ConnectionManager
	mu      sync.RWMutex
}

// rabbitmqConnector RabbitMQ连接器
type rabbitmqConnector struct {
	client *RabbitMQClient
}

func (r *rabbitmqConnector) Connect(ctx context.Context) error {
	r.client.mu.Lock()
	defer r.client.mu.Unlock()

	var conn *amqp.Connection
	var err error

	if r.client.config.Config != nil {
		conn, err = amqp.DialConfig(r.client.config.URL, *r.client.config.Config)
	} else {
		conn, err = amqp.Dial(r.client.config.URL)
	}

	if err != nil {
		return err
	}

	// 验证连接
	if conn.IsClosed() {
		conn.Close()
		return amqp.ErrClosed
	}

	r.client.conn = conn
	return nil
}

func (r *rabbitmqConnector) Close() error {
	r.client.mu.Lock()
	defer r.client.mu.Unlock()

	if r.client.conn != nil && !r.client.conn.IsClosed() {
		err := r.client.conn.Close()
		r.client.conn = nil
		return err
	}
	return nil
}

// rabbitmqHealthChecker RabbitMQ健康检查器
type rabbitmqHealthChecker struct {
	client *RabbitMQClient
}

func (r *rabbitmqHealthChecker) HealthCheck(ctx context.Context) error {
	r.client.mu.RLock()
	conn := r.client.conn
	r.client.mu.RUnlock()

	if conn == nil || conn.IsClosed() {
		return amqp.ErrClosed
	}

	// 尝试创建通道来验证连接
	ch, err := conn.Channel()
	if err != nil {
		return err
	}
	defer ch.Close()

	return nil
}

// NewRabbitMQClient 创建带重连功能的RabbitMQ客户端
func NewRabbitMQClient(cfg RabbitMQClientConfig) (*RabbitMQClient, error) {
	client := &RabbitMQClient{
		config: cfg,
	}

	connector := &rabbitmqConnector{client: client}
	checker := &rabbitmqHealthChecker{client: client}

	client.manager = NewConnectionManager(connector, checker, cfg.ReconnectConfig)

	// 首次连接
	ctx := context.Background()
	if err := client.manager.ConnectWithRetry(ctx); err != nil {
		return nil, err
	}

	return client, nil
}

// GetConn 获取RabbitMQ连接
func (c *RabbitMQClient) GetConn() *amqp.Connection {
	c.mu.RLock()
	defer c.mu.RUnlock()
	return c.conn
}

// Channel 创建通道
func (c *RabbitMQClient) Channel() (*amqp.Channel, error) {
	conn := c.GetConn()
	if conn == nil || conn.IsClosed() {
		return nil, amqp.ErrClosed
	}
	return conn.Channel()
}

// State 获取连接状态
func (c *RabbitMQClient) State() ConnectionState {
	return c.manager.State()
}

// Close 关闭客户端
func (c *RabbitMQClient) Close() error {
	return c.manager.Close()
}

// TriggerReconnect 手动触发重连
func (c *RabbitMQClient) TriggerReconnect() {
	c.manager.TriggerReconnect()
}

// IsClosed 检查连接是否关闭
func (c *RabbitMQClient) IsClosed() bool {
	conn := c.GetConn()
	return conn == nil || conn.IsClosed()
}

// Publish 发布消息（带重连支持）
func (c *RabbitMQClient) Publish(exchange, key string, mandatory, immediate bool, msg amqp.Publishing) error {
	ch, err := c.Channel()
	if err != nil {
		return err
	}
	defer ch.Close()

	return ch.Publish(exchange, key, mandatory, immediate, msg)
}

// Consume 消费消息（带重连支持）
func (c *RabbitMQClient) Consume(queue, consumer string, autoAck, exclusive, noLocal, noWait bool, args amqp.Table) (<-chan amqp.Delivery, error) {
	ch, err := c.Channel()
	if err != nil {
		return nil, err
	}

	return ch.Consume(queue, consumer, autoAck, exclusive, noLocal, noWait, args)
}

// QueueDeclare 声明队列（带重连支持）
func (c *RabbitMQClient) QueueDeclare(name string, durable, autoDelete, exclusive, noWait bool, args amqp.Table) (amqp.Queue, error) {
	ch, err := c.Channel()
	if err != nil {
		return amqp.Queue{}, err
	}
	defer ch.Close()

	return ch.QueueDeclare(name, durable, autoDelete, exclusive, noWait, args)
}

// ExchangeDeclare 声明交换机（带重连支持）
func (c *RabbitMQClient) ExchangeDeclare(name, kind string, durable, autoDelete, internal, noWait bool, args amqp.Table) error {
	ch, err := c.Channel()
	if err != nil {
		return err
	}
	defer ch.Close()

	return ch.ExchangeDeclare(name, kind, durable, autoDelete, internal, noWait, args)
}

// QueueBind 绑定队列到交换机（带重连支持）
func (c *RabbitMQClient) QueueBind(name, key, exchange string, noWait bool, args amqp.Table) error {
	ch, err := c.Channel()
	if err != nil {
		return err
	}
	defer ch.Close()

	return ch.QueueBind(name, key, exchange, noWait, args)
}