package rabbitmq

import (
	"context"
	"encoding/json"
	"sync"
	"time"

	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/frame/g"
	amqp "github.com/rabbitmq/amqp091-go"
)

type Config struct {
	Enabled bool
	Dsn     string
}

var (
	conn   *amqp.Connection
	connMu sync.Mutex
)

func GetConfig(ctx context.Context) Config {
	return Config{
		Enabled: g.Cfg().MustGet(ctx, "rabbitmq.enabled", false).Bool(),
		Dsn:     g.Cfg().MustGet(ctx, "rabbitmq.dsn", "").String(),
	}
}

func Enabled(ctx context.Context) bool {
	cfg := GetConfig(ctx)
	return cfg.Enabled && cfg.Dsn != ""
}

func Publish(ctx context.Context, queue string, data any) error {
	body, err := json.Marshal(data)
	if err != nil {
		return gerror.Wrap(err, "序列化 RabbitMQ 消息失败")
	}
	return PublishBytes(ctx, queue, body)
}

func PublishBytes(ctx context.Context, queue string, body []byte) error {
	if queue == "" {
		return gerror.New("RabbitMQ 队列名不能为空")
	}
	ch, err := channel(ctx)
	if err != nil {
		return err
	}
	defer ch.Close()

	if _, err = ch.QueueDeclare(queue, true, false, false, false, nil); err != nil {
		return gerror.Wrapf(err, "声明 RabbitMQ 队列失败: %s", queue)
	}
	return ch.PublishWithContext(ctx, "", queue, false, false, amqp.Publishing{
		ContentType:  "application/json",
		DeliveryMode: amqp.Persistent,
		Timestamp:    time.Now(),
		Body:         body,
	})
}

func channel(ctx context.Context) (*amqp.Channel, error) {
	c, err := connection(ctx)
	if err != nil {
		return nil, err
	}
	ch, err := c.Channel()
	if err != nil {
		return nil, gerror.Wrap(err, "打开 RabbitMQ Channel 失败")
	}
	return ch, nil
}

func connection(ctx context.Context) (*amqp.Connection, error) {
	cfg := GetConfig(ctx)
	if !cfg.Enabled {
		return nil, gerror.New("RabbitMQ 未启用")
	}
	if cfg.Dsn == "" {
		return nil, gerror.New("RabbitMQ DSN 未配置")
	}

	connMu.Lock()
	defer connMu.Unlock()
	if conn != nil && !conn.IsClosed() {
		return conn, nil
	}

	c, err := amqp.Dial(cfg.Dsn)
	if err != nil {
		return nil, gerror.Wrap(err, "连接 RabbitMQ 失败")
	}
	conn = c
	return conn, nil
}