package centrifugo

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"time"
)

// Client Centrifugo 客戶端
type Client struct {
	apiURL string
	apiKey string
	client *http.Client
}

// NewClient 創建新的 Centrifugo 客戶端
func NewClient(apiURL, apiKey string) *Client {
	return &Client{
		apiURL: apiURL,
		apiKey: apiKey,
		client: &http.Client{
			Timeout: 5 * time.Second,
		},
	}
}

// PublishRequest Centrifugo 發布請求
type PublishRequest struct {
	Channel string      `json:"channel"`
	Data    interface{} `json:"data"`
}

// PublishResponse Centrifugo 發布響應
type PublishResponse struct {
	Error   string `json:"error,omitempty"`
	Result  interface{} `json:"result,omitempty"`
}

// Publish 發布訊息到指定頻道
func (c *Client) Publish(channel string, data []byte) error {
	req := PublishRequest{
		Channel: channel,
		Data:    json.RawMessage(data),
	}
	return c.publishJSON(req)
}

// PublishJSON 發布 JSON 訊息到指定頻道
func (c *Client) PublishJSON(channel string, data interface{}) error {
	req := PublishRequest{
		Channel: channel,
		Data:    data,
	}
	return c.publishJSON(req)
}

func (c *Client) publishJSON(req PublishRequest) error {
	body, err := json.Marshal(req)
	if err != nil {
		return fmt.Errorf("failed to marshal request: %w", err)
	}

	httpReq, err := http.NewRequest("POST", c.apiURL+"/publish", bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	httpReq.Header.Set("Content-Type", "application/json")
	if c.apiKey != "" {
		httpReq.Header.Set("Authorization", "apikey "+c.apiKey)
	}

	resp, err := c.client.Do(httpReq)
	if err != nil {
		return fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return fmt.Errorf("failed to read response: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("centrifugo returned status %d: %s", resp.StatusCode, string(respBody))
	}

	var publishResp PublishResponse
	if err := json.Unmarshal(respBody, &publishResp); err != nil {
		return fmt.Errorf("failed to unmarshal response: %w", err)
	}

	if publishResp.Error != "" {
		return fmt.Errorf("centrifugo error: %s", publishResp.Error)
	}

	return nil
}