package loki

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
)

func (client *Client) sendLogs(entries []logEntry) {
	if len(entries) == 0 {
		return
	}

	var streams []stream
	stream := stream{
		Labels:  client.config.Labels,
		Entries: entries,
	}
	streams = append(streams, stream)

	msg := promtailMsg{Streams: streams}
	jsonMsg, err := json.Marshal(msg)
	if err != nil {
		return
	}

	client.mutex.RLock()
	endpoint := client.config.Endpoint
	client.mutex.RUnlock()

	client.sendRequest("POST", endpoint, "application/json", jsonMsg)
}

func (client *Client) sendRequest(method, url string, ctype string, reqBody []byte) {
	req, err := http.NewRequest(method, url, bytes.NewBuffer(reqBody))
	if err != nil {
		return
	}

	req.Header.Set("Content-Type", ctype)

	resp, _ := client.client.Do(req)
	if resp != nil {
		defer resp.Body.Close()
	}
}

func (p *stream) MarshalJSON() ([]byte, error) {
	return json.Marshal(&struct {
		Labels  string     `json:"labels"`
		Entries []logEntry `json:"entries"`
	}{
		Labels:  p.Labels.String(),
		Entries: p.Entries,
	})
}

func (l labels) String() string {
	var labelPairs []string
	for key, value := range l {
		labelPairs = append(labelPairs, fmt.Sprintf(`%s="%s"`, key, value))
	}
	return fmt.Sprintf("{%s}", strings.Join(labelPairs, ","))
}