package discourse

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

type Session struct {
	apiKey      string
	apiUser     string
	apiEndpoint string
}

func (session Session) SendPM(usernames []string, title string, body string) (string, error) {
	targetUsernames := strings.Join(usernames, ",")

	messageJSON := map[string]interface{}{
		"title":            title,
		"target_usernames": targetUsernames,
		"archetype":        "private_message",
		"raw":              body,
	}

	payload, err := json.Marshal(messageJSON)
	if err != nil {
		return "", err
	}

	url := fmt.Sprintf("%s/posts.json?api_key=%s&api_username=%s", session.apiEndpoint, session.apiKey, session.apiUser)

	response, err := http.Post(url, "application/json", bytes.NewBuffer(payload))

	if err != nil {
		return "", err
	}

	var result map[string]interface{}

	json.NewDecoder(response.Body).Decode(&result)
	topicIDDigit := result["topic_id"].(float64)

	topicID := strconv.FormatFloat(topicIDDigit, 'f', -1, 64)

	return topicID, nil
}