package notifications

import (
	"errors"
	"net/http"
	"strconv"
	"strings"
	"time"
	"velvettear/godyn/config"
	"velvettear/godyn/log"
)

const PRIORITY_MAX = 5
const PRIORITY_HIGH = 4
const PRIORITY_DEFAULT = 3
const PRIORITY_LOW = 2
const PRIORITY_MIN = 1

// exported function(s)
func Send(notification Notification) {
	if !config.NotificationEnabled() {
		return
	}
	timestamp := time.Now().UnixMilli()
	url, error := getNotificationUrl()
	if error != nil {
		log.Warning("encountered an error sending a notification", error.Error())
		return
	}
	request, error := http.NewRequest("POST", url, strings.NewReader(notification.Message))
	if error != nil {
		log.Error("encountered an error creating a notification http request", error.Error())
		return
	}
	request.Header.Set("Title", notification.Title)
	request.Header.Set("Priority", strconv.Itoa(notification.getPriority()))
	if notification.hasEmoji() {
		request.Header.Set("Tags", notification.Emoji)
	}
	authorize(request)
	response, error := http.DefaultClient.Do(request)
	if error != nil {
		log.ErrorTimed("encountered an error sending a notification", timestamp, error.Error())
		return
	}
	if response.StatusCode != 200 {
		log.ErrorTimed("probably encountered an error sending a notification", timestamp, "status code: "+strconv.Itoa(response.StatusCode))
		return
	}
	log.DebugTimed("successfully sent a notification", timestamp)
}

// unexported function(s)
func getNotificationUrl() (string, error) {
	url := config.NotificationUrl()
	if len(url) == 0 {
		return "", errors.New("notification url is not configured")
	}
	topic := config.NotificationTopic()
	if len(topic) == 0 {
		return "", errors.New("notification topic is not configured")
	}
	if !strings.HasSuffix(url, "/") {
		url += "/"
	}
	return url + topic, nil
}

func authorize(request *http.Request) {
	username := config.NotificationUsername()
	password := config.NotificationPassword()
	if len(username) == 0 || len(password) == 0 {
		return
	}
	request.SetBasicAuth(username, password)
}

func (notification *Notification) hasEmoji() bool {
	return len(notification.Emoji) > 0
}

func (notification *Notification) getPriority() int {
	if notification.Priority < PRIORITY_MIN || notification.Priority > PRIORITY_MAX {
		notification.Priority = PRIORITY_DEFAULT
	}
	return notification.Priority
}

// struct(s)
type Notification struct {
	Title    string
	Message  string
	Emoji    string
	Priority int
}