package server

import (
	"heckel.io/ntfy/util"
	"time"
)

// List of possible events
const (
	openEvent      = "open"
	keepaliveEvent = "keepalive"
	messageEvent   = "message"
)

const (
	messageIDLength = 10
)

// message represents a message published to a topic
type message struct {
	ID         string      `json:"id"`    // Random message ID
	Time       int64       `json:"time"`  // Unix time in seconds
	Event      string      `json:"event"` // One of the above
	Topic      string      `json:"topic"`
	Priority   int         `json:"priority,omitempty"`
	Tags       []string    `json:"tags,omitempty"`
	Title      string      `json:"title,omitempty"`
	Message    string      `json:"message,omitempty"`
	Attachment *attachment `json:"attachment,omitempty"`
}

type attachment struct {
	Name       string `json:"name"`
	Type       string `json:"type"`
	Size       int64  `json:"size"`
	Expires    int64  `json:"expires"`
	PreviewURL string `json:"preview_url"`
	URL        string `json:"url"`
}

// messageEncoder is a function that knows how to encode a message
type messageEncoder func(msg *message) (string, error)

// newMessage creates a new message with the current timestamp
func newMessage(event, topic, msg string) *message {
	return &message{
		ID:       util.RandomString(messageIDLength),
		Time:     time.Now().Unix(),
		Event:    event,
		Topic:    topic,
		Priority: 0,
		Tags:     nil,
		Title:    "",
		Message:  msg,
	}
}

// newOpenMessage is a convenience method to create an open message
func newOpenMessage(topic string) *message {
	return newMessage(openEvent, topic, "")
}

// newKeepaliveMessage is a convenience method to create a keepalive message
func newKeepaliveMessage(topic string) *message {
	return newMessage(keepaliveEvent, topic, "")
}

// newDefaultMessage is a convenience method to create a notification message
func newDefaultMessage(topic, msg string) *message {
	return newMessage(messageEvent, topic, msg)
}