namespace LineBotDemo.Controllers
{
    [RoutePrefix("echo")]
    public class LineMessagesSampleController : ApiController
    {
        private static readonly ILog Log4netLogger = LogManager.GetLogger(typeof(LineMessagesSampleController));

        private LineClient lineClient = new LineClient(ConfigurationManager.AppSettings["ChannelToken"].ToString());

        private Logger Logger = new Logger(Log4netLogger);

        [Route]
        public async Task<HttpResponseMessage> Post(HttpRequestMessage request)
        {
            if (!await VaridateSignature(request))
                return Request.CreateResponse(HttpStatusCode.BadRequest);

            var content = await request.Content.ReadAsStringAsync();
            Activity activity = JsonConvert.DeserializeObject<Activity>(content);

            Logger.Info("request=" + content);

            // Line may send multiple events in one message, so need to handle them all.
            foreach (Event lineEvent in activity.Events)
            {
                Profile profile = await lineClient.GetProfile(lineEvent.Source.UserId);

                switch (lineEvent.Type)
                {
                    case EventType.Beacon:
                        Logger.Info("Beacon event");
                        break;
                    case EventType.Follow:
                        Logger.Info("Follow event");
                        break;
                    case EventType.Join:
                        Logger.Info("Join event");
                        break;
                    case EventType.Leave:
                        Logger.Info("Leave event");
                        break;
                    case EventType.Message:
                        Logger.Info("Message event");
                        Message message = JsonConvert.DeserializeObject<Message>(lineEvent.Message.ToString());

                        switch (message.Type)
                        {
                            case MessageType.Text:
                                var textMessageReply = await HandleTextMessage(lineEvent);
                                await Reply(lineEvent, textMessageReply);
                                break;
                            case MessageType.Audio:
                            case MessageType.Image:
                            case MessageType.Video:
                                var mediaReplyMessage = await HandleMediaMessage(lineEvent);
                                await Reply(lineEvent, mediaReplyMessage);
                                break;
                            case MessageType.Sticker:
                                var stickerReplyMessage = await HandleStickerMessage(lineEvent);
                                await Reply(lineEvent, stickerReplyMessage);
                                break;
                            case MessageType.Location:
                                var locationReplyMessage = await HandleLocationMessage(lineEvent);
                                await Reply(lineEvent, locationReplyMessage);
                                break;
                        }
                        break;
                    case EventType.Postback:
                        Logger.Info("Postback event");
                        //
                        var postbackReplyMessage = new TextMessage(lineEvent.Postback.Data);
                        await Reply(lineEvent, postbackReplyMessage);
                        break;
                    case EventType.Unfollow:
                        Logger.Info("Unfollow event");
                        break;
                }
            }

            return Request.CreateResponse(HttpStatusCode.OK);
        }

        private async Task<bool> VaridateSignature(HttpRequestMessage request)
        {
            var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(ConfigurationManager.AppSettings["ChannelSecret"].ToString()));
            var computeHash = hmac.ComputeHash(Encoding.UTF8.GetBytes(await request.Content.ReadAsStringAsync()));
            var contentHash = Convert.ToBase64String(computeHash);
            var headerHash = Request.Headers.GetValues("X-Line-Signature").First();

            return contentHash == headerHash;
        }

        private async Task<Message> HandleTextMessage(Event lineEvent)
        {
            var textMessage = JsonConvert.DeserializeObject<TextMessage>(lineEvent.Message.ToString());
            Message replyMessage = null;

            if (textMessage.Text.ToLower() == "demo")
            {
                List<TemplateAction> actions = new List<TemplateAction>();
                actions.Add(new MessageTemplateAction("Buttons", "buttons"));
                actions.Add(new MessageTemplateAction("Confirm", "confirm"));
                actions.Add(new MessageTemplateAction("Carousel", "carousel"));
                actions.Add(new MessageTemplateAction("Imagemap", "imagemap"));
                ButtonsTemplate buttonsTemplate = new ButtonsTemplate(null, "可用功能", "直接選比較快", actions);

                replyMessage = new TemplateMessage("Buttons", buttonsTemplate);
            }
            else if (textMessage.Text.ToLower() == "buttons")
            {
                List<TemplateAction> actions = new List<TemplateAction>();
                actions.Add(new MessageTemplateAction("Message Label", "sample data"));
                // text 參數為 null 就不會有 message 在畫面上
                actions.Add(new PostbackTemplateAction("Postback Label", "postback data", null));
                actions.Add(new UriTemplateAction("Uri Label", "https://github.com/kenakamu"));
                ButtonsTemplate buttonsTemplate = new ButtonsTemplate("https://github.com/apple-touch-icon.png", "Sample Title", "Sample Text", actions);

                replyMessage = new TemplateMessage("Buttons", buttonsTemplate);
            }
            else if (textMessage.Text.ToLower() == "confirm")
            {
                // Actions
                List<TemplateAction> actions = new List<TemplateAction>();
                actions.Add(new MessageTemplateAction("OK", "ok"));
                actions.Add(new MessageTemplateAction("Cancel", "cancel"));
                // Template
                ConfirmTemplate confirmTemplate = new ConfirmTemplate("Are you sure?", actions);
                // Message
                replyMessage = new TemplateMessage("Confirm", confirmTemplate);
            }
            else if (textMessage.Text.ToLower() == "carousel")
            {
                List<TemplateColumn> columns = new List<TemplateColumn>();
                List<TemplateAction> actions = new List<TemplateAction>();
                actions.Add(new MessageTemplateAction("Message Label", "sample data"));
                // text 內容為 "postback text", 可以和 buttons 的 Postback action 做比較
                actions.Add(new PostbackTemplateAction("Postback Label", "postback data", "postback text"));
                actions.Add(new UriTemplateAction("Uri Label", "https://github.com/kenakamu"));
                columns.Add(new TemplateColumn() { Title = "Casousel 1 Title", Text = "Casousel 1 Text", ThumbnailImageUrl = "https://github.com/apple-touch-icon.png", Actions = actions });
                columns.Add(new TemplateColumn() { Title = "Casousel 2 Title", Text = "Casousel 2 Text", ThumbnailImageUrl = "https://github.com/apple-touch-icon.png", Actions = actions });
                CarouselTemplate carouselTemplate = new CarouselTemplate(columns);

                replyMessage = new TemplateMessage("Carousel", carouselTemplate);
            }
            else if (textMessage.Text.ToLower() == "imagemap")
            {
                // Base URL 圖片路徑請自行定義
                var url = HttpContext.Current.Request.Url;
                var imageUrl = $"{url.Scheme}://{url.Host}:{url.Port}/images/githubicon";
                
                List<ImageMapAction> actions = new List<ImageMapAction>();
                actions.Add(new UriImageMapAction("https://github.com", new ImageMapArea(0, 0, 520, 1040)));
                actions.Add(new MessageImageMapAction("I love LINE!", new ImageMapArea(520, 0, 520, 1040)));

                replyMessage = new ImageMapMessage(imageUrl, "GitHub", new BaseSize(1040, 1040), actions);
            }
            else
            {
                replyMessage = new TextMessage(textMessage.Text);
            }

            return await Task.FromResult(replyMessage);
        }

        private async Task<Message> HandleMediaMessage(Event lineEvent)
        {
            Message message = JsonConvert.DeserializeObject<Message>(lineEvent.Message.ToString());

            // Get media from Line server.
            Media media = await lineClient.GetContent(message.Id);

            // 統一回圖片 
            Message replyMessage = new ImageMessage("https://github.com/apple-touch-icon.png", "https://github.com/apple-touch-icon.png");

            return await Task.FromResult(replyMessage);
        }

        private async Task<Message> HandleStickerMessage(Event lineEvent)
        {
            var stickerMessage = JsonConvert.DeserializeObject<StickerMessage>(lineEvent.Message.ToString());

            // https://devdocs.line.me/files/sticker_list.pdf
            return await Task.FromResult<Message>(new StickerMessage("1", "1"));
        }

        private async Task<Message> HandleLocationMessage(Event lineEvent)
        {
            var locationMessage = JsonConvert.DeserializeObject<LocationMessage>(lineEvent.Message.ToString());

            var replyMessage = new LocationMessage(
                locationMessage.Title,
                locationMessage.Address,
                locationMessage.Latitude,
                locationMessage.Longitude);

            return await Task.FromResult(replyMessage);
        }

        private async Task Reply(Event lineEvent, Message replyMessage)
        {
            try
            {
                await lineClient.ReplyToActivityAsync(lineEvent.CreateReply(message: replyMessage));
            }
            catch
            {
                await lineClient.PushAsync(lineEvent.CreatePush(message: replyMessage));
            }
        }
    }
}