【作品紹介(GAS)】TSUBASAMUSU-COPILOT（Slack App）

let promptBody = null;

let userIdBody = null;

let mentionedUserId = null;

let channelId = null;

function doPost(e) 
{
  const BOT_ID = PropertiesService.getScriptProperties().getProperty("BOT_ID");

  const MENTION_TEXT = "<@" + BOT_ID + ">";

  const PARAMS = JSON.parse(e.postData.getDataAsString());

  channelId = PARAMS.event.channel;

  mentionedUserId = PARAMS.event.user;

  setUpUserIdDocument();

  userIdBody.appendParagraph(mentionedUserId);

  const MENTIONED_MESSAGE = PARAMS.event.text;

  const PROMPT = MENTIONED_MESSAGE.replace(MENTION_TEXT,"");

  setUpPromptDocument();

  promptBody.appendParagraph(PROMPT);

  sendMessageWithButtonsToSlack();
    
  return ContentService.createTextOutput(PARAMS.challenge);
}

function setUpUserIdDocument()
{
  const DOCUMENT_ID = PropertiesService.getScriptProperties().getProperty("USER_DOCUMENT_ID");

  const DOCUMENT = DocumentApp.openById(DOCUMENT_ID);

  userIdBody = DOCUMENT.getBody();

  userIdBody.clear();
}

function setUpPromptDocument()
{
  const DOCUMENT_ID = PropertiesService.getScriptProperties().getProperty("PROMPT_DOCUMENT_ID");

  const DOCUMENT = DocumentApp.openById(DOCUMENT_ID);

  promptBody = DOCUMENT.getBody();

  promptBody.clear();
}

function sendMessageToSlack(text) 
{
  const TOKEN = PropertiesService.getScriptProperties().getProperty("TOKEN");

  const SLACK_APP = SlackApp.create(TOKEN);

  SLACK_APP.postMessage(channelId, text); 
}

function sendMessageWithButtonsToSlack() 
{
  const TOKEN = PropertiesService.getScriptProperties().getProperty("TOKEN");

	const API_URL = "https://slack.com/api/chat.postMessage";

  const MESSAGE = "<@" +  mentionedUserId + ">\n" + "そのプロンプトで生成したいものはどちらですか？";

  const BLOCKS = 
  [
    {
      "type": "section",
      "text": 
      {
        "type": "mrkdwn",
        "text": MESSAGE
      }
    },
    {
      "type": "actions",
      "elements": 
      [
        {
          "type": "button",
          "text": 
          {
            "type": "plain_text",
            "text": "文章"
          },
          "style": "primary",
          "value": "text"
        },
        {
          "type": "button",
          "text": 
          {
            "type": "plain_text",
            "text": "画像"
          },
          "style": "danger",
          "value": "image"
        }
      ]
    }
  ];

  const PAYLOAD = 
  {
    token: TOKEN,
    channel: channelId,
    text: MESSAGE,
    blocks: BLOCKS
  };

  const HEADERS = 
  {
    "Authorization": "Bearer " + TOKEN
  };

  const OPTIONS = 
  {
    method: "post",
    contentType: "application/json",
    payload: JSON.stringify(PAYLOAD),
    headers: HEADERS
  };

  UrlFetchApp.fetch(API_URL, OPTIONS);
}

let channelId = null;

function doPost(e) 
{
  const PAYLOAD = JSON.parse(e.parameter.payload);

  channelId = PAYLOAD.channel.id;

  deleteSlackMessage(PAYLOAD);

  const VALUE = PAYLOAD.actions[0].value;

  const PROMPT = getPromptFromDocument();

  switch(VALUE)
  {
    case "text":
      const MESSAGE = getMentionText() + "\n" + getChatGptAnswer(PROMPT);
      sendMessageToSlack(MESSAGE);
      break;

    case "image":
      const IMAGE_FILE_URL = getDalleAnswer(PROMPT);
      sendFileToSlack(IMAGE_FILE_URL);
      break;
  }
}

function deleteSlackMessage(payload) 
{
  const TOKEN =  PropertiesService.getScriptProperties().getProperty("TOKEN");

  const API_URL = "https://slack.com/api/chat.delete";
  
  const PAYLOAD = 
  {
    token: TOKEN,
    channel: channelId,
    ts: payload.message.ts
  };

  const OPTIONS = 
  {
    method: "post",
    payload: PAYLOAD
  };
    
  UrlFetchApp.fetch(API_URL, OPTIONS);
}

function getPromptFromDocument()
{
  const DOCUMENT_ID = PropertiesService.getScriptProperties().getProperty("PROMPT_DOCUMENT_ID");

  const DOCUMENT = DocumentApp.openById(DOCUMENT_ID);

  const BODY = DOCUMENT.getBody();

  return BODY.getText();
}

function getMentionText()
{
  const DOCUMENT_ID = PropertiesService.getScriptProperties().getProperty("USER_DOCUMENT_ID");

  const DOCUMENT = DocumentApp.openById(DOCUMENT_ID);

  const BODY = DOCUMENT.getBody();

  const MENTIONED_USER_ID = BODY.getText().trim();

  return "<@" + MENTIONED_USER_ID + ">";
}

function getChatGptAnswer(prompt)
{
  const API_KEY = PropertiesService.getScriptProperties().getProperty("OPEN_AI_API_KEY");

  const API_URL = 'https://api.openai.com/v1/chat/completions';

  const MESSAGE =
  {
    role: "user",
    content: prompt
  };

  const MESSAGES = [MESSAGE];

  const PAYLOAD = 
  {
    model: "gpt-3.5-turbo",
    temperature: 0.5,
    max_tokens: 1000,
    messages: MESSAGES
  }

  const HEADERS = 
  {
    "Content-Type": "application/json",
    "Authorization": "Bearer " + API_KEY
  };

  const REQUEST = 
  {
    method: "POST",
    muteHttpExceptions : true,
    headers: HEADERS,
    payload: JSON.stringify(PAYLOAD)
  }

  try 
  {
    const RESPONSE = JSON.parse(UrlFetchApp.fetch(API_URL, REQUEST).getContentText());

    return RESPONSE.choices[0].message.content;
  }
  catch(e)
  {
    return e.toString();
  }
}

function getDalleAnswer(prompt) 
{
  const API_KEY = PropertiesService.getScriptProperties().getProperty("OPEN_AI_API_KEY");

  const API_URL = 'https://api.openai.com/v1/images/generations';

  const PAYLOAD =
  {
    n: 1,
    size : "256x256",
    prompt: prompt
  };
  
  const HEADERS = 
  {
    "Authorization":"Bearer " + API_KEY,
    "Content-type": "application/json",
    "X-Slack-No-Retry": 1
  };

  const OPTIONS = 
  {
    muteHttpExceptions : true,
    headers: HEADERS, 
    method: "POST",
    payload: JSON.stringify(PAYLOAD)
  };

  try
  {
    const RESPONSE = JSON.parse(UrlFetchApp.fetch(API_URL, OPTIONS).getContentText());

    return RESPONSE.data[0].url;
  }
  catch(e)
  {
    const ERROR_MESSAGE = e.toString();

    sendMessageToSlack(ERROR_MESSAGE);

    return null;
  }
}

function sendMessageToSlack(text) 
{
  const TOKEN = PropertiesService.getScriptProperties().getProperty("TOKEN");

  const SLACK_APP = SlackApp.create(TOKEN);

  SLACK_APP.postMessage(channelId, text);
}

function sendFileToSlack(fileUrl)
{
  const TOKEN = PropertiesService.getScriptProperties().getProperty("TOKEN");

  const API_URL = "https://slack.com/api/files.upload";

  let file = null;

  try
  {
    file = UrlFetchApp.fetch(fileUrl).getBlob();
  }
  catch(e)
  {
    const MESSAGE = getMentionText() + "\n画像ファイルの取得に失敗しました。";

    sendMessageToSlack(MESSAGE);

    return;
  }

  const PAYLOAD =
  {
    file: file,
    channels: channelId,
    initial_comment: getMentionText(),
    title: getPromptFromDocument()
  };

  const HEADERS =
  {
    "Authorization": "Bearer " + TOKEN
  };

  const OPTIONS =
  {
    method: "post",
    payload: PAYLOAD,
    headers: HEADERS
  };

  UrlFetchApp.fetch(API_URL,OPTIONS);
}