import { getResumeUrls } from "https://deno.land/x/windmill@v1.85.0/mod.ts";

import { WebClient } from "https://deno.land/x/slack_web_api@1.0.3/mod.ts";

type Slack = {

  token: string;

};

export async function main(approver_emails: string[], slack: Slack) {

  throwOnInvalidApprovers(approver_emails);

  const client = new WebClient(slack.token);

  const usersData = await Promise.all(

    approver_emails.map((email) => getUserData(client, email)),

  );

  console.log(usersData);

  const dmPromises = usersData.map((userData) =>

    sendDirectMessage(client, userData),

  );

  const results = await Promise.all(dmPromises);

  return results;

}

interface UserData {

  id: string;

  email: string;

  real_name: string;

}

async function getUserData(client: WebClient, email: string): UserData {

  try {

    const response = await client.users.lookupByEmail({ email: email });

    const { id, real_name } = response.user;

    return { id, email, real_name };

  } catch (err) {

    return handleApiResponse(email, err);

  }

}

async function sendDirectMessage(client: WebClient, userData: UserData) {

  const text = await getApprovalMsg(userData.email);

  const { ok, ts, channel } = await client.chat.postMessage({

    channel: userData.id,

    text,

  });

  return { ok, ts, channel, email: userData.email };

}

async function getApprovalMsg(to_email) {

  const { approvalPage } = await getResumeUrls(to_email);

  return `There is a Windmill flow at ${Deno.env.get(

    "WM_FLOW_PATH",

  )} run by ${Deno.env.get("WM_USERNAME")} waiting for your approval to resume.

In order to resume or cancel the flow go to ${approvalPage}`;

}

function throwOnInvalidApprovers(approvers: string[]) {

  if (!Array.isArray(approvers) || approvers.length === 0) {

    throw new Error("Expected at least one approver email");

  }

}

function handleApiResponse(email, error) {

  return Promise.reject({ email, err_msg: error.message });

}