import { customAlphabet } from '@nanoid';
import { STATUS_CODE, STATUS_TEXT, StatusCode } from '@std/http/status';

import config from '~config';

import dbClient from 'db/client.ts';

import buildPage from './ssr/buildPage.ts';
import buildLogin from './ssr/buildLogin.ts';
import buildHome from './ssr/buildHome.ts';

// Using custom alphabet to exclude - and _
const alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
const nanoid = customAlphabet(alphabet, 20);

const discordHeaders = new Headers();
discordHeaders.append('Content-Type', 'application/json');
discordHeaders.append('Accept', 'application/json');

const zohoHeaders = new Headers(discordHeaders);
let zohoAuthExpireDT = new Date().getTime();

const genericResponse = (status: StatusCode, customText = '', customHeaders = new Headers()) =>
  new Response(customText || STATUS_TEXT[status], { status: status, statusText: STATUS_TEXT[status], headers: customHeaders });

Deno.serve({ port: config.api.port }, async (req) => {
  try {
    const urlPath = req.url.split('?')[0] ?? '';
    let rawPath = (urlPath.split('api')[1] ?? '').trim();
    if (rawPath.endsWith('/')) rawPath = rawPath.slice(0, -1);
    const path = rawPath;

    let failed = false;
    if (req.method === 'GET') {
      if (path === '') {
        const redirectHeaders = new Headers();
        redirectHeaders.set('Location', '/api/home');
        return genericResponse(STATUS_CODE.PermanentRedirect, undefined, redirectHeaders);
      } else if (path === '/home') {
        // SSR "login page"
        return buildPage(buildLogin);
      } else if (path.startsWith('/home/')) {
        // SSR "home page"
        const userId = path.replace('/home/', '');
        const userMatch = await dbClient.query('SELECT name FROM users WHERE id = ?', [userId]).catch(() => {
          failed = true;
        });
        if (failed) return buildPage("Couldn't read DB.  Please try again.");
        if (!userMatch.length) return buildPage('User ID does not exist.  Please click on the page header to go back to the sign in page.');

        return buildPage(await buildHome(userId, userMatch[0].name));
      } else if (path.startsWith('/read/')) {
        const planId = path.replace('/read/', '');

        const plans = await dbClient.query('SELECT name, folder, data FROM plans WHERE id = ? AND deleted = 0', [planId]).catch(() => {
          failed = true;
        });
        if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
        if (!plans.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist, maybe its marked as deleted?');

        return genericResponse(STATUS_CODE.OK, JSON.stringify(plans[0]));
      } else if (path.startsWith('/list/')) {
        const userId = path.replace('/list/', '');
        const userMatch = await dbClient.query('SELECT id FROM users WHERE id = ?', [userId]).catch(() => {
          failed = true;
        });
        if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
        if (!userMatch.length) return genericResponse(STATUS_CODE.NotFound, 'User ID does not exist.');

        const plans = await dbClient.query('SELECT id, name, folder, lastUpdated FROM plans WHERE ownerId = ? AND deleted = 0', [userId]).catch(() => {
          failed = true;
        });
        if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");

        return genericResponse(STATUS_CODE.OK, JSON.stringify(plans));
      } else if (path.startsWith('/export/')) {
        const userId = path.replace('/export/', '');
        const userMatch = await dbClient.query('SELECT id FROM users WHERE id = ?', [userId]).catch(() => {
          failed = true;
        });
        if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
        if (!userMatch.length) return genericResponse(STATUS_CODE.NotFound, 'User ID does not exist.');

        // WIP: export plans to zip code goes here
        return genericResponse(STATUS_CODE.NotImplemented, 'Export function WIP.');
      }
    } else if (req.method === 'POST' && path === '/enroll') {
      const body = await req.json();

      const userNameMatches = await dbClient.query('SELECT name FROM users WHERE name = ?', [body.name]).catch(() => {
        failed = true;
      });
      if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");

      if (userNameMatches.length === 0) {
        if (body.name.length < 4 || body.name.length > 20)
          return genericResponse(STATUS_CODE.BadRequest, `Name too ${body.name.length < 4 ? 'short' : 'long'}.`);
        if (body.pin.length < 4 || body.pin.length > 20) return genericResponse(STATUS_CODE.BadRequest, `PIN too ${body.pin.length < 4 ? 'short' : 'long'}.`);
        if (body.email.length > 255) return genericResponse(STATUS_CODE.BadRequest, 'Email too long.');

        const id = nanoid();

        await dbClient.execute('INSERT INTO users(id,name,pin,email) values(?,?,?,?)', [id, body.name, body.pin, body.email]).catch(() => {
          failed = true;
        });

        if (failed) {
          return genericResponse(STATUS_CODE.InternalServerError, "Couldn't write DB.");
        } else {
          return genericResponse(STATUS_CODE.OK, JSON.stringify({ id }));
        }
      } else {
        return genericResponse(STATUS_CODE.BadRequest, 'Username Taken.');
      }
    } else {
      const body = await req.json();

      const loginMatch = await dbClient.query('SELECT id, email, deleteCode FROM users WHERE name = ? AND pin = ?', [body.name, body.pin]).catch(() => {
        failed = true;
      });
      if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
      if (loginMatch.length === 0) return genericResponse(STATUS_CODE.Forbidden, 'Invalid name/PIN combination.');
      const id = loginMatch[0].id;
      const email = loginMatch[0].email;
      const hasEmail = email.length > 0;
      const deleteCode = loginMatch[0].deleteCode;

      switch (req.method) {
        case 'POST':
          if (path === '/auth') {
            return genericResponse(STATUS_CODE.OK, JSON.stringify({ id, hasEmail }));
          } else if (path === '/create') {
            if (body.planName.trim().length > 200) return genericResponse(STATUS_CODE.BadRequest, 'Name too long.');
            if (body.folder.trim() && body.folder.trim().length > 200) return genericResponse(STATUS_CODE.BadRequest, 'Folder name too long.');

            const newPlanId = nanoid();
            await dbClient
              .execute('INSERT INTO plans(id,ownerId,name,folder,data) values(?,?,?,?,?)', [newPlanId, id, body.planName.trim(), body.folder.trim(), body.data])
              .catch(() => {
                failed = true;
              });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't write DB.");
            return genericResponse(STATUS_CODE.OK, JSON.stringify({ id: newPlanId, name: body.planName.trim() }));
          }
          break;
        case 'PUT':
          if (path.startsWith('/undelete/')) {
            const planId = path.replace('/undelete/', '');
            const planMatch = await dbClient.query('SELECT ownerId FROM plans WHERE id = ?', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
            if (!planMatch.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist.');
            if (planMatch[0].ownerId !== id) return genericResponse(STATUS_CODE.Forbidden, "You don't own this plan.");

            await dbClient.execute('UPDATE plans SET deleted = 0, lastUpdated = ? WHERE id = ?', [new Date(), planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't update DB.");
            return genericResponse(STATUS_CODE.OK, 'Plan restored.');
          } else if (path.startsWith('/update/')) {
            const planId = path.replace('/update/', '');
            const planMatch = await dbClient.query('SELECT ownerId FROM plans WHERE id = ?', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
            if (!planMatch.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist.');
            if (planMatch[0].ownerId !== id) return genericResponse(STATUS_CODE.Forbidden, "You don't own this plan.");

            await dbClient.execute('UPDATE plans SET data = ?, lastUpdated = ? WHERE id = ?', [body.data, new Date(), planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't update DB.");
            return genericResponse(STATUS_CODE.OK, 'Plan updated.');
          } else if (path.startsWith('/rename/')) {
            if (body.planName.trim().length > 200) return genericResponse(STATUS_CODE.BadRequest, 'Name too long.');

            const planId = path.replace('/rename/', '');
            const planMatch = await dbClient.query('SELECT ownerId FROM plans WHERE id = ?', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
            if (!planMatch.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist.');
            if (planMatch[0].ownerId !== id) return genericResponse(STATUS_CODE.Forbidden, "You don't own this plan.");

            await dbClient.execute('UPDATE plans SET name = ?, lastUpdated = ? WHERE id = ?', [body.planName, new Date(), planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't update DB.");
            return genericResponse(STATUS_CODE.OK, 'Plan renamed.');
          } else if (path.startsWith('/move/')) {
            if (body.folder.trim().length > 200) return genericResponse(STATUS_CODE.BadRequest, 'Folder name too long.');

            const planId = path.replace('/move/', '');
            const planMatch = await dbClient.query('SELECT ownerId FROM plans WHERE id = ?', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
            if (!planMatch.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist.');
            if (planMatch[0].ownerId !== id) return genericResponse(STATUS_CODE.Forbidden, "You don't own this plan.");

            await dbClient.execute('UPDATE plans SET folder = ?, lastUpdated = ? WHERE id = ?', [body.folder, new Date(), planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't update DB.");
            return genericResponse(STATUS_CODE.OK, 'Plan moved.');
          }
          break;
        case 'DELETE':
          if (path === '/unenroll') {
            if (!hasEmail || body.deleteCode.trim() === deleteCode) {
              await dbClient.execute('DELETE FROM plans WHERE ownerId = ?', [id]).catch(() => {
                failed = true;
              });
              if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't delete plans.");

              await dbClient.execute('DELETE FROM users WHERE id = ?', [id]).catch(() => {
                failed = true;
              });
              if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't delete user.");

              return genericResponse(STATUS_CODE.OK, 'Deleted user and plans.');
            } else if (hasEmail && !deleteCode) {
              const newDeleteCode = nanoid();
              await dbClient.execute('UPDATE users SET deleteCode = ? WHERE id = ?', [newDeleteCode, id]).catch(() => {
                failed = true;
              });
              if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't set deleteCode.");

              const nowDT = new Date().getTime();
              if (zohoAuthExpireDT < nowDT) {
                const getNewAuthToken = await fetch(
                  `https://accounts.zoho.com/oauth/v2/token?client_id=${config.email.clientId}&client_secret=${config.email.clientSecret}&grant_type=client_credentials&scope=ZohoMail.messages.CREATE`,
                  { method: 'POST' },
                ).catch(() => {
                  failed = true;
                });
                if (failed || !getNewAuthToken) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't get auth token.");

                const newAuthToken = await getNewAuthToken.json();
                zohoHeaders.set('Authorization', `Zoho-oauthtoken ${newAuthToken.access_token}`);
                zohoAuthExpireDT = nowDT + newAuthToken.expires_in * 1000 - 600000;
              }

              const sendEmailReq = await fetch(`https://mail.zoho.com/api/accounts/${config.email.accountId}/messages`, {
                method: 'POST',
                headers: zohoHeaders,
                body: JSON.stringify({
                  fromAddress: config.email.address,
                  toAddress: email,
                  subject: 'XIVPlan+DB Delete Code',
                  content: `Notice: account deletion is permanent and will delete all plans saved under your account.<br/><br/>Please use the following Delete Code to delete your account:<br/><br/>${newDeleteCode}`,
                }),
              }).catch(() => {
                failed = true;
              });
              if (failed || !sendEmailReq) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't send email.");

              const sentEmail = await sendEmailReq.json();
              if (sentEmail.status.code !== 200) return genericResponse(STATUS_CODE.InternalServerError, 'Failed to send email.');

              const maskedEmail = `${email.slice(0, 2)}***@***${email.slice(-5)}`;
              fetch(config.discordWebhook, {
                method: 'POST',
                headers: discordHeaders,
                body: JSON.stringify({ content: `Delete code email has been sent to \`${maskedEmail}\`.` }),
              }).catch(() => {});
              return genericResponse(STATUS_CODE.PreconditionFailed, `Please resubmit with the confirmation code emailed to "${maskedEmail}".`);
            } else if (hasEmail && body.deleteCode !== deleteCode) {
              return genericResponse(STATUS_CODE.BadRequest, 'Invalid delete code.');
            } else {
              return genericResponse(STATUS_CODE.InternalServerError, 'How are you here?');
            }
          } else if (path.startsWith('/delete/')) {
            const planId = path.replace('/delete/', '');
            const planMatch = await dbClient.query('SELECT ownerId FROM plans WHERE id = ?', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
            if (!planMatch.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist.');
            if (planMatch[0].ownerId !== id) return genericResponse(STATUS_CODE.Forbidden, "You don't own this plan.");

            await dbClient.execute('UPDATE plans SET deleted = 1, lastUpdated = ? WHERE id = ?', [new Date(), planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't update DB.");
            return genericResponse(STATUS_CODE.OK, 'Plan deleted.');
          } else if (path.startsWith('/perm-delete/')) {
            const planId = path.replace('/perm-delete/', '');
            const planMatch = await dbClient.query('SELECT ownerId, deleted FROM plans WHERE id = ?', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
            if (!planMatch.length) return genericResponse(STATUS_CODE.NotFound, 'Plan ID does not exist.');
            if (planMatch[0].ownerId !== id) return genericResponse(STATUS_CODE.Forbidden, "You don't own this plan.");
            if (!planMatch[0].deleted) return genericResponse(STATUS_CODE.Forbidden, 'Plan must be marked as deleted to perm delete.');

            await dbClient.execute('DELETE FROM plans WHERE id = ? AND deleted = 1', [planId]).catch(() => {
              failed = true;
            });
            if (failed) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't update DB.");
            return genericResponse(STATUS_CODE.OK, 'Plan permanently deleted.');
          }
          break;
      }
    }

    return genericResponse(STATUS_CODE.NotImplemented);
  } catch (e) {
    console.error(e);
    return genericResponse(STATUS_CODE.InternalServerError);
  }
});