'use strict';

const express = require('express');
const next = require('next');
const fs = require('fs');
const path = require('path');
const sqlite3 = require('sqlite3').verbose();

const repositoryDirectory = './user-content-access/';
const dbFile = './gitcub.db';

const dev = process.env.NODE_ENV !== 'production';
const port = 3000;
const app = next({ dev });
const handle = app.getRequestHandler();

const directoryExists = (path) => fs.existsSync(path) ? fs.statSync(path).isDirectory() : false;

const repositoryExists = (name, rows) => (
  directoryExists(repositoryDirectory + name) && rows.some((x) => x.name === name)
);

const pathIsValid = (pathArray, rows) => {
  if (pathArray.length > 0) {
    if (repositoryExists(pathArray[0], rows)) {
      if (directoryExists(repositoryDirectory + pathArray.join('/'))) {
        return true;
      } else return false;
    } else return false;
  } else return false;
}

const sendAPIResult = (req, res, rows) => {
  if (req.originalUrl.indexOf('\0') === -1) {
    const pathNormalized = path.normalize(req.path);
    const pathArray = pathNormalized.split('/').filter((x) => x.length > 0);
    
    // remove 'api'
    pathArray.shift();
    
    if (pathArray.length > 0) {
      if (repositoryExists(pathArray[0], rows)) {
        if (pathIsValid(pathArray, rows)) {
          const dirList = fs.readdirSync(
            repositoryDirectory + pathArray.join('/'),
            (err, files) => {
              if (err) {
                console.log(err);
              } else return files;
            }
          );

          const APIResult = {
            resultType: 'data',
            resultContent: dirList,
          }

          res.json(APIResult);
        } else {
          const APIResult = {
            resultType: 'error',
            resultContent: 'Directory does not exist.',
          }
          
          res.json(APIResult);
        }
      } else {
        const APIResult = {
          resultType: 'error',
          resultContent: 'Repository does not exist.',
        }
        
        res.json(APIResult);
      }
    } else {
      const APIResult = {
        resultType: 'error',
        resultContent: 'Repository not specified.',
      }

      // note, this case is not yet reachable
      res.json(APIResult);
    }
  } else {
    const APIResult = {
      resultType: 'error',
      resultContent: 'Null byte found in url. Nice try :)',
    }
    
    res.json(APIResult);
  }
}

app.prepare()
.then(() => {
  const server = express();
  const db = new sqlite3.Database(dbFile, sqlite3.OPEN_READWRITE);

  server.get('/api/*', (req, res) => {
    db.all('select name from repositories', (err, rows) => {
      sendAPIResult(req, res, rows);
    });
  });

  server.get('*', (req, res) => {
    return handle(req, res);
  });

  server.listen(port, () => {
    console.log(`Example app listening on port ${port}`);
  });
})
.catch((ex) => {
  console.error(ex.stack);
  process.exit(1);
});