'use strict';

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

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 + '.git') && rows.some((x) => x.name === name)
);

const sendRepositoryResult = (res, pathArray, tree) => {
  const recursion = (pathArray, tree) => {
    if (pathArray.length > 0) {
      const entries = tree.entries();
      const predicate = (x) => x.name() === pathArray[0] && x.isTree()

      if (entries.some(predicate)) {
        entries.find(predicate).getTree().then((tree) => {
          pathArray.shift();
          recursion(pathArray, tree);
        });
      } else {
        const APIResult = {
          resultType: 'error',
          resultContent: 'Directory does not exist.',
        }
        
        res.json(APIResult);
      }
    } else {
      const dirList = tree.entries().map((entry) => entry.name());
    
      const APIResult = {
        resultType: 'data',
        resultContent: dirList,
      }

      res.json(APIResult);
    }
  }

  recursion(pathArray, tree);
}

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)) {
        const pathToRepo = repositoryDirectory + pathArray[0] + '.git'
        nodeGit.Repository.openBare(pathToRepo).then((repo) => {
          repo.getMasterCommit().then((commit) => {
            commit.getTree().then((tree) => {
              pathArray.shift();
              sendRepositoryResult(res, pathArray, tree);
            });
          });
        });
      } 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);
});