'use-strict';

const dirTree = require('directory-tree');
const express = require('express');
const fs = require('fs');


const app = express();
const path = 'md';

process.on('uncaughtException', function(err) {
    console.error("[" + new Date() + "] > " + "Error - " + err);
});


const report = require('vfile-reporter');

const guide = require('remark-preset-lint-markdown-style-guide');
const html = require('remark-rehype');
const kbd = require('remark-kbd');
const math = require('remark-math');
const mermaid = require('remark-mermaid-simple');
const highlight = require('remark-highlight.js');
const sb = require('remark-special-box');
const qcm = require('remark-qcm');
const lineInput = require('remark-line-input');
const textInput = require('remark-text-input');

const raw = require('rehype-raw');
const rehypeKatex = require('rehype-katex')
const rehypeStringify = require('rehype-stringify')

const unified = require('unified');
const remark = require('remark-parse');

const inspect = require('unist-util-inspect');

const useLandScript = " <script> mermaid.contentLoaded(); </script>"
const userSide_Button = '<button class="raw_button" ><div><div>Raw</div></div></button></form>'

function to_HTML( data, fnc ) {
      unified()
      .use(remark)
//      .use(guide)
      .use(mermaid)
      .use(lineInput)
//      .use(textInput)
      .use(math)
      .use(kbd)
      .use(sb)
      .use(qcm)
      .use(highlight)
      .use(html, {allowDangerousHTML: true})
      .use(rehypeKatex)
      .use(raw)
      .use(rehypeStringify)

      .process(data, fnc );
}



app.use(express.static('public'));

app.get('/' + path + '/*', function(req, res) {
    var url = decodeURI(req._parsedUrl.pathname);
    var query = req.query;

    console.log("[" + new Date() + "] > " + "200 - " + url);
    if( query && query['raw'] == 'true' ) {
      res.sendFile(url, { root: '.',
                          dotfiles:'deny',
                          headers: {
                              'x-timestamp': Date.now(),
                              'x-sent': true} }, function(err) {
                                if( err ) {
                                  next(err);
                                } else {
                                  console.log("Sent : ", url);
                                }
                              });
      return;
    }
    fs.readFile(url.substr(1), 'utf8', function(err, data) {
        if (err)
            return console.log(err);

//    remark()
      /*  Debbug comment
      const a = unified()
      .use(remark)
      .use(mermaid)
      .use(lineInput)
      .use(textInput)
      .use(html, {allowDangerousHTML: true})
      .use(raw)
        .parse(data)
      console.log(inspect(a));
      */

      to_HTML(data, function (err, file) {
        res.send(String(file) + useLandScript +
          '<a href="' +  url + '?raw=true" class="no-style">' + userSide_Button + '</a>');
        console.error(report(err || file));
      });
    });
});

app.get('/data', function(req, res) {
    console.log("[" + new Date() + "] > " + "200 - " + req.url);
    res.send(dirTree(path, {extensions:/\.md/}));
});

app.get('/img/*', function (req, res) {
    console.log("[" + new Date() + "] > " + "200 - " + req.url);
    if( path == '/img/ic_info_black_48px.svg' ||
        path == '/imr/ic_error_black_48px.svg' ||
        path == '/imr/ic_good_black_48px.svg' ||
        path == '/imr/ic_bad_black_48px.svg' ||
        path == '/imr/ic_comment_black_48px.svg' ||
        path == '/imr/ic_help_black_48px.svg' ) {
      const img = fs.readFileSync(path);
      res.writeHead(200, {'Content-Type': 'image/svg' });
      res.end(img, 'binary');
    }else {
      const img = fs.readFileSync(req.url.replace('/img', path));
      res.writeHead(200, {'Content-Type': 'image/gif' });
      res.end(img, 'binary');
    }
});

app.get('/', function(req, res) {
    console.log("[" + new Date() + "] > " + "200 - " + req.url);
    fs.readFile('public/index.html', 'utf8', function(err, data) {
        if (err)
            return console.log(err);
        res.send(data);
    });
});

app.get('*', function(req, res) {
    console.error("[" + new Date() + "] > " + "404 - " + req.url);
    fs.readFile('public/404.md', 'utf8', function(err, data) {
        if (err)
            return console.log(err);
        fs.readFile('public/css/style.css', 'utf8', function(err, style) {
            to_HTML( data, function( err, file ) {
              var html = '<html>';
              html += '<head>';
              html += '<style>' + style + '</style>';
              html += '</head>';
              html += '<body class=\'markdown-preview\' data-use-github-style>';
              html += String(file);
              html += '</body>';
              html += '</html>';
              res.status(404).send(html);
            });
        });
    });
});

var server = app.listen(8090, function() {
    var host = server.address().address;
    var port = server.address().port;
    console.log("[" + new Date() + "] > " + "App listening at http://%s:%s", host, port);
});