// convert our markdown documentation files
// to 'static' html/ejs partials:
// while this is a bit inconvenient (you need to restart
// the server everytime you want to see
// md changes), it is more efficient in
// that we aren't converting MD -> ejs
// on EVERY request
const showdown = require('showdown'),
    showdownHighlight = require("showdown-highlight"),
    fs = require('fs'),
    mkdirp = require('mkdirp'),
    projectInputDir = './project_writeups/',
    projectOutputDir = './views/partials/md/projects/',
    recipeInputDir = './recipes/',
    recipeOutputDir = './views/partials/md/recipes/',
    classMap = {
        h1: 'display-1' //tag type : class to add to all tags of that type (class="display-1" added to all <h1>)
    };

// handles adding classes to specific
// tag types automatically
const addClass = {
    type: 'output', // when it's triggered -> output is at the very end when text is html
    filter: text => {
        var modifiedText = text;
        Object.keys(classMap).forEach(function (key) {
            var regex = new RegExp(`<${key}(.*?)>`, 'g');
            matcher = regex.exec(modifiedText);

            // only proceed if we found a match, and the class we add isn't already on the tag somehow
            while (matcher != null && !matcher[0].includes(classMap[key])) {
                // add the class content WHILE preserving any other properties already in the tag!
                console.log("adding class content in: " + matcher[0]);

                var restOfTag = matcher[1];
                modifiedText = modifiedText.replace(matcher[0], `<${key} class="${classMap[key]}" ${restOfTag}>`);

                matcher = regex.exec(modifiedText);
            }
        });
        return modifiedText;
    }
};

// create our Showdown converter with our custom extension
const converter = new showdown.Converter({
    extensions: [addClass, showdownHighlight],
    tables: true
});


function convertMarkdownInDir(inputDir, outputDir) {
    // make the directory for the html output if necessary
    mkdirp.sync(outputDir);
    fs.readdir(inputDir, (err, files) => {
        files.forEach(file => {
            if (file.endsWith('.md')) {
                let fileNameNoExtension = file.slice(0, -3);
                console.log('converting: ' + fileNameNoExtension);
                fs.readFile(inputDir + file, 'utf8', (err, data) => {
                    if (err) {
                        console.error(err);
                    } else {
                        let html = converter.makeHtml(data); // where the magic happens
                        fs.writeFile(outputDir + fileNameNoExtension + '.ejs', html, 'utf8', (err) => {
                            if (err) {
                                console.error(err);
                            }
                        });
                    }
                });
            }
        });
    });
}

convertMarkdownInDir(projectInputDir, projectOutputDir);
convertMarkdownInDir(recipeInputDir, recipeOutputDir);