function load(textarea, div) {
    div.innerHTML = '';
    let lines = textarea.value.split('\n');
    let firsttableline = null;
    for (let i = 0; i < lines.length; i++) {
        let line = lines[i];
        let elem = formatLine(line);
        div.append(elem);
        if (elem.classList.contains('tablerow')) {
            if (firsttableline == null) {
                firsttableline = elem;
            }
        } else if (firsttableline != null) {
            formatTable(firsttableline);
            firsttableline = null;
        }
    }
}

function save(textarea, div) {
    let lines = div.children;
    let text = '';
    for (let i=0; i<lines.length; i++) {
        if (lines[i].innerText != '\n') {
            text += lines[i].innerText.replace(emsp(), '\t');
        }
        if (i < lines.length - 1) {
            text += '\n';
        }
    }
    textarea.value = text;
}

function emsp() {
    return ' ';
}

function onlinkin(e) {
    let link = e.currentTarget;
    if (document.getElementById('mdnotes') !== document.activeElement) {
        document.getElementById('mdnotes').contentEditable = false;
    }
}

function onlink(e) {
    let mdnotes = document.getElementById('mdnotes');
    if (mdnotes.contentEditable == 'false') {
        e.preventDefault();
        mdnotes.contentEditable = true;
        let link = e.currentTarget;
        if (link.host !== document.location.host) {
            open(link.href);
        } else {
            open(link.href, '_self');
        }
        return false;
    } else {
        return true;
    }
}

function onlinkout(e) {
    let mdnotes = document.getElementById('mdnotes');
    if (mdnotes.contentEditable == 'false') {
        mdnotes.contentEditable = true;
    }    
}

function formatLine(line) {
    let token = null;
    let elem = document.createElement('div');
    elem.classList.add('mdnotes_line');
    if (line == '' || line == '\n') {
        elem.classList.add('body');
        elem.innerHTML = '<br>';
        return elem;
    }
    line = line.replace(/\t/, emsp());
    line = line.replace('&', '&amp;');
    line = line.replace('<', '&lt;');
    let ret = removeMono(line);
    line = ret[0];
    let listMono = ret[1];
    if (line.match(/^\s*-{3,}\s*$/)) {
        token = /^(\s*-{3,}\s*)$/
        elem.classList.add('line');
    } else if (line.match(/^\s*####(\s|$)/i)) {
        token = /^(\s*####(\s|$))/i;
        elem.classList.add('h4');
    } else if (line.match(/^\s*###(\s|$)/i)) {
        token = /^(\s*###(\s|$))/i;
        elem.classList.add('h3');
    } else if (line.match(/^\s*##(\s|$)/)) {
        token = /^(\s*##(\s|$))/i;
        elem.classList.add('h2');
    } else if (line.match(/^\s*#(\s|$)/i)) {
        token = /^(\s*#(\s|$))/i;
        elem.classList.add('h1');
    } else if (line.match(/^\s*>\s*>\s*>(\s|$)/i)) {
        token = /^(\s*>\s*>\s*>(\s|$))/i;
        elem.classList.add('bq3');
        elem.classList.add('bq');
    } else if (line.match(/^\s*>\s*>(\s|$)/i)) {
        token = /^(\s*>\s*>(\s|$))/i;
        elem.classList.add('bq2');
        elem.classList.add('bq');
    } else if (line.match(/^\s*>(\s|$)/i)) {
        token = /^(\s*>(\s|$))/i;
        elem.classList.add('bq1');
        elem.classList.add('bq');
    } else {
        elem.classList.add('body');
    }
    if (elem.classList.contains('bq') || elem.classList.contains('body')) {
        if (line.match(/^\s*((>\s*){0,3}\s)?([\*\-+]\s*){3}(\s|$)/i)) {
            token = /^(\s*(>\s*){0,3}([\*\-+]\s*){3}(\s|$))/i;
            elem.classList.add('ul3');
            elem.classList.remove('body');
        } else if (line.match(/^\s*((>\s*){0,3}\s)?([\*\-+]\s*){2}(\s|$)/i)) {
            token = /^(\s*(>\s*){0,3}([\*\-+]\s*){2}(\s|$))/i;
            elem.classList.add('ul2');
            elem.classList.remove('body');
        } else if (line.match(/^\s*((>\s*){0,3}\s)?[\*\-+](\s|$)/i)) {
            token = /^(\s*(>\s*){0,3}[\*\-+](\s*|$))/;
            elem.classList.add('ul1');
            elem.classList.remove('body');
        } else if (line.match(/^\s*((>\s*){0,3}\s)?([0-9]+\.){3}(\s|$)/i)) {
            token = /^(\s*(>\s*){0,3}(\s*|$))/;
            elem.classList.add('ol3');
            elem.classList.remove('body');
        } else if (line.match(/^\s*((>\s*){0,3}\s)?([0-9]+\.){2}(\s|$)/i)) {
            token = /^(\s*(>\s*){0,3}(\s*|$))/;
            elem.classList.add('ol2');
            elem.classList.remove('body');
        } else if (line.match(/^\s*((>\s*){0,3}\s)?[0-9]+\.(\s|$)/i)) {
            token = /^(\s*(>\s*){0,3}(\s*|$))/;
            elem.classList.add('ol1');
            elem.classList.remove('body');
        }
    }
    if (token != null) {
        line = line.replace(token, '<span class="token">$1</span>');
    }
    line = addLink(line);
    line = addBold(line);
    line = addItalic(line);
    line = addTableLine(line);
    line = addMono(line, listMono);
    elem.innerHTML = line;
    if (elem.getElementsByClassName('tablerow').length > 0) {
        if (elem.childNodes[0].childNodes.length > 0) {
            let child = elem.childNodes[0].childNodes[0];
            while(child != null) {
                if (child.nodeType == 3) {
                    let newchild = document.createElement('span');
                    newchild.innerText = child.nodeValue;
                    child.parentNode.replaceChild(newchild, child);
                    child = newchild;
                }
                child = child.nextSibling;
            }
        }
        elem.classList.remove('body');
        elem.classList.add('tablerow');
    }
    let links = elem.getElementsByClassName('link');
    for (let i=0; i<links.length; i++) {
        let link = links[i];
        link.addEventListener('mouseover', onlinkin);
        link.addEventListener('click', onlink);
        link.addEventListener('mouseout', onlinkout);
    }
    return elem;
}

function addTableLine(line) {
    if (line.match(/^\s*\|(\s*.*?\|)*/)) {
        let cpt = 0;
        let re = /\|/g;
        let match;
        let matches = [];
        while ((match = re.exec(line)) != null) {
            matches[cpt] = match.index;
            if (cpt > 1000) {
                continue;
            }
            cpt++;
        }
        matches = matches.reverse();
        for(let i=0; i<matches.length; i++) {
            let index = matches[i];
            if (i == matches.length - 1) {
                // premier |
                line = line.substring(0, index) + '<span class="token">|</span><span class="lefttablespacer"></span>' + line.substring(index+1, line.length);
                continue;
            }
            if (i == 0 && index == line.length - 1) {
                // dernier |
                line = line.substring(0, index) + '<span class="righttablespacer"></span><span class="token">|</span>' + line.substring(index+1, line.length);
                continue;
            }
            line = line.substring(0, index) + '<span class="righttablespacer"></span><span class="token">|</span><span class="lefttablespacer"></span>' + line.substring(index+1, line.length);
        }
        line = '<span class="tablerow">' + line + '</span>';
    }
    return line;
}

function formatTable(line) {
    if (! line.classList.contains('tablerow')) {
        return;
    }

    let firstline = line;
    let lastline = line;
    while (firstline.previousSibling !== null && firstline.previousSibling.classList.contains('tablerow')) {
        firstline = firstline.previousSibling;
        firstline.classList.remove('firsttablerow');
        firstline.classList.remove('lasttablerow');
    }
    while (lastline.nextSibling !== null && lastline.nextSibling.classList.contains('tablerow')) {
        lastline = lastline.nextSibling;
        lastline.classList.remove('firsttablerow');
        lastline.classList.remove('lasttablerow');
    }
    firstline.classList.add('firsttablerow');
    lastline.classList.add('lasttablerow');
    resizeTableCols(firstline, lastline)
}


function resizeTableCols(firstline, lastline) {
    let colsmaxwidth = [];
    let currentline = firstline;
    while (currentline !== null && currentline.classList.contains('tablerow')) {
        let tablerow = currentline.getElementsByClassName('tablerow')[0];
        let childNodes = tablerow.childNodes;
        let currentwidth = 0;
        let col = 0;
        let currentleft;
        for(let i=0; i<childNodes.length; i++) {
            let child = childNodes[i];
            if (currentleft == null && child.classList != null && child.classList.contains('lefttablespacer')) {
                currentleft = child;
            } else {
                if (child.classList != null && child.classList.contains('righttablespacer')) {
                    if (colsmaxwidth[col] == null || colsmaxwidth[col] < currentwidth) {
                        colsmaxwidth[col] = currentwidth;
                    }
                    child.dataWidth = currentwidth;
                    currentleft.dataWidth = currentwidth;
                    currentleft = null;
                    currentwidth = 0;
                    col += 1;
                } else {
                    let width = child.getBoundingClientRect().width;
                    currentwidth += width;
                }
            }
        }
        currentline = currentline.nextSibling;
    }

    currentline = firstline;
    while (currentline !== null && currentline.classList.contains('tablerow')) {
        let tablerow = currentline.getElementsByClassName('tablerow')[0];
        let childNodes = tablerow.childNodes;
        let col = 0;
        let currentleft;
        for(let i=0; i<childNodes.length; i++) {
            let child = childNodes[i];
            if (currentleft == null && child.classList != null && child.classList.contains('lefttablespacer')) {
                currentleft = child;
            } else {
                if (child.classList != null && child.classList.contains('righttablespacer')) {
                    let leftwidth = 10;
                    let rightwidth = Math.ceil(colsmaxwidth[col] - child.dataWidth) + 10;
                    currentleft.style.width = '' + leftwidth + 'px';
                    child.style.width = '' + rightwidth + 'px';
                    currentleft = null;
                    col += 1;
                }
            }
        }
        currentline = currentline.nextSibling;
    }
}

function removeMono(line) {
    let listMono = line.match(/`(`|.*?)`/g);
    if (listMono == null) {
        return [line, null];
    }
    
    line = line.replace(/`(`|.*?)`/g, "``");
    return [line, listMono.reverse()];
}

function addMono(line, listMono) {
    if (listMono == null) {
        return line;
    }
    let cpt = 0;
    let match;
    let matches = [];
    let re = /``/g;
    while ((match = re.exec(line)) != null) {
        matches[cpt] = match.index;
        if (cpt > 1000) {
            continue;
        }
        cpt++;
    }
    matches = matches.reverse();
    for(let i=0; i<matches.length; i++) {
        let mono = listMono[i];
        mono = mono.substring(1, mono.length - 1);
        line = line.substring(0, matches[i]) + '<span class="token">`</span><span class="mono">' + mono + '</span><span class="token">`</span>' + line.substring(matches[i]+2, line.length);
    }
    return line;
}

function addLink(line) {
    line = line.replace(/(\[([^\]]+?)\]\(([^\)]+?)\))/ig, '<span class="token">[</span><a class="link" data-href="$3" href="$3">$2</a><span class="token">]($3)</span>');
    line = line.replace(/(\[([^\]]+?)\]\(\))/ig, '<span class="token">[</span><a class="link" data-href="$2" href="$2">$2</a><span class="token">]()</span>');
    line = line.replace(/(\[\]\(([^\)]+?)\))/ig, '<span class="token">[](</span><a class="link" data-href="$2" href="$2">$2</a><span class="token">)</span>');
    return line;
}

function addBold(line) {
    line = line.replace(/\*\*([^\s].*?)\*\*/ig, '<span class="bold"><span class="token">**</span>$1<span class="token">**</span></span>');
    line = line.replace(/__([^\s].*?)__/ig, '<span class="bold"><span class="token">__</span>$1<span class="token">__</span></span>');
    return line;
}

function addItalic(line) {
    line = line.replace(/(^|[^\*])\*([^\*\s].*?[^\*\s]|[^\*\s])\*([^\*]|$)/ig, '$1<span class="italic"><span class="token">*</span>$2<span class="token">*</span></span>$3');
    line = line.replace(/(^|[^_])_([^_\s].*?[^_\s]|[^_\s])_([^_]|$)/ig, '$1<span class="italic"><span class="token">_</span>$2<span class="token">_</span></span>$3');
    return line;
}

export { load, save, formatLine, formatTable };