/**
 * SimonUp Core Compiler (Core.js) - Version 1.2
 * Eine moderne, fluss- und blockorientierte Auszeichnungssprache.
 */
class SimonUp {
    constructor() {
        this.plugins = [];
        this.headings = [];
        this.counters = [0, 0, 0, 0, 0, 0];
    }

    /**
     * Registriert eine Erweiterung (Plugin)
     */
    use(plugin) {
        this.plugins.push(plugin);
        return this;
    }

    /**
     * Hauptfunktion: Wandelt SimonUp-Text (.up) in valides HTML um
     */
    parse(text) {
        this.headings = [];
        this.counters = [0, 0, 0, 0, 0, 0];

        let html = text;

        if (this.plugins && this.plugins.length > 0) {
            for (let i = 0; i < this.plugins.length; i++) {
                if (this.plugins[i].before) {
                    html = this.plugins[i].before(html);
                }
            }
        }

        html = this._parseBlocks(html);
        html = this._injectTOC(html);

        if (this.plugins && this.plugins.length > 0) {
            for (let i = 0; i < this.plugins.length; i++) {
                if (this.plugins[i].after) {
                    html = this.plugins[i].after(html);
                }
            }
        }

        return html;
    }

    /**
     * INTERN: Verarbeitet strukturelle Blöcke und freie Strukturen zeilenweise
     */
    _parseBlocks(text) {
        const lines = text.replace(/\r\n/g, '\n').split('\n');
        let result = [];
        let inBlock = false;
        let blockType = null;
        let blockMeta = ""; 
        let blockBuffer = [];

        for (let i = 0; i < lines.length; i++) {
            let line = lines[i];

            if (!inBlock && line.startsWith('&') && line.trim().length > 1) {
                inBlock = true;
                const fullHeader = line.substring(1).trim();
                const spaceIndex = fullHeader.indexOf(' ');

                if (spaceIndex !== -1) {
                    blockType = fullHeader.substring(0, spaceIndex).toLowerCase();
                    blockMeta = fullHeader.substring(spaceIndex).trim();
                } else {
                    blockType = fullHeader.toLowerCase();
                    blockMeta = "";
                }
                blockBuffer = [];
                continue;
            }

            if (inBlock && line.trim().replace(/\u00A0/g, ' ') === '&') {
                result.push(this._renderBlock(blockType, blockMeta, blockBuffer));
                inBlock = false;
                blockType = null;
                blockMeta = "";
                continue;
            }

            if (inBlock) {
                blockBuffer.push(line);
            } else {
                let trimmed = line.trim();
                
                if (trimmed === '___') {
                    result.push('<hr>');
                } else if (trimmed.startsWith('- ')) {
                    let insideUl = this._parseInline(line.replace(/^\s*-\s+/, ''));
                    result.push(`<ul-item>${insideUl}</ul-item>`);
                } else if (/^\d+\.\s+/.test(trimmed)) {
                    let cleanLine = line.replace(/^\s*\d+\.\s+/, '');
                    let insideOl = this._parseInline(cleanLine);
                    result.push(`<ol-item>${insideOl}</ol-item>`);
                } else {
                    result.push(this._parseInline(line));
                }
            }
        }

        return this._processParagraphsAndLists(result);
    }

    /**
     * INTERN: Erzeugt das HTML für einen geschlossenen Block
     */
    _renderBlock(type, meta, lines) {
        const content = lines.join('\n');
        let self = this;

        switch (type) {
            case 'toc':
                let tocWrapper = '';
                if (meta || content.trim()) {
                    tocWrapper = '<div class="simonup-toc-wrapper">\n';
                    if (meta) {
                        tocWrapper += `<h2>${meta}</h2>\n`;
                    }
                    if (content.trim()) {
                        const intro = lines.map(function(l) { return self._parseInline(l); }).join('<br>');
                        tocWrapper += `<p class="toc-intro">${intro}</p>\n`;
                    }
                    tocWrapper += '\n</div>';
                }
                return tocWrapper;

            case 'c': 
                const langClass = meta ? ` class="language-${meta}"` : '';
                const escapedCode = content.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
                return `<pre><code${langClass}>${escapedCode}</code></pre>`;

            case 'q': 
                const qContent = lines.map(function(l) { return self._parseInline(l); }).join('<br>');
                return `<blockquote>${qContent}</blockquote>`;

            case 'b': 
                const bContent = lines.map(function(l) { return self._parseInline(l); }).join('<br>');
                return `<div class="bible-block">${bContent}</div>`;

            case 'f': 
                const fSummary = meta || 'Details';
                const fContent = lines.map(function(l) { return self._parseInline(l); }).join('<br>');
                return `<details>\n<summary>${fSummary}</summary>\n<p>${fContent}</p>\n</details>`;

            case 'i': 
                const iColor = meta || '#ff6347';
                const iContent = lines.map(function(l) { return self._parseInline(l); }).join('<br>');
                return `<div class="infobox" style="border-left: 4px solid ${iColor}; padding: 10px; margin: 10px 0; background: #f8f9fa;">\n${iContent}\n</div>`;

            case 't': 
                return this._renderTable(meta, lines);

            default:
                const defContent = lines.map(function(l) { return self._parseInline(l); }).join('<br>');
                return `<div class="block-${type}">${defContent}</div>`;
        }
    }

    /**
     * INTERN: Hilfsfunktion zum Rendern von Multi-line-Tabellen und Galerien
     */
    _renderTable(meta, lines) {
        let tableHtml = '<table>\n';
        let currentCells = [];
        let cellBuffer = [];
        let self = this;

        for (let i = 0; i < lines.length; i++) {
            let line = lines[i];
            let parts = line.split('|');
            for (let j = 0; j < parts.length; j++) {
                let part = parts[j];
                
                if (j === parts.length - 1) {
                    if (part.trim() !== '') {
                        cellBuffer.push(part);
                    }
                    if (line.endsWith('|') && cellBuffer.length > 0) {
                        currentCells.push(cellBuffer.join('\n'));
                        cellBuffer = [];
                    }
                } else {
                    cellBuffer.push(part);
                    currentCells.push(cellBuffer.join('\n'));
                    cellBuffer = [];
                }
            }

            if (line.endsWith('|') && currentCells.length > 0) {
                let rowContent = currentCells.map(function(c) {
                    let parsedCell = self._parseInline(c.trim()).replace(/\n/g, '<br>');
                    return `<td>${parsedCell}</td>`;
                }).join('\n');
                tableHtml += `<tr>\n${rowContent}\n</tr>\n`;
                currentCells = [];
            }
        }
        tableHtml += '</table>';
        return tableHtml;
    }

    /**
     * INTERN: Verarbeitet Fluss-Formatierungen (Inline) mittels V1.2-RegEx
     */
    _parseInline(text) {
        if (!text) return '';
        let html = text;

        const escapes = [];
        html = html.replace(/\\(.)/g, function(match, char) {
            escapes.push(char);
            return '';
        });

        html = html.replace(/\/\/(( \s|$))/g, '$1');

        let self = this;
        const processHeading = function(pattern, callback) {
            let match;
            while ((match = pattern.exec(html)) !== null) {
                const fullMatch = match[0];
                const level = parseInt(match[1]);
                const titleAndRest = match[2];
                
                let title = titleAndRest;
                let rest = "";
                const closeIdx = titleAndRest.indexOf('/#');
                if (closeIdx !== -1) {
                    title = titleAndRest.substring(0, closeIdx);
                    rest = titleAndRest.substring(closeIdx + 2);
                }

                const result = callback(level, title.trim(), rest);
                html = html.substring(0, match.index) + result + html.substring(match.index + fullMatch.length);
            }
        };

        processHeading(/^([1-6])x#\s*(.*)/g, function(level, title, rest) {
            const numStr = self._getAutoNumber(level);
            const fullTitle = `${numStr} ${title}`;
            const id = self._slugify(fullTitle);
            self.headings.push({ level: level, text: fullTitle, id: id });
            return `<h${level} id="${id}">${fullTitle}</h${level}>${rest}`;
        });

        processHeading(/^([1-6])-#\s*(.*)/g, function(level, title, rest) {
            return `<h${level}>${title}</h${level}>${rest}`;
        });

        processHeading(/^([1-6])#\s*(.*)/g, function(level, title, rest) {
            const id = self._slugify(title);
            self.headings.push({ level: level, text: title, id: id });
            return `<h${level} id="${id}">${title}</h${level}>${rest}`;
        });

        const inlineRules = [
            { tag: 'strong', symbol: '\\*\\*' },
            { tag: 'span style="font-weight: 500;"', symbol: '\\*' },
            { tag: 'em', symbol: '%' },
            { tag: 'u', symbol: '_' },
            { tag: 'del', symbol: '~' },
            { tag: 'mark', symbol: '=' },
            { tag: 'sup', symbol: '\\^' },
            { tag: 'sub', symbol: '°' },
            { tag: 'code', symbol: '`' }
        ];

        for (let k = 0; k < inlineRules.length; k++) {
            let rule = inlineRules[k];
            let tagSimple = rule.tag.split(' ')[0];
            
            let regex = new RegExp(rule.symbol + '(.+?)\\\\' + rule.symbol, 'g');
            html = html.replace(regex, `<${rule.tag}>$1</${tagSimple}>`);

            let resetRegex = new RegExp(rule.symbol + '(.+?)(?=)', 'g');
            html = html.replace(resetRegex, `<${rule.tag}>$1</${tagSimple}>`);
        }
        
        html = html.replace(//g, '');

        const alignMap = { 'l': 'left', 'r': 'right', 'c': 'center', 'j': 'justify' };
        html = html.replace(/>([lrcj])\s+(.+?)\s*\/>/g, function(m, dir, content) {
            return `<div style="text-align: ${alignMap[dir]};">${content}</div>`;
        });

        html = html.replace(/!\[([^\]]+)\s+w:(\d+)\]\(([^)]+)\)/g, '<img src="$3" alt="$1" style="width: $2px; height: auto;">');
        html = html.replace(/!\[([^\]]+)\]\(([^)]+)\)/g, '<img src="$2" alt="$1">');
        html = html.replace(/\[([^\]]+)\]\{([^}]+)\}/g, '<a href="$2" target="_blank" rel="noopener noreferrer">$1</a>');
        html = html.replace(/\[([^\]]+)\]\(([^)]+)\)/g, '<a href="$2">$1</a>');

        html = html.replace(/\^x\[([^\]]+)\]\^x/g, '<span class="footnote-auto" title="$1">[*]</span>'); 
        html = html.replace(/\^(\d+)\[([^\]]+)\]\^x/g, '<sup class="footnote-manual" title="$2">[$1]</sup>');

        html = html.replace(//g, function(match, idx) {
            return escapes[idx];
        });

        return html;
    }

    /**
     * INTERN: Errechnet die nächste fortlaufende Kapitelnummer
     */
    _getAutoNumber(level) {
        let idx = level - 1;
        this.counters[idx]++;
        for (let i = idx + 1; i < 6; i++) {
            this.counters[i] = 0;
        }
        let activeParts = this.counters.slice(0, level);
        return activeParts.join('.') + '.';
    }

    /**
     * INTERN: Macht aus Text eine URL-konforme ID
     */
    _slugify(text) {
        return text.toLowerCase()
            .replace(/[^a-z0-9\s-]/g, '') 
            .replace(/\s+/g, '-');        
    }

    /**
     * INTERN: Erzeugt die fertige HTML-Liste des TOC und injiziert sie in den Block
     */
    _injectTOC(html) {
        if (!html.includes('')) {
            return html;
        }
        if (this.headings.length === 0) {
            return html.replace('', '');
        }

        let tocListHtml = '<div class="simonup-toc">\n<ul>\n';
        let currentLevel = 1;

        for (let i = 0; i < this.headings.length; i++) {
            let heading = this.headings[i];
            if (heading.level > currentLevel) {
                let diffUp = heading.level - currentLevel;
                tocListHtml += '<ul>\n'.repeat(diffUp);
            } else if (heading.level < currentLevel) {
                let diffDown = currentLevel - heading.level;
                tocListHtml += '</ul>\n'.repeat(diffDown);
            }
            currentLevel = heading.level;
            tocListHtml += `<li><a href="#${heading.id}">${heading.text}</a></li>\n`;
        }
        
        if (currentLevel > 1) {
            let diffFinal = currentLevel - 1;
            tocListHtml += '</ul>\n'.repeat(diffFinal);
        }
        tocListHtml += '</ul>\n</div>';

        return html.replace('', tocListHtml);
    }

    /**
     * INTERN: Fasst freie Listen-Elemente zusammen und generiert Absätze (p)
     */
    _processParagraphsAndLists(elements) {
        let processed = [];
        let paragraphBuffer = [];
        let listBuffer = [];
        let currentListType = null; 

        const flushList = function() {
            if (listBuffer.length > 0) {
                let items = listBuffer.map(function(item) { return `  <li>${item}</li>`; }).join('\n');
                processed.push(`<${currentListType}>\n${items}\n</${currentListType}>`);
                listBuffer = [];
                currentListType = null;
            }
        };

        const flushParagraph = function() {
            if (paragraphBuffer.length > 0) {
                let pContent = paragraphBuffer.join('<br>');
                processed.push(`<p>${pContent}</p>`);
                paragraphBuffer = [];
            }
        };

        for (let i = 0; i < elements.length; i++) {
            let element = elements[i];
            let isUlItem = element.startsWith('<ul-item>');
            let isOlItem = element.startsWith('<ol-item>');

            if (isUlItem || isOlItem) {
                flushParagraph();
                let type = isUlItem ? 'ul' : 'ol';
                let content = isUlItem ? element.replace(/<\/?ul-item>/g, '') : element.replace(/<\/?ol-item>/g, '');
                
                if (currentListType && currentListType !== type) {
                    flushList();
                }
                currentListType = type;
                listBuffer.push(content);
            } else if (element.startsWith('<') && !/^(<a>|<strong>|<em>|<u>|<del>|<mark>|<sup>|<sub>|<span>|<code>|<img>|<h\d)/i.test(element)) {
                flushList();
                flushParagraph();
                processed.push(element);
            } else if (element.trim() === '') {
                flushList();
                flushParagraph();
            } else {
                flushList();
                paragraphBuffer.push(element);
            }
        }

        flushList();
        flushParagraph();

        return processed.join('\n');
    }
}