/**
 * SimonUp Core Compiler (Core.js)
 * Eine moderne, fluss- und blockorientierte Auszeichnungssprache.
 */
class SimonUp {
    constructor() {
        this.plugins = [];
        this.headings = [];      // Speichert alle gefundenen Überschriften für das TOC
        this.counters = [0, 0, 0, 0, 0, 0]; // Zähler für die hierarchischen Ebenen 1 bis 6
    }

    /**
     * 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;

        for (const plugin of this.plugins) {
            if (plugin.before) html = plugin.before(html);
        }

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

        for (const plugin of this.plugins) {
            if (plugin.after) html = plugin.after(html);
        }

        return html;
    }

    /**
     * INTERN: Verarbeitet strukturelle Blöcke 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() === '&') {
                result.push(this._renderBlock(blockType, blockMeta, blockBuffer));
                inBlock = false;
                blockType = null;
                blockMeta = "";
                continue;
            }

            if (inBlock) {
                blockBuffer.push(line);
            } else {
                if (line.trim() === '___') {
                    result.push('<hr>');
                } else {
                    result.push(this._parseInline(line));
                }
            }
        }

        return this._processParagraphs(result);
    }

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

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

            case '-': 
                return '<ul>\n' + lines.filter(l => l.trim()).map(l => `<li>${this._parseInline(l)}</li>`).join('\n') + '\n</ul>';

            case '+': 
                return '<ol>\n' + lines.filter(l => l.trim()).map(l => `<li>${this._parseInline(l)}</li>`).join('\n') + '\n</ol>';

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

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

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

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

            case 'i': 
                return `<div class="infobox" style="border-left: 4px solid ${meta || '#007bff'}; padding: 10px; margin: 10px 0; background: #f8f9fa;">\n${lines.map(l => this._parseInline(l)).join('<br>')}\n</div>`;

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

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

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

        for (let line of lines) {
            if (line.trim() === '') continue;

            let parts = line.split('|');
            for (let i = 0; i < parts.length; i++) {
                let part = parts[i];
                if (i === parts.length - 1 && part.trim() === '') {
                    if (cellBuffer.length > 0 || part !== '') {
                        cellBuffer.push(part);
                    }
                    if (cellBuffer.length > 0) {
                        currentCells.push(cellBuffer.join('\n'));
                        cellBuffer = [];
                    }
                    tableHtml += '<tr>\n' + currentCells.map(c => `<td>${this._parseInline(c.trim())}</td>`).join('\n') + '\n</tr>\n';
                    currentCells = [];
                } else {
                    cellBuffer.push(part);
                    if (i < parts.length - 1) {
                        currentCells.push(cellBuffer.join('\n'));
                        cellBuffer = [];
                    }
                }
            }
        }
        tableHtml += '</table>';
        return tableHtml;
    }

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

        // 1. ESCAPE: Temporär schützen
        html = html.replace(/\\(.)/g, (match, char) => ``);

        // 2. ÜBERSCHRIFTEN (Flusssicher angepasst)
        
        // Regel A: Automatische Nummerierung (3#x Titel 3#x Restlicher Text)
        html = html.replace(/([1-6])#x\s*([^#]+?)\s*\1#x(.*)/g, (match, level, title, rest) => {
            const lvl = parseInt(level);
            const numStr = this._getAutoNumber(lvl);
            const fullTitle = `${numStr} ${title.trim()}`;
            const id = this._slugify(fullTitle);
            
            this.headings.push({ level: lvl, text: fullTitle, id: id });
            return '<h' + lvl + ' id="' + id + '" style="display:inline-block; margin-right:10px;">' + fullTitle + '</h' + lvl + '>' + rest; 
        });

        // Regel B: Vom TOC ausgeschlossene Titel (3#- Titel 3#- Restlicher Text)
        html = html.replace(/([1-6])#-\s*([^#]+?)\s*\1#-(.*)/g, (match, level, title, rest) => {
            const lvl = parseInt(level);
            return '<h' + lvl + ' style="display:inline-block; margin-right:10px;">' + title.trim() + '</h' + lvl + '>' + rest;
        });

        // Regel C: Manuelle Nummerierung (3# Titel 3# Restlicher Text)
        html = html.replace(/([1-6])#\s*([^#]+?)\s*\1#(.*)/g, (match, level, title, rest) => {
            const lvl = parseInt(level);
            const id = this._slugify(title.trim());
            
            this.headings.push({ level: lvl, text: title.trim(), id: id });
            return '<h' + lvl + ' id="' + id + '" style="display:inline-block; margin-right:10px;">' + title.trim() + '</h' + lvl + '>' + rest;
        });

        // Regel D: Das schnelle, solitäre # für H1 (# Titel # Restlicher Text)
        html = html.replace(/#([^#]+)#(.*)/g, (match, title, rest) => {
            const id = this._slugify(title.trim());
            this.headings.push({ level: 1, text: title.trim(), id: id });
            return '<h1 id="' + id + '" style="display:inline-block; margin-right:10px;">' + title.trim() + '</h1>' + rest;
        });

        // 3. STANDARD FLUSS-FORMATIERUNGEN (In priorisierter Reihenfolge)
        html = html.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>'); // Fett
        html = html.replace(/\/([^/]+)\//g, '<em>$1</em>');             // Kursiv
        html = html.replace(/_([^_]+)_/g, '<u>$1</u>');                 // Unterstrichen
        html = html.replace(/~([^~]+)~/g, '<del>$1</del>');             // Durchgestrichen
        html = html.replace(/=([^=]+)=/g, '<mark>$1</mark>');           // Highlight
        html = html.replace(/\^([^^]+)\^/g, '<sup>$1</sup>');           // Hochgestellt
        html = html.replace(/°([^°]+)°/g, '<sub>$1</sub>');             // Tiefgestellt
        html = html.replace(/`([^`]+)`/g, '<code>$1</code>');           // Inline-Code

        // 3.1 MEDIUM-FORMATIERUNG (Sucht nach *, ignoriert aber bereits generiertes HTML)
        html = html.replace(/(?<!<[^>]*)\*([^*<\/>]+)\*(?![^<]*>)/g, '<span style="font-weight: 500;">$1</span>');

        // 4. AUSRICHTUNG & EINRÜCKUNG (Basiszeichen '>')
        html = html.replace(/>l ([^>]+)>/g, '<div style="text-align: left; display: inline-block; width: 100%;">$1</div>');
        html = html.replace(/>r ([^>]+)>/g, '<div style="text-align: right; display: inline-block; width: 100%;">$1</div>');
        html = html.replace(/>c ([^>]+)>/g, '<div style="text-align: center; display: inline-block; width: 100%;">$1</div>');
        html = html.replace(/>j ([^>]+)>/g, '<div style="text-align: justify; display: inline-block; width: 100%;">$1</div>');
        html = html.replace(/>tt ([^>]+)>/g, '<div style="margin-left: 4em; display: inline-block;">$1</div>');
        html = html.replace(/>t ([^>]+)>/g, '<div style="margin-left: 2em; display: inline-block;">$1</div>');

        // 5. LINKS & MEDIEN
        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>');

        // 6. FUSSNOTEN 
        html = html.replace(/\^x\[([^\]]+)\]\^/g, '<span class="footnote-auto" title="$1">[*]</span>'); 
        html = html.replace(/\^(\d+)\[([^\]]+)\]\^/g, '<sup class="footnote-manual" title="$2">[$1]</sup>');

        // 7. ESCAPE ZURÜCKWANDELN
        html = html.replace(/<\!--SU_ESC_(\d+)-->/g, (match, code) => String.fromCharCode(parseInt(code)));

        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 Platzhalter
     */
    _injectTOC(html) {
        if (this.headings.length === 0) {
            return html.replace('', '');
        }

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

        for (const heading of this.headings) {
            if (heading.level > currentLevel) {
                tocListHtml += '<ul>\n'.repeat(heading.level - currentLevel);
            } else if (heading.level < currentLevel) {
                tocListHtml += '</ul>\n'.repeat(currentLevel - heading.level);
            }
            currentLevel = heading.level;

            tocListHtml += `<li><a href="#${heading.id}">${heading.text}</a></li>\n`;
        }
        
        if (currentLevel > 1) {
            tocListHtml += '</ul>\n'.repeat(currentLevel - 1);
        }
        tocListHtml += '</ul>\n</div>';

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

    /**
     * INTERN: Analysiert leere Zeilen, um Absätze (<p>) und Zeilenumbrüche (<br>) zu trennen
     */
    _processParagraphs(elements) {
        let processed = [];
        let paragraphBuffer = [];

        for (let element of elements) {
            if (element.startsWith('<') && !element.startsWith('<a>') && !element.startsWith('<strong>') && !element.startsWith('<em>') && !element.startsWith('<span>') && !element.startsWith('<code>') && !element.startsWith('<img') && !element.startsWith('<h')) {
                if (paragraphBuffer.length > 0) {
                    processed.push(`<p>${paragraphBuffer.join('<br>')}</p>`);
                    paragraphBuffer = [];
                }
                processed.push(element);
            } else if (element.trim() === '') {
                if (paragraphBuffer.length > 0) {
                    processed.push(`<p>${paragraphBuffer.join('<br>')}</p>`);
                    paragraphBuffer = [];
                }
            } else {
                paragraphBuffer.push(element);
            }
        }

        if (paragraphBuffer.length > 0) {
            processed.push(`<p>${paragraphBuffer.join('<br>')}</p>`);
        }

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