/**
 * Markup Parser Module
 * Parses author-facing story markup into renderable blocks and timed cue metadata.
 */
import { BaseModule } from './base-module.js';

class MarkupParserModule extends BaseModule {
    constructor() {
        super('markup-parser', 'Markup Parser');
        this.dependencies = [];
        this.assetRoots = {
            images: '/images/',
            music: '/music/',
            sounds: '/sounds/'
        };

        this.bindMethods([
            'parse',
            'parseParagraph',
            'parseInline',
            'parseMusicOptions',
            'markdownToHtml',
            'markdownToPlainText',
            'smartypants',
            'escapeHtml',
            'normalizeParagraph',
            'buildParagraphBlock',
            'resolveAssetUrl'
        ]);
    }

    async initialize() {
        this.reportProgress(100, "Markup parser ready");
        return true;
    }

    parse(input) {
        const text = String(input || '').replace(/\r\n?/g, '\n');
        const blocks = [];
        let paragraphBuffer = [];
        let nextParagraphRole = null;

        const flushParagraph = () => {
            if (paragraphBuffer.length === 0) return;

            const raw = paragraphBuffer.join('\n');
            paragraphBuffer = [];
            const paragraph = this.parseParagraph(raw);
            if (!paragraph.text) return;

            const role = nextParagraphRole || 'body';
            nextParagraphRole = null;
            blocks.push(this.buildParagraphBlock(paragraph, role));
        };

        text.split('\n').forEach((line) => {
            const trimmed = line.trim();

            if (!trimmed) {
                flushParagraph();
                return;
            }

            const chapter = trimmed.match(/^::chapter(?:\[(.*?)\]|\s+(.+))$/i);
            if (chapter) {
                flushParagraph();
                const heading = (chapter[1] || chapter[2] || '').trim();
                if (heading) {
                    const normalizedHeading = this.normalizeParagraph(heading);
                    blocks.push({
                        type: 'heading',
                        text: this.markdownToPlainText(normalizedHeading),
                        layoutText: this.markdownToHtml(normalizedHeading),
                        role: 'chapter-heading'
                    });
                }
                nextParagraphRole = 'chapter-first';
                return;
            }

            const section = trimmed.match(/^::(?:section|textblock)(?:\[(.*?)\]|\s+(.+))?$/i);
            if (section) {
                flushParagraph();
                const heading = (section[1] || section[2] || '').trim();
                if (heading) {
                    const normalizedHeading = this.normalizeParagraph(heading);
                    blocks.push({
                        type: 'heading',
                        text: this.markdownToPlainText(normalizedHeading),
                        layoutText: this.markdownToHtml(normalizedHeading),
                        role: 'section-heading'
                    });
                }
                nextParagraphRole = 'textblock-first';
                return;
            }

            const image = trimmed.match(/^::image\[(widescreen|portrait)\]\(([^)]+)\)$/i);
            if (image) {
                flushParagraph();
                blocks.push({
                    type: 'image',
                    size: image[1].toLowerCase(),
                    filename: image[2].trim(),
                    url: this.resolveAssetUrl('images', image[2].trim())
                });
                return;
            }

            const music = trimmed.match(/^::music(?:\[([^\]]*)\])?\(([^)]+)\)$/i);
            if (music) {
                flushParagraph();
                const options = this.parseMusicOptions(music[1] || 'crossfade');
                blocks.push({
                    type: 'music',
                    ...options,
                    filename: music[2].trim(),
                    url: this.resolveAssetUrl('music', music[2].trim())
                });
                return;
            }

            paragraphBuffer.push(line);
        });

        flushParagraph();

        return blocks;
    }

    parseMusicOptions(optionText) {
        const options = {
            mode: 'crossfade',
            loop: true,
            leadInSeconds: 0
        };

        String(optionText || '')
            .split(/[,\s]+/)
            .map(token => token.trim())
            .filter(Boolean)
            .forEach(token => {
                const lower = token.toLowerCase();
                const [key, value] = lower.split('=');

                if (['queue', 'crossfade', 'cut'].includes(lower)) {
                    options.mode = lower;
                } else if (['loop', 'looped', 'repeat'].includes(lower)) {
                    options.loop = true;
                } else if (['once', 'single', 'no-loop', 'noloop'].includes(lower)) {
                    options.loop = false;
                } else if (key === 'loop') {
                    options.loop = !['false', '0', 'no', 'once'].includes(value);
                } else if (['lead', 'lead-in', 'leadins', 'lead-in-seconds', 'delay', 'intro'].includes(key)) {
                    const seconds = Number(value);
                    options.leadInSeconds = Number.isFinite(seconds) ? Math.max(0, seconds) : 0;
                } else if (/^\d+(\.\d+)?s?$/.test(lower)) {
                    options.leadInSeconds = Number(lower.replace(/s$/, ''));
                }
            });

        return options;
    }

    parseParagraph(rawText) {
        const inline = this.parseInline(this.normalizeParagraph(rawText));
        return {
            text: this.markdownToPlainText(inline.text),
            layoutText: this.markdownToHtml(inline.text),
            cueMarkers: inline.cueMarkers
        };
    }

    buildParagraphBlock(paragraph, role) {
        return {
            type: 'paragraph',
            text: paragraph.text,
            layoutText: paragraph.layoutText,
            cueMarkers: paragraph.cueMarkers,
            role,
            isFirstParagraphInChapter: role === 'chapter-first' || role === 'textblock-first',
            dropCap: role === 'chapter-first',
            addTopSpace: role === 'textblock-first'
        };
    }

    parseInline(text) {
        const cueMarkers = [];
        let output = '';
        let cursor = 0;
        const markerPattern = /\{\{\s*(sfx|music)\s*:\s*(?:(queue|crossfade|cut)\s*:\s*)?([^}]+?)\s*\}\}/gi;

        for (const match of text.matchAll(markerPattern)) {
            output += text.slice(cursor, match.index);
            const charIndex = output.length;
            const wordIndex = this.countWords(output);
            const type = match[1].toLowerCase();
            const mode = type === 'music' ? (match[2] || 'crossfade').toLowerCase() : null;

            cueMarkers.push({
                type,
                mode,
                filename: match[3].trim(),
                url: this.resolveAssetUrl(type === 'sfx' ? 'sounds' : 'music', match[3].trim()),
                charIndex,
                wordIndex
            });

            cursor = match.index + match[0].length;
        }

        output += text.slice(cursor);

        return {
            text: output.replace(/\s{2,}/g, ' ').trim(),
            cueMarkers
        };
    }

    markdownToHtml(text) {
        const escaped = this.smartypants(this.escapeHtml(text));

        return escaped
            .replace(/\*\*\*([^*]+?)\*\*\*/g, '<strong><em>$1</em></strong>')
            .replace(/___([^_]+?)___/g, '<strong><em>$1</em></strong>')
            .replace(/\*\*([^*]+?)\*\*/g, '<strong>$1</strong>')
            .replace(/__([^_]+?)__/g, '<strong>$1</strong>')
            .replace(/\*([^*\s][^*]*?)\*/g, '<em>$1</em>')
            .replace(/_([^_\s][^_]*?)_/g, '<em>$1</em>');
    }

    markdownToPlainText(text) {
        const plain = String(text || '')
            .replace(/\*\*\*([^*]+?)\*\*\*/g, '$1')
            .replace(/___([^_]+?)___/g, '$1')
            .replace(/\*\*([^*]+?)\*\*/g, '$1')
            .replace(/__([^_]+?)__/g, '$1')
            .replace(/\*([^*\s][^*]*?)\*/g, '$1')
            .replace(/_([^_\s][^_]*?)_/g, '$1');

        return this.smartypants(plain).replace(/\s{2,}/g, ' ').trim();
    }

    smartypants(text) {
        return String(text)
            .replace(/---/g, '\u2014')
            .replace(/--/g, '\u2013')
            .replace(/\.\.\./g, '\u2026')
            .replace(/(^|[\s([{\u2014])"([^"]*)"/g, '$1\u201c$2\u201d')
            .replace(/(^|[\s([{\u2014])'([^']*)'/g, '$1\u2018$2\u2019');
    }

    escapeHtml(text) {
        return String(text)
            .replace(/&/g, '&amp;')
            .replace(/</g, '&lt;')
            .replace(/>/g, '&gt;');
    }

    normalizeParagraph(text) {
        return String(text).replace(/\s*\n\s*/g, ' ').trim();
    }

    countWords(text) {
        const words = String(text).trim().match(/\S+/g);
        return words ? words.length : 0;
    }

    resolveAssetUrl(kind, filename) {
        const root = this.assetRoots[kind];
        const safeName = String(filename || '').replace(/\\/g, '/').replace(/^\/+/, '');

        if (!root || !safeName || safeName.includes('..') || /^[a-z]+:/i.test(safeName)) {
            return '';
        }

        return root + safeName.split('/').map(encodeURIComponent).join('/');
    }
}

const MarkupParser = new MarkupParserModule();

export { MarkupParser };

if (window.moduleRegistry) {
    window.moduleRegistry.register(MarkupParser);
}

window.MarkupParser = MarkupParser;