/**
 * @fileoverview Markdown Rendering Wrapper for Rantii
 * @author retoor <retoor@molodetz.nl>
 * @description Markdown parsing and rendering with syntax highlighting
 * @keywords markdown, parsing, syntax, highlight, render
 */

class MarkdownRenderer {
    constructor() {
        this.marked = null;
        this.hljs = null;
        this.initialized = false;
    }

    async init() {
        if (this.initialized) {
            return true;
        }

        try {
            if (window.marked) {
                this.marked = window.marked;
            }
            if (window.hljs) {
                this.hljs = window.hljs;
            }

            if (this.marked && this.hljs) {
                this.marked.setOptions({
                    highlight: (code, lang) => {
                        if (lang && this.hljs.getLanguage(lang)) {
                            try {
                                return this.hljs.highlight(code, { language: lang }).value;
                            } catch (e) {
                                return code;
                            }
                        }
                        return this.hljs.highlightAuto(code).value;
                    },
                    breaks: true,
                    gfm: true
                });
            } else if (this.marked) {
                this.marked.setOptions({
                    breaks: true,
                    gfm: true
                });
            }

            this.initialized = true;
            return true;
        } catch (e) {
            return false;
        }
    }

    render(text) {
        if (!text) {
            return '';
        }

        if (this.marked) {
            try {
                return this.marked.parse(text);
            } catch (e) {
                return this.escapeHtml(text);
            }
        }

        return this.simpleRender(text);
    }

    simpleRender(text) {
        let result = this.escapeHtml(text);

        result = result.replace(/```(\w+)?\n([\s\S]*?)```/g, (match, lang, code) => {
            const highlighted = this.highlightCode(code.trim(), lang);
            return `<pre><code class="language-${lang || 'plaintext'}">${highlighted}</code></pre>`;
        });

        result = result.replace(/`([^`]+)`/g, '<code>$1</code>');

        result = result.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>');
        result = result.replace(/\*([^*]+)\*/g, '<em>$1</em>');

        result = result.replace(/\[([^\]]+)\]\(([^)]+)\)/g, '<a href="$2" target="_blank" rel="noopener noreferrer">$1</a>');

        result = result.replace(/\n/g, '<br>');

        return result;
    }

    highlightCode(code, lang) {
        if (this.hljs && lang && this.hljs.getLanguage(lang)) {
            try {
                return this.hljs.highlight(code, { language: lang }).value;
            } catch (e) {
                return this.escapeHtml(code);
            }
        }
        if (this.hljs) {
            try {
                return this.hljs.highlightAuto(code).value;
            } catch (e) {
                return this.escapeHtml(code);
            }
        }
        return this.escapeHtml(code);
    }

    escapeHtml(text) {
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }

    renderInline(text) {
        if (!text) {
            return '';
        }

        let result = this.escapeHtml(text);
        result = result.replace(/`([^`]+)`/g, '<code>$1</code>');
        result = result.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>');
        result = result.replace(/\*([^*]+)\*/g, '<em>$1</em>');

        return result;
    }

    stripMarkdown(text) {
        if (!text) {
            return '';
        }

        let result = text;
        result = result.replace(/```[\s\S]*?```/g, '');
        result = result.replace(/`([^`]+)`/g, '$1');
        result = result.replace(/\*\*([^*]+)\*\*/g, '$1');
        result = result.replace(/\*([^*]+)\*/g, '$1');
        result = result.replace(/\[([^\]]+)\]\([^)]+\)/g, '$1');

        return result;
    }
}

const markdownRenderer = new MarkdownRenderer();

export { MarkdownRenderer, markdownRenderer };