use serde_json::{json, Value};

use crate::dispatch::CdpContext;

pub async fn handle(
    method: &str,
    _params: &Value,
    ctx: &mut CdpContext,
    session_id: &Option<String>,
) -> Result<Value, String> {
    match method {
        "getMarkdown" => {
            let page = ctx.get_session_page_mut(session_id).ok_or("No page")?;
            let code = r#"
(function() {
    function toMd(el, depth) {
        if (!el) return '';
        var out = '';
        if (el.nodeType === 3) return el.textContent || '';
        if (el.nodeType !== 1) return '';
        var tag = (el.tagName || '').toLowerCase();
        var children = '';
        var cn = el.childNodes || [];
        for (var i = 0; i < cn.length; i++) children += toMd(cn[i], depth);
        children = children.replace(/\n{3,}/g, '\n\n');
        switch(tag) {
            case 'h1': return '\n# ' + children.trim() + '\n\n';
            case 'h2': return '\n## ' + children.trim() + '\n\n';
            case 'h3': return '\n### ' + children.trim() + '\n\n';
            case 'h4': return '\n#### ' + children.trim() + '\n\n';
            case 'h5': return '\n##### ' + children.trim() + '\n\n';
            case 'h6': return '\n###### ' + children.trim() + '\n\n';
            case 'p': return '\n' + children.trim() + '\n\n';
            case 'br': return '\n';
            case 'hr': return '\n---\n\n';
            case 'strong': case 'b': return '**' + children + '**';
            case 'em': case 'i': return '*' + children + '*';
            case 'code': return '`' + children + '`';
            case 'pre': return '\n```\n' + children + '\n```\n\n';
            case 'blockquote': return '\n> ' + children.trim().replace(/\n/g, '\n> ') + '\n\n';
            case 'a':
                var href = el.getAttribute('href') || '';
                if (href && children.trim()) return '[' + children.trim() + '](' + href + ')';
                return children;
            case 'img':
                var src = el.getAttribute('src') || '';
                var alt = el.getAttribute('alt') || '';
                return '![' + alt + '](' + src + ')';
            case 'ul': case 'ol':
                return '\n' + children + '\n';
            case 'li':
                var parent = el.parentNode;
                var isOrdered = parent && parent.tagName && parent.tagName.toLowerCase() === 'ol';
                var bullet = isOrdered ? '1. ' : '- ';
                return bullet + children.trim() + '\n';
            case 'table': return '\n' + children + '\n';
            case 'thead': case 'tbody': case 'tfoot': return children;
            case 'tr':
                var cells = [];
                var tds = el.childNodes || [];
                for (var j = 0; j < tds.length; j++) {
                    if (tds[j].nodeType === 1) cells.push(toMd(tds[j], depth).trim());
                }
                return '| ' + cells.join(' | ') + ' |\n';
            case 'th': case 'td': return children;
            case 'script': case 'style': case 'noscript': case 'link': case 'meta': return '';
            case 'div': case 'section': case 'article': case 'main': case 'aside': case 'nav': case 'header': case 'footer':
                return '\n' + children;
            case 'span': return children;
            default: return children;
        }
    }
    var body = document.body || document.documentElement;
    var md = toMd(body, 0);
    md = md.replace(/\n{3,}/g, '\n\n').trim();
    return md;
})()
"#;
            let result = page.evaluate(code);
            let markdown = result.as_str().unwrap_or("").to_string();
            Ok(json!({ "markdown": markdown }))
        }
        _ => Err(format!("Unknown LP method: {}", method)),
    }
}