import markdown
from pygments.formatters import HtmlFormatter
import re
import hashlib

from latex2mathml.converter import convert


def format_latex(text):
    """
    Convert a Markdown string containing LaTeX formulas to HTML with MathML.
    Handles:
        - Inline math: $...$ or \( ... \)
        - Display math: $$...$$ or \[ ... \]
    Automatically converts `aligned` to `array` and wraps display formulas
    in <span style="display:block;"> for spacing without breaking Markdown lists.

    Args:
        text (str): Markdown string with LaTeX.
        convert (callable): Function that converts LaTeX string to MathML.

    Returns:
        str: HTML string with MathML replacing LaTeX.
    """
    # Pattern for LaTeX delimiters
    pattern = r'(\$\$.*?\$\$|\\\[.*?\\\]|\\\(.*?\\\)|\$.*?\$)'

    def replace_latex(match):
        latex_text = match.group()

        # Determine delimiter type
        is_display = False
        if latex_text.startswith('$$') and latex_text.endswith('$$'):
            latex_text_clean = latex_text[2:-2].strip()
            is_display = True
        elif latex_text.startswith(r'\[') and latex_text.endswith(r'\]'):
            latex_text_clean = latex_text[2:-2].strip()
            is_display = True
        elif latex_text.startswith(r'\(') and latex_text.endswith(r'\)'):
            latex_text_clean = latex_text[2:-2].strip()
        elif latex_text.startswith('$') and latex_text.endswith('$'):
            latex_text_clean = latex_text[1:-1].strip()
        else:
            latex_text_clean = latex_text.strip()

        # Replace aligned -> array
        latex_text_clean = re.sub(
            r'\\begin\{aligned\}', r'\\begin{array}{l}', latex_text_clean
        )
        latex_text_clean = re.sub(
            r'\\end\{aligned\}', r'\\end{array}', latex_text_clean
        )

        # Convert to MathML
        try:
            mathml = convert(latex_text_clean)
            if is_display:
                # Use span with display:block to preserve Markdown list numbering
                mathml = f'<span style="display:block; margin:10px 0;">{mathml}</span>'
            return mathml
        except Exception as e:
            print(f"Warning: failed to convert LaTeX: {latex_text_clean}\nError: {e}")
            return latex_text_clean

    # Replace all LaTeX with MathML
    html_with_mathml = re.sub(pattern, replace_latex, text, flags=re.DOTALL)
    return html_with_mathml


def format_history(history):
    """Format conversation history as HTML with side-by-side responses."""
    
    # Generate Pygments CSS for syntax highlighting
    pygments_css = HtmlFormatter(style='monokai').get_style_defs('.codehilite')

    html = f'''
    <div style="font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;">
    <style>
        /* Pygments syntax highlighting styles */
        {pygments_css}
        
        .response-content pre {{
            background-color: #272822;
            padding: 12px;
            border-radius: 4px;
            overflow-x: auto;
            margin: 10px 0;
        }}
        .response-content code {{
            background-color: #f0f0f0;
            color: #c7254e;
            padding: 2px 6px;
            border-radius: 3px;
            font-family: 'Courier New', monospace;
            font-size: 0.9em;
            white-space: pre-wrap;
            word-wrap: break-word;
        }}
        .response-content pre code {{
            background-color: transparent;
            color: inherit;
            padding: 0;
        }}
        .response-content table {{
            border-collapse: collapse;
            width: 100%;
            margin: 10px 0;
        }}
        .response-content th, .response-content td {{
            border: 1px solid #ddd;
            padding: 8px;
            text-align: left;
        }}
        .response-content th {{
            background-color: #f0f0f0;
        }}
    </style>'''
    
    for turn in history:
        # User message - escape HTML but preserve line breaks
        user_msg = turn["user"].replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;").replace("\n", "<br>")
        html += f'<div style="background-color: var(--color-accent-soft); padding: 10px; margin: 10px 0; border-radius: 5px;"><strong>You:</strong> {user_msg}</div>'
        
        # Determine opacity based on highlight
        opacity_a = "1.0"
        opacity_b = "1.0"
        border_a = "2px solid var(--block-border-color)"
        border_b = "2px solid var(--block-border-color)"
        
        if turn["highlight"] == "left":
            opacity_b = "0.3"
            border_a = "3px solid #4CAF50"
        elif turn["highlight"] == "right":
            opacity_a = "0.3"
            border_b = "3px solid #4CAF50"
        elif turn["highlight"] == "random_left":
            opacity_b = "0.3"
            border_a = "3px solid #4C50AF"
        elif turn["highlight"] == "random_right":  # turn["highlight"] == "light_right"
            opacity_a = "0.3"
            border_b = "3px solid #4C50AF"

        response_a_text_with_mathml = format_latex(turn["response_a"])
        response_a_html = markdown.markdown(
            response_a_text_with_mathml,
            extensions=['fenced_code', 'tables', 'codehilite'],
            extension_configs={'codehilite': {'guess_lang': True, 'linenums': False}}
        )

        response_b_text_with_mathml = format_latex(turn["response_b"])
        response_b_html = markdown.markdown(
            response_b_text_with_mathml,
            extensions=['fenced_code', 'tables', 'codehilite'],
            extension_configs={'codehilite': {'guess_lang': True, 'linenums': False}}
        )
        
        # Responses side by side
        html += f'''
        <div style="display: flex; gap: 10px; margin: 10px 0; align-items: stretch;">
            <div style="flex: 1; background-color: var(--background-fill-secondary); padding: 15px; border-radius: 5px; border: {border_a}; opacity: {opacity_a}; display: flex; flex-direction: column;">
                <div style="margin-bottom: 8px;"><strong>Assistant A</strong></div>
                <div class="response-content" style="line-height: 1.6; overflow-y: auto; flex: 1; max-height: 400px;">{response_a_html}</div>
            </div>
            <div style="flex: 1; background-color: var(--background-fill-secondary); padding: 15px; border-radius: 5px; border: {border_b}; opacity: {opacity_b}; display: flex; flex-direction: column;">
                <div style="margin-bottom: 8px;"><strong>Assistant B</strong></div>
                <div class="response-content" style="line-height: 1.6; overflow-y: auto; flex: 1; max-height: 400px;">{response_b_html}</div>
            </div>
        </div>
        '''
        if turn["highlight"] == "random_left":
            html += '<div><b>Note:</b> you did not specify a preference for either assistant, so in subsequent turns, Assistant A will be used as context.</div>'
        elif turn["highlight"] == "random_right":
             html += '<div><b>Note:</b> you did not specify a preference for either assistant, so in subsequent turns, Assistant B will be used as context.</div>'          
    
    html += '</div>'
    return html