app.py

import gradio as gr
from pathlib import Path
import datetime
import re
import os
import shutil
import fitz  # PyMuPDF
from PIL import Image
from collections import defaultdict
import io
from pypdf import PdfWriter

from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, PageBreak, BaseDocTemplate, Frame, PageTemplate, Image as ReportLabImage
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.pagesizes import letter, A4, legal, landscape
from reportlab.lib.units import inch
from reportlab.lib import colors
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont

# --- Configuration & Setup ---
CWD = Path.cwd()
LAYOUTS = {
    "A4 Portrait": {"size": A4},
    "A4 Landscape": {"size": landscape(A4)},
    "Letter Portrait": {"size": letter},
    "Letter Landscape": {"size": landscape(letter)},
    "Legal Portrait": {"size": legal},
    "Legal Landscape": {"size": landscape(legal)},
}
OUTPUT_DIR = CWD / "generated_pdfs"
PREVIEW_DIR = CWD / "previews"
FONT_DIR = CWD

# Create necessary directories
OUTPUT_DIR.mkdir(exist_ok=True)
PREVIEW_DIR.mkdir(exist_ok=True)


# --- Font & Emoji Handling ---

def register_local_fonts():
    """Finds and registers all .ttf files from the application's base directory."""
    print("--- Font Registration Process Starting ---")
    text_font_names = []
    emoji_font_name = None
    
    print(f"Scanning for fonts in: {FONT_DIR.absolute()}")
    font_files = list(FONT_DIR.glob("*.ttf"))
    print(f"Found {len(font_files)} .ttf files: {[f.name for f in font_files]}")

    for font_path in font_files:
        try:
            font_name = font_path.stem
            pdfmetrics.registerFont(TTFont(font_name, str(font_path)))
            pdfmetrics.registerFont(TTFont(f"{font_name}-Bold", str(font_path)))
            pdfmetrics.registerFont(TTFont(f"{font_name}-Italic", str(font_path)))
            pdfmetrics.registerFont(TTFont(f"{font_name}-BoldItalic", str(font_path)))
            pdfmetrics.registerFontFamily(font_name, normal=font_name, bold=f"{font_name}-Bold", italic=f"{font_name}-Italic", boldItalic=f"{font_name}-BoldItalic")

            if "notocoloremoji-regular" in font_name.lower():
                emoji_font_name = font_name
            elif "notoemoji" not in font_name.lower(): # Exclude other symbol fonts from text selection
                text_font_names.append(font_name)
        except Exception as e:
            print(f"Could not register font {font_path.name}: {e}")

    if not text_font_names:
        print("WARNING: No text fonts found. Adding 'Helvetica' as a default.")
        text_font_names.append('Helvetica')

    print(f"Successfully registered user-selectable fonts: {text_font_names}")
    print(f"Emoji font set to: {emoji_font_name}")
    print("--- Font Registration Process Finished ---")
    return sorted(text_font_names), emoji_font_name

def apply_emoji_font(text: str, emoji_font_name: str) -> str:
    """
    Intelligently wraps emoji characters in a <font> tag, preserving existing HTML-like tags.
    This prevents invalid nested tags like <b><font>...</font></b> which ReportLab handles poorly.
    """
    if not emoji_font_name:
        return text

    # Regex to find emojis
    emoji_pattern = re.compile(f"([{re.escape(''.join(map(chr, range(0x1f600, 0x1f650))))}"
                               f"{re.escape(''.join(map(chr, range(0x1f300, 0x1f5ff))))}"
                               f"{re.escape(''.join(map(chr, range(0x1f900, 0x1f9ff))))}"
                               f"{re.escape(''.join(map(chr, range(0x2600, 0x26ff))))}"
                               f"{re.escape(''.join(map(chr, range(0x2700, 0x27bf))))}]+)")

    # Regex to split the string by existing tags (<b>, <i>)
    tag_pattern = re.compile(r"(<[^>]+>)")
    parts = tag_pattern.split(text)
    
    result = []
    for part in parts:
        if tag_pattern.match(part):
            # It's a tag, append it as is
            result.append(part)
        else:
            # It's text, apply emoji font to any emojis within this segment
            result.append(emoji_pattern.sub(fr'<font name="{emoji_font_name}">\1</font>', part))
            
    return "".join(result)


# --- PDF Generation & Handling ---

def markdown_to_story(markdown_text: str, font_name: str, emoji_font: str):
    """Converts markdown to a ReportLab story, with enhanced styling and page breaks."""
    styles = getSampleStyleSheet()
    style_normal = ParagraphStyle('BodyText', fontName=font_name, spaceAfter=6, leading=14, fontSize=10)
    style_h1 = ParagraphStyle('h1', parent=styles['h1'], fontName=font_name, spaceBefore=12, fontSize=24, leading=28, textColor=colors.darkblue)
    style_h2 = ParagraphStyle('h2', parent=styles['h2'], fontName=font_name, fontSize=18, leading=22, spaceBefore=10)
    style_h3 = ParagraphStyle('h3', parent=styles['h3'], fontName=font_name, fontSize=14, leading=18, spaceBefore=8)
    style_code = ParagraphStyle('Code', fontName='Courier', backColor=colors.whitesmoke, textColor=colors.darkred, borderWidth=1, borderColor=colors.lightgrey, padding=8, leading=12, fontSize=9)
    style_table_header = ParagraphStyle('TableHeader', parent=style_normal, fontName=font_name + "-Bold" if font_name != 'Helvetica' else 'Helvetica-Bold')

    story = []
    lines = markdown_text.split('\n')
    
    in_code_block, in_table = False, False
    code_block_text, table_data = "", []
    first_heading = True

    for line in lines:
        if line.strip().startswith("```"):
            if in_code_block:
                story.append(Paragraph(code_block_text.replace('\n', '<br/>'), style_code)); story.append(Spacer(1, 0.1 * inch))
                in_code_block = False; code_block_text = ""
            else:
                in_code_block = True
            continue
        if in_code_block:
            code_block_text += line.replace('&', '&amp;').replace('<', '&lt;').replace('>', '&gt;') + '\n'
            continue
        
        if line.strip().startswith('|'):
            if not in_table: in_table = True
            if all(c in '-|: ' for c in line.strip()): continue
            cells = [apply_emoji_font(cell.strip(), emoji_font) for cell in line.strip().strip('|').split('|')]
            table_data.append(cells)
            continue
        if in_table:
            in_table = False
            if table_data:
                header = [Paragraph(cell, style_table_header) for cell in table_data[0]]
                formatted_rows = [[Paragraph(cell, style_normal) for cell in row] for row in table_data[1:]]
                table = Table([header] + formatted_rows, hAlign='LEFT', repeatRows=1)
                table.setStyle(TableStyle([('BACKGROUND', (0, 0), (-1, 0), colors.lightgrey), ('GRID', (0, 0), (-1, -1), 1, colors.darkgrey), ('VALIGN', (0,0), (-1,-1), 'MIDDLE')]))
                story.append(table); story.append(Spacer(1, 0.2 * inch))
                table_data = []
        
        # Apply base formatting first
        formatted_line = re.sub(r'_(.*?)_', r'<i>\1</i>', re.sub(r'\*\*(.*?)\*\*', r'<b>\1</b>', line))
        # Then apply emoji font to the already formatted line
        line_with_emoji = apply_emoji_font(formatted_line, emoji_font)

        if line.startswith("# "):
            if not first_heading: story.append(PageBreak())
            # Strip markdown characters from the original line before applying style
            story.append(Paragraph(apply_emoji_font(re.sub(r'\*\*(.*?)\*\*', r'<b>\1</b>', line[2:]), emoji_font), style_h1)); first_heading = False
        elif line.startswith("## "): story.append(Paragraph(apply_emoji_font(re.sub(r'\*\*(.*?)\*\*', r'<b>\1</b>', line[3:]), emoji_font), style_h2))
        elif line.startswith("### "): story.append(Paragraph(apply_emoji_font(re.sub(r'\*\*(.*?)\*\*', r'<b>\1</b>', line[4:]), emoji_font), style_h3))
        elif line.strip().startswith(("- ", "* ")): story.append(Paragraph(line_with_emoji.strip()[2:], style_normal, bulletText='•'))
        elif re.match(r'^\d+\.\s', line.strip()): story.append(Paragraph(line_with_emoji.strip(), style_normal))
        elif line.strip() == "": story.append(Spacer(1, 0.1 * inch))
        else: story.append(Paragraph(line_with_emoji, style_normal))

    return story

def create_pdf_preview(pdf_path: Path):
    preview_path = PREVIEW_DIR / f"{pdf_path.stem}.png"
    try:
        doc = fitz.open(pdf_path); page = doc.load_page(0); pix = page.get_pixmap()
        pix.save(str(preview_path)); doc.close()
        return str(preview_path)
    except Exception as e:
        print(f"Could not create preview for {pdf_path.name}: {e}"); return None

# --- Main API Function ---
def generate_pdfs_api(files, layouts, fonts, num_columns, page_w_mult, page_h_mult, progress=gr.Progress(track_tqdm=True)):
    if not files: raise gr.Error("Please upload at least one Markdown or Image file.")
    if not layouts: raise gr.Error("Please select at least one page layout.")
    if not fonts: raise gr.Error("Please select at least one font.")

    shutil.rmtree(OUTPUT_DIR, ignore_errors=True); shutil.rmtree(PREVIEW_DIR, ignore_errors=True)
    OUTPUT_DIR.mkdir(); PREVIEW_DIR.mkdir()

    grouped_files = defaultdict(lambda: {'md': [], 'img': []})
    for f in files:
        file_path = Path(f.name)
        stem = file_path.stem.split('_')[0] if '_' in file_path.stem else file_path.stem
        if file_path.suffix.lower() == '.md': grouped_files[stem]['md'].append(file_path)
        elif file_path.suffix.lower() in ['.png', '.jpg', '.jpeg']: grouped_files[stem]['img'].append(file_path)

    log_updates, generated_pdf_paths = "", []

    for stem, assets in progress.tqdm(grouped_files.items(), desc="Processing File Groups"):
        for layout_name in layouts:
            for font_name in fonts:
                merger = PdfWriter()
                
                if assets['md']:
                    md_content = "\n".join([p.read_text(encoding='utf-8') for p in assets['md']])
                    md_buffer = io.BytesIO()
                    story = markdown_to_story(md_content, font_name, EMOJI_FONT_NAME)
                    
                    base_w, base_h = LAYOUTS[layout_name]["size"]
                    pagesize = (base_w * page_w_mult, base_h * page_h_mult)
                    
                    if num_columns > 1:
                        doc = BaseDocTemplate(md_buffer, pagesize=pagesize, leftMargin=0.5*inch, rightMargin=0.5*inch, topMargin=0.5*inch, bottomMargin=0.5*inch)
                        frame_width = (doc.width / num_columns) - (num_columns - 1) * 0.1*inch
                        frames = [Frame(doc.leftMargin + i * (frame_width + 0.2*inch), doc.bottomMargin, frame_width, doc.height) for i in range(num_columns)]
                        doc.addPageTemplates([PageTemplate(id='MultiCol', frames=frames)])
                    else:
                        doc = SimpleDocTemplate(md_buffer, pagesize=pagesize)
                    doc.build(story)
                    merger.append(fileobj=md_buffer)

                for img_path in assets['img']:
                    with Image.open(img_path) as img: img_width, img_height = img.size
                    img_buffer = io.BytesIO()
                    doc = SimpleDocTemplate(img_buffer, pagesize=(img_width, img_height), leftMargin=0, rightMargin=0, topMargin=0, bottomMargin=0)
                    doc.build([ReportLabImage(img_path, width=img_width, height=img_height)])
                    merger.append(fileobj=img_buffer)
                
                if len(merger.pages) > 0:
                    time_str = datetime.datetime.now().strftime('%m-%d-%a_%I%M%p').upper()
                    filename = f"{stem}_{time_str}_{layout_name.replace(' ','-')}_{page_w_mult}x{page_h_mult}_{font_name}_Cols{num_columns}.pdf"
                    output_path = OUTPUT_DIR / filename
                    with open(output_path, "wb") as f: merger.write(f)
                    generated_pdf_paths.append(output_path)
                    log_updates += f"Generated: {filename}\n"

    gallery_previews = [create_pdf_preview(p) for p in generated_pdf_paths]
    final_gallery = [g for g in gallery_previews if g is not None]
    
    return final_gallery, log_updates, [str(p) for p in generated_pdf_paths]

# --- Gradio UI Definition ---
AVAILABLE_FONTS, EMOJI_FONT_NAME = register_local_fonts()
SAMPLE_MARKDOWN = """# Deities Guide: Mythology and Moral Lessons 

1. 📜 **Introduction**
   - **Purpose**: Explore deities, spirits, saints, and beings with their epic stories and morals!
   - **Usage**: A guide for learning and storytelling across traditions. ️
   - **Themes**: Justice ️, faith , hubris , redemption , cosmic order .

2. 🛠️ **Core Concepts of Divinity**
   - **Powers**: Creation , omniscience ️‍️, shapeshifting  across entities.
   - **Life Cycle**: Mortality , immortality , transitions like saints and avatars .
   - **Communication**: Omens ️, visions ️, miracles  from gods and spirits.

# ⚔️ Arthurian Legends
 - **Merlin, Morgan le Fay, Arthur**: Mentor , rival ‍️, son .
 - **Relation**: Family tests loyalty .
 - **Lesson**: Honor ️ vs. betrayal ️.

# 🏛️ Greek Mythology
 - **Zeus, Hera, Athena**: Father , mother , daughter .
 - **Relation**: Family rules with tension ️.
 - **Lesson**: Hubris  meets wisdom .

# 🕉️ Hindu Trimurti
 - **Brahma, Vishnu, Shiva**: Creator , preserver ️, destroyer .
 - **Relation**: Divine trio cycles existence .
 - **Lesson**: Balance ️ sustains life .
"""
with open(CWD / "sample.md", "w", encoding="utf-8") as f: f.write(SAMPLE_MARKDOWN)

with gr.Blocks(theme=gr.themes.Soft(), title="Advanced PDF Generator") as demo:
    gr.Markdown("# 📄 Advanced PDF Layout Engine")
    gr.Markdown("Upload Markdown/Image files. The app finds local `.ttf` fonts. Group assets with a common name (e.g., `Doc_part1.md`, `Doc_img1.png`) to combine them. `# Headers` create automatic page breaks.")

    with gr.Row():
        with gr.Column(scale=1):
            gr.Markdown("### ⚙️ Generation Settings")
            uploaded_files = gr.File(label="Upload Markdown & Image Files", file_count="multiple", file_types=[".md", ".png", ".jpg", ".jpeg"])
            
            with gr.Row():
                page_w_mult_slider = gr.Slider(label="Page Width Multiplier", minimum=1, maximum=5, step=1, value=1)
                page_h_mult_slider = gr.Slider(label="Page Height Multiplier", minimum=1, maximum=2, step=1, value=1)
            
            num_columns_slider = gr.Slider(label="Number of Text Columns", minimum=1, maximum=4, step=1, value=1)
            selected_layouts = gr.CheckboxGroup(choices=list(LAYOUTS.keys()), label="Select Base Page Layout", value=["A4 Portrait"])
            selected_fonts = gr.CheckboxGroup(choices=AVAILABLE_FONTS, label="Select Text Font", value=[AVAILABLE_FONTS[0]] if AVAILABLE_FONTS else [])
            generate_btn = gr.Button("🚀 Generate PDFs", variant="primary")
        
        with gr.Column(scale=2):
            gr.Markdown("### 🖼️ PDF Preview Gallery")
            gallery_output = gr.Gallery(label="Generated PDF Previews", show_label=False, elem_id="gallery", columns=3, height="auto", object_fit="contain")
            log_output = gr.Markdown(label="Generation Log", value="Logs will appear here...")
            downloadable_files_output = gr.Files(label="Download Generated PDFs")
            
    generate_btn.click(fn=generate_pdfs_api, inputs=[uploaded_files, selected_layouts, selected_fonts, num_columns_slider, page_w_mult_slider, page_h_mult_slider], outputs=[gallery_output, log_output, downloadable_files_output])

if __name__ == "__main__":
    demo.launch()