app.py

import gradio as gr
from pathlib import Path
import datetime
import re
import requests
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 ---
# Use the current working directory as the base for all paths for robustness.
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 / "fonts"
EMOJI_FONT_NAME = "NotoColorEmoji"

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


# --- Font & Emoji Handling ---

def download_and_register_fonts():
    """Downloads default fonts if needed, then finds and registers all .ttf files."""
    print("--- Font Registration Process Starting ---")
    fonts_to_download = {
        "DejaVuSans.ttf": "https://github.com/dejavu-fonts/dejavu-fonts/blob/main/ttf/DejaVuSans.ttf?raw=true",
        "NotoColorEmoji.ttf": "https://github.com/googlefonts/noto-emoji/blob/main/fonts/NotoColorEmoji.ttf?raw=true"
    }
    for filename, url in fonts_to_download.items():
        font_path = FONT_DIR / filename
        if not font_path.exists():
            print(f"Downloading {filename}...")
            try:
                r = requests.get(url, allow_redirects=True, timeout=20)
                r.raise_for_status()
                with open(font_path, "wb") as f: f.write(r.content)
                print(f"{filename} downloaded.")
            except Exception as e:
                print(f"Failed to download {filename}: {e}")

    font_names = []
    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
            print(f"Registering font: '{font_name}' from {font_path.name}")
            pdfmetrics.registerFont(TTFont(font_name, str(font_path)))
            
            # CRITICAL FIX for bold/italic error:
            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 "emoji" not in font_name.lower():
                font_names.append(font_name)
        except Exception as e:
            print(f"Could not register font {font_path.name}: {e}")
    print(f"Successfully registered user-selectable fonts: {font_names}")
    print("--- Font Registration Process Finished ---")
    return sorted(font_names)

def apply_emoji_font(text: str) -> str:
    """Wraps emoji characters in a <font> tag to use the dedicated emoji font."""
    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))))}]+)")
    return emoji_pattern.sub(fr'<font name="{EMOJI_FONT_NAME}">\1</font>', text)


# --- PDF Generation & Handling ---

def markdown_to_story(markdown_text: str, font_name: str):
    """Converts markdown to a ReportLab story, handling emojis and page breaks."""
    styles = getSampleStyleSheet()
    style_normal = ParagraphStyle('BodyText', fontName=font_name, spaceAfter=6, leading=14)
    style_h1 = ParagraphStyle('h1', parent=styles['h1'], fontName=font_name, spaceBefore=12, fontSize=20, leading=24)
    style_code = ParagraphStyle('Code', fontName='Courier', backColor=colors.whitesmoke)
    
    story = []
    for line in markdown_text.split('\n'):
        line_with_emoji = apply_emoji_font(line)
        formatted_line = re.sub(r'_(.*?)_', r'<i>\1</i>', re.sub(r'\*\*(.*?)\*\*', r'<b>\1</b>', line_with_emoji))
        
        if line.startswith("# "): story.append(Paragraph(formatted_line[2:], style_h1))
        else: story.append(Paragraph(formatted_line, style_normal))
    return story

def create_pdf_preview(pdf_path: Path):
    """Creates a PNG preview of the first page of a PDF."""
    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, progress=gr.Progress(track_tqdm=True)):
    """Main function to drive PDF generation from the Gradio UI."""
    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\n---PAGE_BREAK---\n\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)
                    pagesize = LAYOUTS[layout_name]["size"]
                    
                    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(' ','-')}_{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 = download_and_register_fonts()
SAMPLE_MARKDOWN = "# Sample Document 🚀\n\nThis shows **bold**, _italic_, and emojis like 😊 and 💻.\n\n### A Table\n| Flavor | Rating |\n|---|---|\n| Chocolate 🍫| 10/10 |\n| Vanilla 🍦| 9/10 |\n\n```python\n# Code blocks too!\ndef hello():\n    return 'Hello from PDF!'\n```"
with open(CWD / "sample.md", "w") as f: f.write(SAMPLE_MARKDOWN)

with gr.Blocks(theme=gr.themes.Soft(), title="Advanced PDF Generator") as demo:
    gr.Markdown("# 📄 Advanced PDF Generator")
    gr.Markdown("Upload Markdown and Image files. Group assets with a common name (e.g., `Doc_part1.md`, `Doc_img1.png`). The app will generate PDFs for all selected variations and display them below.")

    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"])
            num_columns_slider = gr.Slider(label="Number of Columns for Text", minimum=1, maximum=4, step=1, value=1)
            selected_layouts = gr.CheckboxGroup(choices=list(LAYOUTS.keys()), label="Select Page Layouts", value=["A4 Portrait"])
            selected_fonts = gr.CheckboxGroup(choices=AVAILABLE_FONTS, label="Select Text Fonts", 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")
            log_output = gr.Markdown(label="Generation Log", value="Logs will appear here...")
            downloadable_files_output = gr.Files(label="Download Generated PDFs")
            
    def auto_run_demo(request: gr.Request):
        """Function to run on app load to generate a sample PDF."""
        print("Running initial demo generation...")
        # Create a dummy file object for Gradio
        with open(CWD / "sample.md", "rb") as f:
            sample_bytes = f.read()
        
        demo_files = [gr.processing_utils.SavedFile(name=str(CWD / "sample.md"), data=sample_bytes, is_file=True)]
        previews, logs, files = generate_pdfs_api(demo_files, ["A4 Portrait"], [AVAILABLE_FONTS[0]] if AVAILABLE_FONTS else [], 1)
        return previews, logs, files

    demo.load(auto_run_demo, inputs=None, outputs=[gallery_output, log_output, downloadable_files_output])
    generate_btn.click(fn=generate_pdfs_api, inputs=[uploaded_files, selected_layouts, selected_fonts, num_columns_slider], outputs=[gallery_output, log_output, downloadable_files_output])

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