"""Render a Studio JSON bundle into PNG slides and optionally MP4."""
import argparse
import json
import subprocess
from pathlib import Path
from PIL import Image, ImageDraw, ImageFont


def validate(bundle):
    if bundle.get("version") != 1 or not isinstance(bundle.get("slides"), list) or not bundle["slides"]:
        raise ValueError("Expected a version 1 Studio bundle with slides")
    for slide in bundle["slides"]:
        if not all(isinstance(slide.get(k), str) for k in ("heading", "body", "color")):
            raise ValueError("Invalid slide")
    return bundle["slides"]


def wrap(draw, text, font, width):
    lines = []
    for paragraph in text.split("\n"):
        line = ""
        for char in paragraph:
            if line and draw.textlength(line + char, font=font) > width:
                lines.append(line)
                line = ""
            line += char
        lines.append(line)
    return lines


def render(bundle, output, font_path):
    slides = validate(bundle)
    output.mkdir(parents=True, exist_ok=True)
    heading = ImageFont.truetype(str(font_path), 76)
    body = ImageFont.truetype(str(font_path), 38)
    for index, slide in enumerate(slides, 1):
        image = Image.new("RGB", (1080, 1440), slide["color"])
        draw = ImageDraw.Draw(image)
        draw.text((80, 80), f"PROMPT / {index:02}", font=body, fill="#353535")
        y = 330
        for text, font, gap in [(slide["heading"], heading, 108), (slide["body"], body, 65)]:
            for line in wrap(draw, text, font, 920):
                if y + gap > 1360:
                    raise ValueError(f"Slide {index} overflows; split the text into more slides")
                draw.text((80, y), line, font=font, fill="#242424")
                y += gap
            y += 70
        image.save(output / f"slide-{index:03}.png")


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("bundle", type=Path)
    parser.add_argument("--output", type=Path, required=True)
    parser.add_argument("--font", type=Path, required=True, help="CJK font TTF/OTF/TTC")
    parser.add_argument("--video", action="store_true")
    args = parser.parse_args()
    bundle = json.loads(args.bundle.read_text())
    render(bundle, args.output, args.font)
    if args.video:
        # Use an explicit temporary input sequence so old PNGs cannot leak into a video.
        import tempfile
        import shutil
        with tempfile.TemporaryDirectory() as staging:
            for index in range(1, len(bundle["slides"]) + 1):
                shutil.copy(args.output / f"slide-{index:03}.png", Path(staging) / f"slide-{index:03}.png")
            subprocess.run(["ffmpeg", "-y", "-framerate", "1/4", "-i", str(Path(staging) / "slide-%03d.png"), "-vf", "fps=30,format=yuv420p", "-c:v", "libx264", "-movflags", "+faststart", str(args.output / "video.mp4")], check=True)

if __name__ == "__main__":
    main()