#!/usr/bin/env python3
"""Generate a first-frame grid per subdir under ICLR/.

For each subdir (task), each episode contributes a row; columns are the video
views (e.g. 37149196_left/right, 11845904_left/right). Each cell is the first
frame of that episode's mp4, labeled. One PNG per subdir saved into ICLR/.
"""
import subprocess, sys
from pathlib import Path
from PIL import Image, ImageDraw, ImageFont

ROOT = Path("/home/jimin/droid/collected_datasets/rlwrld_datasets_jonghoon/ICLR")
THUMB_W = 320          # per-cell frame width; height scales to aspect
PAD = 6                # gap between cells
LABEL_H = 20           # label strip height per cell
HEADER_H = 34          # column-header strip
ROWLABEL_W = 70        # left strip for episode id


def first_frame(mp4: Path) -> Image.Image | None:
    """Extract first frame of an mp4 as a PIL image via ffmpeg (stdout png)."""
    try:
        out = subprocess.run(
            ["ffmpeg", "-nostdin", "-loglevel", "error", "-i", str(mp4),
             "-frames:v", "1", "-f", "image2pipe", "-vcodec", "png", "pipe:1"],
            capture_output=True, check=True).stdout
        if not out:
            return None
        from io import BytesIO
        return Image.open(BytesIO(out)).convert("RGB")
    except subprocess.CalledProcessError as e:
        print(f"    ! ffmpeg failed on {mp4.name}: {e.stderr.decode()[:200]}")
        return None


def font(size=14):
    for p in ["/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf",
              "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf"]:
        if Path(p).exists():
            return ImageFont.truetype(p, size)
    return ImageFont.load_default()


def build_grid(subdir: Path):
    episodes = sorted([d for d in subdir.iterdir() if d.is_dir() and d.name.isdigit()])
    if not episodes:
        print(f"  (no episodes in {subdir.name})")
        return

    # Determine the union of view names (mp4 stems) across episodes, stable order.
    views: list[str] = []
    for ep in episodes:
        vdir = ep / "recorded_videos"
        if not vdir.is_dir():
            continue
        for mp4 in sorted(vdir.glob("*.mp4")):
            if mp4.stem not in views:
                views.append(mp4.stem)
    views = sorted(views)
    if not views:
        print(f"  (no mp4s in {subdir.name})")
        return

    print(f"  {subdir.name}: {len(episodes)} episodes x {len(views)} views")

    # Extract all cells first to learn the thumb height (from first good frame).
    cells: dict[tuple[int, int], Image.Image] = {}
    thumb_h = None
    for r, ep in enumerate(episodes):
        for c, view in enumerate(views):
            mp4 = ep / "recorded_videos" / f"{view}.mp4"
            if not mp4.exists():
                continue
            img = first_frame(mp4)
            if img is None:
                continue
            w, h = img.size
            th = round(THUMB_W * h / w)
            img = img.resize((THUMB_W, th))
            if thumb_h is None:
                thumb_h = th
            cells[(r, c)] = img
    if thumb_h is None:
        print(f"  ! could not extract any frame for {subdir.name}")
        return

    cell_w = THUMB_W
    cell_h = thumb_h + LABEL_H
    ncols, nrows = len(views), len(episodes)
    W = ROWLABEL_W + ncols * cell_w + (ncols + 1) * PAD
    H = HEADER_H + nrows * cell_h + (nrows + 1) * PAD
    canvas = Image.new("RGB", (W, H), (24, 24, 28))
    draw = ImageDraw.Draw(canvas)
    f_hdr, f_lbl, f_row = font(15), font(12), font(14)

    # Column headers
    for c, view in enumerate(views):
        x = ROWLABEL_W + PAD + c * (cell_w + PAD)
        draw.text((x + 4, 8), view, fill=(230, 230, 235), font=f_hdr)

    for r, ep in enumerate(episodes):
        y0 = HEADER_H + PAD + r * (cell_h + PAD)
        draw.text((6, y0 + thumb_h // 2), ep.name, fill=(255, 210, 90), font=f_row)
        for c, view in enumerate(views):
            x0 = ROWLABEL_W + PAD + c * (cell_w + PAD)
            img = cells.get((r, c))
            if img is None:
                draw.rectangle([x0, y0, x0 + cell_w, y0 + thumb_h], fill=(50, 40, 40))
                draw.text((x0 + 8, y0 + thumb_h // 2 - 6), "missing", fill=(200, 120, 120), font=f_lbl)
            else:
                canvas.paste(img, (x0, y0))
            draw.text((x0 + 3, y0 + thumb_h + 3), f"{ep.name}/{view}",
                      fill=(180, 180, 190), font=f_lbl)

    out = ROOT / f"first_frame_grid_{subdir.name}.png"
    canvas.save(out)
    print(f"    -> saved {out}  ({W}x{H})")


def main():
    subdirs = sorted([d for d in ROOT.iterdir()
                      if d.is_dir() and not d.name.startswith("_")])
    print(f"Found {len(subdirs)} subdirs: {[d.name for d in subdirs]}")
    for sd in subdirs:
        build_grid(sd)


if __name__ == "__main__":
    main()