#!/usr/bin/env python3
"""Turn chosen clips (and stills) into footage plates the page can show frame-exactly.

  python3 prep-plates.py plates.json [--out plates/] [--fps 60] [keys...]

plates.json: {"key": {"kind": "clip", "src": "clips/x.mp4", "in": 1.2, "dur": 0.5, "inset": 0.0},
              "key2": {"kind": "still", "src": "stills/y.jpg", "inset": 0.03}}
Clips become plates/<key>/001.jpg… at the render frame rate (dur + 0.25 s of frames, from `in`);
stills become plates/<key>.jpg, 10% larger than the frame so the page can push in without softness.
Everything gets the same grade, so footage from different generators reads as one film.
The page swaps <img> sources per frame inside window.seek (see references/launch-film.md).
"""
import argparse, json, os, pathlib, subprocess
from common import ffmpeg

ap = argparse.ArgumentParser()
ap.add_argument("config"); ap.add_argument("keys", nargs="*")
ap.add_argument("--out", default="plates"); ap.add_argument("--fps", type=int, default=60)
ap.add_argument("--grade", default="eq=contrast=1.06:saturation=0.86:gamma=0.97,colorbalance=rs=-0.02:bs=0.02:rh=0.03:bh=-0.03")
a = ap.parse_args()
FF = ffmpeg(); out = pathlib.Path(a.out); out.mkdir(exist_ok=True)
for k, p in json.load(open(a.config)).items():
    if k.startswith("_") or (a.keys and k not in a.keys):
        continue
    i = p.get("inset", 0)
    crop = f"crop=iw*{1 - 2 * i}:ih*{1 - 2 * i}," if i else ""
    if p["kind"] == "clip":
        d = out / k; d.mkdir(exist_ok=True)
        for f in d.glob("*.jpg"): f.unlink()
        vf = f"{crop}scale=1920:1080:force_original_aspect_ratio=increase:flags=lanczos,crop=1920:1080,{a.grade},fps={a.fps}"
        subprocess.run([FF, "-v", "error", "-y", "-ss", str(p["in"]), "-t", str(p["dur"] + 0.25), "-i", p["src"],
                        "-vf", vf, "-q:v", "3", str(d / "%03d.jpg")], check=True)
        print(k, len(list(d.glob("*.jpg"))), "frames")
    else:
        vf = f"{crop}scale=2112:1188:force_original_aspect_ratio=increase:flags=lanczos,crop=2112:1188,{a.grade}"
        subprocess.run([FF, "-v", "error", "-y", "-i", p["src"], "-vf", vf, "-q:v", "2", str(out / f"{k}.jpg")], check=True)
        print(k, "still")