#!/usr/bin/env python3
"""Build motion previews for bursts: one small looping animated WebP per burst,
from the existing 1400px Previews (deterministic re-encode, no photo changes).

Usage: python3 build_burst_media.py burst_plan.csv
Writes: ClientPicker/Bursts/<first>.webp + .scratch/bursts.json (for build_picker_v3.py)
"""
import csv, json, os, subprocess, sys
from pathlib import Path

SHOOT = Path("/Volumes/Sam Storage/YellowMellow/2026/Monster High Theme (10:01:2026)")
PRE = SHOOT / "ClientPicker" / "Previews"
OUTDIR = SHOOT / "ClientPicker" / "Bursts"
SCRATCH = Path("/Volumes/Sam Storage/YellowMellow/.scratch")

MAX_FRAMES = 20  # cap preview length (~3.3s at 6fps); full sequence browsable in lightbox

plan_file = Path(sys.argv[1])
rows = [r for r in csv.DictReader(open(plan_file)) if int(r["unique_frames"]) >= 5]
print("%d qualifying bursts (>=5 frames)" % len(rows))
OUTDIR.mkdir(exist_ok=True)

def split_parts(first, last):
    """Split card-counter wrap (e.g. 7O9A9971 -> 7O9A0017) into two real bursts."""
    a, b = int(first[4:]), int(last[4:])
    if a <= b:
        return [(first, last)]
    return [(first, "7O9A%04d" % 9999), ("7O9A%04d" % 1, last)]

bursts = {}
for r in rows:
    f0, l0 = os.path.splitext(r["first_file"])[0], os.path.splitext(r["last_file"])[0]
    fps = max(3, min(12, int(float(r.get("playback_fps") or 6))))
    for first, last in split_parts(f0, l0):
        a, b = int(first[4:]), int(last[4:])
        frames = [PRE / ("7O9A%04d.jpg" % n) for n in range(a, b + 1)]
        missing = [f.name for f in frames if not f.exists()]
        if missing:
            print("SKIP %s-%s: missing previews %d" % (first, last, len(missing)))
            continue
        frames = frames[:MAX_FRAMES]
    out = OUTDIR / (first + ".webp")
    cmd = ["magick", "-loop", "0", "-delay", str(round(100 / fps))]
    cmd += [f.as_posix() for f in frames]
    cmd += ["-resize", "384x", "-quality", "75", out.as_posix()]
    p = subprocess.run(cmd, capture_output=True, text=True)
    if p.returncode != 0 or not out.exists():
        print("FAIL %s: %s" % (first, p.stderr[:300]))
        continue
    bursts[first] = {"first": first, "last": last, "fps": fps,
                     "frames": len(frames), "kb": out.stat().st_size // 1024}
    print("OK %s-%s (%d frames @%dfps) -> %.0f KB"
          % (first, last, len(frames), fps, out.stat().st_size / 1024))

json.dump(bursts, open(SCRATCH / "bursts.json", "w"))
total = sum(v["frames"] for v in bursts.values())
print("DONE: %d bursts, %d burst frames" % (len(bursts), total))