#!/usr/bin/env python3
"""P74（启动开场过渡：水墨式渐显）证据分析：真实 xvfb 录启动 0-3 秒序列抽帧。

判据（读真实实跑日志 + 逐帧像素统计）：
  1. 日志含 5 行 `p74-shot=p74-splash-<frame> inkStrength=<v>`，帧号递增 {8,30,60,100,140}。
  2. inkStrength 随帧非增，且在 dissolveFrames(96) 后为 0（墨幕确实在消散）。
  3. 抽帧 PNG：1280x720、非空白（std>=6）、无 24x24 纯黑块（标题/屋脊的纯白属预期，仅报告不判失败）。
  4. 动画在变：任意两帧 pixel diff > 0（且首末帧 diff 显著）。
  5. 画面「是否好看/水墨味」的 vision 复核由 Hermes 侧完成，非本脚本判据。

Usage: python3 scripts/analyze-p74.py <record-dir> <out-txt>
Exit 0 pass / 1 fail / 2 usage.
"""

import itertools
import re
import sys
from pathlib import Path

import numpy as np
from PIL import Image

SHOT_RE = re.compile(r"^p74-shot=p74-splash-(\d+) inkStrength=([\d.]+)$", re.MULTILINE)
EXPECTED = [8, 30, 60, 100, 140]
DARK_SIDE = 24
DARK_MAX = 8
WHITE_SIDE = 64
WHITE_MIN = 250


def max_block(rgba, side, predicate):
    h, w = rgba.shape[0], rgba.shape[1]
    if h < side or w < side:
        return 0
    mask = predicate(rgba).astype(np.int64)
    integral = np.zeros((h + 1, w + 1), dtype=np.int64)
    integral[1:, 1:] = mask.cumsum(axis=0).cumsum(axis=1)
    best = 0
    for y in range(0, h - side + 1):
        for x in range(0, w - side + 1):
            total = (
                integral[y + side, x + side]
                - integral[y, x + side]
                - integral[y + side, x]
                + integral[y, x]
            )
            best = max(best, int(total))
    return best


def main():
    if len(sys.argv) != 3:
        print(__doc__)
        return 2
    rec = Path(sys.argv[1])
    out = Path(sys.argv[2])
    log = (rec / "log.txt").read_text(encoding="utf-8", errors="replace")
    failures = []
    lines = [
        "P74（启动开场过渡：水墨式渐显）证据分析 — 真实 Desktop xvfb 1280x720",
        "钩子：LV_P74_SHOT=1（60Hz 固定步进，splash 帧表 8/30/60/100/140 各一帧）",
        "路径：splashFrame → InkReveal.inkStrength/dabs（预乘墨滴）→ 露出天色/水面/屋脊/标题",
        "",
    ]

    shots = [(int(m.group(1)), float(m.group(2))) for m in SHOT_RE.finditer(log)]
    got = [f for f, _ in shots]
    lines.append("log shots: " + ", ".join(f"{f}(ink={v:.3f})" for f, v in shots))
    if got != EXPECTED:
        failures.append(f"log frames {got} != expected {EXPECTED}")
    strengths = [v for _, v in shots]
    if strengths != sorted(strengths, reverse=True):
        failures.append("inkStrength is not non-increasing across frames")
    if not all(v == 0.0 for f, v in shots if f >= 96):
        failures.append("inkStrength is not 0 after dissolveFrames (96)")
    lines.append("")

    stats = {}
    for frame in EXPECTED:
        path = rec / f"p74-splash-{frame:03d}.png"
        if not path.exists():
            failures.append(f"missing frame {path.name}")
            continue
        rgba = np.asarray(Image.open(path).convert("RGBA"), dtype=np.uint8)
        rgb = rgba[:, :, :3].astype(np.float64)
        h, w = rgb.shape[0], rgb.shape[1]
        brightness = float(rgb.mean())
        std = float(rgb.std())
        dark = max_block(
            rgba, DARK_SIDE,
            lambda a: (a[:, :, 0] <= DARK_MAX) & (a[:, :, 1] <= DARK_MAX) & (a[:, :, 2] <= DARK_MAX) & (a[:, :, 3] >= 250),
        )
        white = max_block(
            rgba, WHITE_SIDE,
            lambda a: (a[:, :, 0] >= WHITE_MIN) & (a[:, :, 1] >= WHITE_MIN) & (a[:, :, 2] >= WHITE_MIN) & (a[:, :, 3] >= 250),
        )
        stats[frame] = {"brightness": brightness, "std": std}
        lines.append(f"p74-splash-{frame:03d}.png: size={w}x{h} brightness={brightness:.1f} std={std:.1f} dark_block={dark} white_block={white}")
        if (w, h) != (1280, 720):
            failures.append(f"{path.name} size {w}x{h} != 1280x720")
        if std < 6.0:
            failures.append(f"{path.name} looks blank (std={std:.1f})")
        if dark > 0:
            failures.append(f"{path.name} has {DARK_SIDE}x{DARK_SIDE} pure-black block")
    lines.append("")

    have = [f for f in EXPECTED if f in stats]
    for a, b in itertools.combinations(have, 2):
        ia = np.asarray(Image.open(rec / f"p74-splash-{a:03d}.png").convert("RGB"), dtype=np.int16)
        ib = np.asarray(Image.open(rec / f"p74-splash-{b:03d}.png").convert("RGB"), dtype=np.int16)
        differing = int((np.abs(ia - ib).sum(axis=2) > 0).sum())
        lines.append(f"diff frame {a:03d} vs {b:03d}: differing_pixels={differing}")
        if differing == 0:
            failures.append(f"frame {a} identical to {b}")

    lines.append("")
    if failures:
        lines.append("verdict=FAIL")
        for f in failures:
            lines.append("  - " + f)
    else:
        lines.append("verdict=PASS")
        lines.append("  ink strength decays to 0 across the captured frames; frames render 1280x720,")
        lines.append("  no big black blocks, and every pair differs (the opening transition animates).")
    out.parent.mkdir(parents=True, exist_ok=True)
    out.write_text("\n".join(lines) + "\n", encoding="utf-8")
    print(f"wrote {out} verdict={'FAIL' if failures else 'PASS'}")
    return 1 if failures else 0


if __name__ == "__main__":
    sys.exit(main())