# -*- coding: utf-8 -*-
"""M11b-2c-A3 交付自洽性重放校验器（可复跑，QC 复核用）。

背景（QC 退回 #10）：上一轮引擎在交付时又代为提交了一次补丁器修正（51c3f26），
说明 agent 交付的仓库状态并非最终自洽状态——补丁器与定稿 tx_write.py 不一致，
靠引擎收口补齐。本脚本把「HEAD 即最终态」变成可机械复验的断言。

做法（不污染工作区，全部在临时目录内完成）：
  1. 从 git 取 HEAD 版本的补丁器 scripts/m11b2c_a3_patch_tx_write.py；
  2. 从 git 取 5542cf5^（修复前）版本的 pbl_runtime_ext/tx_write.py 原文；
  3. 在临时目录里按补丁器自身的 TARGET 相对路径摆好文件，直接 import 并调用其
     main()（等价于在机构工作空间根执行该补丁器）；
  4. 把重放产物与 HEAD 版本的 tx_write.py 逐字节比对（cmp + sha256 双口径）；
  5. 一致 -> REPLAY_IDENTICAL: YES，退出码 0；不一致 -> NO，退出码 1。

用法（在模块仓库内或机构工作空间根均可）：
    python3 scripts/m11b2c_a3_replay_check.py
"""
import hashlib
import io
import os
import shutil
import subprocess
import sys
import tempfile

REPO = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
PATCHER = "scripts/m11b2c_a3_patch_tx_write.py"
TX_WRITE = "pbl_runtime_ext/tx_write.py"
FIX_COMMIT = "5542cf5d5182130aa929e5aa37d0c22a043cee25"


def _git_rev_parse(rev):
    return _git("rev-parse", rev).strip()


def _git(*args):
    out = subprocess.run(["git", "-C", REPO] + list(args),
                         check=True, stdout=subprocess.PIPE)
    return out.stdout.decode("utf-8")


def _sha(path):
    with io.open(path, "rb") as f:
        return hashlib.sha256(f.read()).hexdigest()


def main():
    print("== M11b-2c-A3 补丁器/定稿一致性重放校验 ==")
    print("repo            : %s" % REPO)
    head = _git_rev_parse("HEAD")
    print("HEAD            : %s" % head)
    print("HEAD subject    : %s" % _git("log", "-1", "--format=%s").strip())
    print("fix commit      : %s" % FIX_COMMIT)
    print("patcher@HEAD    : %s" % _git_rev_parse("HEAD:%s" % PATCHER))
    print("tx_write@HEAD   : %s" % _git_rev_parse("HEAD:%s" % TX_WRITE))
    print("tx_write@fix^   : %s" % _git_rev_parse("%s^:%s" % (FIX_COMMIT, TX_WRITE)))

    tmp = tempfile.mkdtemp(prefix="m11b2c_a3_replay_")
    rc = 1
    try:
        # 1) 取 HEAD 版补丁器
        patcher_dir = os.path.join(tmp, "inst", "modules", "pbl_runtime_ext", "scripts")
        target_dir = os.path.join(tmp, "inst", "modules", "pbl_runtime_ext", "pbl_runtime_ext")
        os.makedirs(patcher_dir)
        os.makedirs(target_dir)
        with io.open(os.path.join(patcher_dir, os.path.basename(PATCHER)), "w",
                     encoding="utf-8") as f:
            f.write(_git("show", "HEAD:%s" % PATCHER))

        # 2) 取修复前 tx_write.py 原文，摆到补丁器 TARGET 的相对位置
        pre_path = os.path.join(target_dir, "tx_write.py")
        with io.open(pre_path, "w", encoding="utf-8") as f:
            f.write(_git("show", "%s^:%s" % (FIX_COMMIT, TX_WRITE)))
        head_path = os.path.join(tmp, "tx_write_HEAD.py")
        with io.open(head_path, "w", encoding="utf-8") as f:
            f.write(_git("show", "HEAD:%s" % TX_WRITE))

        pre_sha = _sha(pre_path)
        head_sha = _sha(head_path)
        print("pre-fix  sha256 : %s" % pre_sha)
        print("HEAD     sha256 : %s" % head_sha)

        # 3) 在临时目录内执行 HEAD 版补丁器（TARGET 是相对路径，故 cwd 必须是 inst/）
        sys.path.insert(0, patcher_dir)
        mod_name = "m11b2c_a3_patch_tx_write"
        if mod_name in sys.modules:
            del sys.modules[mod_name]
        patcher = __import__(mod_name)
        cwd = os.getcwd()
        os.chdir(os.path.join(tmp, "inst"))
        try:
            prc = patcher.main()
        finally:
            os.chdir(cwd)
        print("patcher exit rc : %d (0=已应用 4 处补丁, 2=片段命中数异常)" % prc)
        if prc != 0:
            print("REPLAY_IDENTICAL: NO（补丁器在修复前原文上执行失败，rc=%d）" % prc)
            return 1

        # 4) 逐字节比对
        replayed_sha = _sha(pre_path)
        print("replayed sha256 : %s" % replayed_sha)
        cmp_rc = subprocess.run(["cmp", pre_path, head_path]).returncode
        print("cmp 退出码      : %d (0=逐字节一致)" % cmp_rc)
        if replayed_sha == head_sha and cmp_rc == 0:
            print("REPLAY_IDENTICAL: YES（补丁器重放产物 == HEAD 定稿，逐字节一致）")
            print("结论：HEAD 即最终自洽态，补丁器与定稿 tx_write.py 一致，无待引擎收口内容。")
            rc = 0
        else:
            print("REPLAY_IDENTICAL: NO（补丁器与定稿不一致，仓库状态非最终态）")
            rc = 1
        return rc
    finally:
        shutil.rmtree(tmp, ignore_errors=True)


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