#!/usr/bin/env python3
"""Read-only replay of C932--C1131, or a completed prefix via --through N.

The journal writer is never imported. Standard output is the JSON report;
--output may additionally save that report. Replay itself cannot write files.
The supplied packet is trusted research code, not an arbitrary-code sandbox.
"""
from pathlib import Path
from fractions import Fraction
from datetime import datetime
import argparse
import ast
import contextlib
import copy
import hashlib
import io
import json
import os
import runpy
import sys
import types

ROOT = Path(__file__).resolve().parent.parent
FIRST, LAST = 932, 1131
STEP_COUNT = LAST - FIRST + 1
PREDECESSOR_HASH = '55a6faf783579d9119c15adafb3697ab140daddaeda4547bcd674196a4951a9f'
PRIMARY_HASH = 'a5ea84562101158b60d0cf296765d6eff38e7a2abda4e74ad1b353dfd13b9530'
REPLAY_ACTIVE = False


class VerificationError(RuntimeError):
    pass


def require(condition, message):
    if not condition:
        raise VerificationError(message)


def digest(path):
    return hashlib.sha256(path.read_bytes()).hexdigest()


def record_digest(row):
    return hashlib.sha256(json.dumps({k: v for k, v in row.items() if k != 'sha256'}, sort_keys=True).encode()).hexdigest()


def clean(value):
    if isinstance(value, Fraction):
        return value.numerator if value.denominator == 1 else str(value)
    if isinstance(value, dict):
        return {str(k): clean(v) for k, v in value.items()}
    if isinstance(value, (list, tuple)):
        return [clean(v) for v in value]
    return value


class InverseValue(int):
    """Track values descended from inv(), including ordinary integer arithmetic."""
    @staticmethod
    def wrap(value):
        return InverseValue(value) if isinstance(value, int) else value

    def __add__(self, other): return self.wrap(int.__add__(self, other))
    def __radd__(self, other): return self.wrap(int.__add__(self, other))
    def __sub__(self, other): return self.wrap(int.__sub__(self, other))
    def __rsub__(self, other): return self.wrap(int.__rsub__(self, other))
    def __mul__(self, other): return self.wrap(int.__mul__(self, other))
    def __rmul__(self, other): return self.wrap(int.__mul__(self, other))
    def __floordiv__(self, other): return self.wrap(int.__floordiv__(self, other))
    def __rfloordiv__(self, other): return self.wrap(int.__rfloordiv__(self, other))
    def __mod__(self, other): return self.wrap(int.__mod__(self, other))
    def __rmod__(self, other): return self.wrap(int.__rmod__(self, other))
    def __pow__(self, other, modulo=None): return self.wrap(int.__pow__(self, other, modulo))
    def __neg__(self): return InverseValue(int.__neg__(self))
    def __pos__(self): return InverseValue(self)
    def __abs__(self): return InverseValue(int.__abs__(self))


def audit_read_only(event, args):
    if not REPLAY_ACTIVE:
        return
    if event == 'open':
        mode = args[1] if len(args) > 1 else None
        flags = args[2] if len(args) > 2 else 0
        write_flags = os.O_WRONLY | os.O_RDWR | os.O_APPEND | os.O_CREAT | os.O_TRUNC
        require(not (isinstance(mode, str) and any(c in mode for c in 'wax+')), 'Replay attempted a write-capable open')
        require(not (isinstance(flags, int) and flags & write_flags), 'Replay attempted a write-capable file descriptor')
    forbidden = ('subprocess.', 'socket.', 'ctypes.', 'os.exec', 'os.spawn')
    require(not event.startswith(forbidden), f'Replay attempted forbidden action: {event}')
    require(event not in {'os.remove', 'os.rmdir', 'os.rename', 'os.mkdir', 'os.link', 'os.symlink', 'os.truncate', 'os.chmod', 'os.chown', 'os.utime', 'os.system', 'os.fork', 'os.chdir'}, f'Replay attempted mutation: {event}')


def current_candidates(name, workspace, bindings):
    if name in bindings:
        paths = bindings[name]
        paths = [paths] if isinstance(paths, str) else paths
        require(isinstance(paths, list) and all(isinstance(p, str) for p in paths), f'Invalid current-source binding: {name}')
        return [workspace / p for p in paths]
    if len(name) > 3 and name[:2].isdigit() and name[2] == '-':
        return [workspace / 'project_sources' / name]
    special = {
        'File51a.md': ['project_sources/39-File_51a.Rounded_Scaffold_Mod5_Architecture.md'],
        'File52c_latest.md': ['upload/File_52c.Rounded_Whole_Span_Inverse_Detailed_Study_Draft (2)(1).md'],
        'Strategy.md': ['upload/490d_Unification_Research_Strategy_v0_2_20260906.md', 'c482_c531/evidence/sources/Strategy.md'],
        'C931_checkpoint.md': ['c832_c931/deliverables/490d_Chronological_Families_Checkpoint_After_C931.md'],
        'C931_synthesis.md': ['c832_c931/deliverables/490d_Chronological_Families_Integrated_Synthesis_C931.md'],
        'C931_reading_guide.md': ['c832_c931/deliverables/490d_Chronological_Families_Reading_Guide_C931.md'],
        'C931_technical.md': ['c832_c931/deliverables/490d_Chronological_Families_Technical_Companion_C931.md'],
    }
    return [workspace / p for p in special.get(name, [])]


def verify_sources(workspace, require_current):
    manifest = json.loads((ROOT / 'evidence/SOURCE_MANIFEST.json').read_text())
    require(isinstance(manifest, dict) and manifest, 'Missing source manifest')
    require(manifest.get('File52c_latest.md') == PRIMARY_HASH, 'Latest File52c identity mismatch')
    binding_path = ROOT / 'evidence/SOURCE_BINDINGS.json'
    bindings = json.loads(binding_path.read_text()) if binding_path.is_file() else {}
    require(isinstance(bindings, dict), 'Invalid optional SOURCE_BINDINGS.json')
    current, absent = [], []
    for name, expected in manifest.items():
        require(Path(name).name == name, f'Unsafe source snapshot path: {name}')
        snapshot = ROOT / 'evidence/sources' / name
        require(digest(snapshot) == expected, f'Source snapshot hash mismatch: {name}')
        available = [p for p in current_candidates(name, workspace, bindings) if p.is_file()]
        if not available:
            absent.append(name)
        for path in available:
            require(digest(path) == expected, f'Current source differs from frozen snapshot: {path}')
            current.append({'snapshot': name, 'current_path': str(path), 'sha256': expected})
    require(not require_current or not absent, f'Current originals unavailable: {absent}')
    predecessor = json.loads((ROOT / 'evidence/C931_PREDECESSOR.json').read_text())
    require(predecessor['step'] == 931, 'Wrong predecessor step')
    require(record_digest(predecessor) == predecessor['sha256'] == PREDECESSOR_HASH, 'C931 predecessor hash mismatch')
    # C931 closes with a list of fully bound final artifacts. Match source
    # aliases to those artifact identities rather than assuming an older schema.
    final_artifacts = predecessor['results']['final_artifacts']
    require(isinstance(final_artifacts, list) and final_artifacts, 'Missing C931 final artifact bindings')
    deliveries = {Path(item['path']).name: item for item in final_artifacts}
    require(len(deliveries) == len(final_artifacts), 'Ambiguous C931 final artifact basenames')
    required_bindings = {
        'C931_checkpoint.md': '490d_Chronological_Families_Checkpoint_After_C931.md',
        'C931_synthesis.md': '490d_Chronological_Families_Integrated_Synthesis_C931.md',
        'C931_technical.md': '490d_Chronological_Families_Technical_Companion_C931.md',
    }
    optional_bindings = {
        'C931_reading_guide.md': '490d_Chronological_Families_Reading_Guide_C931.md',
    }
    for alias, filename in {**required_bindings, **{k: v for k, v in optional_bindings.items() if k in manifest}}.items():
        require(alias in manifest, f'Missing required predecessor source snapshot: {alias}')
        item = deliveries[filename]
        require(item['sha256'] == manifest[alias], f'C931 artifact binding mismatch: {alias}')
        require((ROOT / 'evidence/sources' / alias).stat().st_size == item['bytes'], f'C931 artifact byte count mismatch: {alias}')
    old_journal = workspace / 'c832_c931/journal.json'
    predecessor_live = False
    if old_journal.is_file():
        old_rows = json.loads(old_journal.read_text())
        prior = [r for r in old_rows if r.get('step') == 931]
        require(prior == [predecessor], 'Current C931 record differs from predecessor snapshot')
        predecessor_live = True
    return manifest, current, absent, predecessor_live


def replay(row):
    global REPLAY_ACTIVE
    number = row['step']
    script = ROOT / 'evidence' / f's{number}.py'
    tree = ast.parse(script.read_text(), filename=str(script))
    # An additional static check complements runtime inverse-value tracking.
    for node in ast.walk(tree):
        if isinstance(node, ast.Call) and isinstance(node.func, ast.Name) and node.func.id == 'inv':
            require(not any(isinstance(inner, ast.Call) and isinstance(inner.func, ast.Name) and inner.func.id == 'inv' for arg in node.args for inner in ast.walk(arg)), f'C{number}: nested inverse execution')
        if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef)):
            require(node.name not in {'inv', 'inverse'}, f'C{number}: replay inverse guard was redefined')
    calls = {'begin': 0, 'finish': 0, 'inverse': 0}

    def inverse(n):
        require(isinstance(n, int) and not isinstance(n, bool) and n >= 0, f'C{number}: inverse input must be a nonnegative integer')
        require(not isinstance(n, InverseValue), f'C{number}: forbidden inverse of an inverse-derived value')
        calls['inverse'] += 1
        if n == 0:
            return InverseValue(0)
        # Independent implementation: string-based core extraction, not the production loop.
        text = str(n)
        core = text.rstrip('0')
        return InverseValue(int(core[::-1]) * 10 ** (len(text) - len(core)))

    def begin(n, title, question, inputs, sources):
        calls['begin'] += 1
        require(calls['begin'] == 1 and calls['finish'] == 0, f'C{number}: invalid begin sequence')
        supplied = (n, title, question, clean(inputs), sources)
        recorded = tuple(row[k] for k in ('step', 'title', 'question', 'inputs', 'sources'))
        require(supplied == recorded, f'C{number}: input/source metadata mismatch')
        return copy.deepcopy({k: row[k] for k in ('step', 'title', 'question', 'inputs', 'sources', 'opened_utc', 'predecessor_sha256')})

    def finish(item, results, finding, next_question, checks):
        calls['finish'] += 1
        require(calls['begin'] == calls['finish'] == 1, f'C{number}: invalid finish sequence')
        for key in ('step', 'title', 'question', 'inputs', 'sources', 'opened_utc', 'predecessor_sha256'):
            require(item.get(key) == row[key], f'C{number}: begin record mutated: {key}')
        require(isinstance(checks, dict) and checks and all(v is True for v in checks.values()), f'C{number}: checks are not all Boolean True')
        require((clean(results), finding, next_question, checks) == (row['results'], row['finding'], row['reassessment'], row['checks']), f'C{number}: result/finding/reassessment/check mismatch')

    def artifact(relative_path, content):
        # Recompute each generation event even when a later step revised the file.
        # The historical generated bytes are bound by the result record's digest.
        path = Path(relative_path)
        require(not path.is_absolute() and '..' not in path.parts, f'C{number}: unsafe artifact path')
        data = content.encode()
        return {'path': relative_path, 'sha256': hashlib.sha256(data).hexdigest(), 'bytes': len(data)}

    fake = types.ModuleType('research')
    exported = {'Path': Path, 'F': Fraction, 'ROOT': ROOT, 'E': Fraction(25, 23), 'P': Fraction(70, 69), 'J': Fraction(300, 299), 'json': json, 'hashlib': hashlib, 'clean': clean, 'inv': inverse, 'begin': begin, 'finish': finish, 'REPLAY': True, 'artifact': artifact}
    for key, value in exported.items():
        setattr(fake, key, value)
    previous = sys.modules.get('research')
    sys.modules['research'] = fake
    capture = io.StringIO()
    try:
        REPLAY_ACTIVE = True
        with contextlib.redirect_stdout(capture):
            runpy.run_path(str(script), run_name=f'replay_{number}')
    finally:
        REPLAY_ACTIVE = False
        if previous is None:
            sys.modules.pop('research', None)
        else:
            sys.modules['research'] = previous
    require(calls['begin'] == calls['finish'] == 1, f'C{number}: missing begin or finish')
    return {'step': number, 'script_sha256': digest(script), 'checks': len(row['checks']), 'single_pass_inverse_calls': calls['inverse']}


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--through', type=int, default=LAST, help='Completed last step to replay;1130 is the199-action preseal prefix; default1131 requires all200')
    parser.add_argument('--workspace', type=Path, default=ROOT.parent, help='Optional workspace holding current originals; default packet parent')
    parser.add_argument('--require-current-sources', action='store_true', help='Fail if any current original is absent; omit for extracted portable packets')
    parser.add_argument('--output', type=Path, help='Optional report path; the only file written by this runner')
    args = parser.parse_args()
    require(FIRST <= args.through <= LAST, f'--through must be in {FIRST}..{LAST}')
    raw = (ROOT / 'journal.json').read_bytes()
    rows = json.loads(raw)
    require(isinstance(rows, list) and rows, 'Empty journal')
    require(len(rows) <= STEP_COUNT, 'Journal exceeds requested200-action range')
    require([r['step'] for r in rows] == list(range(FIRST, FIRST + len(rows))), 'Nonsequential/duplicate journal steps')
    require(rows[-1]['step'] >= args.through, f'Requested C{args.through} is unfinished; use --through {rows[-1]["step"]}')
    selected = [r for r in rows if r['step'] <= args.through]
    if args.through == LAST:
        require(len(rows) == STEP_COUNT, 'Final verification requires all200 completed actions')
        require(not (ROOT / 'pending.json').exists(), 'Final verification found an unfinished pending step')
    required = {'step', 'title', 'question', 'inputs', 'sources', 'opened_utc', 'predecessor_sha256', 'results', 'finding', 'reassessment', 'checks', 'closed_utc', 'sha256'}
    expected_previous = 'C931:' + PREDECESSOR_HASH
    previous_close = None
    for row in selected:
        require(set(row) == required, f'C{row["step"]}: unexpected record schema')
        require(record_digest(row) == row['sha256'], f'C{row["step"]}: record hash mismatch')
        require(row['predecessor_sha256'] == expected_previous, f'C{row["step"]}: predecessor chain mismatch')
        require(all(isinstance(row[k], str) and row[k].strip() for k in ('title', 'question', 'finding', 'reassessment')), f'C{row["step"]}: empty research metadata')
        require(isinstance(row['sources'], list) and row['sources'], f'C{row["step"]}: missing sources')
        opened, closed = datetime.fromisoformat(row['opened_utc']), datetime.fromisoformat(row['closed_utc'])
        require(opened.tzinfo is not None and closed.tzinfo is not None and opened <= closed, f'C{row["step"]}: invalid timestamps')
        require(previous_close is None or previous_close <= opened, f'C{row["step"]}: overlapping numbered sequence')
        previous_close, expected_previous = closed, row['sha256']
    manifest, current, absent, predecessor_live = verify_sources(args.workspace.resolve(), args.require_current_sources)
    sys.dont_write_bytecode = True
    sys.addaudithook(audit_read_only)
    replays = [replay(row) for row in selected]
    # A lead agent may append later completed steps during an intermediate run.
    # Existing records must remain byte-equivalent after canonical serialization;
    # final verification additionally requires the entire file to stay unchanged.
    after_raw = (ROOT / 'journal.json').read_bytes()
    after_rows = json.loads(after_raw)
    require(after_rows[:len(rows)] == rows, 'Journal prefix mutated during replay')
    require([r['step'] for r in after_rows] == list(range(FIRST, FIRST + len(after_rows))), 'Invalid concurrent journal append')
    if args.through == LAST:
        require(after_raw == raw, 'Final verification journal changed during replay')
    report = {
        'status': 'PASS', 'first': FIRST, 'last': args.through, 'sequential_steps': len(selected),
        'final_200_step_verification': args.through == LAST, 'requested_steps': STEP_COUNT, 'preseal_199_step_verification': args.through == LAST - 1, 'journal_steps_available_at_read': len(rows),
        'journal_sha256_at_read': hashlib.sha256(raw).hexdigest(), 'last_record_sha256': expected_previous,
        'record_metadata_and_results_replayed': True, 'journal_hash_chain_verified': True,
        'C931_predecessor_snapshot_verified': True, 'C931_current_record_checked': predecessor_live,
        'source_snapshot_hashes_verified': len(manifest), 'current_source_copies_checked': len(current),
        'current_sources': current, 'current_originals_absent': absent,
        'latest_File52c_sha256': PRIMARY_HASH,
        'step_checks_replayed': sum(r['checks'] for r in replays),
        'independent_reversal_used': True, 'single_pass_inverse_calls': sum(r['single_pass_inverse_calls'] for r in replays),
        'second_inverse_guard_violations': 0,
        'inverse_guard_scope': 'Nested inv calls and inversion of provenance-tracked inv outputs are rejected. This is not a proof against arbitrary manual reimplementation or deliberate provenance erasure.',
        'replay_writes_blocked': True, 'journal_prefix_unchanged_after_replay': True,
        'journal_bytes_unchanged_after_replay': after_raw == raw,
        'concurrent_completed_steps_appended': len(after_rows) - len(rows), 'replays': replays,
        'independent_review_notes': sorted(p.name for p in (ROOT / 'evidence').glob('REVIEW_*.md')),
        'scope': 'Exact record and script replay, source identity, and declared operation checks. Check counts are not independent discoveries or statistical evidence. Historical source suites were not rerun.'
    }
    text = json.dumps(report, indent=2, ensure_ascii=False) + '\n'
    if args.output:
        target = args.output.resolve()
        require(target != ROOT / 'journal.json' and target.suffix == '.json', 'Output must be a separate JSON report')
        target.write_text(text)
    print(text, end='')


if __name__ == '__main__':
    try:
        main()
    except (VerificationError, KeyError, ValueError, OSError) as exc:
        print(json.dumps({'status': 'FAIL', 'error': str(exc)}, ensure_ascii=False), file=sys.stderr)
        sys.exit(1)