"""Execute the reviewed move plan without deleting or rewriting evidence."""
from pathlib import Path
import hashlib
import json
import os
import subprocess
import time

HERE = Path(__file__).resolve().parent
REPO = Path('/Users/tboudreaux/Programming/4DSTAR/MeanField')


def inventory(path):
    entries = []
    paths = [path] if not path.is_dir() else sorted(path.rglob('*'))
    for item in paths:
        relative = '.' if item == path else str(item.relative_to(path))
        if item.is_symlink():
            entries.append({'path': relative, 'kind': 'symlink', 'target': os.readlink(item)})
        elif item.is_file():
            digest = hashlib.sha256()
            with item.open('rb') as stream:
                for block in iter(lambda: stream.read(1024 * 1024), b''):
                    digest.update(block)
            entries.append({'path': relative, 'kind': 'file', 'bytes': item.stat().st_size,
                            'sha256': digest.hexdigest()})
        elif item.is_dir():
            entries.append({'path': relative, 'kind': 'directory'})
        else:
            raise RuntimeError(f'Unsupported evidence type: {item}')
    return entries


plan = json.loads((HERE / 'move_plan.json').read_text())
tracked = [REPO / x for x in subprocess.check_output(
    ['git', 'ls-files', '-z'], cwd=REPO).decode().split('\0') if x]
for move in plan:
    source, destination = Path(move['source']), Path(move['destination'])
    if not source.exists() or source.is_symlink():
        raise RuntimeError(f'Missing/already-moved source: {source}')
    if destination.exists() or destination.is_symlink():
        raise RuntimeError(f'Destination already exists: {destination}')
    if any(x == source or source in x.parents for x in tracked):
        raise RuntimeError(f'Plan would move tracked source: {source}')

manifest = {'started_at_unix': time.time(), 'moves': []}
record = HERE / 'move_manifest.json'
for move in plan:
    source, destination = Path(move['source']), Path(move['destination'])
    before = inventory(source)
    entry = {**move, 'entries': before, 'verified': False}
    manifest['moves'].append(entry)
    record.write_text(json.dumps(manifest, indent=2) + '\n')
    destination.parent.mkdir(parents=True, exist_ok=True)
    # Atomic rename preserves contents, permissions and directory structure.
    source.rename(destination)
    if move['compatibility_symlink']:
        source.symlink_to(destination, target_is_directory=destination.is_dir())
    if inventory(destination) != before:
        raise RuntimeError(f'Post-move evidence mismatch: {destination}')
    entry['verified'] = True
    record.write_text(json.dumps(manifest, indent=2) + '\n')
    print(f'Preserved and verified: {source.name} ({len(before)} entries)', flush=True)
manifest['completed_at_unix'] = time.time()
manifest['all_verified'] = all(x['verified'] for x in manifest['moves'])
record.write_text(json.dumps(manifest, indent=2) + '\n')
print('All moves verified; no artifacts deleted.', flush=True)