#!/usr/bin/env python3
"""Slot-only runner. Every mutation restores and verifies the complete broker bytes."""
from pathlib import Path
import hashlib, os, re, subprocess, sys

ROOT = Path(__file__).resolve().parents[4]
SOURCE = ROOT / 'packages/bus/src/broker.mjs'
OUT = Path(__file__).resolve().parent / 'logs'
MUTANTS = [
    ('M01-human', 'human-required', 'room verbs require the human', '        this.#human(s);\n', ''),
    ('M02-tester', 'tester-refused', 'room verbs require the human', None, None),
    ('M03-project', 'project-not-found', 'room verbs refuse missing projects', "        if (!this.#store.get('SELECT 1 FROM projects WHERE id=? AND business=?', project, s.business)) fail('project-not-found');\n", ''),
    ('M04-members', 'thread-instance-missing', 'room verbs refuse missing projects', "        if (!members.length) fail('thread-instance-missing');\n", ''),
    ('M05-collision', 'room-thread-name-taken', 'room.open preflights instance collisions', "          if (t && (t.instance !== instance || t.owner !== owner))\n            fail(opening ? 'room-thread-name-taken' : 'room-not-open');\n", ''),
    ('M06-open', 'room-not-open', 'send/read refuse a missing canonical member', "          if (!t && !opening) fail('room-not-open');\n", ''),
    ('M07-body', 'invalid-request', 'unknown or non-member addressees and tags-only bodies', "          if (!addressed.body.trim()) fail('invalid-request');\n", ''),
    ('M08-unknown', 'unknown-addressee', 'unknown or non-member addressees and tags-only bodies', "            if (!candidates.size) fail('unknown-addressee');\n", ''),
    ('M09-ambiguous', 'addressee-ambiguous', 'a legacy name colliding with another member key', "            if (candidates.size > 1) fail('addressee-ambiguous');\n", ''),
    ('M10-messaging', 'message-sender-refused', 'messaging denial on the last target', "            this.#checkMessaging(s.business, 'human', t.instance);\n", ''),
    ('M11-cursor', 'message-not-found', 'room.read groups one send, pages', "          if (after === undefined) fail('message-not-found');\n", '          if (after === undefined) after = 0;\n'),
    ('M12-fence', 'session-clearing', 'a clearing last member fences the whole send', '            this.#sessionFence(session);\n', ''),
]

def sha(data): return hashlib.sha256(data).hexdigest()

def main():
    OUT.mkdir(exist_ok=True)
    original = SOURCE.read_bytes()
    text = original.decode()
    start = text.index("      case 'room.open':")
    end = text.index("      // A thread belongs", start)
    block = text[start:end]
    for name, refusal, expected, old, new in MUTANTS:
        if old is None:
            needle = 'export const TESTER_VERBS = Object.freeze(['
            assert text.count(needle) == 1
            changed = text.replace(needle, needle + "\n  'room.open', 'room.send', 'room.read',", 1)
        else:
            assert block.count(old) == 1, (name, block.count(old))
            changed = text[:start] + block.replace(old, new, 1) + text[end:]
        # Save conventional original→mutant diff without relying on shell interpolation.
        import difflib
        (OUT / f'{name}.diff').write_text(''.join(difflib.unified_diff(text.splitlines(True), changed.splitlines(True), fromfile='broker.original', tofile=name)))
        tmp = subprocess.check_output(['mktemp', '-d', '/mnt/storage/scratch/tmp/XXXXXX'], text=True).strip()
        env = {**os.environ, 'TMPDIR': tmp}
        log = OUT / f'{name}.log'
        try:
            SOURCE.write_text(changed)
            with log.open('w') as stream:
                for command in [['date', '-u'], ['uptime'], ['bash', '-c', 'bash /mnt/storage/scratch/sage-busy-now.sh 2>/dev/null | tail -1']]:
                    subprocess.run(command, cwd=ROOT, env=env, stdout=stream, stderr=subprocess.STDOUT, check=True)
                stream.write(f'TMPDIR={tmp}\nmutant={name} refusal={refusal} original_sha256={sha(original)}\n')
                stream.flush()
                result = subprocess.run(['timeout', '-k', '10', '120', 'node', '--test', '--test-reporter=tap', 'packages/bus/tests/rooms.test.mjs'],
                                        cwd=ROOT, env=env, stdout=stream, stderr=subprocess.STDOUT)
            output = log.read_text()
            killed = result.returncode == 1 and re.search(r'(?m)^not ok \d+ - ' + re.escape(expected), output)
            print(f'{name}: exit={result.returncode} target_killed={bool(killed)} log={log}', flush=True)
            if not killed: return 1
        finally:
            SOURCE.write_bytes(original)
            assert SOURCE.read_bytes() == original
            assert sha(SOURCE.read_bytes()) == sha(original)
            with log.open('a') as stream: stream.write(f'RESTORED sha256={sha(original)}\n')
    return 0

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