#!/usr/bin/env python3
"""Verify benchmark gates without depending on noisy real-machine timings."""
import json
from pathlib import Path
import subprocess
import sys
import tempfile

with tempfile.TemporaryDirectory(prefix='xtc-benchmark-') as directory:
    root = Path(directory)
    binary = root / 'measurement'
    binary.write_text('''#!/usr/bin/env python3
import json, sys
nodes, channels, rate, frames, blocks = map(int, sys.argv[1:])
print(json.dumps(dict(nodes=nodes, channels=channels, rate=rate, frames=frames,
                     blocks=blocks, mean_us=10, p99_us=12, deadline_misses=0,
                     process_cpu_ms=1, peak_rss_kib=1024)))
''')
    binary.chmod(0o700)
    report, baseline = root / 'report.json', root / 'baseline.json'
    command = [sys.executable, 'tools/benchmark.py', '--binary', str(binary),
               '--output', str(report)]

    def run(arguments, success, message=None):
        result = subprocess.run(arguments, capture_output=True, text=True, timeout=30)
        assert (result.returncode == 0) == success, result.stdout + result.stderr
        if message:
            assert message in result.stdout + result.stderr

    run(command, True)
    original = json.loads(report.read_text())
    baseline.write_text(json.dumps(original))
    compare = command + ['--baseline', str(baseline)]
    run(compare, True)
    changed = json.loads(json.dumps(original))
    changed['cases'][0]['mean_us'] = 1
    baseline.write_text(json.dumps(changed))
    run(compare, False, 'exceeds')
    changed = json.loads(json.dumps(original))
    changed['cases'].pop()
    baseline.write_text(json.dumps(changed))
    run(compare, False, 'missing baseline case')
    changed = json.loads(json.dumps(original))
    changed['context']['flags'] = 'incompatible'
    baseline.write_text(json.dumps(changed))
    run(compare, False, 'mismatch')
    changed = json.loads(json.dumps(original))
    changed['context']['workload'] = 'project'
    baseline.write_text(json.dumps(changed))
    run(compare, False, 'workload mismatch')
print('Benchmark matching, regression, missing-case and context gates passed.')