"""Run the isolated synthetic C# harness and measure its own source FFmpeg only.

No Jellyfin configuration changes, restarts, API keys or receiver connections.
"""
import argparse
import json
import os
from pathlib import Path
import signal
import subprocess
import time


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--harness', required=True)
    parser.add_argument('--ffmpeg', default='/usr/lib/jellyfin-ffmpeg/ffmpeg')
    parser.add_argument('--output', required=True)
    parser.add_argument('--long', action='store_true')
    args = parser.parse_args()
    root = Path(args.output).resolve()
    if root.exists():
        raise ValueError('Choose a new output directory')
    samples, previous = [], {}
    with Path(str(root) + '.log').open('x') as log:
        process = subprocess.Popen([args.harness, '--long-continuity-e2e' if args.long else '--continuity-e2e', args.ffmpeg, str(root)], stdout=log,
                                   stderr=subprocess.STDOUT, start_new_session=True)
        deadline = time.monotonic() + 240
        try:
            while process.poll() is None:
                if time.monotonic() > deadline:
                    raise TimeoutError('Synthetic harness deadline exceeded')
                now = time.monotonic()
                for proc in Path('/proc').glob('[0-9]*'):
                    try:
                        if not str((proc / 'cwd').resolve()).startswith(str(root / 'cache' / 'source-')):
                            continue
                        value = (proc / 'stat').read_text()
                        fields = value[value.rfind(')') + 2:].split()
                        cpu = (int(fields[11]) + int(fields[12])) / os.sysconf('SC_CLK_TCK')
                        rss = int(fields[21]) * os.sysconf('SC_PAGE_SIZE') / 1048576
                        if proc.name in previous:
                            before, at = previous[proc.name]
                            samples.append({'one_core_percent': round((cpu-before)/(now-at)*100, 1),
                                            'rss_mib': round(rss, 1)})
                        previous[proc.name] = (cpu, now)
                    except OSError:
                        pass
                time.sleep(1)
        finally:
            if process.poll() is None:
                os.killpg(process.pid, signal.SIGTERM)
                try:
                    process.wait(timeout=5)
                except subprocess.TimeoutExpired:
                    os.killpg(process.pid, signal.SIGKILL)
                    process.wait()
    report = {'harness_exit_code': process.returncode, 'samples': samples,
              'scope': 'Only synthetic plugin source encoding; excludes fixture and player decoders'}
    (root / 'cpu-sample.json').write_text(json.dumps(report, indent=2))
    if process.returncode == 0 and args.long:
        subprocess.run(['python3', str(Path(__file__).with_name('verify-continuity-recording.py')), '--output', str(root), '--ffmpeg', args.ffmpeg], check=True)
    print(Path(str(root) + '.log').read_text()[-3500:])
    print(json.dumps({'exit_code': process.returncode, 'cpu_samples': len(samples),
                      'maximum_one_core_percent': max((s['one_core_percent'] for s in samples), default=None),
                      'maximum_rss_mib': max((s['rss_mib'] for s in samples), default=None)}))
    raise SystemExit(0 if process.returncode == 0 else 1)


if __name__ == '__main__':
    main()