import concurrent.futures
import json
import os
from pathlib import Path
import subprocess
import tempfile

helper = Path('scripts/test_native_build.py').resolve()
with tempfile.TemporaryDirectory(dir='tmp', prefix='native-cache-probe.') as work:
    root = Path(work).resolve()
    header = root / 'nested header.h'
    header.write_text('#define VALUE 0\n')
    source = root / 'a.cpp'
    source.write_text('#include "nested header.h"\nint main(){return VALUE;}\n')
    other = root / 'b.cpp'
    other.write_text('int other(){return 0;}\n')
    output = root / 'test'
    cmd = ['python3', str(helper), str(output), '--', 'g++', str(source), str(other)]
    def run(command=cmd, success=True):
        result = subprocess.run(command, timeout=30)
        assert (result.returncode == 0) == success
        return output.stat().st_mtime_ns
    first = run()
    assert run() == first
    state = json.loads(Path(str(output)+'.json').read_text())
    assert str(header) in state['dependencies'] and str(source) in state['dependencies']
    times = header.stat()
    header.write_text('#define VALUE 1\n')
    os.utime(header, ns=(times.st_atime_ns, times.st_mtime_ns))
    changed = run()
    assert changed != first and subprocess.run([output], timeout=10).returncode == 1
    header.write_text('#define VALUE 0\n')
    os.utime(header, ns=(times.st_atime_ns, times.st_mtime_ns))
    reverted = run()
    assert reverted != changed and subprocess.run([output], timeout=10).returncode == 0
    flagged = run(cmd+['-DOTHER=1'])
    assert flagged != reverted and run(cmd+['-DOTHER=1']) == flagged
    run(cmd+['-invalid-flag'], False)
    assert not Path(str(output)+'.json').exists()
    run()
    source.write_text('broken source\n')
    run(success=False)
    assert not Path(str(output)+'.json').exists()
    source.write_text('#include "nested header.h"\nint main(){return VALUE;}\n')
    with concurrent.futures.ThreadPoolExecutor(max_workers=4) as pool:
        stamps = list(pool.map(lambda _: run(), range(4)))
    assert len(set(stamps)) == 1
    output.write_bytes(b'corrupt')
    run()
    assert subprocess.run([output], timeout=10).returncode == 0
    wrapper = root / 'compiler'
    wrapper.write_text('#!/bin/sh\nexec g++ "$@"\n')
    wrapper.chmod(0o755)
    custom = cmd.copy()
    custom[4] = str(wrapper)
    before = run(custom)
    wrapper.write_text('#!/bin/sh\n# changed compiler\nexec g++ "$@"\n')
    assert run(custom) != before
    print('PASS: first/hit, transitive content/timestamp/revert, flags, failed scan/build, concurrency, binary corruption, compiler identity')