#!/usr/bin/env python3
"""Linux host integration tests for the real dladdr/symlinkat helper; needs cc."""
import ctypes
import os
from pathlib import Path
import subprocess
import sys
import tempfile

HEADER = Path(__file__).resolve().parents[1] / 'component-source/component'
CASES = ['missing', 'correct', 'file', 'wrong_link', 'dangling', 'same_directory', 'unwritable', 'missing_source']

def child(case, base):
    base = Path(base)
    module = base / 'PlcLogic/libCmpAtomModbus.so'
    lib = ctypes.CDLL(str(module), use_errno=True)
    lib.warning_count.restype = ctypes.c_int
    lib.info_count.restype = ctypes.c_int
    os.chdir(base)
    link = base / 'libCmpAtomModbus.so'
    if case == 'correct':
        link.symlink_to('PlcLogic/libCmpAtomModbus.so')
    elif case == 'file':
        link.write_text('do not replace me')
    elif case in ('wrong_link', 'dangling'):
        if case == 'wrong_link':
            (base / 'other').write_text('other file')
        link.symlink_to('other')
    elif case == 'same_directory':
        os.chdir(module.parent)
    elif case == 'missing_source':
        module.unlink()
    elif case == 'unwritable':
        # sysfs cannot accept arbitrary regular symlinks, even as root.
        os.chdir('/sys')
        link = Path('/sys/libCmpAtomModbus.so')
        assert not os.path.lexists(link)
    ctypes.set_errno(123)
    lib.run_check()
    assert ctypes.get_errno() == 123, 'caller errno changed'
    warnings = lib.warning_count()
    infos = lib.info_count()
    lib.run_check()
    assert (warnings, infos) == (lib.warning_count(), lib.info_count()), 'retried or logged twice'
    if case == 'missing':
        assert link.is_symlink() and link.resolve() == module
        assert (warnings, infos) == (0, 1)
    elif case == 'correct':
        assert os.readlink(link) == 'PlcLogic/libCmpAtomModbus.so'
        assert (warnings, infos) == (0, 0)
    elif case == 'same_directory':
        assert module.is_file() and not module.is_symlink()
        assert (warnings, infos) == (0, 0)
    else:
        assert (warnings, infos) == (1, 0)
        if case == 'file':
            assert link.read_text() == 'do not replace me'
        elif case in ('wrong_link', 'dangling'):
            assert os.readlink(link) == 'other'
        else:
            assert not os.path.lexists(link)
    print('PASS', case)

if len(sys.argv) == 3:
    child(sys.argv[1], sys.argv[2])
else:
    with tempfile.TemporaryDirectory(prefix='atmb-link-test-') as temp:
        root = Path(temp)
        root.chmod(0o755)
        harness = root / 'harness.c'
        harness.write_text('''#define _GNU_SOURCE
#define syslog test_syslog
#include "atmb_boot_link.h"
static int warnings, infos;
void test_syslog(int priority, const char *format, ...) {
    (void)format;
    if (priority == LOG_WARNING) ++warnings;
    if (priority == LOG_INFO) ++infos;
}
void run_check(void) { atmb_ensure_boot_link(); }
int warning_count(void) { return warnings; }
int info_count(void) { return infos; }
''')
        output = root / 'test.so'
        subprocess.run([os.environ.get('CC', 'cc'), '-std=c99', '-Wall', '-Wextra', '-Werror',
                        '-fPIC', '-shared', '-I', str(HEADER), str(harness), '-ldl', '-o', str(output)], check=True)
        for case in CASES:
            base = root / case
            (base / 'PlcLogic').mkdir(parents=True)
            (base / 'PlcLogic/libCmpAtomModbus.so').write_bytes(output.read_bytes())
            subprocess.run([sys.executable, __file__, case, str(base)], check=True)
            base.chmod(0o755)