#!/usr/bin/env python3
"""Offline, path-relocated installer contract tests. All external commands mocked.
Do not equate these tests with genuine Postfix/PostSRSd integration.
"""
from pathlib import Path
import os, subprocess, tempfile, re, sys, shutil, signal, types

SOURCE = Path(sys.argv[1]).resolve() if len(sys.argv) > 1 else Path(__file__).resolve().parents[1]

def putexe(file, content):
    file.parent.mkdir(parents=True, exist_ok=True)
    file.write_text('#!/usr/bin/env bash\n' + content)
    file.chmod(0o755)

def setup(root):
    root.mkdir(parents=True, exist_ok=True)
    repo = root / 'repo'
    repo.mkdir()
    # Copy only public SRS source files needed by the test. Never copy the
    # complete mailserver repository, .git, credentials, local conf/srs.conf,
    # or unrelated applications into an executable test fixture.
    if not SOURCE.is_dir():
        raise RuntimeError(f'SOURCE must be a repository directory: {SOURCE}')
    required = [
        'install-update-srs.sh',
        'helpers/srs-common.sh',
        'helpers/srs-dns-check.py',
        'helpers/srs-virtual-alias.py',
        'files/srs/srs-alias-decision.py',
        'files/srs/srs-forward.py',
        'files/srs/srs-reverse-map.py',
        'files/srs/srs-reverse-policy.py',
    ]
    templates = SOURCE/'files/srs/templates'
    required += [str(f.relative_to(SOURCE)) for f in templates.iterdir() if f.is_file() and not f.is_symlink()]
    for rel in required:
        src = SOURCE/rel
        if not src.is_file() or src.is_symlink():
            raise RuntimeError(f'Missing or symlinked source file: {src}')
        dst = repo/rel
        dst.parent.mkdir(parents=True, exist_ok=True)
        shutil.copy2(src, dst)
    for path in (repo/'install-update-srs.sh', repo/'helpers/srs-common.sh',
                 *list((repo/'files/srs').glob('*.py')),
                 *list((repo/'files/srs/templates').glob('*'))):
        s = path.read_text()
        # Keep all managed install/config/queue paths in an unprivileged fixture tree.
        # The postconf absolute command must also be relocated.
        s = s.replace('/usr/sbin/postconf', str(root/'bin/postconf'))
        for prefix in ['/etc/', '/usr/local/', '/var/', '/run/lock/', '/root/srs-installer-backups']:
            new = str(root) + prefix
            s = s.replace(prefix, new)
        # prevent reading the real original root Postfix config in our fixtures
        if path == repo/'helpers/srs-common.sh':
            # The test runner uses a pipe for scripted confirmations;
            # allow that only inside the copied, isolated helper fixture.
            needle = 'if [[ -t 1 ]]; then'
            if s.count(needle) != 1:
                raise RuntimeError('Unexpected terminal gate in helper')
            s = s.replace(needle, 'if true; then', 1)
        path.write_text(s)
    (repo/'install-update-srs.sh').chmod(0o755)
    for p in ['etc/postfix','usr/local/sbin','run/lock','var/spool','var/lib','etc/systemd/system','flags']:
        (root/p).mkdir(parents=True, exist_ok=True)
    (root/'etc/postfix/main.cf').write_text('myhostname = mail.example.org\n')
    (root/'etc/postfix/master.cf').write_text('smtp inet n - y - - smtpd\nlocalhost:10025 inet n - y - - smtpd\n  -o receive_override_options=no_unknown_recipient_checks\n')
    (repo/'conf').mkdir(exist_ok=True)
    # All expected lookup paths are extracted from the (relocated) reference source.
    alias = (repo/'files/srs/srs-alias-decision.py').read_text()
    for typ,name in set(re.findall(r'"(pgsql|btree):([^" ]+)"', alias)):
        f = Path(name + ('.db' if typ == 'btree' else ''))
        f.parent.mkdir(parents=True,exist_ok=True)
        f.touch()
    bin = root/'bin'
    bin.mkdir()
    putexe(bin/'postconf', '''
name="${@: -1}"
# e.mx.oopen.de has two pre-existing unrelated warnings in main.cf.
# They are emitted on every postconf call while the requested value is valid.
echo "postconf: warning: ${SRS_TEST_ROOT}/etc/postfix/main.cf: unused parameter: policyd-spf_time_limit=3600" >&2
# The warning path matches the source main.cf in the relocated fixture.
# Existing warnings must be distinguished from queried-param errors.
if [[ -f "${SRS_TEST_ROOT}/flags/unknown_parameter_warning" ]]; then
 echo "postconf: warning: smtp_tls_cafile: unknown parameter" >&2
fi
case "$name" in
mail_owner) echo postfix;;
myhostname) echo mail.example.org;;
mydomain) echo example.org;;
myorigin) echo /etc/mailname;;
mydestination) echo 'mail.example.org localhost';;
relay_domains) echo '\u0024mydestination';;
virtual_alias_maps) echo 'pgsql:some-alias';;
virtual_alias_domains) echo 'btree:some-domain';;
virtual_mailbox_maps) echo 'pgsql:some-mailbox';;
virtual_mailbox_domains) echo 'pgsql:some-domain';;
smtp_bind_address) echo 192.0.2.22;;
smtp_bind_address6) echo 2001:db8::22;;
smtp_dns_support_level) echo dnssec;;
smtp_host_lookup) echo dns;;
smtp_tls_CAfile) echo /etc/ssl/certs/ca-certificates.crt;;
smtp_tls_mandatory_protocols|smtp_tls_protocols) echo '>=TLSv1.2';;
smtp_tls_security_level) echo dane;;
*) echo "unknown $name" >&2; exit 1;;
esac
''')
    putexe(bin/'id', '''
if [[ "$1" == -u && "$2" == postfix ]]; then echo 123; exit 0; fi
if [[ "$1" == -g && "$2" == postfix ]]; then echo 123; exit 0; fi
exec /usr/bin/id "$@"
''')
    putexe(bin/'systemctl', '''
if [[ "$1" == is-active ]]; then exit 3; fi
exit 0
''')
    putexe(bin/'git', '''
if [[ "$1" == clone ]]; then
  mkdir -p "${@: -1}"; exit 0
fi
exec /usr/bin/git "$@"
''')
    putexe(bin/'cmake', '''
if [[ "$1" == --version ]]; then echo 'cmake version 3.31.6'; exit 0; fi
if [[ "$1" == -S ]]; then
  for ((i=1; i<=$#; i++)); do
    arg="${!i}"
    if [[ "$arg" == -B ]]; then n=$((i+1)); build="${!n}"; fi
    if [[ "$arg" == -DCMAKE_INSTALL_PREFIX=* ]]; then prefix="${arg#*=}"; fi
  done
  mkdir -p "$build"; printf '%s\\n' "$prefix" > "$build/prefix"; exit 0
fi
if [[ "$1" == --build ]]; then exit 0; fi
if [[ "$1" == --install ]]; then
  prefix="$(cat "$2/prefix")"
  mkdir -p "${DESTDIR}${prefix}/sbin"
  printf '#!/bin/sh\\nexit 0\\n' > "${DESTDIR}${prefix}/sbin/postsrsd"
  chmod +x "${DESTDIR}${prefix}/sbin/postsrsd"
  exit 0
fi
exit 9
''')
    putexe(bin/'ctest','exit 0\n')
    putexe(bin/'dig','exit 0\n')
    putexe(bin/'postmap','''
case "$1" in
 btree:*) dest="${1#btree:}"; touch "${dest}.db";;
 *) exit 1;;
esac
if [[ -f "${SRS_TEST_ROOT}/flags/fail_postmap" ]]; then exit 1; fi
exit 0
''')
    putexe(bin/'postfix','''
if [[ "$*" == *check* ]]; then
 mkdir -p "${SRS_TEST_ROOT}/var/spool/postfix-srs-delivery/private" "${SRS_TEST_ROOT}/var/lib/postfix-srs-delivery"
 if [[ -f "${SRS_TEST_ROOT}/flags/fail_postfix" ]]; then echo 'forced postfix check error' >&2; exit 1; fi
fi
exit 0
''')
    (repo/'helpers/srs-dns-check.py').write_text('print("   Simulated authoritative DNS: OK")\n')
    return repo

def run(root, repo, *, fail=None, version=None):
    if fail: (root/'flags'/('fail_'+fail)).touch()
    argv = [str(repo/'install-update-srs.sh'), '--install']
    if version: argv.extend(['--version', version])
    env = os.environ.copy()
    env.update({'PATH':str(root/'bin') + ':' + env['PATH'], 'SRS_TEST_ROOT':str(root), 'LC_ALL':'C'})
    # No real PTY is needed: the terminal requirement is disabled only in the
    # relocated helper copy, never in the actual repository.
    # File-backed capture prevents subprocess pipe hangs from descendant
    # processes retaining output fds. A timeout kills the entire fixture group.
    with tempfile.TemporaryFile(mode='w+t') as out:
        proc = subprocess.Popen(argv, stdin=subprocess.PIPE, stdout=out,
                                stderr=subprocess.STDOUT, text=True, env=env,
                                start_new_session=True)
        try:
            proc.communicate(input='srs.example.org\nyes\nyes\n', timeout=20)
        except subprocess.TimeoutExpired:
            os.killpg(proc.pid, signal.SIGKILL)
            proc.wait(timeout=5)
            raise RuntimeError('Mock installer timed out')
        out.seek(0)
        return types.SimpleNamespace(returncode=proc.returncode, stdout=out.read())

def assert_ok(condition, msg):
    if not condition: raise AssertionError(msg)

with tempfile.TemporaryDirectory(prefix='oopen-srs-test-') as tmp:
    base=Path(tmp)
    os.chmod(base, 0o2700)  # Test SGID inheritance without granting group access.
    root=base/'initial'
    repo=setup(root)
    result=run(root,repo)
    print('initial install', result.returncode)
    if result.returncode: print(result.stdout[-2500:])
    assert_ok(result.returncode == 0,'initial installation failed')
    assert_ok((root/'usr/local/postsrsd').is_symlink(), 'missing symlink')
    assert_ok((root/'usr/local/sbin/srs-forward.py').exists(), 'missing srs forward')
    assert_ok((root/'etc/postsrsd-srs/secret').stat().st_mode & 0o777 == 0o600, 'secret mode')
    assert_ok('smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt' in (root/'etc/postfix-srs/delivery/main.cf').read_text(),'rendered TLS CA')
    print("  secret dir mode:", oct((root/"etc/postsrsd-srs").stat().st_mode & 0o777), "uid", (root/"etc/postsrsd-srs").stat().st_uid)
    print("  stat check:", subprocess.check_output(["stat", "-c", "%u:%g:%a", str(root/"etc/postsrsd-srs")], text=True).strip())
    print('  initial install: state, secret, config, symlink, CAfile verified')
    original_secret=(root/'etc/postsrsd-srs/secret').read_bytes()
    original_forward=(root/'usr/local/sbin/srs-forward.py').read_bytes()
    original_link=os.readlink(root/'usr/local/postsrsd')
    result=run(root,repo)
    print('maintenance update', result.returncode)
    if result.returncode: print(result.stdout[-2500:])
    assert_ok(result.returncode == 0,'maintenance update failed')
    assert_ok((root/'etc/postsrsd-srs/secret').read_bytes()==original_secret,'secret changed')
    assert_ok(os.readlink(root/'usr/local/postsrsd')==original_link,'link changed')
    print('  maintenance update: original secret and binary retained')
    # Force late failure, after Postfix configuration and all units have been deployed.
    source=repo/'files/srs/srs-forward.py'
    source.write_text(source.read_text()+'\n# injected test change\n')
    result=run(root,repo,fail='postfix')
    print('failed maintenance rollback', result.returncode)
    if result.returncode==0: print(result.stdout[-2500:])
    assert_ok(result.returncode != 0,'injected failure not detected')
    assert_ok((root/'usr/local/sbin/srs-forward.py').read_bytes()==original_forward,'rollback did not restore file')
    assert_ok((root/'etc/postsrsd-srs/secret').read_bytes()==original_secret,'rollback changed secret')
    assert_ok(os.readlink(root/'usr/local/postsrsd')==original_link,'rollback changed symlink')
    print('  failure rollback: file restored; secret and symlink preserved')
    (root/'flags/fail_postfix').unlink()
    result=run(root,repo,version='2.4.2')
    print('version upgrade', result.returncode)
    if result.returncode: print(result.stdout[-2500:])
    assert_ok(result.returncode == 0,'version upgrade failed')
    assert_ok((root/'usr/local/postsrsd-2.4.1').exists(),'prior prefix missing')
    assert_ok(os.readlink(root/'usr/local/postsrsd')=='postsrsd-2.4.2','new link incorrect')
    print('  version upgrade: previous prefix retained; link updated')
    (root/'flags/fail_postfix').touch()
    result=run(root,repo,version='2.4.3')
    print('failed version upgrade rollback', result.returncode)
    assert_ok(result.returncode != 0,'injected failure not detected')
    assert_ok(os.readlink(root/'usr/local/postsrsd')=='postsrsd-2.4.2','previous version link not restored')
    assert_ok(not (root/'usr/local/postsrsd-2.4.3').exists(),'failed version prefix not removed')
    print('  failed version upgrade: symlink restored, new prefix removed')

    # Active SRS configuration must prohibit any maintenance update before writes.
    (root/'flags/fail_postfix').unlink()
    active_marker = '# BEGIN OOPEN-SRS-MANAGED'
    existing_main=(root/'etc/postfix/main.cf')
    original_main=existing_main.read_text()
    existing_main.write_text(original_main + active_marker + '\n')
    before=(root/'usr/local/sbin/srs-forward.py').read_bytes()
    result=run(root,repo,version='2.4.2')
    print('active integration guard', result.returncode)
    assert_ok(result.returncode != 0,'active SRS was not refused')
    assert_ok((root/'usr/local/sbin/srs-forward.py').read_bytes() == before, 'active check changed scripts')
    existing_main.write_text(original_main)
    print('  active integration guard: blocked before file changes')

    # Independent initial installation with late failure. New SRS files must be removed.
    root=base/'failed-first'
    repo=setup(root)
    result=run(root,repo,fail='postfix')
    print('failed first install', result.returncode)
    assert_ok(result.returncode != 0,'injected first-install failure not detected')
    assert_ok(not (root/'usr/local/postsrsd').exists(), 'first-install rollback left symlink')
    assert_ok(not (root/'usr/local/postsrsd-2.4.1').exists(), 'first-install rollback left prefix')
    assert_ok(not (root/'etc/postsrsd-srs/secret').exists(), 'first-install rollback left secret')
    assert_ok(not (root/'etc/postfix-srs/delivery/main.cf').exists(), 'first-install rollback left config')
    assert_ok((root/'var/spool/postfix-srs-delivery/private').is_dir(), 'test Postfix runtime queue unexpectedly deleted')
    print('  failed first install: tracked files removed; Postfix runtime directory safely preserved')

    # Fail at postmap, before systemd and Postfix checks.
    root=base/'failed-map'
    repo=setup(root)
    result=run(root,repo,fail='postmap')
    print('failed postmap rollback', result.returncode)
    assert_ok(result.returncode != 0, 'injected postmap failure not detected')
    assert_ok(not (root/'etc/postfix-srs/delivery/transport.db').exists(),'failed postmap index remains')
    assert_ok(not (root/'etc/postsrsd-srs/secret').exists(),'failed postmap secret remains')
    assert_ok(not (root/'usr/local/postsrsd').exists(),'failed postmap link remains')
    print('  failed postmap: generated index and secret removed')

    # Unexpected warnings must never be silently swallowed.
    root=base/'unexpected-warning'
    repo=setup(root)
    (root/'flags/unknown_parameter_warning').touch()
    result=run(root, repo)
    print('unexpected postconf warning', result.returncode)
    assert_ok(result.returncode != 0, 'unexpected postconf warning accepted')
    assert_ok(not (root/'usr/local/postsrsd').exists(), 'unexpected warning allowed installation')
    print('  unrelated existing warnings tolerated, queried-parameter warning rejected')

    # A template referencing an unknown Postfix parameter must fail closed.
    root=base/'bad-template-parameter'
    repo=setup(root)
    template=root/'repo/files/srs/templates/delivery-main.cf.in'
    contents=template.read_text()
    assert_ok('smtp_tls_CAfile = @SMTP_TLS_CAFILE@' in contents, 'missing expected template parameter')
    template.write_text(contents.replace('smtp_tls_CAfile = @SMTP_TLS_CAFILE@',
                                        'smtp_tls_cafile = @SMTP_TLS_CAFILE@'))
    result=run(root, repo)
    print('invalid template parameter', result.returncode)
    assert_ok(result.returncode != 0, 'unknown template Postfix parameter accepted')
    assert_ok(not (root/'usr/local/postsrsd').exists(), 'invalid template allowed installation')
    print('  unknown requested Postfix parameter rejected')

print('ALL OFFLINE MOCK CONTRACT TESTS PASSED')