"""Verify deployment decisions without connecting to a server or Docker daemon."""
import gzip
import hashlib
import os
from pathlib import Path
import subprocess
import tempfile
import unittest

SCRIPTS = Path(__file__).resolve().parents[1]
SHA = "a" * 40
OLD = "sundynix/veyra:" + "b" * 40

class ReleaseTests(unittest.TestCase):
    def setUp(self):
        self.temp = tempfile.TemporaryDirectory(prefix="veyra-release-")
        self.addCleanup(self.temp.cleanup)
        self.root = Path(self.temp.name)
        (self.root / "configs").mkdir()
        (self.root / "configs/.env").write_text("TEST_SETTING=unchanged\n")
        self.release = self.root / "releases" / SHA
        self.release.mkdir(parents=True)
        archive = gzip.compress(b"fake image")
        (self.release / "image.tar.gz").write_bytes(archive)
        digest = hashlib.sha256(archive).hexdigest()
        (self.release / "image.tar.gz.sha256").write_text(digest + "  image.tar.gz\n")
        (self.release / "docker-compose.yml").write_text("new compose\n")
        (self.root / "docker-compose.yml").write_text("old compose\n")
        (self.root / ".current-image").write_text(OLD + "\n")
        tools = self.root / "tools"
        tools.mkdir()
        mock = tools / "docker"
        mock.write_text(r"""#!/usr/bin/env python3
import os, sys
from pathlib import Path
args = sys.argv[1:]
with open(os.environ['MOCK_LOG'], 'a') as log:
    log.write(os.environ.get('VEYRA_IMAGE', '') + ' ' + ' '.join(args) + '\n')
if args and args[0] == 'load':
    sys.stdin.buffer.read()
if '-command' in args and args[-1] == 'db-migrate' and os.environ.get('FAIL_MIGRATION'):
    sys.exit(1)
if 'up' in args and os.environ.get('FAIL_READINESS') and os.environ.get('VEYRA_IMAGE') != os.environ['OLD_IMAGE']:
    sys.exit(1)
""")
        mock.chmod(0o755)
        # macOS has no flock; emulate it for this single-process decision test.
        if not __import__('shutil').which('flock'):
            (tools / 'flock').write_text('#!/bin/sh\nexit 0\n')
            (tools / 'flock').chmod(0o755)
        if not __import__('shutil').which('sha256sum'):
            checksum = tools / 'sha256sum'
            checksum.write_text("""#!/usr/bin/env python3
import hashlib, sys
from pathlib import Path
for line in Path(sys.argv[2]).read_text().splitlines():
    digest, name = line.split('  ', 1)
    if hashlib.sha256(Path(name).read_bytes()).hexdigest() != digest:
        sys.exit(1)
""")
            checksum.chmod(0o755)
        self.env = dict(os.environ, PATH=str(tools) + os.pathsep + os.environ['PATH'],
                        MOCK_LOG=str(self.root / 'commands'), OLD_IMAGE=OLD)

    def run_release(self, **flags):
        return subprocess.run(['bash', str(SCRIPTS / 'release.sh'), str(self.root), SHA],
                              env=dict(self.env, **flags), capture_output=True, text=True)

    def test_success_promotes_exact_commit(self):
        result = self.run_release()
        self.assertEqual(result.returncode, 0, result.stderr)
        self.assertEqual((self.root / '.current-image').read_text().strip(), 'sundynix/veyra:' + SHA)
        self.assertEqual((self.root / 'configs/.env').read_text(), 'TEST_SETTING=unchanged\n')
        self.assertFalse((self.release / 'image.tar.gz').exists())
        calls = (self.root / 'commands').read_text()
        self.assertLess(calls.index('db-migrate'), calls.index(' up '))

    def test_failed_readiness_restores_previous_application(self):
        self.assertNotEqual(self.run_release(FAIL_READINESS='1').returncode, 0)
        self.assertEqual((self.root / '.current-image').read_text().strip(), OLD)
        self.assertEqual((self.root / 'docker-compose.yml').read_text(), 'old compose\n')
        self.assertIn(OLD + ' compose', (self.root / 'commands').read_text())

    def test_failed_migration_does_not_replace_running_application(self):
        self.assertNotEqual(self.run_release(FAIL_MIGRATION='1').returncode, 0)
        self.assertNotIn(' up ', (self.root / 'commands').read_text())
        self.assertEqual((self.root / 'docker-compose.yml').read_text(), 'old compose\n')

    def test_invalid_archive_never_loads_image(self):
        (self.release / 'image.tar.gz').write_bytes(b'corrupt')
        self.assertNotEqual(self.run_release().returncode, 0)
        self.assertFalse((self.root / 'commands').exists())

    def test_missing_configuration_fails_before_image_load(self):
        (self.root / 'configs/.env').unlink()
        self.assertNotEqual(self.run_release().returncode, 0)
        self.assertFalse((self.root / 'commands').exists())

    def test_bootstrap_preserves_existing_configuration(self):
        for _ in range(2):
            result = subprocess.run(['bash', str(SCRIPTS / 'bootstrap-config.sh'), str(self.root)],
                                    input='TEST_SETTING=new\n', capture_output=True, text=True)
            self.assertEqual(result.returncode, 0, result.stderr)
        self.assertEqual((self.root / 'configs/.env').read_text(), 'TEST_SETTING=unchanged\n')
        (self.root / 'configs/.env').unlink()
        result = subprocess.run(['bash', str(SCRIPTS / 'bootstrap-config.sh'), str(self.root)],
                                input='TEST_SETTING=new\n', capture_output=True, text=True)
        self.assertEqual(result.returncode, 0, result.stderr)
        self.assertEqual((self.root / 'configs/.env').stat().st_mode & 0o777, 0o600)

if __name__ == '__main__':
    unittest.main()