from __future__ import annotations

import subprocess
from pathlib import Path
from tempfile import TemporaryDirectory

from django import forms
from django.core.management import call_command
from django.test import SimpleTestCase, TestCase, override_settings

from pobsync_backend.forms import normalize_private_key, validate_ssh_private_key
from pobsync_backend.models import GlobalConfig, SshCredential


class SshCredentialValidationTests(SimpleTestCase):
    def test_normalize_private_key_repairs_wrapped_openssh_body(self) -> None:
        with TemporaryDirectory() as tmp:
            key_path = Path(tmp) / "identity"
            subprocess.run(
                ["ssh-keygen", "-t", "ed25519", "-N", "", "-C", "test", "-f", str(key_path)],
                check=True,
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
                text=True,
            )
            private_key = key_path.read_text(encoding="utf-8")

        begin_marker = "-----BEGIN OPENSSH PRIVATE KEY-----"
        end_marker = "-----END OPENSSH PRIVATE KEY-----"
        body = private_key.split(begin_marker, 1)[1].split(end_marker, 1)[0]
        damaged_body = " \n ".join(body.split())
        damaged_key = f"{begin_marker}\n{damaged_body}\n{end_marker}"

        normalized_key = normalize_private_key(damaged_key)

        self.assertEqual(validate_ssh_private_key(normalized_key), validate_ssh_private_key(private_key))

    def test_validate_private_key_rejects_pem_key_with_actionable_message(self) -> None:
        with self.assertRaises(forms.ValidationError) as exc:
            validate_ssh_private_key("-----BEGIN RSA PRIVATE KEY-----\nabc\n-----END RSA PRIVATE KEY-----")

        self.assertIn("PEM private keys are not supported", str(exc.exception))


class SshCredentialManagementTests(TestCase):
    def test_ensure_ssh_key_command_generates_default_key(self) -> None:
        with TemporaryDirectory() as tmp, override_settings(POBSYNC_HOME=str(Path(tmp) / "home")):
            call_command("ensure_pobsync_ssh_key", "--name", "default")

            credential = SshCredential.objects.get(name="default")
            self.assertTrue(credential.generated)
            self.assertTrue(Path(credential.key_path).exists())
            self.assertTrue(credential.public_key.startswith("ssh-ed25519 "))

    def test_ensure_ssh_key_command_sets_global_default_when_available(self) -> None:
        global_config = GlobalConfig.objects.create(name="default", backup_root="/backups")

        with TemporaryDirectory() as tmp, override_settings(POBSYNC_HOME=str(Path(tmp) / "home")):
            call_command("ensure_pobsync_ssh_key", "--name", "default", "--set-global-default")

        global_config.refresh_from_db()
        self.assertEqual(global_config.default_ssh_credential.name, "default")