import io
import os
import tempfile
import unittest
from contextlib import redirect_stderr, redirect_stdout
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import patch

from dns_sync.adapters import (
    DNS_RECORDS,
    PROXY_HOSTS,
    Capability,
    CapabilityOperation,
    DiscoveredObject,
    Endpoint,
)
from dns_sync.cli import build_parser, run_reconcile


class FakeAdapter:
    def __init__(
        self,
        endpoint,
        capabilities,
        discovered,
    ):
        self.endpoint = endpoint
        self.capabilities = capabilities
        self.discovered = discovered
        self.apply_count = 0
        self.verify_count = 0

    def connect(self):
        pass

    def discover(self, object_type):
        return list(self.discovered.get(object_type, []))

    def apply(self, action):
        self.apply_count += 1
        raise AssertionError("read-only CLI called apply")

    def verify(self, object):
        self.verify_count += 1
        raise AssertionError("read-only CLI called verify")


class ReconcileCliTests(unittest.TestCase):
    def test_parser_exposes_read_only_reconcile_command(self):
        args = build_parser().parse_args(
            [
                "reconcile",
                "--state-db",
                "/tmp/test-state.sqlite3",
                "--include-disabled",
            ]
        )

        self.assertEqual(args.command, "reconcile")
        self.assertEqual(
            args.state_db,
            "/tmp/test-state.sqlite3",
        )
        self.assertTrue(args.include_disabled)

    def test_reconcile_builds_plan_without_applying_it(self):
        npm_endpoint = Endpoint("npm", "192.168.1.3:81")
        verizon_endpoint = Endpoint(
            "verizon",
            "192.168.1.1:443",
        )
        npm = FakeAdapter(
            npm_endpoint,
            frozenset(
                {
                    Capability(
                        PROXY_HOSTS,
                        CapabilityOperation.DISCOVER,
                    )
                }
            ),
            {
                PROXY_HOSTS: [
                    DiscoveredObject(
                        object_type=PROXY_HOSTS,
                        local_key="12",
                        payload={
                            "domain_names": [
                                "app.example.com"
                            ],
                            "forward_scheme": "http",
                            "forward_host": "192.168.1.50",
                            "forward_port": 8080,
                            "enabled": True,
                        },
                    )
                ]
            },
        )
        verizon = FakeAdapter(
            verizon_endpoint,
            frozenset(
                {
                    Capability(
                        DNS_RECORDS,
                        CapabilityOperation.DISCOVER,
                    ),
                    Capability(
                        DNS_RECORDS,
                        CapabilityOperation.APPLY,
                    ),
                }
            ),
            {
                DNS_RECORDS: [
                    DiscoveredObject(
                        object_type=DNS_RECORDS,
                        local_key="41",
                        payload={
                            "hostname": "app.example.com",
                            "ip": "192.168.1.50",
                            "record_type": "A",
                        },
                    )
                ]
            },
        )
        adapters = {
            npm_endpoint.identity: npm,
            verizon_endpoint.identity: verizon,
        }

        def loader(name, config, endpoint):
            return adapters[endpoint.identity]

        with tempfile.TemporaryDirectory() as directory:
            state_path = Path(directory) / "state.sqlite3"
            stdout = io.StringIO()
            stderr = io.StringIO()

            with patch.dict(
                os.environ,
                {
                    "NPM_ENDPOINTS": "192.168.1.3",
                    "VERIZON_ENDPOINTS": "192.168.1.1",
                    "DNS_TARGET_IP": "192.168.1.101",
                },
                clear=True,
            ), patch(
                "dns_sync.cli.load_adapter",
                side_effect=loader,
            ), redirect_stdout(stdout), redirect_stderr(stderr):
                result = run_reconcile(
                    SimpleNamespace(
                        state_db=str(state_path),
                        include_disabled=False,
                    )
                )

            self.assertTrue(state_path.exists())

        output = stdout.getvalue()
        self.assertEqual(result, 0)
        self.assertEqual(stderr.getvalue(), "")
        self.assertIn(
            "Generic reconciliation mode: READ ONLY",
            output,
        )
        self.assertIn(
            "UPDATE   dns_records app.example.com "
            "-> 192.168.1.101",
            output,
        )
        self.assertIn(
            "READ ONLY: no endpoint changes were applied.",
            output,
        )
        self.assertEqual(npm.apply_count, 0)
        self.assertEqual(verizon.apply_count, 0)
        self.assertEqual(npm.verify_count, 0)
        self.assertEqual(verizon.verify_count, 0)


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