import asyncio
from typing import Any
import pytest
import uuid
import asyncssh
import tempfile
from contextlib import asynccontextmanager
from unittest.mock import AsyncMock, MagicMock
from ipaddress import IPv4Network, IPv6Network

from sshecret_sshd.ssh_server import run_ssh_server
from sshecret_sshd.settings import ClientRegistrationSettings

from .types import (
    Client,
    ClientKey,
    ClientRegistry,
    SshServerFixtureFun,
    SshServerFixture,
)


@pytest.fixture(scope="function")
def client_registry() -> ClientRegistry:
    clients = {}
    secrets = {}

    async def add_client(
        name: str,
        secret_names: list[str] | None = None,
        policies: list[str] | None = None,
    ) -> str:
        private_key = asyncssh.generate_private_key("ssh-rsa")
        public_key = private_key.export_public_key()
        clients[name] = ClientKey(name, private_key, public_key.decode().rstrip())
        secrets.update({(name, s): f"mocked-secret-{s}" for s in (secret_names or [])})
        return clients[name]

    return {"clients": clients, "secrets": secrets, "add_client": add_client}


@pytest.fixture(scope="function")
async def mock_backend(client_registry: ClientRegistry) -> MagicMock:
    backend = MagicMock()
    clients_data = client_registry["clients"]
    secrets_data = client_registry["secrets"]

    async def get_client(name: str) -> Client | None:
        client_key = clients_data.get(name)
        if client_key:
            response_model = Client(
                id=uuid.uuid4(),
                name=name,
                description=f"Mock client {name}",
                public_key=client_key.public_key,
                secrets=[s for (c, s) in secrets_data if c == name],
                policies=[IPv4Network("0.0.0.0/0"), IPv6Network("::/0")],
            )
            return response_model
        return None

    async def get_client_secret(name: str, secret_name: str) -> str | None:
        secret = secrets_data.get((name, secret_name), None)
        return secret

    async def create_client(name: str, public_key: str) -> None:
        """Create client.

        This only works if you register a client called template first.
        Otherwise we can't test this...
        """
        if "template" not in clients_data:
            raise RuntimeError(
                "Error, must have a client called template for this to work."
            )
        clients_data[name] = clients_data["template"]
        for secret_key, secret in secrets_data.items():
            s_client, secret_name = secret_key
            if s_client != "template":
                continue
            secrets_data[(name, secret_name)] = secret

    async def write_audit(*args, **kwargs):
        """Write audit mock."""
        return None

    backend.get_client = AsyncMock(side_effect=get_client)
    backend.get_client_secret = AsyncMock(side_effect=get_client_secret)
    backend.create_client = AsyncMock(side_effect=create_client)

    audit = MagicMock()
    audit.write_async = AsyncMock(side_effect=write_audit)
    backend.audit = MagicMock(return_value=audit)

    return backend


@pytest.fixture(scope="function")
async def ssh_server(
    mock_backend: MagicMock, unused_tcp_port: int
) -> SshServerFixtureFun:
    port = unused_tcp_port

    private_key = asyncssh.generate_private_key("ssh-ed25519")
    key_str = private_key.export_private_key()
    with tempfile.NamedTemporaryFile("w+", delete=True) as key_file:
        key_file.write(key_str.decode())
        key_file.flush()

        registration_settings = ClientRegistrationSettings(
            enabled=True, allow_from=[IPv4Network("0.0.0.0/0")]
        )
        server = await run_ssh_server(
            backend=mock_backend,
            listen_address="localhost",
            port=port,
            keys=[key_file.name],
            registration=registration_settings,
            enable_ping_command=True,
        )

        await asyncio.sleep(0.1)

        yield server, port

        server.close()
        await server.wait_closed()


@pytest.fixture(scope="function")
def ssh_command_runner(ssh_server: SshServerFixture, client_registry: ClientRegistry):
    """Run a single command.

    Tricky typing!
    """
    _, port = ssh_server

    async def run_command_as(name: str, command: str):
        client_key = client_registry["clients"][name]
        conn = await asyncssh.connect(
            "127.0.0.1",
            port=port,
            username=name,
            client_keys=[client_key.private_key],
            known_hosts=None,
        )
        try:
            result = await conn.run(command)
            return result
        finally:
            conn.close()
            await conn.wait_closed()

    return run_command_as


@pytest.fixture(scope="function")
def ssh_session(ssh_server: SshServerFixture, client_registry: ClientRegistry):
    """Yield an interactive session."""

    _, port = ssh_server

    @asynccontextmanager
    async def run_process_as(name: str, command: str, client: str | None = None):
        if not client:
            client = name
        client_key = client_registry["clients"][client]
        conn = await asyncssh.connect(
            "127.0.0.1",
            port=port,
            username=name,
            client_keys=[client_key.private_key],
            known_hosts=None,
        )
        try:
            async with conn.create_process(command) as process:
                yield process

        finally:
            conn.close()
            await conn.wait_closed()

    return run_process_as