"""Unit tests for the dynamo_cli Lambda handler."""

import boto3
import pytest
from moto import mock_aws

TABLE_NAME = 'offboarding-automation-snapshots'
REGION = 'us-east-1'


def _make_table() -> None:
    """Create the DynamoDB table for tests."""
    dynamodb = boto3.resource('dynamodb', region_name=REGION)
    dynamodb.create_table(
        TableName=TABLE_NAME,
        KeySchema=[{'AttributeName': 'ticket_id', 'KeyType': 'HASH'}],
        AttributeDefinitions=[{'AttributeName': 'ticket_id', 'AttributeType': 'S'}],
        BillingMode='PAY_PER_REQUEST',
    )


def _make_put_event(dry_run: bool = False) -> dict:
    return {
        'action': 'put-snapshot',
        'ticket_id': 'SYS-123',
        'email': 'john.doe@company.com',
        'full_name': 'John Doe',
        'last_working_day': '2026-04-30',
        'auth0_matches': [],
        'terraform_hits': [],
        'dry_run': dry_run,
    }


class TestHandlerRouting:
    """Tests for the handler action dispatcher."""

    def test_unknown_action_raises(self) -> None:
        """Unknown action raises ValueError."""
        from dynamo_client.app import handler

        with pytest.raises(ValueError, match='Unknown action'):
            handler({'action': 'nonexistent'}, None)

    def test_missing_action_raises(self) -> None:
        """Missing action key raises ValueError."""
        from dynamo_client.app import handler

        with pytest.raises(ValueError, match='Unknown action'):
            handler({}, None)


@mock_aws
class TestPutSnapshot:
    """Tests for the put-snapshot action."""

    def setup_method(self, method: object = None) -> None:
        """Reset module-level singletons before each test."""
        import dynamo_client.app as app_module

        app_module._config = None
        app_module._client = None

    def test_stores_snapshot(self) -> None:
        """put-snapshot stores the item and returns stored=True."""
        _make_table()
        from dynamo_client.app import handler

        result = handler(_make_put_event(), None)

        assert result['stored'] is True
        assert result['ticket_id'] == 'SYS-123'
        assert result['dry_run'] is False

    def test_dry_run_does_not_store(self) -> None:
        """put-snapshot with dry_run=True returns stored=False without writing."""
        _make_table()
        from dynamo_client.app import handler

        result = handler(_make_put_event(dry_run=True), None)

        assert result['stored'] is False
        assert result['dry_run'] is True

        # Verify nothing was written
        item = (
            boto3.resource('dynamodb', region_name=REGION)
            .Table(TABLE_NAME)
            .get_item(Key={'ticket_id': 'SYS-123'})
            .get('Item')
        )
        assert item is None


@mock_aws
class TestGetSnapshot:
    """Tests for the get-snapshot action."""

    def setup_method(self, method: object = None) -> None:
        """Reset module-level singletons before each test."""
        import dynamo_client.app as app_module

        app_module._config = None
        app_module._client = None

    def test_returns_snapshot_when_found(self) -> None:
        """get-snapshot returns found=True with snapshot when item exists."""
        _make_table()
        from dynamo_client.app import handler

        handler(_make_put_event(), None)

        result = handler({'action': 'get-snapshot', 'ticket_id': 'SYS-123'}, None)

        assert result['found'] is True
        assert result['snapshot']['email'] == 'john.doe@company.com'

    def test_returns_not_found(self) -> None:
        """get-snapshot returns found=False when item does not exist."""
        _make_table()
        from dynamo_client.app import handler

        result = handler({'action': 'get-snapshot', 'ticket_id': 'SYS-MISSING'}, None)

        assert result['found'] is False
        assert result['snapshot'] is None


@mock_aws
class TestDeleteSnapshot:
    """Tests for the delete-snapshot action."""

    def setup_method(self, method: object = None) -> None:
        """Reset module-level singletons before each test."""
        import dynamo_client.app as app_module

        app_module._config = None
        app_module._client = None

    def test_deletes_snapshot(self) -> None:
        """delete-snapshot removes the item and returns deleted=True."""
        _make_table()
        from dynamo_client.app import handler

        handler(_make_put_event(), None)
        result = handler(
            {'action': 'delete-snapshot', 'ticket_id': 'SYS-123', 'dry_run': False},
            None,
        )

        assert result['deleted'] is True
        assert result['dry_run'] is False

        get_result = handler({'action': 'get-snapshot', 'ticket_id': 'SYS-123'}, None)
        assert get_result['found'] is False

    def test_dry_run_does_not_delete(self) -> None:
        """delete-snapshot with dry_run=True leaves the item intact."""
        _make_table()
        from dynamo_client.app import handler

        handler(_make_put_event(), None)
        result = handler(
            {'action': 'delete-snapshot', 'ticket_id': 'SYS-123', 'dry_run': True}, None
        )

        assert result['deleted'] is False
        assert result['dry_run'] is True

        get_result = handler({'action': 'get-snapshot', 'ticket_id': 'SYS-123'}, None)
        assert get_result['found'] is True