# Copyright Materialize, Inc. and contributors. All rights reserved.
#
# Use of this software is governed by the Business Source License
# included in the LICENSE file at the root of this repository.
#
# As of the Change Date specified in that file, in accordance with
# the Business Source License, use of this software will be governed
# by the Apache License, Version 2.0.

"""
Test that setting feature flags works
"""

import argparse
from textwrap import dedent, indent

from materialize.mzcompose.composition import Composition, WorkflowArgumentParser
from materialize.mzcompose.services.materialized import Materialized
from materialize.mzcompose.services.redpanda import Redpanda
from materialize.mzcompose.services.testdrive import Testdrive
from materialize.util import all_subclasses

SERVICES = [
    Redpanda(),
    Materialized(unsafe_mode=False),
    Testdrive(no_reset=True, seed=1),
]

MZ_SYSTEM_CONNECTION_URL = (
    "postgres://mz_system:materialize@${testdrive.materialize-internal-sql-addr}"
)
USER_CONNECTION_URL = (
    "postgres://materialize:materialize@${testdrive.materialize-sql-addr}"
)


def header(test_name: str, drop_schema: bool) -> str:
    """Generate a TD header for a SQL feature test scenario."""
    header = dedent(
        f"""
        # Feature test for SQL feature test: {test_name}
        #####################################{'#' * len(test_name)}
        """
    )
    # Re-create schema (optional).
    if drop_schema:
        header += dedent(
            f"""
            $ postgres-execute connection=postgres://mz_system@materialized:6877/materialize
            DROP SCHEMA IF EXISTS public CASCADE;
            CREATE SCHEMA public /* {test_name} */;
            GRANT ALL PRIVILEGES ON SCHEMA public TO materialize;
            """
        )
    # Create connections.
    header += dedent(
        f"""
        $ postgres-connect name=user url={USER_CONNECTION_URL}
        $ postgres-connect name=mz_system url={MZ_SYSTEM_CONNECTION_URL}
        """
    )
    return header.strip()


def statement_error(statement: str, error_msg: str) -> str:
    """Generate a TD command that asserts that `statement` fails with `error_msg`."""
    return "\n".join(
        [
            indent(statement.strip(), prefix="  ").replace("  ", "! ", 1),
            f"contains:{error_msg}",
        ]
    )


def statement_ok(statement: str) -> str:
    """Generate a TD command that executes `statement`."""
    return indent(statement.strip(), prefix="  ").replace("  ", "> ", 1)


def query_ok(query: str) -> str:
    """Generate a TD command that asserts that a query does not fail."""
    return "\n".join(
        [
            "$ postgres-execute connection=user",
            query.strip(),
        ]
    )


def alter_system_set(name: str, value: str) -> str:
    """Generate a TD command that sets a system parameter."""
    return dedent(
        f"""
        $ postgres-execute connection=mz_system
        ALTER SYSTEM SET {name} = '{value}';
        """
    ).strip()


def alter_system_reset(name: str) -> str:
    """Generate a TD command that resets a system parameter."""
    return dedent(
        f"""
        $ postgres-execute connection=mz_system
        ALTER SYSTEM RESET {name};
        """
    ).strip()


def alter_system_reset_all() -> str:
    """Generate a TD command that reset all system parameters."""
    return dedent(
        """
        $ postgres-execute connection=mz_system
        ALTER SYSTEM RESET ALL;
        """
    ).strip()


class FeatureTestScenario:
    """
    A base class for all feature test scenarios.

    Each scenario is a `FeatureTestScenario` defined in this file. All
    subclasses are included in the `default` mzcompose workflow by default.
    """

    @classmethod
    def phase1(cls) -> str:
        return "\n\n".join(
            [
                # Include the header.
                header(f"{cls.__name__} (phase 1)", drop_schema=True),
                cls.initialize(),
                # Ensure the feature is off, regardless of CI config.
                alter_system_set(cls.feature_name(), "off"),
                # We cannot create item #1 when the feature is turned off (default).
                statement_error(cls.create_item(ordinal=1), cls.feature_error()),
                # Turn the feature on.
                alter_system_set(cls.feature_name(), "on"),
                # We can create item #1 when the feature is turned on.
                statement_ok(cls.create_item(ordinal=1)),
                # We can query item #1 when the feature is turned on.
                query_ok(cls.query_item(ordinal=1)),
                # Turn the feature off.
                alter_system_set(cls.feature_name(), "off"),
                # We cannot create item #2 when the feature is turned off.
                statement_error(cls.create_item(ordinal=2), cls.feature_error()),
            ]
        )

    @classmethod
    def phase2(cls) -> str:
        return "\n\n".join(
            [
                # Include the header.
                header(f"{cls.__name__} (phase 2)", drop_schema=False),
                cls.initialize(),
                # We can query item #1 when the feature is turned on. Ensures
                # that catalog rehydration ignores SQL-level feature flags.
                query_ok(cls.query_item(ordinal=1)),
                # We can drop item #1.
                statement_ok(cls.drop_item(ordinal=1)),
                # We cannot create item #2 when the feature is turned off.
                # Ensures that the feature flag is respected for new items.
                statement_error(cls.create_item(ordinal=2), cls.feature_error()),
            ]
        )

    @classmethod
    def phase3(cls) -> str:
        return "\n\n".join(
            [
                # Include the header.
                header(f"{cls.__name__} (phase 3)", drop_schema=False),
                # Because we have restarted, we need to ensure that we're getting
                # the parameter's default value, which will be "on".
                alter_system_reset(cls.feature_name()),
                cls.initialize(),
                # The feature is immediately turned on because it's a default parameter.
                statement_ok(cls.create_item(ordinal=1)),
                query_ok(cls.query_item(ordinal=1)),
                # We can drop item #1.
                statement_ok(cls.drop_item(ordinal=1)),
            ]
        )

    @classmethod
    def reset_all(cls) -> str:
        return "\n\n".join(
            [
                cls.initialize(),
                # The feature is immediately turned on because it's a default parameter.
                statement_ok(cls.create_item(ordinal=1)),
                query_ok(cls.query_item(ordinal=1)),
                # We can drop item #1.
                statement_ok(cls.drop_item(ordinal=1)),
            ]
        )

    @classmethod
    def feature_name(cls) -> str:
        """The name of the feature flag under test."""
        raise NotImplementedError

    @classmethod
    def feature_error(cls) -> str:
        """The error expected when the feature is disabled."""
        raise NotImplementedError

    @classmethod
    def initialize(cls) -> str:
        """Any SQL statements that must be executed before the statement under test."""
        return ""

    @classmethod
    def create_item(cls, ordinal: int) -> str:
        """A SQL statement that creates an item that depends on the feature."""
        raise NotImplementedError

    @classmethod
    def drop_item(cls, ordinal: int) -> str:
        """A SQL statement that drops an item that depends on the feature."""
        raise NotImplementedError

    @classmethod
    def query_item(cls, ordinal: int) -> str:
        """A SQL query referencing an item that depends on the feature."""
        raise NotImplementedError


def run_test(c: Composition, args: argparse.Namespace) -> None:
    c.up("redpanda", "materialized", {"name": "testdrive", "persistent": True})

    scenarios = (
        [globals()[args.scenario]]
        if args.scenario
        else all_subclasses(FeatureTestScenario)
    )

    # To add a new scenario create a new FeatureTestScenario subclass
    for scenario in scenarios:
        print(f"--- Running scenario {scenario.__name__} phase 1")
        c.testdrive(scenario.phase1())

        c.stop("materialized")
        c.up("materialized")

        print(f"--- Running scenario {scenario.__name__} phase 2")
        c.testdrive(scenario.phase2())

        materialized = Materialized(
            unsafe_mode=False,
            additional_system_parameter_defaults={
                scenario.feature_name(): "on",
            },
        )

        with c.override(materialized):
            c.stop("materialized")
            c.up("materialized")

            print(f"--- Running scenario {scenario.__name__} phase 3")
            c.testdrive(scenario.phase3())

    # Dedicated test for ALTER SYSTEM RESET ALL
    print("--- Running ALTER SYSTEM RESET ALL")
    tmp = [header("(phase reset-all)", drop_schema=False)]
    for scenario in scenarios:
        # Turn all features off.
        tmp.append(alter_system_set(scenario.feature_name(), "off"))

    # Run ALTER SYSTEM RESET ALL
    tmp.append(alter_system_reset_all())
    for scenario in scenarios:
        # Write each scenarios reset all data
        tmp.append(scenario.reset_all())

    # Create MZ config with all features set on by default
    materialized = Materialized(
        unsafe_mode=False,
        additional_system_parameter_defaults={
            scenario.feature_name(): "on" for scenario in scenarios
        },
    )
    with c.override(materialized):
        c.stop("materialized")
        c.up("materialized")
        c.testdrive("\n\n".join(tmp))


def workflow_default(c: Composition, parser: WorkflowArgumentParser) -> None:
    parser.add_argument(
        "--scenario", metavar="SCENARIO", type=str, help="Scenario to run."
    )
    run_test(c, parser.parse_args())