from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any

import pytest

from src.storage.exceptions import StorageMigrationError
from src.storage.migrations import (
    STORAGE_MIGRATION_ADVISORY_LOCK_ID,
    STORAGE_MIGRATIONS,
    StorageMigration,
    StorageMigrationRunner,
)


@dataclass
class RecordingCursor:
    applied_rows: list[tuple[int, str]] = field(default_factory=list)
    fail_on: str | None = None
    calls: list[tuple[str, object | None]] = field(default_factory=list)

    def __enter__(self) -> RecordingCursor:
        return self

    def __exit__(self, *args: object) -> None:
        return None

    def execute(
        self,
        statement: str,
        parameters: object | None = None,
    ) -> None:
        normalized = " ".join(statement.split())
        self.calls.append((normalized, parameters))

        if self.fail_on is not None and self.fail_on in normalized:
            raise RuntimeError("database failed")

    def fetchall(self) -> list[tuple[int, str]]:
        return list(self.applied_rows)


@dataclass
class RecordingConnection:
    cursor_value: RecordingCursor
    entered: int = 0
    exited: int = 0

    def __enter__(self) -> RecordingConnection:
        self.entered += 1
        return self

    def __exit__(self, *args: object) -> None:
        self.exited += 1
        return None

    def cursor(self) -> RecordingCursor:
        return self.cursor_value


@dataclass
class RecordingProvider:
    connection: RecordingConnection
    calls: int = 0

    def __call__(self) -> RecordingConnection:
        self.calls += 1
        return self.connection


def _runner(
    *,
    applied_rows: list[tuple[int, str]] | None = None,
    fail_on: str | None = None,
    migrations: tuple[StorageMigration, ...] = STORAGE_MIGRATIONS,
) -> tuple[
    StorageMigrationRunner,
    RecordingCursor,
    RecordingConnection,
    RecordingProvider,
]:
    cursor = RecordingCursor(
        applied_rows=applied_rows or [],
        fail_on=fail_on,
    )
    connection = RecordingConnection(cursor)
    provider = RecordingProvider(connection)
    runner = StorageMigrationRunner(
        connection_provider=provider,
        migrations=migrations,
    )
    return runner, cursor, connection, provider


def test_default_migrations_have_stable_order_and_names() -> None:
    assert tuple(
        (migration.version, migration.name)
        for migration in STORAGE_MIGRATIONS
    ) == (
        (1, "create_market_data_schema"),
        (2, "create_canonical_trades"),
        (3, "create_canonical_quotes"),
        (4, "create_canonical_candle_revisions"),
        (5, "add_trade_observation_sources"),
        (6, "add_quote_and_candle_observation_sources"),
        (7, "create_market_data_partition_registry"),
        (8, "create_trade_stream_checkpoints"),
    )


def test_default_schema_defines_partitions_identities_and_constraints() -> None:
    sql = "\n".join(
        statement
        for migration in STORAGE_MIGRATIONS
        for statement in migration.statements
    )

    assert "CREATE SCHEMA IF NOT EXISTS market_data" in sql
    assert "CREATE TABLE market_data.trades" in sql
    assert "PRIMARY KEY (venue, symbol, trade_id, executed_at)" in sql
    assert "trade_id BETWEEN -2147483648 AND 2147483647" in sql
    assert sql.count("CHECK (BTRIM(venue) <> '')") == 4
    assert sql.count("CHECK (BTRIM(symbol) <> '')") == 4
    assert sql.count("CHECK (BTRIM(source) <> '')") == 3
    assert "PARTITION BY RANGE (executed_at)" in sql
    assert "CREATE TABLE market_data.quotes" in sql
    assert "PRIMARY KEY (venue, symbol, received_at)" in sql
    assert "PARTITION BY RANGE (received_at)" in sql
    assert "CREATE TABLE market_data.candle_revisions" in sql
    assert "open_time,\n                    observed_at" in sql
    assert "PARTITION BY RANGE (open_time)" in sql
    assert sql.count("PARTITION OF") == 3
    assert "ADD COLUMN observation_sources TEXT[]" in sql
    assert "SET observation_sources = ARRAY[source]" in sql
    assert "CARDINALITY(observation_sources) > 0" in sql
    assert "ALTER TABLE market_data.quotes" in sql
    assert "ALTER TABLE market_data.candle_revisions" in sql
    assert "quotes_observation_sources_not_empty" in sql
    assert "candle_revisions_observation_sources_not_empty" in sql
    assert "CREATE TABLE market_data.partition_registry" in sql
    assert "PRIMARY KEY (data_type, range_start)" in sql
    assert "UNIQUE (partition_name)" in sql
    assert "partition_bound TEXT NOT NULL" in sql
    assert "BTRIM(partition_bound) <> ''" in sql
    assert "range_end > range_start" in sql
    assert "CREATE TABLE market_data.trade_stream_checkpoints" in sql
    assert "PRIMARY KEY (venue, symbol)" in sql
    assert "revision BIGINT NOT NULL" in sql
    assert "checkpoint_schema_version INTEGER NOT NULL DEFAULT 1" in sql
    assert "CONSTRAINT trade_stream_checkpoints_trade_fk" in sql
    assert "FOREIGN KEY (" in sql
    assert ") REFERENCES market_data.trades (" in sql
    assert "ON UPDATE NO ACTION" in sql
    assert "ON DELETE NO ACTION" in sql
    assert "DEFERRABLE INITIALLY DEFERRED" in sql
    assert "CHECK (revision > 0)" in sql
    assert "CHECK (checkpoint_schema_version > 0)" in sql


def test_run_locks_and_applies_every_pending_migration_in_order() -> None:
    runner, cursor, connection, provider = _runner()

    result = runner.run()

    assert result == (1, 2, 3, 4, 5, 6, 7, 8)
    assert provider.calls == 1
    assert connection.entered == 1
    assert connection.exited == 1
    assert cursor.calls[0] == (
        "SELECT pg_advisory_xact_lock(%s)",
        (STORAGE_MIGRATION_ADVISORY_LOCK_ID,),
    )
    assert "public.storage_schema_migrations" in cursor.calls[1][0]
    inserted_versions = tuple(
        parameters[0]
        for statement, parameters in cursor.calls
        if statement.startswith(
            "INSERT INTO public.storage_schema_migrations"
        )
        and isinstance(parameters, tuple)
    )
    assert inserted_versions == (1, 2, 3, 4, 5, 6, 7, 8)


def test_run_skips_already_applied_migrations() -> None:
    applied = [
        (migration.version, migration.name)
        for migration in STORAGE_MIGRATIONS
    ]
    runner, cursor, _, _ = _runner(applied_rows=applied)

    result = runner.run()

    assert result == ()
    assert not any(
        statement.startswith("CREATE SCHEMA")
        or statement.startswith("CREATE TABLE market_data")
        for statement, _ in cursor.calls
    )


def test_run_applies_only_migrations_after_existing_prefix() -> None:
    applied = [
        (migration.version, migration.name)
        for migration in STORAGE_MIGRATIONS[:2]
    ]
    runner, cursor, _, _ = _runner(applied_rows=applied)

    result = runner.run()

    assert result == (3, 4, 5, 6, 7, 8)
    inserted_versions = tuple(
        parameters[0]
        for statement, parameters in cursor.calls
        if statement.startswith(
            "INSERT INTO public.storage_schema_migrations"
        )
        and isinstance(parameters, tuple)
    )
    assert inserted_versions == (3, 4, 5, 6, 7, 8)


def test_run_rejects_unknown_applied_version() -> None:
    runner, _, _, _ = _runner(applied_rows=[(99, "future")])

    with pytest.raises(StorageMigrationError, match="unknown.*99"):
        runner.run()


def test_run_rejects_changed_applied_name() -> None:
    runner, _, _, _ = _runner(applied_rows=[(1, "renamed")])

    with pytest.raises(StorageMigrationError, match="name mismatch"):
        runner.run()


def test_run_rejects_non_prefix_applied_history() -> None:
    second = STORAGE_MIGRATIONS[1]
    runner, _, _, _ = _runner(
        applied_rows=[(second.version, second.name)],
    )

    with pytest.raises(StorageMigrationError, match="ordered prefix"):
        runner.run()


def test_database_error_is_wrapped() -> None:
    runner, _, _, _ = _runner(fail_on="CREATE SCHEMA")

    with pytest.raises(StorageMigrationError) as error_info:
        runner.run()

    assert isinstance(error_info.value.__cause__, RuntimeError)


def test_keyboard_interrupt_is_not_wrapped() -> None:
    def interrupted_provider() -> Any:
        raise KeyboardInterrupt

    runner = StorageMigrationRunner(
        connection_provider=interrupted_provider,
    )

    with pytest.raises(KeyboardInterrupt):
        runner.run()


def test_runner_rejects_duplicate_versions() -> None:
    migration = StorageMigration(
        version=1,
        name="one",
        statements=("SELECT 1",),
    )

    with pytest.raises(ValueError, match="unique"):
        StorageMigrationRunner(
            connection_provider=lambda: None,  # type: ignore[arg-type]
            migrations=(migration, migration),
        )


def test_runner_rejects_out_of_order_versions() -> None:
    first = StorageMigration(1, "one", ("SELECT 1",))
    second = StorageMigration(2, "two", ("SELECT 2",))

    with pytest.raises(ValueError, match="ordered"):
        StorageMigrationRunner(
            connection_provider=lambda: None,  # type: ignore[arg-type]
            migrations=(second, first),
        )


@pytest.mark.parametrize(
    "arguments",
    (
        {"version": 0, "name": "zero", "statements": ("SELECT 0",)},
        {"version": True, "name": "one", "statements": ("SELECT 1",)},
        {"version": 1, "name": " ", "statements": ("SELECT 1",)},
        {"version": 1, "name": "one", "statements": ()},
        {"version": 1, "name": "one", "statements": (" ",)},
    ),
)
def test_migration_rejects_invalid_definition(
    arguments: dict[str, object],
) -> None:
    with pytest.raises(ValueError):
        StorageMigration(**arguments)  # type: ignore[arg-type]