import pytest

from datasette.utils.sqlite import sqlite3
from datasette.utils.sql_analysis import analyze_sql_tables


@pytest.fixture
def conn():
    conn = sqlite3.connect(":memory:")
    conn.executescript("""
        create table dogs (id integer primary key, name text, age integer);
        create table cats (id integer primary key, name text);
        create table log (message text);
        create view dog_names as select id, name from dogs;
        create trigger dogs_after_insert after insert on dogs begin
            update cats set name = new.name where id = new.id;
            insert into log (message) values (new.name);
        end;
        create trigger dog_names_instead_of_update instead of update on dog_names begin
            update dogs set name = new.name where id = old.id;
        end;
        """)
    try:
        yield conn
    finally:
        conn.close()


def as_tuples(analysis):
    return [
        (
            access.operation,
            access.database,
            access.sqlite_schema,
            access.table,
            access.columns,
            access.source,
        )
        for access in analysis.table_accesses
    ]


def test_analyze_select_tables(conn):
    analysis = analyze_sql_tables(
        conn,
        "select dogs.name, cats.name from dogs join cats on dogs.id = cats.id where dogs.age > ?",
        (2,),
        database_name="data",
    )

    assert set(as_tuples(analysis)) == {
        ("read", "data", "main", "cats", ("id", "name"), None),
        ("read", "data", "main", "dogs", ("age", "id", "name"), None),
    }


def test_analyze_uses_sqlite_schema_as_default_database(conn):
    analysis = analyze_sql_tables(conn, "select name from dogs")

    assert set(as_tuples(analysis)) == {
        ("read", "main", "main", "dogs", ("name",), None),
    }


def test_analyze_insert_tables(conn):
    analysis = analyze_sql_tables(
        conn,
        "insert into dogs (name, age) values (:name, :age)",
        {"name": "Cleo", "age": 4},
        database_name="data",
    )

    assert set(as_tuples(analysis)) == {
        ("insert", "data", "main", "dogs", (), None),
        ("read", "data", "main", "dogs", ("id", "name"), "dogs_after_insert"),
        ("update", "data", "main", "cats", ("name",), "dogs_after_insert"),
        ("read", "data", "main", "cats", ("id",), "dogs_after_insert"),
        ("insert", "data", "main", "log", (), "dogs_after_insert"),
    }


def test_analyze_update_tables(conn):
    analysis = analyze_sql_tables(
        conn,
        "update dogs set age = age + 1 where name = ?",
        ("Cleo",),
        database_name="data",
    )

    assert set(as_tuples(analysis)) == {
        ("update", "data", "main", "dogs", ("age",), None),
        ("read", "data", "main", "dogs", ("age", "name"), None),
    }


def test_analyze_delete_tables(conn):
    analysis = analyze_sql_tables(
        conn,
        "delete from dogs where name = ?",
        ("Cleo",),
        database_name="data",
    )

    assert set(as_tuples(analysis)) == {
        ("delete", "data", "main", "dogs", (), None),
        ("read", "data", "main", "dogs", ("name",), None),
    }


def test_analyze_insert_select_with_cte(conn):
    analysis = analyze_sql_tables(
        conn,
        """
        with old_dogs as (
            select name from dogs where age > :age
        )
        insert into cats (name)
        select name from old_dogs
        """,
        {"age": 10},
        database_name="data",
    )

    assert set(as_tuples(analysis)) == {
        ("insert", "data", "main", "cats", (), None),
        ("read", "data", "main", "dogs", ("age", "name"), "old_dogs"),
    }


def test_analyze_view_with_instead_of_trigger(conn):
    analysis = analyze_sql_tables(
        conn,
        "update dog_names set name = :name where id = :id",
        {"name": "Zelda", "id": 1},
        database_name="data",
    )

    assert set(as_tuples(analysis)) == {
        ("update", "data", "main", "dog_names", ("name",), None),
        ("read", "data", "main", "dogs", ("id", "name"), "dog_names"),
        ("read", "data", "main", "dog_names", ("id", "name"), "dog_names"),
        (
            "read",
            "data",
            "main",
            "dog_names",
            ("id", "name"),
            "dog_names_instead_of_update",
        ),
        ("update", "data", "main", "dogs", ("name",), "dog_names_instead_of_update"),
        ("read", "data", "main", "dogs", ("id",), "dog_names_instead_of_update"),
    }


def test_analyze_attached_database_tables(conn):
    conn.execute("attach database ':memory:' as extra")
    conn.execute("create table extra.people (id integer primary key, name text)")

    analysis = analyze_sql_tables(
        conn,
        "insert into extra.people (name) select name from dogs",
        database_name="data",
        schema_to_database={"extra": "extra_db"},
    )

    assert set(as_tuples(analysis)) == {
        ("insert", "extra_db", "extra", "people", (), None),
        ("read", "data", "main", "dogs", ("name",), None),
    }


def test_analyze_invalid_sql_cleans_up_authorizer(conn):
    with pytest.raises(sqlite3.OperationalError):
        analyze_sql_tables(conn, "insert into missing_table values (1)")

    conn.execute("select name from dogs").fetchall()


def test_analyze_clears_authorizer_on_error():
    class FakeConnection:
        def __init__(self):
            self.authorizers = []

        def set_authorizer(self, authorizer):
            self.authorizers.append(authorizer)

        def execute(self, sql, params):
            raise sqlite3.OperationalError("bad SQL")

    conn = FakeConnection()

    with pytest.raises(sqlite3.OperationalError):
        analyze_sql_tables(conn, "bad SQL")

    assert conn.authorizers[-1] is None