from sqlalchemy import Column
from sqlalchemy import column
from sqlalchemy import desc
from sqlalchemy import exc
from sqlalchemy import Integer
from sqlalchemy import MetaData
from sqlalchemy import Numeric
from sqlalchemy import select
from sqlalchemy import Table
from sqlalchemy import table
from sqlalchemy.ext.compiler import compiles
from sqlalchemy.ext.compiler import deregister
from sqlalchemy.schema import CreateColumn
from sqlalchemy.schema import CreateTable
from sqlalchemy.schema import DDLElement
from sqlalchemy.sql.expression import BindParameter
from sqlalchemy.sql.expression import ClauseElement
from sqlalchemy.sql.expression import ColumnClause
from sqlalchemy.sql.expression import FunctionElement
from sqlalchemy.sql.expression import Select
from sqlalchemy.testing import assert_raises_message
from sqlalchemy.testing import AssertsCompiledSQL
from sqlalchemy.testing import eq_
from sqlalchemy.testing import fixtures
from sqlalchemy.types import TypeEngine


class UserDefinedTest(fixtures.TestBase, AssertsCompiledSQL):
    __dialect__ = "default"

    def test_column(self):
        class MyThingy(ColumnClause):
            def __init__(self, arg=None):
                super(MyThingy, self).__init__(arg or "MYTHINGY!")

        @compiles(MyThingy)
        def visit_thingy(thingy, compiler, **kw):
            return ">>%s<<" % thingy.name

        self.assert_compile(
            select([column("foo"), MyThingy()]), "SELECT foo, >>MYTHINGY!<<"
        )

        self.assert_compile(
            select([MyThingy("x"), MyThingy("y")]).where(MyThingy() == 5),
            "SELECT >>x<<, >>y<< WHERE >>MYTHINGY!<< = :MYTHINGY!_1",
        )

    def test_create_column_skip(self):
        @compiles(CreateColumn)
        def skip_xmin(element, compiler, **kw):
            if element.element.name == "xmin":
                return None
            else:
                return compiler.visit_create_column(element, **kw)

        t = Table(
            "t",
            MetaData(),
            Column("a", Integer),
            Column("xmin", Integer),
            Column("c", Integer),
        )

        self.assert_compile(
            CreateTable(t), "CREATE TABLE t (a INTEGER, c INTEGER)"
        )

    def test_types(self):
        class MyType(TypeEngine):
            pass

        @compiles(MyType, "sqlite")
        def visit_sqlite_type(type_, compiler, **kw):
            return "SQLITE_FOO"

        @compiles(MyType, "postgresql")
        def visit_pg_type(type_, compiler, **kw):
            return "POSTGRES_FOO"

        from sqlalchemy.dialects.sqlite import base as sqlite
        from sqlalchemy.dialects.postgresql import base as postgresql

        self.assert_compile(MyType(), "SQLITE_FOO", dialect=sqlite.dialect())

        self.assert_compile(
            MyType(), "POSTGRES_FOO", dialect=postgresql.dialect()
        )

    def test_stateful(self):
        class MyThingy(ColumnClause):
            def __init__(self):
                super(MyThingy, self).__init__("MYTHINGY!")

        @compiles(MyThingy)
        def visit_thingy(thingy, compiler, **kw):
            if not hasattr(compiler, "counter"):
                compiler.counter = 0
            compiler.counter += 1
            return str(compiler.counter)

        self.assert_compile(
            select([column("foo"), MyThingy()]).order_by(desc(MyThingy())),
            "SELECT foo, 1 ORDER BY 2 DESC",
        )

        self.assert_compile(
            select([MyThingy(), MyThingy()]).where(MyThingy() == 5),
            "SELECT 1, 2 WHERE 3 = :MYTHINGY!_1",
        )

    def test_callout_to_compiler(self):
        class InsertFromSelect(ClauseElement):
            def __init__(self, table, select):
                self.table = table
                self.select = select

        @compiles(InsertFromSelect)
        def visit_insert_from_select(element, compiler, **kw):
            return "INSERT INTO %s (%s)" % (
                compiler.process(element.table, asfrom=True),
                compiler.process(element.select),
            )

        t1 = table("mytable", column("x"), column("y"), column("z"))
        self.assert_compile(
            InsertFromSelect(t1, select([t1]).where(t1.c.x > 5)),
            "INSERT INTO mytable (SELECT mytable.x, mytable.y, mytable.z "
            "FROM mytable WHERE mytable.x > :x_1)",
        )

    def test_no_default_but_has_a_visit(self):
        class MyThingy(ColumnClause):
            pass

        @compiles(MyThingy, "postgresql")
        def visit_thingy(thingy, compiler, **kw):
            return "mythingy"

        eq_(str(MyThingy("x")), "x")

    def test_no_default_has_no_visit(self):
        class MyThingy(TypeEngine):
            pass

        @compiles(MyThingy, "postgresql")
        def visit_thingy(thingy, compiler, **kw):
            return "mythingy"

        assert_raises_message(
            exc.CompileError,
            "<class 'test.ext.test_compiler..*MyThingy'> "
            "construct has no default compilation handler.",
            str,
            MyThingy(),
        )

    def test_no_default_message(self):
        class MyThingy(ClauseElement):
            pass

        @compiles(MyThingy, "postgresql")
        def visit_thingy(thingy, compiler, **kw):
            return "mythingy"

        assert_raises_message(
            exc.CompileError,
            "<class 'test.ext.test_compiler..*MyThingy'> "
            "construct has no default compilation handler.",
            str,
            MyThingy(),
        )

    def test_default_subclass(self):
        from sqlalchemy.types import ARRAY

        class MyArray(ARRAY):
            pass

        @compiles(MyArray, "sqlite")
        def sl_array(elem, compiler, **kw):
            return "array"

        self.assert_compile(
            MyArray(Integer), "INTEGER[]", dialect="postgresql"
        )

    def test_annotations(self):
        """test that annotated clause constructs use the
        decorated class' compiler.

        """

        t1 = table("t1", column("c1"), column("c2"))

        dispatch = Select._compiler_dispatch
        try:

            @compiles(Select)
            def compile_(element, compiler, **kw):
                return "OVERRIDE"

            s1 = select([t1])
            self.assert_compile(s1, "OVERRIDE")
            self.assert_compile(s1._annotate({}), "OVERRIDE")
        finally:
            Select._compiler_dispatch = dispatch
            if hasattr(Select, "_compiler_dispatcher"):
                del Select._compiler_dispatcher

    def test_dialect_specific(self):
        class AddThingy(DDLElement):
            __visit_name__ = "add_thingy"

        class DropThingy(DDLElement):
            __visit_name__ = "drop_thingy"

        @compiles(AddThingy, "sqlite")
        def visit_add_thingy_sqlite(thingy, compiler, **kw):
            return "ADD SPECIAL SL THINGY"

        @compiles(AddThingy)
        def visit_add_thingy(thingy, compiler, **kw):
            return "ADD THINGY"

        @compiles(DropThingy)
        def visit_drop_thingy(thingy, compiler, **kw):
            return "DROP THINGY"

        self.assert_compile(AddThingy(), "ADD THINGY")

        self.assert_compile(DropThingy(), "DROP THINGY")

        from sqlalchemy.dialects.sqlite import base

        self.assert_compile(
            AddThingy(), "ADD SPECIAL SL THINGY", dialect=base.dialect()
        )

        self.assert_compile(
            DropThingy(), "DROP THINGY", dialect=base.dialect()
        )

        @compiles(DropThingy, "sqlite")
        def visit_drop_thingy_sqlite(thingy, compiler, **kw):
            return "DROP SPECIAL SL THINGY"

        self.assert_compile(
            DropThingy(), "DROP SPECIAL SL THINGY", dialect=base.dialect()
        )

        self.assert_compile(DropThingy(), "DROP THINGY")

    def test_functions(self):
        from sqlalchemy.dialects import postgresql

        class MyUtcFunction(FunctionElement):
            pass

        @compiles(MyUtcFunction)
        def visit_myfunc(element, compiler, **kw):
            return "utcnow()"

        @compiles(MyUtcFunction, "postgresql")
        def visit_myfunc_pg(element, compiler, **kw):
            return "timezone('utc', current_timestamp)"

        self.assert_compile(
            MyUtcFunction(), "utcnow()", use_default_dialect=True
        )
        self.assert_compile(
            MyUtcFunction(),
            "timezone('utc', current_timestamp)",
            dialect=postgresql.dialect(),
        )

    def test_function_calls_base(self):
        from sqlalchemy.dialects import mssql

        class greatest(FunctionElement):
            type = Numeric()
            name = "greatest"

        @compiles(greatest)
        def default_greatest(element, compiler, **kw):
            return compiler.visit_function(element)

        @compiles(greatest, "mssql")
        def case_greatest(element, compiler, **kw):
            arg1, arg2 = list(element.clauses)
            return "CASE WHEN %s > %s THEN %s ELSE %s END" % (
                compiler.process(arg1),
                compiler.process(arg2),
                compiler.process(arg1),
                compiler.process(arg2),
            )

        self.assert_compile(
            greatest("a", "b"),
            "greatest(:greatest_1, :greatest_2)",
            use_default_dialect=True,
        )
        self.assert_compile(
            greatest("a", "b"),
            "CASE WHEN :greatest_1 > :greatest_2 "
            "THEN :greatest_1 ELSE :greatest_2 END",
            dialect=mssql.dialect(),
        )

    def test_subclasses_one(self):
        class Base(FunctionElement):
            name = "base"

        class Sub1(Base):
            name = "sub1"

        class Sub2(Base):
            name = "sub2"

        @compiles(Base)
        def visit_base(element, compiler, **kw):
            return element.name

        @compiles(Sub1)
        def visit_sub1(element, compiler, **kw):
            return "FOO" + element.name

        self.assert_compile(
            select([Sub1(), Sub2()]),
            "SELECT FOOsub1, sub2",
            use_default_dialect=True,
        )

    def test_subclasses_two(self):
        class Base(FunctionElement):
            name = "base"

        class Sub1(Base):
            name = "sub1"

        @compiles(Base)
        def visit_base(element, compiler, **kw):
            return element.name

        class Sub2(Base):
            name = "sub2"

        class SubSub1(Sub1):
            name = "subsub1"

        self.assert_compile(
            select([Sub1(), Sub2(), SubSub1()]),
            "SELECT sub1, sub2, subsub1",
            use_default_dialect=True,
        )

        @compiles(Sub1)
        def visit_sub1(element, compiler, **kw):
            return "FOO" + element.name

        self.assert_compile(
            select([Sub1(), Sub2(), SubSub1()]),
            "SELECT FOOsub1, sub2, FOOsubsub1",
            use_default_dialect=True,
        )


class DefaultOnExistingTest(fixtures.TestBase, AssertsCompiledSQL):
    """Test replacement of default compilation on existing constructs."""

    __dialect__ = "default"

    def teardown(self):
        for cls in (Select, BindParameter):
            deregister(cls)

    def test_select(self):
        t1 = table("t1", column("c1"), column("c2"))

        @compiles(Select, "sqlite")
        def compile_(element, compiler, **kw):
            return "OVERRIDE"

        s1 = select([t1])
        self.assert_compile(s1, "SELECT t1.c1, t1.c2 FROM t1")

        from sqlalchemy.dialects.sqlite import base as sqlite

        self.assert_compile(s1, "OVERRIDE", dialect=sqlite.dialect())

    def test_binds_in_select(self):
        t = table("t", column("a"), column("b"), column("c"))

        @compiles(BindParameter)
        def gen_bind(element, compiler, **kw):
            return "BIND(%s)" % compiler.visit_bindparam(element, **kw)

        self.assert_compile(
            t.select().where(t.c.c == 5),
            "SELECT t.a, t.b, t.c FROM t WHERE t.c = BIND(:c_1)",
            use_default_dialect=True,
        )

    def test_binds_in_dml(self):
        t = table("t", column("a"), column("b"), column("c"))

        @compiles(BindParameter)
        def gen_bind(element, compiler, **kw):
            return "BIND(%s)" % compiler.visit_bindparam(element, **kw)

        self.assert_compile(
            t.insert(),
            "INSERT INTO t (a, b) VALUES (BIND(:a), BIND(:b))",
            {"a": 1, "b": 2},
            use_default_dialect=True,
        )
