


""" Code generation for implicit and explicit exception raises.

Exceptions from other operations are consider ErrorCodes domain.

"""

from qutayba import Options
from qutayba.Builtins import isBaseExceptionSimpleExtension
from qutayba.PythonVersions import python_version

from .CodeHelpers import (
    generateChildExpressionsCode,
    generateExpressionCode,
    withObjectCodeTemporaryAssignment,
)
from .ErrorCodes import getErrorExitCode, getFrameVariableTypeDescriptionCode
from .ExceptionCodes import getExceptionIdentifier
from .LabelCodes import getGotoCode
from .LineNumberCodes import (
    emitErrorLineNumberUpdateCode,
    getErrorLineNumberUpdateCode,
)
from .PythonAPICodes import getReferenceExportCode


def generateReraiseCode(statement, emit, context):
    with context.withCurrentSourceCodeReference(
        value=statement.getCompatibleSourceReference()
    ):
        getReRaiseExceptionCode(emit=emit, context=context)


def _haveQuickExceptionCreationCode(exception_name):
    result = exception_name in ("StopIteration",)

    # TODO: Get this complete for larger test suites.
    # assert result, exception_name

    return result


def _generateExceptionNormalizeCode(to_name, exception_type, emit, context):

    if exception_type.isExpressionBuiltinExceptionRef():
        exception_name = exception_type.getExceptionName()
        if isBaseExceptionSimpleExtension(exception_type.getCompileTimeConstant()):
            emit(
                "%s = MAKE_BASE_EXCEPTION_DERIVED_EMPTY(%s);"
                % (to_name, getExceptionIdentifier(exception_name))
            )
            context.addCleanupTempName(to_name)

            return
        elif _haveQuickExceptionCreationCode(exception_type.getExceptionName()):
            # TODO: Code generation like this here, ought to be shared with
            # the one for ExpressionBuiltinMakeExceptionRef once that is
            # done too.
            if exception_name == "StopIteration":
                emit("%s = MAKE_STOP_ITERATION_EMPTY();" % to_name)
            else:
                assert False, exception_name

            context.addCleanupTempName(to_name)
            return

    # TODO: Can only fall through if exception builtins are not fully handled,
    # but we should make sure that doesn't ever happen by handling them all.

    if exception_type.isExpressionBuiltinMakeException():
        # TODO: Make this shape based, but currently the nodes do not
        # provide the shape, we need to add that.

        # No need to normalize these.
        generateExpressionCode(
            to_name=to_name,
            expression=exception_type,
            emit=emit,
            context=context,
        )
    else:
        # Need to normalize exceptions.
        raise_type_input_name = context.allocateTempName("raise_type_input")

        generateExpressionCode(
            to_name=raise_type_input_name,
            expression=exception_type,
            emit=emit,
            context=context,
        )

        emit(
            "%s = NORMALIZE_EXCEPTION_VALUE_FOR_RAISE(tstate, %s);"
            % (to_name, raise_type_input_name)
        )

        getErrorExitCode(
            check_name=to_name,
            release_name=raise_type_input_name,
            needs_check=True,
            emit=emit,
            context=context,
        )

        context.addCleanupTempName(to_name)


def generateRaiseCode(statement, emit, context):
    exception_type = statement.subnode_exception_type
    exception_value = statement.subnode_exception_value
    exception_tb = statement.subnode_exception_trace
    exception_cause = statement.subnode_exception_cause

    # Exception cause is only possible with simple raise form.
    if exception_cause is not None:
        assert exception_type is not None
        assert exception_value is None
        assert exception_tb is None

        raise_type_name = context.allocateTempName("raise_type")

        if python_version >= 0x3C0:
            _generateExceptionNormalizeCode(
                to_name=raise_type_name,
                exception_type=exception_type,
                emit=emit,
                context=context,
            )
        else:
            generateExpressionCode(
                to_name=raise_type_name,
                expression=exception_type,
                emit=emit,
                context=context,
            )

        raise_cause_name = context.allocateTempName("raise_cause")

        generateExpressionCode(
            to_name=raise_cause_name,
            expression=exception_cause,
            emit=emit,
            context=context,
        )

        with context.withCurrentSourceCodeReference(
            exception_cause.getSourceReference()
        ):
            _getRaiseExceptionWithCauseCode(
                raise_type_name=raise_type_name,
                raise_cause_name=raise_cause_name,
                emit=emit,
                context=context,
            )
    elif exception_type is None:
        assert False, statement
    elif exception_value is None and exception_tb is None:
        raise_type_name = context.allocateTempName("raise_type")

        if python_version >= 0x3C0:
            _generateExceptionNormalizeCode(
                to_name=raise_type_name,
                exception_type=exception_type,
                emit=emit,
                context=context,
            )
        else:
            generateExpressionCode(
                to_name=raise_type_name,
                expression=exception_type,
                emit=emit,
                context=context,
            )

        with context.withCurrentSourceCodeReference(
            value=exception_type.getCompatibleSourceReference()
        ):
            _getRaiseExceptionWithTypeCode(
                raise_type_name=raise_type_name, emit=emit, context=context
            )

    elif exception_tb is None:
        raise_type_name = context.allocateTempName("raise_type")

        generateExpressionCode(
            to_name=raise_type_name,
            expression=exception_type,
            emit=emit,
            context=context,
        )

        raise_value_name = context.allocateTempName("raise_value")

        generateExpressionCode(
            to_name=raise_value_name,
            expression=exception_value,
            emit=emit,
            context=context,
        )

        with context.withCurrentSourceCodeReference(
            exception_value.getCompatibleSourceReference()
        ):
            _getRaiseExceptionWithValueCode(
                raise_type_name=raise_type_name,
                raise_value_name=raise_value_name,
                emit=emit,
                context=context,
            )
    else:
        raise_type_name = context.allocateTempName("raise_type")

        generateExpressionCode(
            to_name=raise_type_name,
            expression=exception_type,
            emit=emit,
            context=context,
        )

        raise_value_name = context.allocateTempName("raise_value")

        generateExpressionCode(
            to_name=raise_value_name,
            expression=exception_value,
            emit=emit,
            context=context,
        )

        raise_tb_name = context.allocateTempName("raise_tb")

        generateExpressionCode(
            to_name=raise_tb_name, expression=exception_tb, emit=emit, context=context
        )

        with context.withCurrentSourceCodeReference(exception_tb.getSourceReference()):
            _getRaiseExceptionWithTracebackCode(
                raise_type_name=raise_type_name,
                raise_value_name=raise_value_name,
                raise_tb_name=raise_tb_name,
                emit=emit,
                context=context,
            )


def generateRaiseExpressionCode(to_name, expression, emit, context):
    (exception_value_name,) = generateChildExpressionsCode(
        expression=expression, emit=emit, context=context
    )

    # Missed optimization opportunity, please report it, this should not
    # normally happen. We are supposed to propagate this upwards.
    if Options.is_debug:
        # TODO: Need to optimize ExpressionLocalsVariableRefOrFallback once we know
        # it handles cases where the value is not in locals dict properly.

        parent = expression.parent
        assert (
            parent.isExpressionSideEffects()
            or parent.isExpressionConditional()
            or parent.isExpressionConditionalOr()
            or parent.isExpressionConditionalAnd()
            or parent.isExpressionLocalsVariableRefOrFallback()
        ), (expression, expression.parent, expression.asXmlText())

    with withObjectCodeTemporaryAssignment(
        to_name, "raise_exception_result", expression, emit, context
    ) as value_name:
        # That's how we indicate exception to the surrounding world.
        emit("%s = NULL;" % value_name)

        _getRaiseExceptionWithTypeCode(
            raise_type_name=exception_value_name,
            emit=emit,
            context=context,
        )


def getReRaiseExceptionCode(emit, context):
    (
        exception_state_name,
        exception_lineno,
    ) = context.variable_storage.getExceptionVariableDescriptions()

    (
        keeper_exception_state_name,
        _keeper_lineno,
    ) = context.getExceptionKeeperVariables()

    if keeper_exception_state_name is None:
        emit(
            """\
%(bool_res_name)s = RERAISE_EXCEPTION(tstate, &%(exception_state_name)s);
if (unlikely(%(bool_res_name)s == false)) {
    %(update_code)s
}
"""
            % {
                "exception_state_name": exception_state_name,
                "bool_res_name": context.getBoolResName(),
                "update_code": getErrorLineNumberUpdateCode(context),
            }
        )

        frame_handle = context.getFrameHandle()

        if frame_handle:
            emit(
                """\
{
    PyTracebackObject *exception_tb = GET_EXCEPTION_STATE_TRACEBACK(&%(exception_state_name)s);

    if ((exception_tb != NULL) && (exception_tb->tb_frame == &%(frame_identifier)s->m_frame)) {
        %(frame_identifier)s->m_frame.f_lineno = exception_tb->tb_lineno;
    }
}"""
                % {
                    "exception_state_name": exception_state_name,
                    "frame_identifier": context.getFrameHandle(),
                }
            )

            emit(getFrameVariableTypeDescriptionCode(context))
    else:
        (
            keeper_exception_state_name,
            keeper_lineno,
        ) = context.getExceptionKeeperVariables()

        emit(
            """\
// Re-raise.
%(exception_state_name)s = %(keeper_exception_state_name)s;
%(exception_lineno)s = %(keeper_lineno)s;
"""
            % {
                "exception_state_name": exception_state_name,
                "exception_lineno": exception_lineno,
                "keeper_exception_state_name": keeper_exception_state_name,
                "keeper_lineno": keeper_lineno,
            }
        )

    getGotoCode(context.getExceptionEscape(), emit)


def _getRaiseExceptionWithCauseCode(raise_type_name, raise_cause_name, emit, context):
    (
        exception_state_name,
        _exception_lineno,
    ) = context.variable_storage.getExceptionVariableDescriptions()

    if python_version < 0x3C0:
        emit("%s.exception_type = %s;" % (exception_state_name, raise_type_name))
    else:
        emit("%s.exception_value = %s;" % (exception_state_name, raise_type_name))

    getReferenceExportCode(raise_type_name, emit, context)

    getReferenceExportCode(raise_cause_name, emit, context)

    emitErrorLineNumberUpdateCode(emit, context)
    emit(
        "RAISE_EXCEPTION_WITH_CAUSE(tstate, &%s, %s);"
        % (exception_state_name, raise_cause_name)
    )

    emit(getFrameVariableTypeDescriptionCode(context))

    getGotoCode(context.getExceptionEscape(), emit)

    if context.needsCleanup(raise_type_name):
        context.removeCleanupTempName(raise_type_name)
    if context.needsCleanup(raise_cause_name):
        context.removeCleanupTempName(raise_cause_name)


def _getRaiseExceptionWithTypeCode(raise_type_name, emit, context):
    (
        exception_state_name,
        _exception_lineno,
    ) = context.variable_storage.getExceptionVariableDescriptions()

    if python_version < 0x3C0:
        emit("%s.exception_type = %s;" % (exception_state_name, raise_type_name))
        getReferenceExportCode(raise_type_name, emit, context)

        emitErrorLineNumberUpdateCode(emit, context)

        emit("RAISE_EXCEPTION_WITH_TYPE(tstate, &%s);" % exception_state_name)
    else:
        emit("%s.exception_value = %s;" % (exception_state_name, raise_type_name))
        getReferenceExportCode(raise_type_name, emit, context)

        emitErrorLineNumberUpdateCode(emit, context)

        emit("RAISE_EXCEPTION_WITH_VALUE(tstate, &%s);" % exception_state_name)

    emit(getFrameVariableTypeDescriptionCode(context))

    getGotoCode(context.getExceptionEscape(), emit)

    if context.needsCleanup(raise_type_name):
        context.removeCleanupTempName(raise_type_name)


def _getRaiseExceptionWithValueCode(raise_type_name, raise_value_name, emit, context):
    (
        exception_state_name,
        _exception_lineno,
    ) = context.variable_storage.getExceptionVariableDescriptions()

    emit("%s.exception_type = %s;" % (exception_state_name, raise_type_name))
    getReferenceExportCode(raise_type_name, emit, context)
    emit("%s.exception_value = %s;" % (exception_state_name, raise_value_name))
    getReferenceExportCode(raise_value_name, emit, context)

    emitErrorLineNumberUpdateCode(emit, context)

    emit("RAISE_EXCEPTION_WITH_TYPE_AND_VALUE(tstate, &%s);" % (exception_state_name,))

    emit(getFrameVariableTypeDescriptionCode(context))

    getGotoCode(context.getExceptionEscape(), emit)

    if context.needsCleanup(raise_type_name):
        context.removeCleanupTempName(raise_type_name)
    if context.needsCleanup(raise_value_name):
        context.removeCleanupTempName(raise_value_name)


def _getRaiseExceptionWithTracebackCode(
    raise_type_name, raise_value_name, raise_tb_name, emit, context
):
    (
        exception_state_name,
        _exception_lineno,
    ) = context.variable_storage.getExceptionVariableDescriptions()

    emit("%s.exception_type = %s;" % (exception_state_name, raise_type_name))
    getReferenceExportCode(raise_type_name, emit, context)
    emit("%s.exception_value = %s;" % (exception_state_name, raise_value_name))
    getReferenceExportCode(raise_value_name, emit, context)
    emit(
        "%s.exception_tb = (PyTracebackObject *)%s;"
        % (exception_state_name, raise_tb_name)
    )
    getReferenceExportCode(raise_tb_name, emit, context)

    emit("RAISE_EXCEPTION_WITH_TRACEBACK(tstate, &%s);" % (exception_state_name))

    # If anything is wrong, that will be used.
    emitErrorLineNumberUpdateCode(emit, context)

    emit(getFrameVariableTypeDescriptionCode(context))

    getGotoCode(context.getExceptionEscape(), emit)

    if context.needsCleanup(raise_type_name):
        context.removeCleanupTempName(raise_type_name)
    if context.needsCleanup(raise_value_name):
        context.removeCleanupTempName(raise_value_name)
    if context.needsCleanup(raise_tb_name):
        context.removeCleanupTempName(raise_tb_name)



