# Copyright 2016 The Meson development team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# This class contains the basic functionality needed to run any interpreter
# or an interpreter-based tool.

from .visitor import AstVisitor
from .. import interpreterbase, mparser, mesonlib
from .. import environment

from ..interpreterbase import InvalidArguments, BreakRequest, ContinueRequest

import os, sys
from typing import List

class DontCareObject(interpreterbase.InterpreterObject):
    pass

class MockExecutable(interpreterbase.InterpreterObject):
    pass

class MockStaticLibrary(interpreterbase.InterpreterObject):
    pass

class MockSharedLibrary(interpreterbase.InterpreterObject):
    pass

class MockCustomTarget(interpreterbase.InterpreterObject):
    pass

class MockRunTarget(interpreterbase.InterpreterObject):
    pass

ADD_SOURCE = 0
REMOVE_SOURCE = 1

class AstInterpreter(interpreterbase.InterpreterBase):
    def __init__(self, source_root: str, subdir: str, visitors: List[AstVisitor] = []):
        super().__init__(source_root, subdir)
        self.visitors = visitors
        self.visited_subdirs = {}
        self.assignments = {}
        self.reverse_assignment = {}
        self.funcs.update({'project': self.func_do_nothing,
                           'test': self.func_do_nothing,
                           'benchmark': self.func_do_nothing,
                           'install_headers': self.func_do_nothing,
                           'install_man': self.func_do_nothing,
                           'install_data': self.func_do_nothing,
                           'install_subdir': self.func_do_nothing,
                           'configuration_data': self.func_do_nothing,
                           'configure_file': self.func_do_nothing,
                           'find_program': self.func_do_nothing,
                           'include_directories': self.func_do_nothing,
                           'add_global_arguments': self.func_do_nothing,
                           'add_global_link_arguments': self.func_do_nothing,
                           'add_project_arguments': self.func_do_nothing,
                           'add_project_link_arguments': self.func_do_nothing,
                           'message': self.func_do_nothing,
                           'generator': self.func_do_nothing,
                           'error': self.func_do_nothing,
                           'run_command': self.func_do_nothing,
                           'assert': self.func_do_nothing,
                           'subproject': self.func_do_nothing,
                           'dependency': self.func_do_nothing,
                           'get_option': self.func_do_nothing,
                           'join_paths': self.func_do_nothing,
                           'environment': self.func_do_nothing,
                           'import': self.func_do_nothing,
                           'vcs_tag': self.func_do_nothing,
                           'add_languages': self.func_do_nothing,
                           'declare_dependency': self.func_do_nothing,
                           'files': self.func_do_nothing,
                           'executable': self.func_do_nothing,
                           'static_library': self.func_do_nothing,
                           'shared_library': self.func_do_nothing,
                           'library': self.func_do_nothing,
                           'build_target': self.func_do_nothing,
                           'custom_target': self.func_do_nothing,
                           'run_target': self.func_do_nothing,
                           'subdir': self.func_subdir,
                           'set_variable': self.func_do_nothing,
                           'get_variable': self.func_do_nothing,
                           'is_variable': self.func_do_nothing,
                           'disabler': self.func_do_nothing,
                           'gettext': self.func_do_nothing,
                           'jar': self.func_do_nothing,
                           'warning': self.func_do_nothing,
                           'shared_module': self.func_do_nothing,
                           'option': self.func_do_nothing,
                           'both_libraries': self.func_do_nothing,
                           'add_test_setup': self.func_do_nothing,
                           'find_library': self.func_do_nothing,
                           'subdir_done': self.func_do_nothing,
                           })

    def func_do_nothing(self, node, args, kwargs):
        return True

    def load_root_meson_file(self):
        super().load_root_meson_file()
        for i in self.visitors:
            self.ast.accept(i)

    def func_subdir(self, node, args, kwargs):
        args = self.flatten_args(args)
        if len(args) != 1 or not isinstance(args[0], str):
            sys.stderr.write('Unable to evaluate subdir({}) in AstInterpreter --> Skipping\n'.format(args))
            return

        prev_subdir = self.subdir
        subdir = os.path.join(prev_subdir, args[0])
        absdir = os.path.join(self.source_root, subdir)
        buildfilename = os.path.join(subdir, environment.build_filename)
        absname = os.path.join(self.source_root, buildfilename)
        symlinkless_dir = os.path.realpath(absdir)
        if symlinkless_dir in self.visited_subdirs:
            sys.stderr.write('Trying to enter {} which has already been visited --> Skipping\n'.format(args[0]))
            return
        self.visited_subdirs[symlinkless_dir] = True

        if not os.path.isfile(absname):
            sys.stderr.write('Unable to find build file {} --> Skipping\n'.format(buildfilename))
            return
        with open(absname, encoding='utf8') as f:
            code = f.read()
        assert(isinstance(code, str))
        try:
            codeblock = mparser.Parser(code, subdir).parse()
        except mesonlib.MesonException as me:
            me.file = buildfilename
            raise me

        self.subdir = subdir
        for i in self.visitors:
            codeblock.accept(i)
        self.evaluate_codeblock(codeblock)
        self.subdir = prev_subdir

    def method_call(self, node):
        return True

    def evaluate_arithmeticstatement(self, cur):
        return 0

    def evaluate_plusassign(self, node):
        assert(isinstance(node, mparser.PlusAssignmentNode))
        if node.var_name not in self.assignments:
            self.assignments[node.var_name] = []
        self.assignments[node.var_name] += [node.value] # Save a reference to the value node
        if hasattr(node.value, 'ast_id'):
            self.reverse_assignment[node.value.ast_id] = node
        self.evaluate_statement(node.value) # Evaluate the value just in case

    def evaluate_indexing(self, node):
        return 0

    def unknown_function_called(self, func_name):
        pass

    def reduce_arguments(self, args):
        assert(isinstance(args, mparser.ArgumentNode))
        if args.incorrect_order():
            raise InvalidArguments('All keyword arguments must be after positional arguments.')
        return args.arguments, args.kwargs

    def evaluate_comparison(self, node):
        return False

    def evaluate_foreach(self, node):
        try:
            self.evaluate_codeblock(node.block)
        except ContinueRequest:
            pass
        except BreakRequest:
            pass

    def evaluate_if(self, node):
        for i in node.ifs:
            self.evaluate_codeblock(i.block)
        if not isinstance(node.elseblock, mparser.EmptyNode):
            self.evaluate_codeblock(node.elseblock)

    def get_variable(self, varname):
        return 0

    def assignment(self, node):
        assert(isinstance(node, mparser.AssignmentNode))
        self.assignments[node.var_name] = [node.value] # Save a reference to the value node
        if hasattr(node.value, 'ast_id'):
            self.reverse_assignment[node.value.ast_id] = node
        self.evaluate_statement(node.value) # Evaluate the value just in case

    def flatten_args(self, args, include_unknown_args: bool = False):
        # Resolve mparser.ArrayNode if needed
        flattend_args = []
        temp_args = []
        if isinstance(args, mparser.ArrayNode):
            args = [x for x in args.args.arguments]
        elif isinstance(args, mparser.ArgumentNode):
            args = [x for x in args.arguments]
        for i in args:
            if isinstance(i, mparser.ArrayNode):
                temp_args += [x for x in i.args.arguments]
            else:
                temp_args += [i]
        for i in temp_args:
            if isinstance(i, mparser.ElementaryNode) and not isinstance(i, mparser.IdNode):
                flattend_args += [i.value]
            elif isinstance(i, (str, bool, int, float)) or include_unknown_args:
                flattend_args += [i]
        return flattend_args

    def flatten_kwargs(self, kwargs: object, include_unknown_args: bool = False):
        flattend_kwargs = {}
        for key, val in kwargs.items():
            if isinstance(val, mparser.ElementaryNode):
                flattend_kwargs[key] = val.value
            elif isinstance(val, (mparser.ArrayNode, mparser.ArgumentNode)):
                flattend_kwargs[key] = self.flatten_args(val, include_unknown_args)
            elif isinstance(val, (str, bool, int, float)) or include_unknown_args:
                flattend_kwargs[key] = val
        return flattend_kwargs