import ast
import io
import os
import textwrap

# This was taken from /scripts/analyze_deps.py

def parse_setup(setup_filename):
    kwargs = parse_kwargs(setup_filename)

    version = kwargs['version']
    name = kwargs['name']
    requires = []
    if 'install_requires' in kwargs:
        requires += kwargs['install_requires']
    if 'extras_require' in kwargs:
        for extra in kwargs['extras_require'].values():
            requires += extra
    return name, version, requires


def parse_kwargs(setup_filename):
    mock_setup = textwrap.dedent('''\
    def setup(*args, **kwargs):
        __setup_calls__.append((args, kwargs))
    ''')
    parsed_mock_setup = ast.parse(mock_setup, filename=setup_filename)
    with io.open(setup_filename, 'r', encoding='utf-8-sig') as setup_file:
        parsed = ast.parse(setup_file.read())
        for index, node in enumerate(parsed.body[:]):
            if (
                not isinstance(node, ast.Expr) or
                not isinstance(node.value, ast.Call) or
                not hasattr(node.value.func, 'id') or
                node.value.func.id != 'setup'
            ):
                continue
            parsed.body[index:index] = parsed_mock_setup.body
            break

    fixed = ast.fix_missing_locations(parsed)
    codeobj = compile(fixed, setup_filename, 'exec')
    local_vars = {}
    global_vars = {'__setup_calls__': []}
    current_dir = os.getcwd()
    working_dir = os.path.dirname(setup_filename)
    os.chdir(working_dir)
    exec(codeobj, global_vars, local_vars)
    os.chdir(current_dir)
    _, kwargs = global_vars['__setup_calls__'][0]

    return kwargs


def get_install_requires(setup_filename):
    kwargs = parse_kwargs(setup_filename)
    requires = []
    if 'install_requires' in kwargs:
        requires += kwargs['install_requires']
    return requires