# Copyright 2018-2021 The glTF-Blender-IO authors.
#
# 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.

import os
import sys
from pathlib import Path
import bpy

from ...io.com.gltf2_io_debug import print_console


def dll_path() -> Path:
    """
    Get the DLL path depending on the underlying platform.
    :return: DLL path.
    """
    lib_name = 'extern_draco'
    blender_root = Path(bpy.app.binary_path).parent
    python_lib = Path('{v[0]}.{v[1]}/python/lib'.format(v=bpy.app.version))
    python_version = 'python{v[0]}.{v[1]}'.format(v=sys.version_info)

    path = os.environ.get('BLENDER_EXTERN_DRACO_LIBRARY_PATH')
    if path is None:
        path = {
            'win32': blender_root / python_lib / 'site-packages',
            'linux': blender_root / python_lib / python_version / 'site-packages',
            'darwin': blender_root.parent / 'Resources' / python_lib / python_version / 'site-packages'
        }.get(sys.platform)
    else:
        path = Path(path)

    library_name = {
        'win32': '{}.dll'.format(lib_name),
        'linux': 'lib{}.so'.format(lib_name),
        'darwin': 'lib{}.dylib'.format(lib_name)
    }.get(sys.platform)

    if sys.platform.startswith('openbsd'):
        path = blender_root.parent / 'lib'
        library_name = 'libdraco.so'

    lib_file = sorted(Path(path).glob(library_name + '*'))

    if not lib_file:
        print_console('WARNING', 'Unsupported platform {}, Draco mesh compression is unavailable'.format(sys.platform))
        return path / library_name
    else:
        return lib_file[-1]

def dll_exists(quiet=False) -> bool:
    """
    Checks whether the DLL path exists.
    :return: True if the DLL exists.
    """
    exists = dll_path().exists()
    if quiet is False:
        print("'{}' ".format(dll_path().absolute()) + ("exists, draco mesh compression is available" if exists else
                                                       "{} {} {}".format(
                                                           "does not exist, draco mesh compression not available,",
                                                           "please add it or create environment variable BLENDER_EXTERN_DRACO_LIBRARY_PATH",
                                                           "pointing to the folder"
                                                      )))
    return exists
