# Copyright 2018 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.

#
# Imports
#

import json
import struct

#
# Globals
#

#
# Functions
#


def save_gltf(glTF, export_settings, encoder, glb_buffer):
    indent = None
    separators = separators = (',', ':')

    if export_settings['gltf_format'] == 'ASCII':
        indent = 4
        # The comma is typically followed by a newline, so no trailing whitespace is needed on it.
        separators = separators = (',', ' : ')

    glTF_encoded = json.dumps(glTF, indent=indent, separators=separators, sort_keys=True, cls=encoder, allow_nan=False)

    #

    if export_settings['gltf_format'] == 'ASCII':
        file = open(export_settings['gltf_filepath'], "w", encoding="utf8", newline="\n")
        file.write(glTF_encoded)
        file.write("\n")
        file.close()

        binary = export_settings['gltf_binary']
        if len(binary) > 0 and not export_settings['gltf_embed_buffers']:
            file = open(export_settings['gltf_filedirectory'] + export_settings['gltf_binaryfilename'], "wb")
            file.write(binary)
            file.close()

    else:
        file = open(export_settings['gltf_filepath'], "wb")

        glTF_data = glTF_encoded.encode()
        binary = glb_buffer

        length_gtlf = len(glTF_data)
        spaces_gltf = (4 - (length_gtlf & 3)) & 3
        length_gtlf += spaces_gltf

        length_bin = len(binary)
        zeros_bin = (4 - (length_bin & 3)) & 3
        length_bin += zeros_bin

        length = 12 + 8 + length_gtlf
        if length_bin > 0:
            length += 8 + length_bin

        # Header (Version 2)
        file.write('glTF'.encode())
        file.write(struct.pack("I", 2))
        file.write(struct.pack("I", length))

        # Chunk 0 (JSON)
        file.write(struct.pack("I", length_gtlf))
        file.write('JSON'.encode())
        file.write(glTF_data)
        for i in range(0, spaces_gltf):
            file.write(' '.encode())

        # Chunk 1 (BIN)
        if length_bin > 0:
            file.write(struct.pack("I", length_bin))
            file.write('BIN\0'.encode())
            file.write(binary)
            for i in range(0, zeros_bin):
                file.write('\0'.encode())

        file.close()

    return True