# SPDX-FileCopyrightText: 2020 The Magma Authors.
# SPDX-FileCopyrightText: 2022 Open Networking Foundation <support@opennetworking.org>
#
# SPDX-License-Identifier: BSD-3-Clause

import os
import shutil
import sys
from typing import Iterable, List

from grpc.tools import protoc


def find_all_proto_files_in_dir(input_dir: str) -> List[str]:
    """
    Returns a list of filenames of .proto files in the given directory

    Args:
        input_dir: Directory to search in

    Returns:
        list(str): List of .proto filenames in the directory
    """
    proto_files = []
    for root, _, names in os.walk(input_dir):
        for name in names:
            full_filename = os.path.join(root, name)
            extn = os.path.splitext(name)[1]

            # Recurse into subdirectories
            if os.path.isdir(full_filename):
                proto_files += find_all_proto_files_in_dir(full_filename)
            if os.path.isfile(full_filename) and extn == '.proto':
                # TODO: find a better way to exclude the prometheus proto
                if not full_filename.endswith('prometheus/metrics.proto'):
                    proto_files.append(full_filename)
    return proto_files


def gen_bindings(
        input_dir: str,
        include_paths: Iterable[str],
        proto_path: str,
        output_dir: str,
) -> None:
    """
    Generates python and Go bindings for all .proto files in input dir
       @input_dir - input directory with .proto files to generate code for
       @include_paths - a list of include paths to resolve relative imports in .protos
       @output_dir - output directory to put generated code in
    """
    protofiles = find_all_proto_files_in_dir(input_dir)

    inouts = [
        '-I' + proto_path,
        '--python_out=' + output_dir,
        '--grpc_python_out=' + output_dir,
    ]
    # Only run mypy (dev dependency) when the protoc-consumed executable exists
    if shutil.which('protoc-gen-mypy') is not None:
        inouts.append('--mypy_out=' + output_dir)

    protoc.main(
        ('',) +
        tuple('-I' + path for path in include_paths) +
        tuple(inouts) +
        tuple(f for f in protofiles),
    )


def main():
    """
    Default main module. Generates .py code for all proto files
    specified by the arguments
    """
    if len(sys.argv) != 5:
        print(
            "Usage: ./gen_protos.py <dir containing .proto's> <include paths CSV> <proto_path for imports> <output dir>",
        )
        exit(1)
    input_dir = sys.argv[1]
    include_paths = sys.argv[2].split(',')
    # The deprecated vagrant box image amarpad/magma_dev has grpc installed
    # from source, with header files located at /usr/local/include. In the new
    # box image amarpad/debian_jessie, grpc is installed from deb package, with
    # headers located at /usr/include. Currently, only the magma_test vm uses
    # amarpad/magma_dev.
    #
    # TODO: Migrate magma_test to amarpad/debian_jessie to to remove the
    # '/usr/local/include'
    include_paths.append('/usr/local/include')
    proto_path = sys.argv[3]
    output_dir = sys.argv[4]
    gen_bindings(input_dir, include_paths, proto_path, output_dir)


if __name__ == "__main__":
    main()