#!/usr/bin/env python

# SPDX-License-Identifier: Apache-2.0
from __future__ import annotations

import argparse
import glob
import os
import re
import subprocess
from collections.abc import Iterable
from textwrap import dedent

autogen_header = """\
//
// WARNING: This file is automatically generated!  Please edit onnx.in.proto.
//


"""

LITE_OPTION = """

// For using protobuf-lite
option optimize_for = LITE_RUNTIME;

"""

DEFAULT_PACKAGE_NAME = "onnx"

IF_ONNX_ML_REGEX = re.compile(r"\s*//\s*#if\s+ONNX-ML\s*$")
ENDIF_ONNX_ML_REGEX = re.compile(r"\s*//\s*#endif\s*$")
ELSE_ONNX_ML_REGEX = re.compile(r"\s*//\s*#else\s*$")


def process_ifs(lines: Iterable[str], onnx_ml: bool) -> Iterable[str]:
    in_if = 0
    for line in lines:
        if IF_ONNX_ML_REGEX.match(line):
            assert in_if == 0
            in_if = 1
        elif ELSE_ONNX_ML_REGEX.match(line):
            assert in_if == 1
            in_if = 2
        elif ENDIF_ONNX_ML_REGEX.match(line):
            assert in_if in (1, 2)
            in_if = 0
        else:  # noqa: PLR5501
            if in_if == 0:
                yield line
            elif in_if == 1 and onnx_ml:
                yield line
            elif in_if == 2 and not onnx_ml:  # noqa: PLR2004
                yield line


IMPORT_REGEX = re.compile(r'(\s*)import\s*"([^"]*)\.proto";\s*$')
PACKAGE_NAME_REGEX = re.compile(r"\{PACKAGE_NAME\}")
ML_REGEX = re.compile(r"(.*)\-ml")


def process_package_name(lines: Iterable[str], package_name: str) -> Iterable[str]:
    need_rename = package_name != DEFAULT_PACKAGE_NAME
    for line in lines:
        m = IMPORT_REGEX.match(line) if need_rename else None
        if m:
            include_name = m.group(2)
            ml = ML_REGEX.match(include_name)
            if ml:
                include_name = f"{ml.group(1)}_{package_name}-ml"
            else:
                include_name = f"{include_name}_{package_name}"
            yield m.group(1) + f'import "{include_name}.proto";'
        else:
            yield PACKAGE_NAME_REGEX.sub(package_name, line)


PROTO_SYNTAX_REGEX = re.compile(r'(\s*)syntax\s*=\s*"proto2"\s*;\s*$')
OPTIONAL_REGEX = re.compile(r"(\s*)optional\s(.*)$")


def convert_to_proto3(lines: Iterable[str]) -> Iterable[str]:
    for line in lines:
        # Set the syntax specifier
        m = PROTO_SYNTAX_REGEX.match(line)
        if m:
            yield m.group(1) + 'syntax = "proto3";'
            continue

        # Remove optional keywords
        m = OPTIONAL_REGEX.match(line)
        if m:
            yield m.group(1) + m.group(2)
            continue

        # Rewrite import
        m = IMPORT_REGEX.match(line)
        if m:
            yield m.group(1) + f'import "{m.group(2)}.proto3";'
            continue

        yield line


def gen_proto3_code(
    protoc_path: str, proto3_path: str, include_path: str, cpp_out: str, python_out: str
) -> None:
    print(f"Generate pb3 code using {protoc_path}")
    build_args = [protoc_path, proto3_path, "-I", include_path]
    build_args.extend(["--cpp_out", cpp_out, "--python_out", python_out])
    subprocess.check_call(build_args)


def translate(source: str, proto: int, onnx_ml: bool, package_name: str) -> str:
    lines: Iterable[str] = source.splitlines()
    lines = process_ifs(lines, onnx_ml=onnx_ml)
    lines = process_package_name(lines, package_name=package_name)
    if proto == 3:  # noqa: PLR2004
        lines = convert_to_proto3(lines)
    else:
        assert proto == 2  # noqa: PLR2004
    return os.linesep.join(lines)


def qualify(f: str, pardir: str | None = None) -> str:
    if pardir is None:
        pardir = os.path.realpath(os.path.dirname(__file__))
    return os.path.join(pardir, f)


def convert(
    stem: str,
    package_name: str,
    output: str,
    do_onnx_ml: bool = False,
    lite: bool = False,
    protoc_path: str = "",
) -> None:
    proto_in = qualify(f"{stem}.in.proto")
    need_rename = package_name != DEFAULT_PACKAGE_NAME
    # Having a separate variable for import_ml ensures that the import statements for the generated
    # proto files can be set separately from the ONNX_ML environment variable setting.
    import_ml = do_onnx_ml
    # We do not want to generate the onnx-data-ml.proto files for onnx-data.in.proto,
    # as there is no change between onnx-data.proto and the ML version.
    if "onnx-data" in proto_in:
        do_onnx_ml = False
    if do_onnx_ml:
        proto_base = f"{stem}_{package_name}-ml" if need_rename else f"{stem}-ml"
    else:
        proto_base = f"{stem}_{package_name}" if need_rename else f"{stem}"
    proto = qualify(f"{proto_base}.proto", pardir=output)
    proto3 = qualify(f"{proto_base}.proto3", pardir=output)

    print(f"Processing {proto_in}")
    with open(proto_in, encoding="utf-8") as fin:
        source = fin.read()
        print(f"Writing {proto}")
        with open(proto, "w", newline="", encoding="utf-8") as fout:
            fout.write(autogen_header)
            fout.write(
                translate(source, proto=2, onnx_ml=import_ml, package_name=package_name)
            )
            if lite:
                fout.write(LITE_OPTION)
        print(f"Writing {proto3}")
        with open(proto3, "w", newline="", encoding="utf-8") as fout:
            fout.write(autogen_header)
            fout.write(
                translate(source, proto=3, onnx_ml=import_ml, package_name=package_name)
            )
            if lite:
                fout.write(LITE_OPTION)
        if protoc_path:
            porto3_dir = os.path.dirname(proto3)
            base_dir = os.path.dirname(porto3_dir)
            gen_proto3_code(protoc_path, proto3, base_dir, base_dir, base_dir)
            pb3_files = glob.glob(os.path.join(porto3_dir, f"{proto_base}.proto3.*"))
            for pb3_file in pb3_files:
                print(f"Removing {pb3_file}")
                os.remove(pb3_file)

        if need_rename:
            if do_onnx_ml:
                proto_header = qualify(f"{stem}-ml.pb.h", pardir=output)
            else:
                proto_header = qualify(f"{stem}.pb.h", pardir=output)
            print(f"Writing {proto_header}")
            with open(proto_header, "w", newline="", encoding="utf-8") as fout:
                fout.write("#pragma once\n")
                fout.write(f'#include "{proto_base}.pb.h"\n')

    # Generate py mapping
    # "-" is invalid in python module name, replaces '-' with '_'
    pb_py = qualify(f"{stem.replace('-', '_')}_pb.py", pardir=output)
    if need_rename:
        pb2_py = qualify(f"{proto_base.replace('-', '_')}_pb2.py", pardir=output)
    else:  # noqa: PLR5501
        if do_onnx_ml:
            pb2_py = qualify(f"{stem.replace('-', '_')}_ml_pb2.py", pardir=output)
        else:
            pb2_py = qualify(f"{stem.replace('-', '_')}_pb2.py", pardir=output)

    print(f"generating {pb_py}")
    with open(pb_py, "w", encoding="utf-8") as f:
        f.write(
            dedent(
                f"""\
                # This file is generated by setup.py. DO NOT EDIT!


                from .{os.path.splitext(os.path.basename(pb2_py))[0]} import *  # noqa
                """
            )
        )


def main() -> None:
    parser = argparse.ArgumentParser(
        description="Generates .proto file variations from .in.proto"
    )
    parser.add_argument(
        "-p",
        "--package",
        default="onnx",
        help="package name in the generated proto files (default: %(default)s)",
    )
    parser.add_argument("-m", "--ml", action="store_true", help="ML mode")
    parser.add_argument(
        "-l",
        "--lite",
        action="store_true",
        help="generate lite proto to use with protobuf-lite",
    )
    parser.add_argument(
        "-o",
        "--output",
        default=os.path.realpath(os.path.dirname(__file__)),
        help="output directory (default: %(default)s)",
    )
    parser.add_argument(
        "--protoc_path", default="", help="path to protoc for proto3 file validation"
    )
    parser.add_argument(
        "stems",
        nargs="*",
        default=["onnx", "onnx-operators", "onnx-data"],
        help="list of .in.proto file stems (default: %(default)s)",
    )
    args = parser.parse_args()

    if not os.path.exists(args.output):
        os.makedirs(args.output)

    for stem in args.stems:
        convert(
            stem,
            package_name=args.package,
            output=args.output,
            do_onnx_ml=args.ml,
            lite=args.lite,
            protoc_path=args.protoc_path,
        )


if __name__ == "__main__":
    main()
