#!/usr/bin/env fuchsia-vendored-python

# Copyright 2021 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# Generates hermeitc inputs file for the corresponding go_build action.

import argparse
import glob
import os
import sys

from gen_library_metadata import get_sources


def go_dep_files_inputs(go_dep_files, is_test):
    """Collect all inputs from go_dep files."""
    inputs = []
    for _, src in get_sources(go_dep_files).items():
        if not os.path.exists(src):
            raise ValueError(f'source "{src}" in go_deps file does not exist')

        if os.path.isfile(src):
            inputs.append(src)
            continue

        # TODO(https://fxbug.dev/42160667): always expect files after we deprecate
        # support for globbing.
        #
        # Currently globbing is only used by syzkaller-go (see bug above), which
        # only have .go sources.
        if os.path.isdir(src):
            inputs += glob.glob(os.path.join(src, "**", "*.go"))
            continue

        raise ValueError(
            f'source "{src}" in go_deps file is neither a file or a directory'
        )

    if not is_test:
        inputs = [f for f in inputs if not f.endswith("_test.go")]

    return inputs


# All possible extensions for source files Go knows about.
#
# See https://pkg.go.dev/cmd/go/internal/list#pkg-variables
GO_SRC_EXTS = {
    ".go",
    ".c",
    ".cc",
    ".cxx",
    ".cpp",
    ".m",
    ".h",
    ".hh",
    ".hpp",
    ".hxx",
    ".f",
    ".F",
    ".for",
    ".f90",
    ".s",
    ".swig",
    ".swigcxx",
    ".syso",
}


def goroot_inputs(goroot):
    """Collect all inputs from goroot."""

    # The Go compiler is an input, it's used by the build script.
    inputs = [os.path.join(goroot, "bin", "go")]

    for f in glob.glob(os.path.join(goroot, "**", "*")):
        # Skip all test files from goroot, they won't be used for building.
        if f.endswith("_test.go"):
            continue
        if "/test/" in f:
            continue
        _, ext = os.path.splitext(f)
        if ext in GO_SRC_EXTS:
            inputs.append(f)

    return inputs


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--go-dep-files",
        help="List of files describing library dependencies",
        nargs="*",
        default=[],
    )
    parser.add_argument(
        "--output",
        help="Path to output hermetic inputs file",
        required=True,
    )
    parser.add_argument(
        "--go-root",
        help="Path to GOROOT to use",
        required=True,
    )
    parser.add_argument(
        "--is-test", help="True if the target is a go test", default=False
    )
    args = parser.parse_args()

    inputs = (
        go_dep_files_inputs(args.go_dep_files, args.is_test)
        if args.go_dep_files
        else []
    )
    inputs += goroot_inputs(args.go_root)
    with open(args.output, "w") as f:
        f.write("\n".join(sorted(inputs)))


if __name__ == "__main__":
    sys.exit(main())