#!/usr/bin/env fuchsia-vendored-python
# Copyright 2019 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.

import argparse
import json
import os
import sys

sys.path.append(
    os.path.join(
        os.path.dirname(__file__),
        os.pardir,
        "cpp",
    )
)
import binaries


# Rewrite a debug file name (or list of them) into its .build-id/...
# name for publication, collecting the mappings in the `manifest` dict.
def rewrite(debug, manifest):
    if isinstance(debug, list):
        return [rewrite(x, manifest) for x in debug]
    id_path = binaries.get_sdk_debug_path(debug)
    manifest[id_path] = debug
    return id_path


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--input",
        type=argparse.FileType("r"),
        help="Input JSON file",
        required=True,
    )
    parser.add_argument(
        "--output",
        type=argparse.FileType("w"),
        help="Output JSON file",
        required=True,
    )
    parser.add_argument(
        "--manifest",
        type=argparse.FileType("w"),
        help="Output manifest file",
        required=True,
    )
    parser.add_argument(
        "--depfile",
        type=argparse.FileType("w"),
        required=True,
    )
    parser.add_argument("--location", help="JSON pointer", required=False)
    args = parser.parse_args()

    # Read in the original JSON tree.
    data = json.load(args.input)

    # Poor man's JSON pointer: /foo/bar/baz looks up in dicts.
    manifest = {}
    if args.location:
        ptr = args.location.split("/")
        assert ptr[0] == "", (
            "%s should be absolute JSON pointer" % args.location
        )

        # Follow the pointer steps until the last one, so walk[ptr[0]] points
        # at the requested location in the JSON tree.
        walk = {"": data}
        while len(ptr) > 1:
            walk = walk[ptr[0]]
            ptr = ptr[1:]

        # Apply the rewrites to the string or list at that spot in the tree.
        walk[ptr[0]] = rewrite(walk[ptr[0]], manifest)
    else:
        # If no location argument is passed in, we will find the value from the variants section
        debug = data["variants"][0]["values"]["debug_libs"]
        data["variants"][0]["values"]["debug_libs"] = rewrite(debug, manifest)

    # Write out the manifest collected while rewriting original debug files
    # names to .build-id/... names for publication.
    #
    # Original debug files are read during the rewrite above, so include them in
    # a depfile.
    mappings = []
    deps = []
    for dest, source in manifest.items():
        mappings.append(f"{dest}={source}")
        deps.append(os.path.relpath(source))
    args.manifest.write("\n".join(mappings))
    args.depfile.write(
        "{} {}: {}\n".format(
            args.manifest.name, args.output.name, " ".join(deps)
        )
    )

    # Write out the modified JSON tree.
    json.dump(data, args.output, indent=2, sort_keys=True)

    return 0


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