#!/usr/bin/env fuchsia-vendored-python
# Copyright 2023 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 the necessary files to provide an sdk_atom() target
for including a package in the SDK, and writes these to the output
directory. See `//build/sdk/sdk_atom.gni` for exact description of each file.

Files include:
* `file_path`
* `metadata`

Additionally, each package manifest has their `source_path` entries altered
such that both blobs and subpackage manifests point to their new SDK locations.
These final package manifests are also written to the output directory.
For use in sdk_fuchsia_package() template."""

import argparse
import json
import os
import sys
from pathlib import Path
from typing import Any, Dict, List, Set

# SDK directory of blobs across all package manifests,
# each renamed to their merkle.
BLOBS_DIR = "packages/blobs"

# SDK directory of subpackage manifests, each renamed to their merkle.
SUBPACKAGE_MANIFEST_DIR = "packages/subpackage_manifests"

# sdk://
# └── packages/
#     ├── blobs/
#     │   └── CONTENT_HASH_1
#     ├── PACKAGE_BAR/
#     │   ├── VARIANT/
#     │   │   └── release/
#     │   │       └── package_manifest.json
#     │   └── meta.json
#     └── subpackage_manifests/
#         └── META_FAR_MERKLE.package_manifest.json
# SDK directory of blobs, relative to each SDK package.
PACKAGE_DIR_TO_BLOBS_DIR = "../../../blobs"
# SDK directory of blobs, relative to `subpackage_manifests`.
SUBPACKAGE_MANIFESTS_DIR_TO_BLOBS_DIR = "../blobs"
# SDK directory of subpackage manifests, relative to individual SDK packages.
PACKAGE_DIR_TO_SUBPACKAGE_MANIFESTS_DIR = "../../../subpackage_manifests"


def handle_package_manifest(
    output_dir: Path,
    input_manifest_path: Path,
    sdk_file_map: Set[str],
    sdk_metadata: Dict[str, Any],
    depfile_collection: Dict[Path, Path],
    inputs: Dict[str, str],
    visited_subpackages: Set[Path],
    content_checklist_path: Path,
    is_subpackage=False,
) -> Path:
    """
    For the given `input_manifest_path`, does the following:
    * Re-writes all source paths to be relative to SDK location,
      where relative location is determined by if it is a subpackage.
    * Adds files for inclusion to the `sdk_atom`'s `file_list`.
    * Adds files and base package manifest to the `sdk_atom`'s
      `metadata`.
    * Adds files to `depfile`.
    * Writes re-written package manifest to desired `output_dir` location.

    Above is recursed across all subpackages.

    Args:
        output_dir:             Path to build directory to write final package
                                manifest filepath to.
        input_manifest_path:    Path to package manifest to convert into
                                SDK-friendly format.
        sdk_file_map:           Set containing <dst>=<src> entries, for use in
                               `sdk_atom`'s `file_list`.
        sdk_metadata:           Object used to build a
                                `//build/sdk/meta/package.json` entry.
        depfile_collection:     Object constructed for use as a depfile.
        inputs:                 Object containing `api_level`, `arch`, and
                                `distribution_name`. Used for constructing end
                                paths and other structures.
        visited_subpackages:    Set used for tracking levels of recursion in
                                subpackages.
        content_checklist_path: Path to content_checklist file which will be
                                added to files of this variant.
        is_subpackage:          Boolean used to track if this iteration is
                                processing a subpackages. Used to determine if
                                `sdk_metadata` changes are required, as well as
                                pathing.
    """
    api_level, arch, distribution_name = (
        inputs["api_level"],
        inputs["arch"],
        inputs["distribution_name"],
    )

    subtype = f"{arch}-api-{api_level}"

    with open(input_manifest_path, "r") as manifest_file:
        input_manifest = json.load(manifest_file)

    # Re-wire will be relative to package manifest location.
    input_manifest["blob_sources_relative"] = "file"

    # Subpackage manifests have different relative paths.
    relative_blobs_dir = (
        SUBPACKAGE_MANIFESTS_DIR_TO_BLOBS_DIR
        if is_subpackage
        else PACKAGE_DIR_TO_BLOBS_DIR
    )
    relative_subpackage_manifests_dir = (
        "" if is_subpackage else PACKAGE_DIR_TO_SUBPACKAGE_MANIFESTS_DIR
    )

    target_files = [content_checklist_path]
    # `meta_far_merkle` necessary for naming subpackage manifests.
    meta_far_merkle = ""
    for blob in input_manifest["blobs"]:
        merkle, source_path = blob["merkle"], blob["source_path"]
        relative_blob_path = f"{relative_blobs_dir}/{merkle}"

        if blob["path"] == "meta/":
            meta_far_merkle = merkle

        # Re-wire source path to point to SDK blob store.
        blob["source_path"] = relative_blob_path

        sdk_file_map.add(f"{BLOBS_DIR}/{merkle}={source_path}")
        target_files.append(f"{BLOBS_DIR}/{merkle}")

    # Handle subpackages.
    subpackage_list = input_manifest.get("subpackages", [])
    for subpackage in subpackage_list:
        subpackage_manifest_path, subpackage_merkle = (
            subpackage["manifest_path"],
            subpackage["merkle"],
        )
        # Re-wire subpackage manifest paths.
        subpackage[
            "manifest_path"
        ] = f"{relative_subpackage_manifests_dir}/{subpackage_merkle}"

        if subpackage_manifest_path in visited_subpackages:
            # No need to re-visit same subpackage multiple times.
            continue

        # Recursively handle subpackages.
        target_files.append(
            handle_package_manifest(
                output_dir,
                subpackage_manifest_path,
                sdk_file_map,
                sdk_metadata,
                depfile_collection,
                inputs,
                visited_subpackages,
                is_subpackage=True,
            )
        )

    if is_subpackage:
        manifest_file_name = f"{meta_far_merkle}.package_manifest.json"
        sdk_output_manifest_path = (
            f"{SUBPACKAGE_MANIFEST_DIR}/{manifest_file_name}"
        )

        visited_subpackages.add(input_manifest_path)
    else:
        manifest_file_name = "package_manifest.json"

        sdk_output_manifest_path = f"packages/{distribution_name}/{subtype}/release/{manifest_file_name}"

        target_files.append(sdk_output_manifest_path)
        target_files = sorted(list(set(target_files)))
        # Ensure metadata is aware of SDK manifest location.
        sdk_metadata["variants"] = [
            {
                "manifest_file": sdk_output_manifest_path,
                "arch": arch,
                "api_level": api_level,
                "files": target_files,
            }
        ]
        # Ensure package name matches distribution name.
        input_manifest["package"]["name"] = distribution_name

    build_output_manifest_path = f"{output_dir}/{manifest_file_name}"

    sdk_file_map.add(f"{sdk_output_manifest_path}={build_output_manifest_path}")

    # Write altered manifest to build output location.
    with open(build_output_manifest_path, "w") as manifest_file:
        json.dump(input_manifest, manifest_file, indent=2)
        depfile_collection[build_output_manifest_path] = [input_manifest_path]

    return sdk_output_manifest_path


def main():
    parser = argparse.ArgumentParser(description=__doc__)

    parser.add_argument(
        "--distribution-name",
        help="Name of package for publication in the SDK.",
        required=True,
    )
    parser.add_argument(
        "--manifest", help="Path to the package manifest.", required=True
    )
    parser.add_argument(
        "--sdk-package-content-checklist-path",
        help="Path to the SDK package content checklist file.",
        required=True,
    )
    parser.add_argument(
        "--output", help="Directory to write SDK objects to.", required=True
    )
    parser.add_argument("--api-level", help="Target API level.", required=True)
    parser.add_argument(
        "--target-cpu", help="Target build architecture.", required=True
    )
    parser.add_argument(
        "--depfile", help="Path for generating depfile.", required=False
    )

    args = parser.parse_args()

    # File containing file mappings. Each line in the file should contain a
    # "dest=source" mapping, similarly to file scopes.
    # See `sdk_atom` template definition of `file_list`.
    sdk_file_map = set()

    # Inputs used for directory naming.
    api_level, arch, distribution_name = (
        args.api_level,
        args.target_cpu,
        args.distribution_name,
    )
    inputs = {
        "api_level": int(api_level),
        "arch": arch,
        "distribution_name": distribution_name,
    }

    # See `sdk_atom` template definition of `metadata`.
    sdk_metadata = {
        "name": distribution_name,
        "variants": [],
        "type": "package",
    }

    depfile_collection = {}
    visited_subpackages = set()

    # Capture content checklist file in metadata and file list.
    subtype = f"{arch}-api-{api_level}"
    content_checklist_path = (
        f"packages/{distribution_name}/{subtype}/release/content_checklist_path"
    )
    sdk_file_map.add(
        f"{content_checklist_path}={args.sdk_package_content_checklist_path}"
    )

    handle_package_manifest(
        args.output,
        args.manifest,
        sdk_file_map,
        sdk_metadata,
        depfile_collection,
        inputs,
        visited_subpackages,
        content_checklist_path,
        is_subpackage=False,
    )

    # Write out sorted file list.
    sdk_file_list = sorted(list(sdk_file_map))
    sdk_file_list_path = os.path.join(args.output, "file_list.fini")
    with open(sdk_file_list_path, "w") as out_file:
        out_file.write("\n".join(sdk_file_list))
        out_file.write("\n")

    # Write out metadata.
    metadata_path = os.path.join(args.output, "metadata")
    with open(metadata_path, "w") as metadata_file:
        json.dump(
            sdk_metadata,
            metadata_file,
            indent=2,
            sort_keys=True,
            separators=(",", ": "),
        )

    # Write out depfile
    if args.depfile:
        os.makedirs(os.path.dirname(args.depfile), exist_ok=True)
        with open(args.depfile, "w") as f:
            for out_file in sorted(depfile_collection.keys()):
                in_file_list = sorted(depfile_collection[out_file])
                f.write(f"{out_file}: {' '.join(in_file_list)}")

    return 0


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