#! /usr/bin/env nix-shell
#! nix-shell -i python -p python3.pkgs.joblib python3.pkgs.click python3.pkgs.click-log nix nurl prefetch-yarn-deps prefetch-npm-deps gclient2nix
"""
electron updater

A script for updating electron source hashes.

It supports the following modes:

| Mode         | Description                                     |
|------------- | ----------------------------------------------- |
| `update`     | for updating a specific Electron release        |
| `update-all` | for updating all electron releases at once      |

The `update` commands requires a `--version` flag
to specify the major release to be updated.
The `update-all command updates all non-eol major releases.

The `update` and `update-all` commands accept an optional `--commit`
flag to automatically commit the changes for you, and `--force` to
skip the up-to-date version check.
"""
import base64
import json
import logging
import os
import random
import re
import subprocess
import sys
import tempfile
import urllib.request
import click
import click_log

from datetime import datetime, UTC
from typing import Iterable, Tuple
from urllib.request import urlopen
from joblib import Parallel, delayed, Memory
from update_util import *


# Relative path to the electron-source info.json
SOURCE_INFO_JSON = "info.json"

os.chdir(os.path.dirname(__file__))

# Absolute path of nixpkgs top-level directory
NIXPKGS_PATH = subprocess.check_output(["git", "rev-parse", "--show-toplevel"]).decode("utf-8").strip()

memory: Memory = Memory("cache", verbose=0)

logger = logging.getLogger(__name__)
click_log.basic_config(logger)


def get_gclient_data(rev: str) -> any:
    output = subprocess.check_output(
        ["gclient2nix", "generate",
         f"https://github.com/electron/electron@{rev}",
         "--root", "src/electron"]
    )

    return json.loads(output)


def get_chromium_file(chromium_tag: str, filepath: str) -> str:
    return base64.b64decode(
        urlopen(
            f"https://chromium.googlesource.com/chromium/src.git/+/{chromium_tag}/{filepath}?format=TEXT"
        ).read()
        ).decode("utf-8")


def get_electron_file(electron_tag: str, filepath: str) -> str:
    return (
        urlopen(
            f"https://raw.githubusercontent.com/electron/electron/{electron_tag}/{filepath}"
        )
        .read()
        .decode("utf-8")
    )


@memory.cache
def get_gn_hash(gn_version, gn_commit):
    print("gn.override", file=sys.stderr)
    expr = f'(import {NIXPKGS_PATH} {{}}).gn.override {{ version = "{gn_version}"; rev = "{gn_commit}"; hash = ""; }}'
    out = subprocess.check_output(["nurl", "--hash", "--expr", expr])
    return out.decode("utf-8").strip()

@memory.cache
def get_chromium_gn_source(chromium_tag: str) -> dict:
    gn_pattern = r"'gn_version': 'git_revision:([0-9a-f]{40})'"
    gn_commit = re.search(gn_pattern, get_chromium_file(chromium_tag, "DEPS")).group(1)

    gn_commit_info = json.loads(
        urlopen(f"https://gn.googlesource.com/gn/+/{gn_commit}?format=json")
        .read()
        .decode("utf-8")
        .split(")]}'\n")[1]
    )

    gn_commit_date = datetime.strptime(gn_commit_info["committer"]["time"], "%a %b %d %H:%M:%S %Y %z")
    gn_date = gn_commit_date.astimezone(UTC).date().isoformat()
    gn_version = f"0-unstable-{gn_date}"

    return {
        "gn": {
            "version": gn_version,
            "rev": gn_commit,
            "hash": get_gn_hash(gn_version, gn_commit),
        }
    }

@memory.cache
def get_electron_yarn_hash(electron_tag: str) -> str:
    print(f"prefetch-yarn-deps", file=sys.stderr)
    with tempfile.TemporaryDirectory() as tmp_dir:
        with open(tmp_dir + "/yarn.lock", "w") as f:
            f.write(get_electron_file(electron_tag, "yarn.lock"))
        return (
            subprocess.check_output(["prefetch-yarn-deps", tmp_dir + "/yarn.lock"])
            .decode("utf-8")
            .strip()
        )

@memory.cache
def get_chromium_npm_hash(chromium_tag: str) -> str:
    print(f"prefetch-npm-deps", file=sys.stderr)
    with tempfile.TemporaryDirectory() as tmp_dir:
        with open(tmp_dir + "/package-lock.json", "w") as f:
            f.write(get_chromium_file(chromium_tag, "third_party/node/package-lock.json"))
        return (
            subprocess.check_output(
                ["prefetch-npm-deps", tmp_dir + "/package-lock.json"]
            )
            .decode("utf-8")
            .strip()
        )


def get_update(major_version: str, m: str, gclient_data: any) -> Tuple[str, dict]:

    tasks = []
    a = lambda: (("electron_yarn_hash", get_electron_yarn_hash(gclient_data["src/electron"]["args"]["tag"])))
    tasks.append(delayed(a)())
    a = lambda: (
        (
            "chromium_npm_hash",
            get_chromium_npm_hash(gclient_data["src"]["args"]["tag"]),
        )
    )
    tasks.append(delayed(a)())
    random.shuffle(tasks)

    task_results = {
        n[0]: n[1]
        for n in Parallel(n_jobs=3, require="sharedmem", return_as="generator")(tasks)
        if n != None
    }

    return (
        f"{major_version}",
        {
            "deps": gclient_data,
            **{key: m[key] for key in ["version", "modules", "chrome", "node"]},
            "chromium": {
                "version": m["chrome"],
                "deps": get_chromium_gn_source(gclient_data["src"]["args"]["tag"]),
            },
            **task_results,
        },
    )


def non_eol_releases(releases: Iterable[int]) -> Iterable[int]:
    """Returns a list of releases that have not reached end-of-life yet."""
    return tuple(filter(lambda x: x in supported_version_range(), releases))


def update_source(version: str, commit: bool, force: bool) -> None:
    """Update a given electron-source release

    Args:
        version: The major version number, e.g. '27'
        commit: Whether the updater should commit the result
        force: Whether to fetch even when the version is already up-to-date
    """
    major_version = version

    package_name = f"electron-source.electron_{major_version}"
    print(f"Updating electron-source.electron_{major_version}")

    old_info = load_info_json(SOURCE_INFO_JSON)
    old_version = (
        old_info[major_version]["version"]
        if major_version in old_info
        else None
    )

    m, rev = get_latest_version(major_version)
    if old_version == m["version"] and not force:
        print(f"{package_name} is up-to-date")
        return

    gclient_data = get_gclient_data(rev)
    new_info = get_update(major_version, m, gclient_data)
    out = old_info | {new_info[0]: new_info[1]}

    save_info_json(SOURCE_INFO_JSON, out)

    new_version = new_info[1]["version"]
    if commit:
        commit_result(package_name, old_version, new_version, SOURCE_INFO_JSON)


@click.group()
def cli() -> None:
    """A script for updating electron-source hashes"""
    pass


@cli.command("update", help="Update a single major release")
@click.option("-v", "--version", required=True, type=str, help="The major version, e.g. '23'")
@click.option("-c", "--commit", is_flag=True, default=False, help="Commit the result")
@click.option("-f", "--force", is_flag=True, default=False, help="Skip up-to-date version check")
def update(version: str, commit: bool, force: bool) -> None:
    update_source(version, commit, force)


@cli.command("update-all", help="Update all releases at once")
@click.option("-c", "--commit", is_flag=True, default=False, help="Commit the result")
@click.option("-f", "--force", is_flag=True, default=False, help="Skip up-to-date version check")
def update_all(commit: bool, force: bool) -> None:
    """Update all eletron-source releases at once

    Args:
        commit: Whether to commit the result
    """
    old_info = load_info_json(SOURCE_INFO_JSON)

    filtered_releases = non_eol_releases(tuple(map(lambda x: int(x), old_info.keys())))

    for major_version in filtered_releases:
        update_source(str(major_version), commit, force)


if __name__ == "__main__":
    cli()
