#!/usr/bin/env python

# Copyright 2022, TUF contributors
# SPDX-License-Identifier: MIT OR Apache-2.0

"""verify_release - verify that published release matches a locally built one

Builds a release from current commit and verifies that the release artifacts
on GitHub and PyPI match the built release artifacts.
"""

import json
import os
import subprocess
import sys
from filecmp import dircmp
from tempfile import TemporaryDirectory

import requests

# Project variables
# Note that only these project artifacts are supported:
# [f"{PYPI_PROJECT}-{VER}-none-any.whl",  f"{PYPI_PROJECT}-{VER}.tar.gz"]
GITHUB_ORG = "theupdateframework"
GITHUB_PROJECT = "python-tuf"
PYPI_PROJECT = "tuf"


def build(build_dir: str) -> str:
    """Build release locally. Return version as string"""
    cmd = ["python3", "-m", "build", "--outdir", build_dir]
    subprocess.run(cmd, stdout=subprocess.DEVNULL, check=True)
    build_version = None
    for filename in os.listdir(build_dir):
        prefix, postfix = f"{PYPI_PROJECT}-", ".tar.gz"
        if filename.startswith(prefix) and filename.endswith(postfix):
            build_version = filename[len(prefix) : -len(postfix)]
    assert build_version
    return build_version


def get_git_version() -> str:
    """Return version string from git describe"""
    cmd = ["git", "describe"]
    process = subprocess.run(cmd, text=True, capture_output=True, check=True)
    assert process.stdout.startswith("v") and process.stdout.endswith("\n")
    return process.stdout[1:-1]


def get_github_version() -> str:
    """Return version string of latest GitHub release"""
    release_json = f"https://api.github.com/repos/{GITHUB_ORG}/{GITHUB_PROJECT}/releases/latest"
    releases = json.loads(requests.get(release_json).content)
    return releases["tag_name"][1:]


def get_pypi_pip_version() -> str:
    """Return latest version string available on PyPI according to pip"""
    # pip can't tell us what the newest available version is... So we download
    # newest tarball and figure out the version from the filename
    with TemporaryDirectory() as pypi_dir:
        cmd = ["pip", "download", "--no-deps", "--dest", pypi_dir]
        source_download = cmd + ["--no-binary", ":all:", PYPI_PROJECT]
        subprocess.run(source_download, stdout=subprocess.DEVNULL, check=True)
        for filename in os.listdir(pypi_dir):
            prefix, postfix = f"{PYPI_PROJECT}-", ".tar.gz"
            if filename.startswith(prefix) and filename.endswith(postfix):
                return filename[len(prefix) : -len(postfix)]
        assert False


def verify_github_release(version: str, compare_dir: str) -> bool:
    """Verify that given GitHub version artifacts match expected artifacts"""
    base_url = (
        f"https://github.com/{GITHUB_ORG}/{GITHUB_PROJECT}/releases/download"
    )
    tar = f"{PYPI_PROJECT}-{version}.tar.gz"
    wheel = f"{PYPI_PROJECT}-{version}-py3-none-any.whl"
    with TemporaryDirectory() as github_dir:
        for filename in [tar, wheel]:
            url = f"{base_url}/v{version}/{filename}"
            response = requests.get(url, stream=True)
            with open(os.path.join(github_dir, filename), "wb") as f:
                for data in response.iter_content():
                    f.write(data)

        same = dircmp(github_dir, compare_dir).same_files
        return sorted(same) == [wheel, tar]


def verify_pypi_release(version: str, compare_dir: str) -> bool:
    """Verify that given PyPI version artifacts match expected artifacts"""
    tar = f"{PYPI_PROJECT}-{version}.tar.gz"
    wheel = f"{PYPI_PROJECT}-{version}-py3-none-any.whl"

    with TemporaryDirectory() as pypi_dir:
        cmd = ["pip", "download", "--no-deps", "--dest", pypi_dir]
        target = f"{PYPI_PROJECT}=={version}"
        binary_download = cmd + [target]
        source_download = cmd + ["--no-binary", ":all:", target]

        subprocess.run(binary_download, stdout=subprocess.DEVNULL, check=True)
        subprocess.run(source_download, stdout=subprocess.DEVNULL, check=True)

        same = dircmp(pypi_dir, compare_dir).same_files
        return sorted(same) == [wheel, tar]


def finished(s: str) -> None:
    # clear line
    sys.stdout.write("\033[K")
    print(f"* {s}")


def progress(s: str) -> None:
    # clear line
    sys.stdout.write("\033[K")
    # carriage return but no newline: next print will overwrite this one
    print(f"  {s}...", end="\r", flush=True)


def main() -> int:
    success = True
    with TemporaryDirectory() as build_dir:

        progress("Building release")
        build_version = build(build_dir)
        finished(f"Built release {build_version}")

        git_version = get_git_version()
        assert git_version.startswith(build_version)
        if git_version != build_version:
            finished(f"WARNING: Git describes version as {git_version}")

        progress("Checking GitHub latest version")
        github_version = get_github_version()
        if github_version != build_version:
            finished(f"WARNING: GitHub latest version is {github_version}")

        progress("Checking PyPI latest version")
        pypi_version = get_pypi_pip_version()
        if pypi_version != build_version:
            finished(f"WARNING: PyPI latest version is {pypi_version}")

        progress("Downloading release from PyPI")
        if not verify_pypi_release(build_version, build_dir):
            # This is expected while build is not reproducible
            finished("ERROR: PyPI artifacts do not match built release")
            success = False

        progress("Downloading release from GitHub")
        if not verify_github_release(build_version, build_dir):
            # This is expected while build is not reproducible
            finished("ERROR: GitHub artifacts do not match built release")
            success = False

        if success:
            finished("Github and PyPI artifacts match the built release")

    return 0 if success else 1


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