from dataclasses import dataclass
from typing import Mapping
from pants.core.util_rules.system_binaries import (
    BinaryPath,
    BinaryPathRequest,
    BinaryPaths,
    BinaryPathTest,
    BinaryShims,
    BinaryShimsRequest,
)
from pants.engine.environment import Environment, EnvironmentRequest
from pants.engine.fs import Digest
from pants.engine.rules import Get, rule, collect_rules
from pants.util.logging import LogLevel
import os


@dataclass
class BuildahBinary(BinaryPath):
    """The `buildah` binary."""

    extra_env: Mapping[str, str]
    extra_input_digests: Mapping[str, Digest]

    def __init__(
        self,
        path: str,
        fingerprint: str,
        extra_env: Mapping[str, str],
        extra_input_digests: Mapping[str, Digest],
    ) -> None:
        self.extra_env = {} if extra_env is None else extra_env
        self.extra_input_digests = extra_input_digests
        super().__init__(path, fingerprint)


@rule(level=LogLevel.DEBUG)
async def get_buildah_binary() -> BuildahBinary:
    request = BinaryPathRequest(
        binary_name="buildah",
        search_path=["/usr/local/bin"],
        test=BinaryPathTest(args=["-v"]),
    )
    paths = await Get(BinaryPaths, BinaryPathRequest, request)
    first_path = paths.first_path_or_raise(request, rationale="use buildah")

    # fixes these warnings:
    # "The cgroupv2 manager is set to systemd but there is no systemd user session available"
    # "For using systemd, you may need to login using an user session"
    # "Alternatively, you can enable lingering with: `loginctl enable-linger 1000` (possibly as root)"
    # "Falling back to --cgroup-manager=cgroupfs"
    env = await Get(Environment, EnvironmentRequest(["DBUS_SESSION_BUS_ADDRESS"]))

    tools = await Get(
        BinaryShims,
        BinaryShimsRequest,
        BinaryShimsRequest.for_binaries(
            *["newgidmap", "newuidmap", "ls"],
            rationale="use buildah",
            output_directory="bin",
            search_path=["/usr/bin"],
        ),
    )
    tools_path = ".shims"
    extra_env = {**env, "PATH": os.path.join(tools_path, tools.bin_directory)}
    extra_input_digests = {tools_path: tools.digest}

    return BuildahBinary(
        first_path.path,
        first_path.fingerprint,
        extra_env=extra_env,
        extra_input_digests=extra_input_digests,
    )


def rules():
    return collect_rules()