from pathlib import Path
import shlex
import textwrap
from typing import cast, TYPE_CHECKING

from beartype import beartype

from test_driver.machine import Machine
from test_driver.errors import RequestedAssertionFailed

if TYPE_CHECKING:
    global machine
    machine = cast(Machine, ...)
    assert machine.shell is not None

ls = "eza -lah --color=always --group-directories-first"

@beartype
def run_log(machine: Machine, *commands: str, timeout: int | None = 60) -> str:
    output = ""
    for command in commands:
        with machine.nested(f"must succeed: {command}"):
            (status, out) = machine.execute(f"{command} | tee /dev/stderr", timeout=timeout)
            if status != 0:
                machine.log(f"output: {out}")
                raise RequestedAssertionFailed(
                    f"command `{command}` failed (exit code {status})",
                )
            output += out

    return output

@beartype
def get_config_file() -> str:
    machine.wait_for_unit("gotosocial.service")
    gotosocial_pid = int(machine.get_unit_property("gotosocial.service", "MainPID"))
    print(f"{gotosocial_pid=}")

    cmdline = machine.succeed(f"cat /proc/{gotosocial_pid}/cmdline")
    cmdline_args = cmdline.split("\0")

    config_file_idx = cmdline_args.index("--config-path") + 1
    config_file = Path(cmdline_args[config_file_idx])

    machine.log(f"copying from VM: {config_file=}")
    machine.copy_from_vm(config_file.as_posix())

    config_file_path = machine.out_dir / config_file.name
    with open(config_file_path, "r") as f:
        return f.read()


machine.wait_for_unit("default.target")
assert "lix" in machine.succeed("nix --version").lower()

run_log(machine, "nixos-generate-config")
machine.succeed("mkdir -vp /etc/nixos")
machine.succeed("cp -rv /run/current-system/sw/share/nixos/* /etc/nixos/")
machine.succeed("env PAGER= nixos-rebuild switch --log-format raw-with-logs -v --fallback >&2")

config_text = get_config_file()
lines = config_text.splitlines()
application_name = next((line for line in lines if line.startswith("application-name:")), None)
assert application_name is not None, f"no 'application-name:' found in config file: {textwrap.indent(config_text, "")}"
assert "gotosocial-for-machine" in application_name, f"'gotosocial-for-machine' should be in {application_name=}"

new_app_name = "yay!"
expr = textwrap.dedent(f"""
    let
        nixos = import <nixpkgs/nixos> {{ }};
    in nixos.config.dynamicism.doChange {{
        option = "services.gotosocial.settings.application-name";
        value = "{new_app_name}";
    }}
""").strip()
machine.succeed(rf"""
    nix run --show-trace --log-format raw-with-logs --impure -E {shlex.quote(expr)}
""".strip())

config_file_new = get_config_file()
lines = config_file_new.splitlines()

application_name = next(line for line in lines if line.startswith("application-name:"))
assert new_app_name in application_name, f"'{new_app_name}' should be in {application_name=}"