"""Self-management commands for bin."""

import os
import shutil
import subprocess
import sys
from pathlib import Path

import click


def _get_project_root() -> Path:
    """Get mytoolkit project root from source tree."""
    return Path(__file__).parent.parent.parent


def _run(cmd: list[str], cwd: Path | None = None, check: bool = True) -> None:
    result = subprocess.run(cmd, cwd=str(cwd) if cwd else None, check=False)
    if check and result.returncode != 0:
        raise click.Exit(result.returncode)


def _has_uv() -> bool:
    return shutil.which("uv") is not None


def _install(root: Path) -> None:
    venv_toolkit = root / ".venv" / "bin" / "mytoolkit"
    user_local = Path.home() / ".local" / "bin" / "mytoolkit"
    comp_dir = Path.home() / ".local" / "bin" / "completions"

    # 1. Sync venv / install package
    click.secho("Installing package…", fg="cyan")
    if _has_uv():
        _run(["uv", "sync"], cwd=root)
    else:
        venv_pip = root / ".venv" / "bin" / "pip"
        if not venv_pip.exists():
            _run([sys.executable, "-m", "venv", str(root / ".venv")])
        _run([str(venv_pip), "install", "-e", str(root)], cwd=root)

    if not venv_toolkit.exists():
        click.secho(f"error: missing {venv_toolkit}", fg="red", err=True)
        raise click.Exit(1)

    # 2. Symlink to ~/.local/bin
    click.secho(f"Linking {user_local} → {venv_toolkit}…", fg="cyan")
    user_local.parent.mkdir(parents=True, exist_ok=True)
    if user_local.exists() or user_local.is_symlink():
        user_local.unlink()
    user_local.symlink_to(venv_toolkit)

    # 3. Install completions
    comp_dir.mkdir(parents=True, exist_ok=True)
    shell = os.environ.get("SHELL", "")
    if "zsh" in shell:
        comp_file = comp_dir / "_mytoolkit"
        result = subprocess.run(
            [str(venv_toolkit)],
            env={**os.environ, "_MYTOOLKIT_COMPLETE": "zsh_source"},
            capture_output=True,
            text=True,
        )
        if result.returncode == 0:
            comp_file.write_text(result.stdout)
            click.secho(f"Installed zsh completion: {comp_file}", fg="green")
        else:
            click.secho("Warning: failed to generate zsh completion", fg="yellow")
    elif "bash" in shell:
        comp_file = comp_dir / "mytoolkit.bash"
        result = subprocess.run(
            [str(venv_toolkit)],
            env={**os.environ, "_MYTOOLKIT_COMPLETE": "bash_source"},
            capture_output=True,
            text=True,
        )
        if result.returncode == 0:
            comp_file.write_text(result.stdout)
            click.secho(f"Installed bash completion: {comp_file}", fg="green")
        else:
            click.secho("Warning: failed to generate bash completion", fg="yellow")


def _uninstall() -> None:
    user_local = Path.home() / ".local" / "bin" / "mytoolkit"
    comp_dir = Path.home() / ".local" / "bin" / "completions"
    for f in (comp_dir / "_mytoolkit", comp_dir / "mytoolkit.bash", user_local):
        if f.exists() or f.is_symlink():
            f.unlink()
            click.secho(f"Removed {f}", fg="green")


@click.command(name="update")
def update_cmd():
    """Update mytoolkit from the local repository."""
    root = _get_project_root()
    click.secho("Updating mytoolkit…", fg="cyan")
    _install(root)
    click.secho("mytoolkit updated.", fg="green")


@click.command(name="uninstall")
def uninstall_cmd():
    """Uninstall mytoolkit."""
    click.secho("Uninstalling mytoolkit…", fg="cyan")
    _uninstall()
    click.secho("mytoolkit removed.", fg="green")