"""Shell completion command."""
from __future__ import annotations

import sys
from pathlib import Path

import click
from rich.console import Console

console = Console()

@click.command("completion")
@click.argument("shell", type=click.Choice(["zsh", "bash", "fish"]))
@click.option("--script", is_flag=True, help="Output the raw completion script instead of instructions")
@click.pass_context
def cmd_completion(ctx, shell, script):
  """Print shell completion setup instructions (or output the script with --script)."""
  if script:
    from click.shell_completion import BashComplete, FishComplete, ZshComplete
    cls = {"zsh": ZshComplete, "bash": BashComplete, "fish": FishComplete}[shell]
    comp = cls(ctx.find_root().command, {}, "browser-cli", "_BROWSER_CLI_COMPLETE")
    click.echo(comp.source())
    return

  exe = sys.executable.replace("/python", "/browser-cli").replace("/python3", "/browser-cli")
  if not Path(exe).exists():
    exe = "browser-cli"

  env_var = "_BROWSER_CLI_COMPLETE"

  if shell == "zsh":
    console.print("[bold]Quickest setup — generate the file once:[/bold]")
    console.print()
    console.print("  [cyan]uv run browser-cli completion zsh --script > ~/.zfunc/_browser-cli[/cyan]")
    console.print()
    console.print("  Then add these lines to [bold]~/.zshrc[/bold] (before any compinit call):")
    console.print("  [cyan]fpath=(~/.zfunc $fpath)[/cyan]")
    console.print("  [cyan]autoload -Uz compinit && compinit[/cyan]")
    console.print()
    console.print("  Reload: [cyan]exec zsh[/cyan]")
    console.print()
    console.print("[bold]Alternative — eval on every shell start (simpler but slower):[/bold]")
    console.print(f'  [cyan]eval "$({env_var}=zsh_source {exe})"[/cyan]')
  elif shell == "bash":
    console.print("[bold]Quickest setup — generate the file once:[/bold]")
    console.print()
    console.print("  [cyan]uv run browser-cli completion bash --script > ~/.bash_completion.d/browser-cli[/cyan]")
    console.print()
    console.print("  Reload: [cyan]source ~/.bashrc[/cyan]")
    console.print()
    console.print("[bold]Alternative — eval on every shell start:[/bold]")
    console.print(f'  [cyan]eval "$({env_var}=bash_source {exe})"[/cyan]')
  elif shell == "fish":
    console.print("[bold]Setup:[/bold]")
    console.print()
    console.print("  [cyan]uv run browser-cli completion fish --script > ~/.config/fish/completions/browser-cli.fish[/cyan]")