"""Alias suggestion command."""

import os
from typing import Optional

import click
from rich.console import Console
from rich.panel import Panel

from shellhist.core import HistoryLoader
from shellhist.core.patterns import (
    detect_command_pairs,
    detect_command_triplets,
    detect_repetitive_commands,
)


@click.command("suggest-aliases")
@click.option(
    "--history",
    "-H",
    type=str,
    help="Path to history file",
)
@click.option(
    "--auto-create",
    "-a",
    is_flag=True,
    default=False,
    help="Automatically create aliases without prompting",
)
@click.option(
    "--dry-run",
    "-d",
    is_flag=True,
    default=False,
    help="Show what would be created without making changes",
)
@click.option(
    "--shell",
    "-s",
    type=click.Choice(["bash", "zsh"]),
    help="Shell type for parsing",
)
@click.pass_context
def alias_command(
    ctx: click.Context,
    history: Optional[str],
    auto_create: bool,
    dry_run: bool,
    shell: Optional[str],
) -> None:
    """Generate alias suggestions for detected patterns.
    
    Examples:
    
        \b
        shellhist suggest-aliases
        shellhist suggest-aliases --auto-create
        shellhist suggest-aliases --dry-run
    """
    console = Console()
    
    try:
        loader = HistoryLoader(history_path=history)
        store = loader.load()
        
        if not store.entries:
            console.print("[yellow]No entries found in history.[/yellow]")
            return
        
        pairs = detect_command_pairs(store, min_frequency=2)
        triplets = detect_command_triplets(store, min_frequency=2)
        
        sequences = [
            (p.commands, p.frequency)
            for p in pairs + triplets
            if len(p.commands) >= 2
        ]
        
        if not sequences:
            console.print(
                "[yellow]No command sequences found for alias suggestions.[/yellow]"
            )
            console.print("Try running more commands first.")
            return
        
        console.print(f"\n[bold cyan]Detected Command Sequences[/bold cyan]")
        
        for i, (cmds, freq) in enumerate(sequences[:10], 1):
            seq = " && ".join(cmds)
            console.print(f"{i}. {seq} (frequency: {freq})")
        
        console.print("\n[bold cyan]Suggested Aliases[/bold cyan]")
        
        for i, (cmds, freq) in enumerate(sequences[:10], 1):
            alias_name = generate_alias_name(cmds)
            alias_cmd = " && ".join(cmds)
            alias_str = f"alias {alias_name}='{alias_cmd}'"
            
            panel = Panel(
                f"[green]{alias_str}[/green]",
                title=f"Alias {i}",
                expand=False,
            )
            console.print(panel)
            
            if not dry_run:
                if auto_create:
                    append_to_shell_file(alias_str)
                    console.print(f"  [green]Created alias '{alias_name}'[/green]")
                else:
                    if click.confirm(f"  Create this alias?"):
                        append_to_shell_file(alias_str)
                        console.print(f"  [green]Created alias '{alias_name}'[/green]")
    
    except FileNotFoundError as e:
        console.print(f"[red]Error: {e}[/red]")
        ctx.exit(1)
    except Exception as e:
        console.print(f"[red]Error generating aliases: {e}[/red]")
        ctx.exit(1)


def generate_alias_name(commands: list[str]) -> str:
    """Generate a meaningful alias name from command list."""
    if not commands:
        return "custom"
    
    keywords = []
    for cmd in commands:
        parts = cmd.split()
        if parts:
            keywords.append(parts[0])
    
    keywords = [k for k in keywords if k not in ("sudo", "do", "run", "exec")]
    
    if not keywords:
        return "custom"
    
    base = "".join(keywords[:3]).lower()
    
    if len(base) > 12:
        base = base[:12]
    
    return base


def append_to_shell_file(alias_str: str) -> None:
    """Append alias to shell config file."""
    shell = os.environ.get("SHELL", "")
    
    if "zsh" in shell:
        rc_file = os.path.expanduser("~/.zshrc")
    else:
        rc_file = os.path.expanduser("~/.bashrc")
    
    with open(rc_file, "a", encoding="utf-8") as f:
        f.write(f"\n{alias_str}\n")