"""Patterns command for detecting command sequences."""

from typing import Optional

import click
from rich.console import Console
from rich.table import Table

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


@click.command("patterns")
@click.option(
    "--history",
    "-H",
    type=str,
    help="Path to history file",
)
@click.option(
    "--min-frequency",
    "-m",
    type=int,
    default=2,
    help="Minimum frequency for pattern detection (default: 2)",
)
@click.option(
    "--type",
    "-t",
    type=click.Choice(["pairs", "triplets", "repetitive", "all"]),
    default="all",
    help="Type of patterns to detect",
)
@click.option(
    "--shell",
    "-s",
    type=click.Choice(["bash", "zsh"]),
    help="Shell type for parsing",
)
@click.pass_context
def patterns_command(
    ctx: click.Context,
    history: Optional[str],
    min_frequency: int,
    type: str,
    shell: Optional[str],
) -> None:
    """Detect repetitive command patterns in your shell history.
    
    Examples:
    
        \b
        shellhist patterns
        shellhist patterns --min-frequency 3
        shellhist patterns --type pairs
        shellhist patterns --type triplets
    """
    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
        
        total_entries = len(store.entries)
        
        if type in ("pairs", "all"):
            pairs = detect_command_pairs(store, min_frequency=min_frequency)
        
        if type in ("triplets", "all"):
            triplets = detect_command_triplets(store, min_frequency=min_frequency)
        
        if type in ("repetitive", "all"):
            repetitive = detect_repetitive_commands(store, min_frequency=min_frequency)
        
        if type == "pairs":
            _display_patterns(console, "Command Pairs", pairs, total_entries)
        elif type == "triplets":
            _display_patterns(console, "Command Triplets", triplets, total_entries)
        elif type == "repetitive":
            _display_patterns(console, "Repetitive Commands", repetitive, total_entries)
        else:
            if pairs:
                _display_patterns(console, "Command Pairs", pairs, total_entries)
            if triplets:
                _display_patterns(console, "Command Triplets", triplets, total_entries)
            if repetitive:
                _display_patterns(console, "Repetitive Commands", repetitive, total_entries)
            
            if not pairs and not triplets and not repetitive:
                console.print(
                    f"[yellow]No patterns found with minimum frequency {min_frequency}.[/yellow]"
                )
                console.print("Try lowering the --min-frequency threshold.")
        
    except FileNotFoundError as e:
        console.print(f"[red]Error: {e}[/red]")
        ctx.exit(1)
    except Exception as e:
        console.print(f"[red]Error detecting patterns: {e}[/red]")
        ctx.exit(1)


def _display_patterns(
    console: Console,
    title: str,
    patterns: list[CommandPattern],
    total_entries: int,
) -> None:
    """Display detected patterns in a table."""
    if not patterns:
        return
    
    console.print(f"\n[bold cyan]{title}[/bold cyan]")
    
    table = Table(show_header=True, header_style="bold magenta")
    table.add_column("#", width=4)
    table.add_column("Count", width=8)
    table.add_column("%", width=8)
    table.add_column("Pattern", width=70)
    
    for i, pattern in enumerate(patterns[:30], 1):
        if hasattr(pattern, 'commands'):
            cmd_str = " -> ".join(pattern.commands)
        else:
            cmd_str = str(pattern)
        
        if len(cmd_str) > 68:
            cmd_str = cmd_str[:68] + "..."
        
        pct = f"{pattern.percentage:.1f}%" if hasattr(pattern, 'percentage') else "N/A"
        table.add_row(
            str(i),
            str(pattern.frequency),
            pct,
            cmd_str,
        )
    
    console.print(table)