#!/usr/bin/env bash
# detect_wsl
# ----------
# Detecta si el sistema actual es WSL (Windows Subsystem for Linux).
# Con --check solo retorna exit code (0=WSL, 1=no WSL) sin output.
# Sin argumentos, imprime información completa del entorno WSL.
#
# USO:
#   source detect_wsl.sh
#   detect_wsl [--check]

detect_wsl() {
    local check_only=false
    [[ "${1:-}" == "--check" ]] && check_only=true

    # Detección interna de WSL
    _is_wsl() {
        if [[ -f /proc/version ]] && grep -qi "microsoft\|wsl" /proc/version; then
            return 0
        fi
        if [[ -f /proc/sys/kernel/osrelease ]] && grep -qi "microsoft\|wsl" /proc/sys/kernel/osrelease; then
            return 0
        fi
        if [[ -d /mnt/c ]] && [[ -f /proc/sys/fs/binfmt_misc/WSLInterop ]]; then
            return 0
        fi
        return 1
    }

    _get_wsl_version() {
        if [[ -f /proc/version ]]; then
            if grep -qi "WSL2" /proc/version; then
                echo "WSL2"
            elif grep -qi "microsoft" /proc/version; then
                echo "WSL1"
            else
                echo "Unknown"
            fi
        else
            echo "Unknown"
        fi
    }

    _get_windows_username() {
        if [[ -n "${WSLENV:-}" ]]; then
            cmd.exe /c "echo %USERNAME%" 2>/dev/null | tr -d '\r\n' || echo "Unknown"
        else
            echo "Unknown"
        fi
    }

    # Modo --check: solo exit code
    if [[ "$check_only" == true ]]; then
        _is_wsl && return 0 || return 1
    fi

    # Modo informativo
    if ! _is_wsl; then
        echo "detect_wsl: este sistema NO es WSL" >&2
        return 1
    fi

    local wsl_version
    wsl_version="$(_get_wsl_version)"

    local win_user
    win_user="$(_get_windows_username)"

    local distro="Unknown"
    if [[ -f /etc/os-release ]]; then
        distro="$(. /etc/os-release && echo "${PRETTY_NAME:-${ID:-Unknown}}")"
    fi

    echo "=== Entorno WSL ==="
    echo "  Versión de WSL:    ${wsl_version}"
    echo "  Usuario Windows:   ${win_user}"
    echo "  Distribución:      ${distro}"
    echo "  Hostname:          $(hostname)"
    echo ""

    echo "=== Unidades de Windows montadas ==="
    ls /mnt/ 2>/dev/null | grep -E "^[a-z]$" | while IFS= read -r drive; do
        echo "  ${drive}: → /mnt/${drive}"
    done
    echo ""

    local current_win_path
    current_win_path="$(wslpath -w "$(pwd)" 2>/dev/null || echo "N/A")"
    echo "=== Directorio actual en Windows ==="
    echo "  ${current_win_path}"
    echo ""
}

# Ejecutar si se invoca directamente
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
    detect_wsl "$@"
fi