{% extends "base.html" %}
{% block title %}Asignación Usuario-Sistema{% endblock %}

{% block content %}
<div class="d-flex align-items-center mb-4">
  <a href="{{ url_for('relacion.lista') }}" class="btn btn-sm btn-outline-secondary me-3">
    <i class="bi bi-arrow-left"></i> Volver
  </a>
  <h2 class="fw-bold mb-0">
    <i class="bi bi-diagram-3 text-primary"></i> Asignar Usuarios a Sistema
  </h2>
</div>

<div class="card shadow-sm border-0" style="max-width:680px;">
  <div class="card-body p-4">
    <form method="POST" novalidate>
      {{ form.hidden_tag() }}

      <div class="mb-4">
        {{ form.sistema_id.label(class="form-label fw-semibold") }}
        {{ form.sistema_id(class="form-select" + (" is-invalid" if form.sistema_id.errors else ""),
                           id="sistema_id") }}
        {% for e in form.sistema_id.errors %}<div class="invalid-feedback">{{ e }}</div>{% endfor %}
      </div>

      <div class="mb-4">
        <label class="form-label fw-semibold">
          <i class="bi bi-people"></i> Usuarios asignados
        </label>
        <div class="border rounded p-3" style="max-height:320px; overflow-y:auto;">
          {% for value, label in form.usuario_ids.choices %}
            <div class="form-check mb-1">
              <input class="form-check-input" type="checkbox"
                     name="usuario_ids" value="{{ value }}"
                     id="usr_{{ value }}"
                     {% if value in (asignados or []) %}checked{% endif %}>
              <label class="form-check-label" for="usr_{{ value }}">
                {{ label }}
              </label>
            </div>
          {% else %}
            <p class="text-muted mb-0">No hay usuarios activos disponibles.</p>
          {% endfor %}
        </div>
        <div class="mt-2 d-flex gap-2">
          <button type="button" class="btn btn-sm btn-outline-secondary"
                  onclick="document.querySelectorAll('[name=usuario_ids]').forEach(c=>c.checked=true)">
            Seleccionar todos
          </button>
          <button type="button" class="btn btn-sm btn-outline-secondary"
                  onclick="document.querySelectorAll('[name=usuario_ids]').forEach(c=>c.checked=false)">
            Quitar todos
          </button>
        </div>
      </div>

      <div class="d-flex gap-2">
        {{ form.submit(class="btn btn-primary px-4") }}
        <a href="{{ url_for('relacion.lista') }}" class="btn btn-outline-secondary px-4">Cancelar</a>
      </div>
    </form>
  </div>
</div>
{% endblock %}