.gitignore

@@ -163,3 +163,6 @@ cython_debug/
 
 staticfiles/
 *.bak
+
+# graphify
+graphify-out/

expenses_manager/expenses/forms.py

@@ -25,7 +25,43 @@ def _hide_is_transfer_when_editing(form):
         form.fields.pop("is_transfer", None)
 
 
-class ExpenseForm(forms.ModelForm):
+class _GoalLinksMixin:
+    """Campo "Objetivos" en el formulario de un movimiento.
+
+    `goals` es el lado inverso de Goal.linked_expenses / linked_incomes, y un
+    ModelForm no guarda relaciones inversas: hay que poblarlo al abrir y
+    escribirlo a mano al guardar. Lo comparten gastos e ingresos para que qué
+    objetivo admite cada movimiento se decida en un solo sitio
+    (Goal.KINDS_LINKING_*, en el modelo).
+    """
+
+    goal_kinds = ()
+
+    def setup_goal_links(self, user):
+        self.fields["goals"] = forms.ModelMultipleChoiceField(
+            queryset=Goal.objects.filter(owner=user, kind__in=self.goal_kinds),
+            required=False,
+            label="Objetivos",
+            widget=forms.CheckboxSelectMultiple(),
+            help_text="Este movimiento cuenta en los objetivos que marques.",
+        )
+
+        if self.instance.pk:
+            self.initial["goals"] = list(
+                self.instance.goals.values_list("pk", flat=True)
+            )
+
+    def _save_m2m(self):
+        super()._save_m2m()
+
+        # Si el formulario se construyó sin usuario no hay campo, y entonces no
+        # se toca nada: un set() a ciegas borraría las vinculaciones que ya haya.
+        if "goals" in self.cleaned_data:
+            self.instance.goals.set(self.cleaned_data["goals"])
+
+
+class ExpenseForm(_GoalLinksMixin, forms.ModelForm):
+    goal_kinds = Goal.KINDS_LINKING_EXPENSES
 
     def __init__(self, *args, **kwargs):
         # Get user
@@ -40,6 +76,7 @@ class ExpenseForm(forms.ModelForm):
                 owner=user, active=True
             )
             self.fields["date"].input_formats = ["%Y-%m-%d"]
+            self.setup_goal_links(user)
 
         _hide_is_transfer_when_editing(self)
 
@@ -73,7 +110,9 @@ class AccountForm(forms.ModelForm):
         fields = ["name", "initial_balance", "active"]
 
 
-class IncomeForm(forms.ModelForm):
+class IncomeForm(_GoalLinksMixin, forms.ModelForm):
+    goal_kinds = Goal.KINDS_LINKING_INCOMES
+
     class Meta:
         model = Income
         fields = ["account", "name", "amount", "date", "is_transfer"]
@@ -86,6 +125,7 @@ class IncomeForm(forms.ModelForm):
             owner=user,
             active=True,
         )
+        self.setup_goal_links(user)
         _hide_is_transfer_when_editing(self)
 
 
@@ -226,6 +266,18 @@ class GoalForm(forms.ModelForm):
                 )
             cleaned["category"] = None
 
+        if kind == Goal.KIND_COLLECTION:
+            # Un cobro pendiente se mide solo con los ingresos que se le
+            # vinculen, así que no lleva categoría ni cuenta; la fecha de inicio
+            # sí, porque es la que acota desde cuándo cuentan.
+            if not cleaned.get("start_date"):
+                self.add_error(
+                    "start_date",
+                    "Indica desde cuándo se cuentan los cobros.",
+                )
+            cleaned["category"] = None
+            cleaned["account"] = None
+        
         if kind == Goal.KIND_BUDGET:
             if cleaned.get("period") == Goal.PERIOD_NONE:
                 self.add_error(

expenses_manager/expenses/migrations/0017_goal_linked_expenses_goal_linked_incomes_and_more.py

@@ -0,0 +1,28 @@
+# Generated by Django 5.2.10 on 2026-10-08 14:42
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('expenses', '0016_alter_transfer_expense_leg_alter_transfer_income_leg'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='goal',
+            name='linked_expenses',
+            field=models.ManyToManyField(blank=True, related_name='goals', to='expenses.expense', verbose_name='Gastos vinculados'),
+        ),
+        migrations.AddField(
+            model_name='goal',
+            name='linked_incomes',
+            field=models.ManyToManyField(blank=True, related_name='goals', to='expenses.income', verbose_name='Ingresos vinculados'),
+        ),
+        migrations.AlterField(
+            model_name='goal',
+            name='kind',
+            field=models.CharField(choices=[('payment', 'Pago / deuda'), ('budget', 'Presupuesto'), ('saving', 'Ahorro'), ('collection', 'Cobro pendiente')], default='payment', max_length=10),
+        ),
+    ]

expenses_manager/expenses/models.py

@@ -3,7 +3,7 @@ from decimal import Decimal
 from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.db import models, transaction
 from django.conf import settings
-from django.db.models import Sum
+from django.db.models import Q, Sum
 from functools import cached_property
 from django.utils.text import slugify
 from django.db.models.functions import ExtractMonth, Lower
@@ -551,17 +551,47 @@ class FuelEntry(models.Model):
         return None
 
 
+def _deduped_total(movements):
+    """Suma importes sin que el JOIN del M2M cuente la misma fila dos veces.
+
+    Un aggregate() sobre un queryset que lleva el JOIN de la vinculación dentro
+    suma cada movimiento tantas veces como objetivos tenga vinculados, y
+    .distinct() no lo arregla: el DISTINCT se aplica a las filas del SELECT
+    final y en un aggregate no hay filas que deduplicar, porque el JOIN ya
+    multiplicó antes de sumar. Sum("amount", distinct=True) es todavía peor,
+    porque deduplica por el valor del importe: dos gastos distintos de 10 € se
+    sumarían como uno.
+
+    Así que primero los ids (ahí el DISTINCT sí vale) y luego la suma. El
+    `pk__in` con un queryset dentro es una subconsulta, no un segundo viaje.
+    """
+    ids = movements.values("pk").distinct()
+    total = movements.model.objects.filter(pk__in=ids).aggregate(
+        total=Sum("amount")
+    )["total"]
+
+    return total or Decimal("0")
+
+
 class Goal(models.Model):
     KIND_PAYMENT = "payment"
     KIND_BUDGET = "budget"
     KIND_SAVING = "saving"
+    KIND_COLLECTION = "collection"
 
     KIND_CHOICES = [
         (KIND_PAYMENT, "Pago / deuda"),
         (KIND_BUDGET, "Presupuesto"),
         (KIND_SAVING, "Ahorro"),
+        (KIND_COLLECTION, "Cobro pendiente"),
     ]
 
+    # Qué objetivos admiten vincular cada tipo de movimiento. Las dos vías de
+    # marcado (el formulario del movimiento y la pantalla del objetivo) leen de
+    # aquí: si cada una lo decidiera por su cuenta, acabarían divergiendo.
+    KINDS_LINKING_EXPENSES = (KIND_PAYMENT, KIND_BUDGET)
+    KINDS_LINKING_INCOMES = (KIND_COLLECTION,)
+
     PERIOD_NONE = "none"
     PERIOD_MONTH = "month"
     PERIOD_YEAR = "year"
@@ -604,6 +634,57 @@ class Goal(models.Model):
     created_at = models.DateTimeField(auto_now_add=True)
     show_on_home = models.BooleanField(default=False)
 
+    # Movimientos sueltos vinculados a mano. Conviven con la selección por
+    # categoría, no la sustituyen: un objetivo puede tirar de categoría, de
+    # movimientos sueltos, o de los dos a la vez.
+    #
+    # blank=True y no null: un M2M no admite null. Borrar el objetivo limpia la
+    # tabla intermedia y no toca los movimientos, que es lo que se quiere.
+    linked_expenses = models.ManyToManyField(
+        "Expense", blank=True, related_name="goals", verbose_name="Gastos vinculados"
+    )
+    linked_incomes = models.ManyToManyField(
+        "Income", blank=True, related_name="goals", verbose_name="Ingresos vinculados"
+    )
+
+    @property
+    def links_incomes(self):
+        """Si este objetivo se mide con ingresos en vez de con gastos."""
+        return self.kind in self.KINDS_LINKING_INCOMES
+
+    @property
+    def links(self):
+        """El M2M que le toca a este objetivo, para no repetir el if por ahí."""
+        return self.linked_incomes if self.links_incomes else self.linked_expenses
+
+    @property
+    def accepts_links(self):
+        """Si vincularle movimientos significa algo.
+
+        El ahorro no: se mide con el saldo de su cuenta, así que un gasto
+        vinculado ahí quedaría guardado y no contaría en el progreso.
+        """
+        return self.kind in self.KINDS_LINKING_EXPENSES + self.KINDS_LINKING_INCOMES
+
+    def candidate_movements(self):
+        """Movimientos que este objetivo puede vincular.
+
+        Único sitio donde se decide qué es vinculable; lo usan las dos vías de
+        marcado. Fuera las patas de un traspaso: mover dinero entre cuentas
+        propias no es ni un pago ni un cobro. La comisión sí entra, porque es
+        gasto real (va con is_transfer=False) y cuenta en los análisis.
+        """
+        model = Income if self.links_incomes else Expense
+        movements = model.objects.filter(owner_id=self.owner_id).exclude(
+            is_transfer=True
+        )
+
+        start = self._period_start()
+        if start:
+            movements = movements.filter(date__gte=start)
+
+        return movements
+
     def _period_start(self):
         """Fecha desde la que se cuenta el progreso, o None si es todo."""
         if self.kind == self.KIND_BUDGET:
@@ -632,25 +713,46 @@ class Goal(models.Model):
             # así que no filtres is_transfer en esta rama.
             return self.account.current_balance() if self.account else Decimal("0")
 
-        if not self.category:
+        if self.kind == self.KIND_COLLECTION:
-            return Decimal("0")
+            # Un cobro pendiente mide lo que te han devuelto, así que suma los
+            # ingresos vinculados a mano. Aquí no hay selección por categoría
+            # que valga: Income no tiene categoría, que es justo el motivo de
+            # que exista la vinculación.
+            incomes = Income.objects.filter(goals=self, owner_id=self.owner_id).exclude(
+                is_transfer=True
+            )
 
-        if self.include_subcategories:
+            return _deduped_total(self._since_start(incomes))
-            category_ids = self.category.descendant_ids()
+
-        else:
+        category_ids = []
-            category_ids = [self.category_id]
+        # Por _id y no por el objeto: mirar self.category traería la categoría
+        # de la base de datos, una consulta por objetivo al pintar una lista.
+        if self.category_id:
+            if self.include_subcategories:
+                category_ids = self.category.descendant_ids()
+            else:
+                category_ids = [self.category_id]
+
+        # Un solo queryset con un OR, y no dos sumas por separado: un gasto que
+        # esté en la categoría del objetivo Y además vinculado a mano se
+        # contaría dos veces. No daría error, daría un número mal.
+        scope = Q(goals=self)
+        if category_ids:
+            scope |= Q(category_id__in=category_ids)
 
         # Pago y presupuesto miden gasto real, así que los traspasos entre
         # cuentas propias no cuentan. La rama de ahorro de arriba es la opuesta.
-        expenses = Expense.objects.filter(
+        expenses = Expense.objects.filter(scope, owner_id=self.owner_id).exclude(
-            owner=self.owner, category_id__in=category_ids
+            is_transfer=True
-        ).exclude(is_transfer=True)
+        )
 
+        return _deduped_total(self._since_start(expenses))
+
+    def _since_start(self, movements):
+        """Acota al periodo del objetivo. El cobro pendiente lo necesita igual."""
         start = self._period_start()
-        if start:
-            expenses = expenses.filter(date__gte=start)
 
-        return expenses.aggregate(total=Sum("amount"))["total"] or Decimal("0")
+        return movements.filter(date__gte=start) if start else movements
 
     def percentage(self):
         if not self.target_amount:

expenses_manager/expenses/templates/expenses/_form_fields.html

@@ -1,6 +1,6 @@
 {% for field in form %}
     <div class="form-field {% if field.field.widget.input_type == 'checkbox' %}form-field-checkbox{% endif %}">
-        {% if field.name == "tags" %}
+        {% if field.name == "tags" or field.name == "goals" %}
             {{ field.label_tag }}
             <div class="tag-chip-list">
                 {% for checkbox in field %}

expenses_manager/expenses/templates/goals/form.html

@@ -25,7 +25,8 @@
                 Para ponerte un límite de gasto que no quieres superar. El progreso
                 se reinicia cada mes o cada año, según el periodo que elijas.
                 Aquí acercarse al 100% es un aviso, no un logro: la barra pasa a
-                naranja al llegar al 80% y a rojo si te pasas del límite.
+                naranja al llegar al 80% y a rojo si te pasas del límite. Cuenta
+                los gastos de su categoría y además los que le vincules a mano.
             </p>
 
             <h2>Ahorro</h2>
@@ -35,6 +36,46 @@
                 categoría.
             </p>
 
+            <h2>Cobro pendiente</h2>
+            <p>
+                El inverso del de pago: para dinero que te tienen que devolver y vas
+                cobrando a plazos. El progreso es la suma de los ingresos que le
+                vincules desde la fecha de inicio, y llegar al 100% es haberlo
+                cobrado todo. No lleva categoría ni cuenta, porque los ingresos no
+                tienen categoría: se mide solo con los ingresos que marques.
+            </p>
+
+            <h2>Vincular movimientos</h2>
+            <p>
+                Además de contar una categoría entera, un objetivo puede contar
+                gastos o ingresos concretos. Se marcan de dos maneras: con el campo
+                <strong>Objetivos</strong> del formulario del gasto o del ingreso, o
+                desde <strong>Vincular</strong> en la lista de objetivos, que permite
+                marcar varios de golpe.
+            </p>
+            <p>
+                Lo admiten tres tipos, y cada uno vincula lo que mide:
+            </p>
+            <ul>
+                <li><strong>Pago / deuda</strong> y <strong>presupuesto</strong> — gastos.</li>
+                <li><strong>Cobro pendiente</strong> — ingresos.</li>
+                <li>
+                    <strong>Ahorro</strong> — no admite vinculación: se mide con el
+                    saldo de su cuenta, así que un gasto marcado ahí no contaría.
+                </li>
+            </ul>
+            <p>
+                La categoría y las vinculaciones conviven: un presupuesto de ocio
+                puede contar su categoría y además un gasto suelto de otra que
+                quieras que compute. Un gasto que esté en la categoría y también
+                vinculado a mano cuenta una sola vez.
+            </p>
+            <p>
+                Los dos movimientos de un traspaso no se pueden vincular (mover
+                dinero entre tus cuentas no es un gasto ni un cobro), pero su
+                comisión sí, porque es gasto real.
+            </p>
+
             <h2>Los demás campos</h2>
             <ul>
                 <li>
@@ -51,8 +92,8 @@
                 </li>
                 <li>
                     <strong>Start date</strong> — desde cuándo se cuentan los gastos
-                    en un pago. En un presupuesto no se usa: manda el reinicio del
+                    en un pago, o los ingresos en un cobro pendiente. En un
-                    periodo.
+                    presupuesto no se usa: manda el reinicio del periodo.
                 </li>
                 <li>
                     <strong>Period</strong> — solo para presupuesto: cada cuánto

expenses_manager/expenses/templates/goals/links.html

@@ -0,0 +1,102 @@
+{% extends "expenses/base.html" %}
+
+{% block title %}
+    Vincular movimientos
+{% endblock %}
+
+{% block content %}
+<h1>Vincular movimientos</h1>
+
+<p>
+    Objetivo: <strong>{{ goal.name }}</strong> ({{ goal.get_kind_display|lower }}).
+    {% if goal.links_incomes %}
+        Marca los ingresos que cuentan como cobrados.
+    {% else %}
+        Marca los gastos que cuentan en este objetivo.
+    {% endif %}
+</p>
+
+<p>
+    Vinculado ahora mismo: <strong>{{ linked_total|floatformat:2 }}€</strong>
+    de {{ goal.target_amount|floatformat:2 }}€.
+</p>
+
+{% if goal.start_date %}
+    <p><small>Solo se listan movimientos desde el {{ goal.start_date|date:"d/m/Y" }}.</small></p>
+{% endif %}
+
+<form method="post" class="app-form">
+    {% csrf_token %}
+
+    <div class="table-wrap">
+    <table>
+        <thead>
+            <tr>
+                <th></th>
+                <th>Fecha</th>
+                <th>Importe</th>
+                <th>Cuenta</th>
+                <th>Concepto</th>
+            </tr>
+        </thead>
+        <tbody>
+            {% for movement in page_obj %}
+            <tr>
+                <td>
+                    {# shown viaja con cada fila de la página: así al guardar solo #}
+                    {# se toca lo que había aquí y no lo marcado en otras páginas. #}
+                    <input type="hidden" name="shown" value="{{ movement.pk }}">
+                    <input type="checkbox"
+                           name="movements"
+                           value="{{ movement.pk }}"
+                           id="movement{{ movement.pk }}"
+                           {% if movement.pk in linked_ids %}checked{% endif %}>
+                    <label class="sr-only" for="movement{{ movement.pk }}">
+                        Vincular movimiento del {{ movement.date|date:"d/m/Y" }}
+                    </label>
+                </td>
+                <td>{{ movement.date|date:"d/m/Y" }}</td>
+                <td>{{ movement.amount|floatformat:2 }}€</td>
+                <td>{{ movement.account.name }}</td>
+                <td>
+                    {% if goal.links_incomes %}
+                        {{ movement.name }}
+                    {% else %}
+                        {{ movement.description|default:movement.category.name }}
+                    {% endif %}
+                </td>
+            </tr>
+            {% empty %}
+            <tr>
+                <td colspan="5" class="empty-state">
+                    <p>No hay movimientos que vincular</p>
+                </td>
+            </tr>
+            {% endfor %}
+        </tbody>
+    </table>
+    </div>
+
+    <div class="form-actions">
+        <button type="submit" class="btn btn-primary">Guardar vinculaciones</button>
+        <a class="btn btn-secondary" href="{% url 'goal_list' %}">Volver</a>
+    </div>
+</form>
+
+<nav class="pagination" aria-label="Paginación de movimientos">
+    <span class="step-links">
+        {% if page_obj.has_previous %}
+            <a href="?page=1">&laquo; Primero</a>
+            <a href="?page={{ page_obj.previous_page_number }}">Anterior</a>
+        {% endif %}
+
+        <span>Página {{ page_obj.number }} de {{ page_obj.paginator.num_pages }}</span>
+
+        {% if page_obj.has_next %}
+            <a href="?page={{ page_obj.next_page_number }}">Siguiente</a>
+            <a href="?page={{ page_obj.paginator.num_pages }}">Último &raquo;</a>
+        {% endif %}
+    </span>
+</nav>
+
+{% endblock %}

expenses_manager/expenses/templates/goals/list.html

@@ -76,6 +76,9 @@
 
             <td class="table-actions">
                 <a href="{% url 'goal_edit' goal.id %}">Editar</a>
+                {% if goal.accepts_links %}
+                    <a href="{% url 'goal_links' goal.id %}">Vincular</a>
+                {% endif %}
                 <a href="{% url 'goal_delete' goal.id %}" class="danger">Eliminar</a>
             </td>
         </tr>

expenses_manager/expenses/tests/test_goal_links.py

@@ -0,0 +1,749 @@
+"""Vinculación de movimientos a objetivos y el tipo "cobro pendiente".
+
+El test central es el del doble conteo: con la selección por categoría y la
+vinculación a mano conviviendo, un gasto que esté en las dos tiene que contar
+una sola vez. No da error si se cuenta dos veces, da un número mal, que es peor.
+"""
+
+from datetime import date
+from decimal import Decimal
+
+import pytest
+from django.db import connection
+from django.test.utils import CaptureQueriesContext
+from django.urls import reverse
+
+from expenses.forms import ExpenseForm, GoalForm, IncomeForm
+from expenses.models import Account, Category, Expense, Goal, Income, Transfer
+
+pytestmark = pytest.mark.django_db
+
+
+@pytest.fixture
+def savings(user):
+    return Account.objects.create(
+        owner=user, name="Ahorro", initial_balance=Decimal("0"), active=True
+    )
+
+
+def make_payment_goal(user, category=None, target="1000", start=date(2024, 1, 1)):
+    return Goal.objects.create(
+        owner=user,
+        name="Pago",
+        kind=Goal.KIND_PAYMENT,
+        category=category,
+        include_subcategories=False,
+        start_date=start,
+        target_amount=Decimal(target),
+    )
+
+
+def make_budget_goal(user, category, target="100", period=Goal.PERIOD_MONTH):
+    return Goal.objects.create(
+        owner=user,
+        name="Presupuesto",
+        kind=Goal.KIND_BUDGET,
+        category=category,
+        include_subcategories=False,
+        period=period,
+        target_amount=Decimal(target),
+    )
+
+
+def make_collection_goal(user, target="1000", start=date(2024, 1, 1)):
+    return Goal.objects.create(
+        owner=user,
+        name="Cobro",
+        kind=Goal.KIND_COLLECTION,
+        start_date=start,
+        target_amount=Decimal(target),
+    )
+
+
+def make_expense(user, account, category, amount="10", on=date(2024, 5, 11)):
+    return Expense.objects.create(
+        owner=user,
+        account=account,
+        category=category,
+        amount=Decimal(amount),
+        date=on,
+    )
+
+
+def make_income(user, account, amount="10", on=date(2024, 5, 11), name="Devolución"):
+    return Income.objects.create(
+        owner=user, account=account, name=name, amount=Decimal(amount), date=on
+    )
+
+
+# --------------------------------------------------------------------------
+# El doble conteo: el test central de la fase
+# --------------------------------------------------------------------------
+
+
+def test_an_expense_in_the_category_and_linked_by_hand_counts_once(
+    user, account, category
+):
+    expense = make_expense(user, account, category, amount="100")
+    goal = make_payment_goal(user, category=category)
+
+    goal.linked_expenses.add(expense)
+
+    assert goal.progress == Decimal("100")
+
+
+def test_the_category_and_the_links_add_up_without_overlapping(
+    user, account, category
+):
+    other_category = Category.objects.create(owner=user, name="Otra")
+    in_category = make_expense(user, account, category, amount="100")
+    linked_outside = make_expense(user, account, other_category, amount="30")
+    goal = make_payment_goal(user, category=category)
+
+    # El de la categoría también vinculado a mano, para que el solape exista.
+    goal.linked_expenses.add(in_category, linked_outside)
+
+    assert goal.progress == Decimal("130")
+
+
+def test_a_linked_expense_counted_in_several_goals_is_not_inflated(
+    user, account, category
+):
+    expense = make_expense(user, account, category, amount="100")
+    goal = make_payment_goal(user, category=category)
+    other_goal = make_payment_goal(user, category=category)
+
+    # El JOIN del M2M devuelve una fila por objetivo vinculado: si se suma sin
+    # deduplicar, este gasto cuenta tantas veces como objetivos tenga.
+    goal.linked_expenses.add(expense)
+    other_goal.linked_expenses.add(expense)
+
+    assert goal.progress == Decimal("100")
+
+
+def test_a_goal_with_links_and_no_category_still_measures(user, account, category):
+    expense = make_expense(user, account, category, amount="40")
+    goal = make_payment_goal(user, category=None)
+
+    goal.linked_expenses.add(expense)
+
+    assert goal.progress == Decimal("40")
+
+
+def test_links_respect_the_start_date(user, account, category):
+    old = make_expense(user, account, category, amount="99", on=date(2023, 5, 1))
+    goal = make_payment_goal(user, category=None, start=date(2024, 1, 1))
+
+    goal.linked_expenses.add(old)
+
+    assert goal.progress == Decimal("0")
+
+
+# --------------------------------------------------------------------------
+# Presupuesto: el caso con más riesgo de duplicar, porque siempre tiene
+# categoría y además admite vinculaciones
+# --------------------------------------------------------------------------
+
+
+def test_a_budget_counts_a_linked_expense_of_its_own_category_once(
+    user, account, category
+):
+    # Un presupuesto siempre lleva categoría, así que el solape con la
+    # vinculación a mano es el caso normal, no el raro.
+    expense = make_expense(user, account, category, amount="30", on=date.today())
+    goal = make_budget_goal(user, category, target="100")
+
+    goal.linked_expenses.add(expense)
+
+    assert goal.progress == Decimal("30")
+
+
+def test_a_budget_adds_a_linked_expense_from_another_category(
+    user, account, category
+):
+    other_category = Category.objects.create(owner=user, name="Ocio")
+    make_expense(user, account, category, amount="30", on=date.today())
+    outside = make_expense(user, account, other_category, amount="20", on=date.today())
+    goal = make_budget_goal(user, category, target="100")
+
+    # El caso que motiva vincular en un presupuesto: un gasto de otra categoría
+    # que quieres que compute aquí.
+    goal.linked_expenses.add(outside)
+
+    assert goal.progress == Decimal("50")
+
+
+def test_a_budget_blown_by_a_linked_expense_is_still_flagged(user, account, category):
+    other_category = Category.objects.create(owner=user, name="Ocio")
+    outside = make_expense(user, account, other_category, amount="120", on=date.today())
+    goal = make_budget_goal(user, category, target="100")
+
+    goal.linked_expenses.add(outside)
+
+    assert goal.progress == Decimal("120")
+    assert goal.is_exceeded() is True
+    assert goal.progress_state() == "danger"
+
+
+def test_a_budget_accepts_links(user, category):
+    assert make_budget_goal(user, category).accepts_links is True
+
+
+def test_only_the_budget_inverts_the_criterion(user, account, category):
+    # Pasado del objetivo: el presupuesto lo marca como excedido, el pago lo
+    # considera conseguido. Solo el presupuesto invierte el criterio.
+    over_budget = make_budget_goal(user, category, target="100")
+    over_budget.linked_expenses.add(
+        make_expense(user, account, category, amount="120", on=date.today())
+    )
+    over_payment = make_payment_goal(user, category=None, target="100")
+    over_payment.linked_expenses.add(
+        make_expense(user, account, category, amount="120")
+    )
+
+    assert over_budget.is_exceeded() is True
+    assert over_budget.progress_state() == "danger"
+    assert over_payment.is_exceeded() is False
+    assert over_payment.progress_state() == "complete"
+
+
+def test_a_budget_at_eighty_percent_warns(user, account, category):
+    goal = make_budget_goal(user, category, target="100")
+    goal.linked_expenses.add(
+        make_expense(user, account, category, amount="80", on=date.today())
+    )
+
+    assert goal.progress_state() == "warning"
+    assert goal.is_exceeded() is False
+
+
+def test_a_linked_expense_outside_the_budget_period_does_not_count(
+    user, account, category
+):
+    other_category = Category.objects.create(owner=user, name="Ocio")
+    old = make_expense(
+        user, account, other_category, amount="50", on=date(2020, 1, 15)
+    )
+    goal = make_budget_goal(user, category, target="100")
+
+    # El presupuesto se reinicia cada mes: vincular algo viejo no lo resucita.
+    goal.linked_expenses.add(old)
+
+    assert goal.progress == Decimal("0")
+
+
+# --------------------------------------------------------------------------
+# Cobro pendiente
+# --------------------------------------------------------------------------
+
+
+def test_a_collection_goal_sums_its_linked_incomes(user, account):
+    income = make_income(user, account, amount="250")
+    goal = make_collection_goal(user)
+
+    goal.linked_incomes.add(income)
+
+    assert goal.progress == Decimal("250")
+
+
+def test_an_income_outside_the_collection_goal_does_not_count(user, account):
+    make_income(user, account, amount="250")
+    goal = make_collection_goal(user)
+
+    assert goal.progress == Decimal("0")
+
+
+def test_a_collection_goal_respects_the_start_date(user, account):
+    old = make_income(user, account, amount="250", on=date(2023, 1, 1))
+    goal = make_collection_goal(user, start=date(2024, 1, 1))
+
+    goal.linked_incomes.add(old)
+
+    assert goal.progress == Decimal("0")
+
+
+def test_a_collection_goal_at_half_way_is_not_flagged(user, account):
+    goal = make_collection_goal(user, target="100")
+    goal.linked_incomes.add(make_income(user, account, amount="50"))
+
+    assert goal.percentage() == Decimal("50")
+    # Acercarse al 100% es bueno aquí, como en pago y ahorro: solo el
+    # presupuesto invierte el criterio.
+    assert goal.progress_state() == "ok"
+    assert goal.is_exceeded() is False
+
+
+def test_a_fully_collected_goal_is_complete(user, account):
+    goal = make_collection_goal(user, target="100")
+    goal.linked_incomes.add(make_income(user, account, amount="100"))
+
+    assert goal.progress_state() == "complete"
+    assert goal.is_exceeded() is False
+
+
+def test_the_new_kind_is_offered_in_the_goal_list_filter(auth_client, user):
+    make_collection_goal(user)
+    make_payment_goal(user)
+
+    response = auth_client.get(reverse("goal_list"), {"kind": Goal.KIND_COLLECTION})
+
+    assert response.status_code == 200
+    assert [g.kind for g in response.context["goals"]] == [Goal.KIND_COLLECTION]
+
+
+def test_a_collection_goal_needs_a_start_date(user):
+    form = GoalForm(
+        {
+            "name": "Cobro",
+            "kind": Goal.KIND_COLLECTION,
+            "target_amount": "100",
+            "period": Goal.PERIOD_NONE,
+        },
+        user=user,
+    )
+
+    assert not form.is_valid()
+    assert "start_date" in form.errors
+
+
+def test_a_collection_goal_needs_neither_category_nor_account(user, category):
+    form = GoalForm(
+        {
+            "name": "Cobro",
+            "kind": Goal.KIND_COLLECTION,
+            "target_amount": "100",
+            "start_date": "2024-01-01",
+            "period": Goal.PERIOD_NONE,
+        },
+        user=user,
+    )
+
+    assert form.is_valid(), form.errors
+    goal = form.save(commit=False)
+    assert goal.category is None
+    assert goal.account is None
+
+
+# --------------------------------------------------------------------------
+# Qué es vinculable: las patas del traspaso no, la comisión sí
+# --------------------------------------------------------------------------
+
+
+def test_a_transfer_leg_is_not_a_candidate(user, account, savings, category):
+    transfer = Transfer(
+        owner=user,
+        date=date(2024, 5, 11),
+        amount=Decimal("400"),
+        from_account=account,
+        to_account=savings,
+    )
+    transfer.sync()
+    goal = make_payment_goal(user, category=category)
+
+    candidates = list(goal.candidate_movements())
+
+    # Mover dinero entre cuentas propias no es ni un pago ni un cobro.
+    assert transfer.expense_leg not in candidates
+
+
+def test_the_income_leg_is_not_a_candidate_for_a_collection_goal(
+    user, account, savings
+):
+    transfer = Transfer(
+        owner=user,
+        date=date(2024, 5, 11),
+        amount=Decimal("400"),
+        from_account=account,
+        to_account=savings,
+    )
+    transfer.sync()
+    goal = make_collection_goal(user)
+
+    assert transfer.income_leg not in list(goal.candidate_movements())
+
+
+def test_the_transfer_fee_is_a_candidate(user, account, savings, category):
+    transfer = Transfer(
+        owner=user,
+        date=date(2024, 5, 11),
+        amount=Decimal("400"),
+        from_account=account,
+        to_account=savings,
+        fee_amount=Decimal("1.50"),
+    )
+    transfer.sync()
+    goal = make_payment_goal(user, category=category)
+
+    # La comisión es gasto real: va con is_transfer=False y cuenta en análisis.
+    assert transfer.fee_expense in list(goal.candidate_movements())
+
+
+def test_a_saving_goal_does_not_offer_linking(user, savings):
+    goal = Goal.objects.create(
+        owner=user,
+        name="Ahorro",
+        kind=Goal.KIND_SAVING,
+        account=savings,
+        target_amount=Decimal("100"),
+    )
+
+    assert goal.accepts_links is False
+
+
+def test_the_linking_screen_turns_away_a_saving_goal(auth_client, user, savings):
+    goal = Goal.objects.create(
+        owner=user,
+        name="Ahorro",
+        kind=Goal.KIND_SAVING,
+        account=savings,
+        target_amount=Decimal("100"),
+    )
+
+    response = auth_client.get(reverse("goal_links", args=[goal.pk]))
+
+    assert response.status_code == 302
+
+
+# --------------------------------------------------------------------------
+# Vía 1: el formulario del movimiento
+# --------------------------------------------------------------------------
+
+
+def test_the_expense_form_only_offers_goals_that_take_expenses(
+    user, savings, category
+):
+    payment = make_payment_goal(user, category=category)
+    budget = make_budget_goal(user, category)
+    collection = make_collection_goal(user)
+    saving = Goal.objects.create(
+        owner=user,
+        name="Ahorro",
+        kind=Goal.KIND_SAVING,
+        account=savings,
+        target_amount=Decimal("100"),
+    )
+
+    offered = list(ExpenseForm(user=user).fields["goals"].queryset)
+
+    assert payment in offered
+    assert budget in offered
+    assert collection not in offered
+    assert saving not in offered
+
+
+def test_the_goal_list_offers_linking_on_a_budget(auth_client, user, category):
+    goal = make_budget_goal(user, category)
+
+    response = auth_client.get(reverse("goal_list"))
+
+    assert reverse("goal_links", args=[goal.pk]) in response.content.decode()
+
+
+def test_the_income_form_only_offers_collection_goals(user, category):
+    collection = make_collection_goal(user)
+    payment = make_payment_goal(user, category=category)
+
+    offered = list(IncomeForm(user=user).fields["goals"].queryset)
+
+    assert collection in offered
+    assert payment not in offered
+
+
+def test_the_expense_form_does_not_offer_another_users_goals(
+    user, category, django_user_model
+):
+    intruder = django_user_model.objects.create_user(username="otro", password="x")
+    theirs = make_payment_goal(intruder, category=None)
+
+    assert theirs not in list(ExpenseForm(user=user).fields["goals"].queryset)
+
+
+def test_creating_an_expense_links_it_to_the_chosen_goal(
+    auth_client, user, account, category
+):
+    goal = make_payment_goal(user, category=None)
+
+    response = auth_client.post(
+        reverse("expense_create"),
+        {
+            "date": "2024-05-11",
+            "amount": "75",
+            "category": category.pk,
+            "account": account.pk,
+            "description": "Compra",
+            "goals": [goal.pk],
+        },
+    )
+
+    assert response.status_code == 302
+    assert goal.progress == Decimal("75")
+
+
+def test_creating_an_income_links_it_to_the_chosen_goal(auth_client, user, account):
+    goal = make_collection_goal(user)
+
+    response = auth_client.post(
+        reverse("income_create"),
+        {
+            "date": "2024-05-11",
+            "amount": "75",
+            "account": account.pk,
+            "name": "Devolución",
+            "goals": [goal.pk],
+        },
+    )
+
+    assert response.status_code == 302
+    assert goal.progress == Decimal("75")
+
+
+def test_editing_an_expense_can_unlink_it(auth_client, user, account, category):
+    expense = make_expense(user, account, category, amount="75")
+    goal = make_payment_goal(user, category=None)
+    goal.linked_expenses.add(expense)
+
+    auth_client.post(
+        reverse("expense_edit", args=[expense.pk]),
+        {
+            "date": "2024-05-11",
+            "amount": "75",
+            "category": category.pk,
+            "account": account.pk,
+            "description": "",
+            # Sin "goals": se queda sin vincular.
+        },
+    )
+
+    assert goal.linked_expenses.count() == 0
+
+
+def test_the_expense_form_shows_the_current_links_when_editing(
+    user, account, category
+):
+    expense = make_expense(user, account, category)
+    goal = make_payment_goal(user, category=None)
+    goal.linked_expenses.add(expense)
+
+    form = ExpenseForm(instance=expense, user=user)
+
+    assert form.initial["goals"] == [goal.pk]
+
+
+# --------------------------------------------------------------------------
+# Vía 2: la pantalla del objetivo
+# --------------------------------------------------------------------------
+
+
+def test_the_linking_screen_lists_the_candidates(auth_client, user, account, category):
+    expense = make_expense(user, account, category)
+    goal = make_payment_goal(user, category=None)
+
+    response = auth_client.get(reverse("goal_links", args=[goal.pk]))
+
+    assert response.status_code == 200
+    assert expense in list(response.context["page_obj"])
+
+
+def test_linking_from_the_goal_screen_saves(auth_client, user, account, category):
+    expense = make_expense(user, account, category, amount="60")
+    goal = make_payment_goal(user, category=None)
+
+    auth_client.post(
+        reverse("goal_links", args=[goal.pk]),
+        {"shown": [expense.pk], "movements": [expense.pk]},
+    )
+
+    assert list(goal.linked_expenses.all()) == [expense]
+
+
+def test_both_ways_of_linking_end_up_the_same(auth_client, user, account, category):
+    first = make_expense(user, account, category, amount="60")
+    second = make_expense(user, account, category, amount="60")
+    by_screen = make_payment_goal(user, category=None)
+    by_form = make_payment_goal(user, category=None)
+
+    auth_client.post(
+        reverse("goal_links", args=[by_screen.pk]),
+        {"shown": [first.pk], "movements": [first.pk]},
+    )
+    auth_client.post(
+        reverse("expense_edit", args=[second.pk]),
+        {
+            "date": second.date.isoformat(),
+            "amount": "60",
+            "category": category.pk,
+            "account": account.pk,
+            "description": "",
+            "goals": [by_form.pk],
+        },
+    )
+
+    assert by_screen.progress == by_form.progress == Decimal("60")
+
+
+def test_unchecking_on_the_goal_screen_unlinks(auth_client, user, account, category):
+    expense = make_expense(user, account, category)
+    goal = make_payment_goal(user, category=None)
+    goal.linked_expenses.add(expense)
+
+    auth_client.post(
+        reverse("goal_links", args=[goal.pk]),
+        {"shown": [expense.pk]},
+    )
+
+    assert goal.linked_expenses.count() == 0
+
+
+def test_a_get_on_the_linking_screen_saves_nothing(
+    auth_client, user, account, category
+):
+    expense = make_expense(user, account, category)
+    goal = make_payment_goal(user, category=None)
+
+    auth_client.get(
+        reverse("goal_links", args=[goal.pk]),
+        {"shown": [expense.pk], "movements": [expense.pk]},
+    )
+
+    assert goal.linked_expenses.count() == 0
+
+
+def test_saving_one_page_leaves_the_other_pages_alone(
+    auth_client, user, account, category
+):
+    # La pantalla pagina de 10 en 10: un set() a secas con lo marcado en una
+    # página desvincularía todo lo de las demás.
+    expenses = [
+        make_expense(user, account, category, on=date(2024, 5, day))
+        for day in range(1, 15)
+    ]
+    goal = make_payment_goal(user, category=None)
+    goal.linked_expenses.set(expenses)
+
+    first_page = list(auth_client.get(reverse("goal_links", args=[goal.pk])).context["page_obj"])
+    # Se reenvía la primera página sin ninguna marca: solo esos se desvinculan.
+    auth_client.post(
+        reverse("goal_links", args=[goal.pk]),
+        {"shown": [m.pk for m in first_page]},
+    )
+
+    assert goal.linked_expenses.count() == len(expenses) - len(first_page)
+
+
+# --------------------------------------------------------------------------
+# Aislamiento por usuario
+# --------------------------------------------------------------------------
+
+
+def test_another_users_movement_cannot_be_linked_by_post(
+    auth_client, user, django_user_model
+):
+    intruder = django_user_model.objects.create_user(username="otro", password="x")
+    their_account = Account.objects.create(
+        owner=intruder, name="Ajena", initial_balance=Decimal("0"), active=True
+    )
+    their_category = Category.objects.create(owner=intruder, name="Ajena")
+    theirs = make_expense(intruder, their_account, their_category, amount="500")
+    goal = make_payment_goal(user, category=None)
+
+    response = auth_client.post(
+        reverse("goal_links", args=[goal.pk]),
+        {"shown": [theirs.pk], "movements": [theirs.pk]},
+    )
+
+    assert response.status_code == 302
+    assert goal.linked_expenses.count() == 0
+    assert goal.progress == Decimal("0")
+
+
+def test_another_users_goal_cannot_be_opened(auth_client, django_user_model):
+    intruder = django_user_model.objects.create_user(username="otro", password="x")
+    theirs = make_payment_goal(intruder, category=None)
+
+    response = auth_client.get(reverse("goal_links", args=[theirs.pk]))
+
+    assert response.status_code == 404
+
+
+def test_another_users_goal_cannot_be_chosen_from_the_expense_form(
+    auth_client, user, account, category, django_user_model
+):
+    intruder = django_user_model.objects.create_user(username="otro", password="x")
+    theirs = make_payment_goal(intruder, category=None)
+
+    auth_client.post(
+        reverse("expense_create"),
+        {
+            "date": "2024-05-11",
+            "amount": "75",
+            "category": category.pk,
+            "account": account.pk,
+            "description": "Compra",
+            "goals": [theirs.pk],
+        },
+    )
+
+    assert theirs.linked_expenses.count() == 0
+
+
+# --------------------------------------------------------------------------
+# Borrado y rendimiento
+# --------------------------------------------------------------------------
+
+
+def test_deleting_a_goal_keeps_the_linked_movements(user, account, category):
+    expense = make_expense(user, account, category)
+    goal = make_payment_goal(user, category=None)
+    goal.linked_expenses.add(expense)
+
+    goal.delete()
+
+    # Se limpia la tabla intermedia y el gasto sigue ahí.
+    expense.refresh_from_db()
+    assert Expense.objects.filter(pk=expense.pk).exists()
+
+
+def test_deleting_a_linked_movement_leaves_the_goal_alone(user, account, category):
+    expense = make_expense(user, account, category)
+    goal = make_payment_goal(user, category=None)
+    goal.linked_expenses.add(expense)
+
+    expense.delete()
+    goal.refresh_from_db()
+
+    assert goal.linked_expenses.count() == 0
+    assert goal.progress == Decimal("0")
+
+
+def _queries_painting(auth_client, user, account, category, goals, links_each):
+    """Consultas que cuesta pintar goal_list con esos objetivos y vinculaciones."""
+    Goal.objects.filter(owner=user).delete()
+    for _ in range(goals):
+        goal = make_payment_goal(user, category=None)
+        goal.linked_expenses.set(
+            [make_expense(user, account, category) for _ in range(links_each)]
+        )
+
+    with CaptureQueriesContext(connection) as captured:
+        assert auth_client.get(reverse("goal_list")).status_code == 200
+
+    return len(captured)
+
+
+def test_linked_movements_do_not_cost_a_query_each(
+    auth_client, user, account, category
+):
+    # El N+1 que reaparece con el M2M: una consulta por movimiento vinculado al
+    # pintar la lista. Triplicar las vinculaciones no debe mover el número.
+    few = _queries_painting(auth_client, user, account, category, 2, 1)
+    many = _queries_painting(auth_client, user, account, category, 2, 3)
+
+    assert few == many
+
+
+def test_each_extra_goal_costs_a_single_query(auth_client, user, account, category):
+    # Cada objetivo cuesta el agregado de su progress(), y nada más.
+    two = _queries_painting(auth_client, user, account, category, 2, 2)
+    four = _queries_painting(auth_client, user, account, category, 4, 2)
+
+    assert four - two == 2

expenses_manager/expenses/urls.py

@@ -39,5 +39,6 @@ urlpatterns = [
     path('goals/new/', views.goal_create, name='goal_create'),
     path('goals/<int:pk>/edit/', views.goal_edit, name='goal_edit'),
     path('goals/<int:pk>/delete/', views.goal_delete, name='goal_delete'),
+    path('goals/<int:pk>/links/', views.goal_links, name='goal_links'),
     path('password_help', TemplateView.as_view(template_name="registration/password_help.html"), name="password_help"),
 ]

expenses_manager/expenses/views.py

@@ -1107,6 +1107,9 @@ def income_create(request):
             income = form.save(commit=False)
             income.owner = request.user
             income.save()
+            # Hace falta por el campo de objetivos: sin esto la vinculación
+            # hecha al crear se perdería sin avisar.
+            form.save_m2m()
             messages.success(request, "Ingreso creado correctamente.")
             return redirect("income_list")
     else:
@@ -1486,7 +1489,9 @@ def category_delete(request, pk):
 
 @login_required
 def goal_list(request):
-    goals = Goal.objects.filter(owner=request.user)
+    goals = Goal.objects.filter(owner=request.user).select_related(
+        "category", "account"
+    )
 
     selected_kind = request.GET.get("kind") or ""
     if selected_kind in dict(Goal.KIND_CHOICES):
@@ -1578,6 +1583,64 @@ def goal_delete(request, pk):
     )
 
 
+@login_required
+def goal_links(request, pk):
+    """Vincular movimientos a un objetivo de golpe, desde su ficha.
+
+    La otra vía de marcado es el campo "Objetivos" del formulario del
+    movimiento. Las dos escriben en la misma tabla y las dos preguntan a
+    Goal.candidate_movements() qué es vinculable.
+    """
+    goal = get_object_or_404(Goal, pk=pk, owner=request.user)
+
+    if not goal.accepts_links:
+        messages.error(
+            request,
+            "Un objetivo de ahorro se mide con el saldo de su cuenta, así que no "
+            "se le vinculan movimientos.",
+        )
+        return redirect("goal_list")
+
+    candidates = goal.candidate_movements()
+
+    if request.method == "POST":
+        shown = {int(v) for v in request.POST.getlist("shown") if v.isdigit()}
+        checked = {int(v) for v in request.POST.getlist("movements") if v.isdigit()}
+
+        # Se parte de lo que de verdad podía marcarse en la página enviada: así
+        # un id de otro usuario o de un movimiento no vinculable se cae solo.
+        allowed = set(
+            candidates.filter(pk__in=shown).values_list("pk", flat=True)
+        )
+        # Solo se toca lo de esa página: con paginación, un set() a secas
+        # desvincularía lo marcado en las demás.
+        goal.links.add(*(checked & allowed))
+        goal.links.remove(*(allowed - checked))
+
+        messages.success(request, "Movimientos vinculados actualizados.")
+        return redirect("goal_links", pk=goal.pk)
+
+    movements = candidates.select_related("account").order_by("-date", "-id")
+    paginator = Paginator(movements, 10)
+    page_obj = paginator.get_page(request.GET.get("page"))
+
+    return render(
+        request,
+        "goals/links.html",
+        {
+            "active_menu": "settings",
+            "goal": goal,
+            "page_obj": page_obj,
+            "linked_ids": set(goal.links.values_list("pk", flat=True)),
+            # Solo lo vinculado a mano, que es lo que se está tocando aquí; el
+            # progreso del objetivo puede llevar además los gastos de su
+            # categoría.
+            "linked_total": goal.links.aggregate(total=Sum("amount"))["total"]
+            or Decimal("0"),
+        },
+    )
+
+
 @login_required
 def settings_index(request):
     return render(request, "settings/index.html", {"active_menu": "settings"})