create IndividualBudget model and migration

fix #351

scipost_django/finances/migrations/0048_subsidy_individual_budget_alter_subsidy_subsidy_type.py

+# Generated by Django 4.2.15 on 2024-11-29 12:17
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("finances", "0047_subsidycollective"),
+        ("funders", "0016_individualbudget_and_more"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="subsidy",
+            name="subsidy_type",
+            field=models.CharField(
+                choices=[
+                    ("sponsorshipagreement", "Sponsorship Agreement"),
+                    ("incidentalgrant", "Incidental Grant"),
+                    ("developmentgrant", "Development Grant"),
+                    ("collaborationagreement", "Collaboration Agreement"),
+                    ("coordinationsupportaction", "Coordination and Support Action"),
+                    ("donation", "Donation"),
+                    ("individualbudget", "Individual Budget"),
+                ],
+                max_length=256,
+            ),
+        ),
+        migrations.AddField(
+            model_name="subsidy",
+            name="individual_budget",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.SET_NULL,
+                related_name="subsidies_funded",
+                to="funders.individualbudget",
+            ),
+        ),
+    ]

scipost_django/funders/admin.py

@@ -4,7 +4,9 @@ __license__ = "AGPL v3"
 
 from django.contrib import admin
 
-from .models import Funder, Grant
+from finances.admin import SubsidyInline
+
+from .models import Funder, Grant, IndividualBudget
 
 
 @admin.register(Funder)
@@ -21,8 +23,6 @@ class FunderAdmin(admin.ModelAdmin):
     ]
 
 
-
-
 @admin.register(Grant)
 class GrantAdmin(admin.ModelAdmin):
     search_fields = [
@@ -37,3 +37,18 @@ class GrantAdmin(admin.ModelAdmin):
     ]
 
 
+@admin.register(IndividualBudget)
+class IndividualBudgetAdmin(admin.ModelAdmin):
+    search_fields = [
+        "organization__name",
+        "organization__acronym",
+        "holder__first_name",
+        "holder__last_name",
+    ]
+    autocomplete_fields = [
+        "organization",
+        "holder",
+    ]
+    inlines = [
+        SubsidyInline,
+    ]

scipost_django/funders/migrations/0016_individualbudget_and_more.py

+# Generated by Django 4.2.15 on 2024-12-02 12:26
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("organizations", "0024_contactperson_info_source"),
+        ("profiles", "0043_alter_profile_first_name_original_and_more"),
+        ("funders", "0015_alter_grant_funder_alter_grant_recipient"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="IndividualBudget",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("description", models.TextField(blank=True)),
+                (
+                    "budget_number",
+                    models.CharField(blank=True, max_length=64, null=True),
+                ),
+                ("fundref_id", models.CharField(blank=True, max_length=64, null=True)),
+                (
+                    "holder",
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        to="profiles.profile",
+                    ),
+                ),
+                (
+                    "organization",
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        to="organizations.organization",
+                    ),
+                ),
+            ],
+            options={
+                "ordering": ["organization", "holder"],
+                "default_related_name": "individual_budgets",
+            },
+        ),
+        migrations.AddConstraint(
+            model_name="individualbudget",
+            constraint=models.UniqueConstraint(
+                fields=("organization", "budget_number"),
+                name="unique_organization_budget_number",
+                violation_error_message="This organization already has a budget with this number.",
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name="individualbudget",
+            constraint=models.CheckConstraint(
+                check=models.Q(("holder", None), ("organization", None), _negated=True),
+                name="organization_or_holder_must_be_set",
+                violation_error_message="Either an organization or a holder must be set for the budget.",
+            ),
+        ),
+    ]

scipost_django/funders/models.py

@@ -4,9 +4,13 @@ __license__ = "AGPL v3"
 
 from django.db import models
 from django.db.models import Q
+from django.forms import ValidationError
 from django.urls import reverse
 
 from journals.models import Publication
+from organizations.models import Organization
+from profiles.models import Profile
+from scipost.models import Contributor
 
 from .managers import FunderQuerySet
 
@@ -78,3 +82,51 @@ class Grant(models.Model):
         if self.further_details:
             grantstring += " [%s]" % self.further_details
         return grantstring
+
+
+class IndividualBudget(models.Model):
+    """
+    Generic structure of a budget from an Organization given to a single individual.
+    The funding source of individual subsidies.
+    """
+
+    required_css_class = "required-asterisk"
+
+    description = models.TextField(blank=True)
+    organization = models.ForeignKey["Organization"](
+        "organizations.Organization", on_delete=models.CASCADE, blank=True, null=True
+    )
+    holder = models.ForeignKey["Profile"](
+        "profiles.Profile", on_delete=models.CASCADE, blank=True, null=True
+    )
+    budget_number = models.CharField(max_length=64, blank=True, null=True)
+    fundref_id = models.CharField(max_length=64, blank=True, null=True)
+
+    class Meta:
+        default_related_name = "individual_budgets"
+        ordering = ["organization", "holder"]
+        constraints = [
+            models.UniqueConstraint(
+                fields=["organization", "budget_number"],
+                name="unique_organization_budget_number",
+                violation_error_message="This organization already has a budget with this number.",
+            ),
+            models.CheckConstraint(
+                check=~models.Q(organization=None, holder=None),
+                name="organization_or_holder_must_be_set",
+                violation_error_message="Either an organization or a holder must be set for the budget.",
+            ),
+        ]
+
+    @property
+    def name(self):
+        if self.budget_number:
+            return f"Budget {self.budget_number}"
+        return "Unnamed budget"
+
+    def __str__(self):
+        str_repr = f"{self.name} from {self.organization}"
+        if self.holder:
+            str_repr += f" to {self.holder}"
+
+        return str_repr