feat: allow custom target dates per target grade (doubtfire-lms#575)

* feat: allow custom target dates per target grade

* refactor: rename to target dates for clarity

* refactor: throw error if target date is before start date

* chore: require flexible dates to be enabled

Author: b0ink

app/api/entities/task_definition_entity.rb

@@ -19,6 +19,10 @@ def staff?(my_role)
       expose :target_date
       expose :due_date
       expose :start_date
+      # expose :p_target_date, expose_nil: false
+      expose :c_target_date, expose_nil: false
+      expose :d_target_date, expose_nil: false
+      expose :hd_target_date, expose_nil: false
     end
 
     expose :upload_requirements, expose_nil: false do |task_definition, options|

app/api/task_definitions_api.rb

@@ -136,6 +136,10 @@ class TaskDefinitionsApi < Grape::API
       optional :assess_in_portfolio_only, type: Boolean,  desc: 'Whether a task can only be signed off during portfolio assessment'
       optional :use_resources_for_jplag_base_code, type: Boolean, desc: 'Include the common base code from task resources for JPlag comparisons'
       optional :lock_assessments_to_tutorial_stream, type: Boolean, desc: 'Only allow tutors in this tutorial stream to assess this task'
+      # optional :p_target_date, type: Date, desc: 'Pass due date override'
+      optional :c_target_date, type: Date, desc: 'Credit due date override'
+      optional :d_target_date, type: Date, desc: 'Distinction due date override'
+      optional :hd_target_date, type: Date, desc: 'High Distinction due date override'
     end
   end
   put '/units/:unit_id/task_definitions/:id' do
@@ -146,6 +150,10 @@ class TaskDefinitionsApi < Grape::API
       error!({ error: 'Not authorised to create a task definition of this unit' }, 403)
     end
 
+    # strip these out so TaskDefinition#update! never sees them
+    grade_due_overrides = params[:task_def].slice('p_target_date', 'c_target_date', 'd_target_date', 'hd_target_date')
+    params[:task_def].except!('p_target_date', 'c_target_date', 'd_target_date', 'hd_target_date')
+
     task_params = ActionController::Parameters.new(params)
                                               .require(:task_def)
                                               .permit(
@@ -218,6 +226,25 @@ class TaskDefinitionsApi < Grape::API
       end
     end
 
+    grade_map = { 'c_target_date' => 1, 'd_target_date' => 2, 'hd_target_date' => 3 }
+
+    grade_due_overrides.each do |key, date|
+      next if date.blank?
+      next unless grade_map.key?(key) # skip p_target_date
+
+      if task_def.start_date > date
+        error!({ error: 'Target date cannot be earlier than start date' }, 400)
+      end
+
+      unless unit.allow_flexible_dates
+        error!({ error: 'This unit must have Allow Flexible Dates enabled to modify target dates per grade' }, 403)
+      end
+
+      TaskDefinitionGradeDueDate
+        .find_or_initialize_by(task_definition: task_def, target_grade: grade_map[key])
+        .update!(target_due_date: date)
+    end
+
     present task_def, with: Entities::TaskDefinitionEntity, my_role: unit.role_for(current_user)
   end
 

app/models/task_definition.rb

@@ -81,6 +81,10 @@ def self.permissions
   has_many :task_prerequisites, dependent: :destroy
   has_many :prerequisites, through: :task_prerequisites, source: :prerequisite
 
+  has_many :grade_due_dates,
+           class_name: "TaskDefinitionGradeDueDate",
+           dependent: :destroy
+
   has_many :discussion_prompts, dependent: :destroy
 
   serialize :upload_requirements, coder: JSON
@@ -109,6 +113,22 @@ def self.permissions
   include TaskDefinitionTiiModule
   include TaskDefinitionSimilarityModule
 
+  # def p_target_date
+  #   due_date
+  # end
+
+  def c_target_date
+    grade_due_dates.find { |g| g.target_grade == 1 }&.target_due_date
+  end
+
+  def d_target_date
+    grade_due_dates.find { |g| g.target_grade == 2 }&.target_due_date
+  end
+
+  def hd_target_date
+    grade_due_dates.find { |g| g.target_grade == 3 }&.target_due_date
+  end
+
   def unit_must_be_same
     if unit.present? and tutorial_stream.present? and not unit.eql? tutorial_stream.unit
       errors.add(:unit, "should be same as the unit in the associated tutorial stream")

app/models/task_definition_grade_due_date.rb

@@ -0,0 +1,3 @@
+class TaskDefinitionGradeDueDate < ApplicationRecord
+  belongs_to :task_definition
+end

db/migrate/20260222043513_create_task_definition_grade_due_dates.rb

@@ -0,0 +1,16 @@
+class CreateTaskDefinitionGradeDueDates < ActiveRecord::Migration[8.0]
+  def change
+    create_table :task_definition_grade_due_dates do |t|
+      t.references :task_definition, null: false
+      t.integer :target_grade, null: false
+      t.datetime :target_due_date, null: false
+
+      t.timestamps
+    end
+
+    add_index :task_definition_grade_due_dates,
+              [:task_definition_id, :target_grade],
+              unique: true,
+              name: "idx_td_grade_due_unique"
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_01_13_033152) do
+ActiveRecord::Schema[8.0].define(version: 2026_02_22_043513) do
   create_table "activity_types", charset: "utf8mb4", collation: "utf8mb4_general_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "abbreviation", null: false
@@ -396,6 +396,16 @@
     t.index ["user_id"], name: "index_task_comments_on_user_id"
   end
 
+  create_table "task_definition_grade_due_dates", charset: "utf8mb4", collation: "utf8mb4_general_ci", force: :cascade do |t|
+    t.bigint "task_definition_id", null: false
+    t.integer "target_grade", null: false
+    t.datetime "target_due_date", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["task_definition_id", "target_grade"], name: "idx_td_grade_due_unique", unique: true
+    t.index ["task_definition_id"], name: "index_task_definition_grade_due_dates_on_task_definition_id"
+  end
+
   create_table "task_definitions", charset: "utf8mb4", collation: "utf8mb4_general_ci", force: :cascade do |t|
     t.bigint "unit_id"
     t.string "name"

test/factories/task_definition_grade_due_dates.rb

@@ -0,0 +1,5 @@
+FactoryBot.define do
+  factory :task_definition_grade_due_date do
+    
+  end
+end

test/models/task_definition_grade_due_date_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+describe TaskDefinitionGradeDueDate do
+  # it "does a thing" do
+  #   value(1+1).must_equal 2
+  # end
+end