Task Prioritisation Recommender Service

app/api/api_root.rb

@@ -105,6 +105,7 @@ class ApiRoot < Grape::API
   mount MarkingSessionsApi
   mount DiscussionPromptsApi
   mount OverseerStepsApi
+  mount TaskPrioritizationApi
 
   mount Feedback::FeedbackChipApi
 

app/api/task_prioritization_api.rb

@@ -0,0 +1,108 @@
+require 'grape'
+
+class TaskPrioritizationApi < Grape::API
+  helpers AuthenticationHelpers
+  helpers AuthorisationHelpers
+  helpers DbHelpers
+
+  before do
+    authenticated?
+  end
+
+  desc 'Get prioritized task recommendations for a student',
+       detail: 'Returns a ranked list of tasks across all active enrolled units based on deadline, effort, and workload scoring.'
+
+  get '/tasks/recommended' do
+    tasks = fetch_active_tasks
+    workload_score = calculate_workload_score(tasks)
+
+    results = tasks.map { |task| build_task_response(task, workload_score) }
+
+    sorted = results.sort_by { |t| -t[:priority_score] }
+    present sorted
+  rescue StandardError => e
+    Rails.logger.error "TaskPrioritizationApi Error: #{e.message}"
+    Rails.logger.error e.backtrace.join("\n")
+    error!({ error: 'An unexpected error occurred' }, 500)
+  end
+
+  helpers do
+    # Fetch Active Tasks
+    def fetch_active_tasks
+      Task
+        .joins(project: :unit)
+        .joins(:task_definition)
+        .where(projects: { user_id: current_user&.id, enrolled: true })
+        .where(units: { active: true })
+        .where.not(task_status_id: 2) # completed
+    end
+
+    # Build Response Object
+    def build_task_response(task, workload_score)
+      deadline = deadline_score(task)
+      effort   = effort_score(task)
+
+      priority = (0.5 * deadline) + (0.3 * effort) + (0.2 * workload_score)
+
+      {
+        task_id: task.id,
+        task_name: task.task_definition.name,
+        unit_id: task.project.unit_id,
+        priority_score: priority.round(2)
+      }
+    end
+
+    # Deadline Score
+    def deadline_score(task)
+      due_date = task.task_definition.due_date
+      return 0 unless due_date
+
+      days_left = (due_date.to_date - Time.zone.today).to_i
+
+      return 100 if days_left <= 1
+      return 80  if days_left <= 3
+      return 60  if days_left <= 7
+      return 40  if days_left <= 14
+
+      20
+    end
+
+    # Effort Score (Temporary - to be replaced by AI Task Prioritisation Service)
+    def effort_score(task)
+      weighting = task.task_definition.weighting.to_f
+
+      return 30 if weighting <= 10
+      return 50 if weighting <= 20
+      return 70 if weighting <= 40
+
+      90
+    end
+
+    # Workload Score
+    def calculate_workload_score(tasks)
+      total_tasks = tasks.count
+
+      avg_target_grade = Project
+                         .where(user_id: current_user&.id, enrolled: true)
+                         .average(:target_grade)
+                         .to_f
+
+      task_pressure_score =
+        case total_tasks
+        when 0..4 then 30
+        when 5..9 then 60
+        else 90
+        end
+
+      target_grade_score =
+        case avg_target_grade.round
+        when 3 then 90   # High Distinction
+        when 2 then 75   # Distinction
+        when 1 then 60   # Credit
+        else 40          # Pass
+        end
+
+      ((0.6 * task_pressure_score) + (0.4 * target_grade_score)).round
+    end
+  end
+end