Finished phase006

app/models/maintenance_schedule_status.rb

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+class MaintenanceScheduleStatus
+  UPCOMING_PERCENT = 0.05
+
+  attr_reader :schedule, :latest_entry, :status, :due_odometer, :due_date
+
+  def initialize(schedule, latest_entry, current_odometer:)
+    @schedule = schedule
+    @latest_entry = latest_entry
+    @current_odometer = current_odometer
+    @due_odometer = baseline_odometer + schedule.mileage_interval
+    @due_date = baseline_date + schedule.time_interval.days
+    @status = calculate_status
+  end
+
+  def overdue?
+    status == "overdue"
+  end
+
+  def upcoming?
+    status == "upcoming"
+  end
+
+  def no_history?
+    status == "no_history"
+  end
+
+  def current?
+    status == "current"
+  end
+
+  def status_label
+    case status
+    when "overdue" then "Overdue"
+    when "upcoming" then "Upcoming"
+    when "no_history" then "No history"
+    else "Current"
+    end
+  end
+
+  def reason
+    case status
+    when "overdue"
+      overdue_reasons.join(" and ")
+    when "upcoming"
+      upcoming_reasons.join(" and ")
+    when "no_history"
+      "No matching maintenance entry has been recorded."
+    else
+      "Maintenance is current."
+    end
+  end
+
+  private
+
+  attr_reader :current_odometer
+
+  def calculate_status
+    return "overdue" if mileage_overdue? || time_overdue?
+    return "upcoming" if mileage_upcoming? || time_upcoming?
+    return "no_history" if latest_entry.blank?
+
+    "current"
+  end
+
+  def baseline_odometer
+    latest_entry&.odometer || schedule.baseline_odometer
+  end
+
+  def baseline_date
+    latest_entry&.date || schedule.baseline_date
+  end
+
+  def mileage_overdue?
+    current_odometer >= due_odometer
+  end
+
+  def time_overdue?
+    Date.current >= due_date
+  end
+
+  def mileage_upcoming?
+    current_odometer >= due_odometer - mileage_upcoming_window
+  end
+
+  def time_upcoming?
+    Date.current >= due_date - time_upcoming_window.days
+  end
+
+  def mileage_upcoming_window
+    (schedule.mileage_interval * UPCOMING_PERCENT).ceil
+  end
+
+  def time_upcoming_window
+    (schedule.time_interval * UPCOMING_PERCENT).ceil
+  end
+
+  def overdue_reasons
+    reasons = []
+    reasons << "mileage interval reached" if mileage_overdue?
+    reasons << "time interval reached" if time_overdue?
+    reasons
+  end
+
+  def upcoming_reasons
+    reasons = []
+    reasons << "within #{mileage_upcoming_window} miles of due odometer" if mileage_upcoming?
+    reasons << "within #{time_upcoming_window} days of due date" if time_upcoming?
+    reasons
+  end
+end