class Task < ActiveRecord::Base
  set_table_name :task
  set_primary_key :task_id
  include Openmrs

  # Try to find the next task for the patient at the given location
  def self.next_task(location, patient, session_date = Date.today, current_encounter_types = nil)

    tasks                   = self.all(:conditions => ["location = ? OR location = ?", "MNCH Hotline Station", "*"], :order => 'sort_weight ASC')
    current_encounter_types = patient.encounters.find_by_date(session_date).map{|e| e.type.name rescue ''}.uniq rescue [] if current_encounter_types.nil?

    tasks.each do |task|

      # By default, we don't want to skip this task
      skip = false

      # Skip this task if we already run it
      next if task.encounter_type.present? && current_encounter_types.include?(task.encounter_type)
      if task.gender.present?
        #skip this task if patient is not a female adult
        skip = true if (task.gender == "F" && !patient.female_adult?)

        # skip this task if the patient is female_adult
        # because the question is for children of either sex
        skip = true if task.gender == "*" && patient.female_adult?

      end

      # skip if there is neither PREGNANCY STATUS nor CHILD HEALTH SYMPTOMS encounter
      skip = true if (!(current_encounter_types.include?("PREGNANCY STATUS") || current_encounter_types.include?("CHILD HEALTH SYMPTOMS")))

      # return to patient dashboard
      skip = !skip if task.location == "*"
      # We need to skip this task for some reason
      next if skip

      # Nothing failed, this is the next task, lets replace any macros
      task.url = task.url.gsub(/\{patient\}/, "#{patient.patient_id}")
      task.url = task.url.gsub(/\{person\}/, "#{patient.person.person_id rescue nil}")
      task.url = task.url.gsub(/\{location\}/, "#{location.location_id}")

      logger.debug "next_task: #{task.id} - #{task.description}"

      return task
    end
    # if all fails, return to the patient dashboard
    task      = tasks.last
    task.url  = task.url.gsub(/\{patient\}/, "#{patient.patient_id}")
    return task
  end 
  
  def self.validate_task(patient, task, location, session_date = Date.today)
    #return task unless task.has_program_id == 1
    return task if task.encounter_type == 'REGISTRATION'

    #check if the latest HIV program is closed - if yes, the app should redirect the user to update state screen
    if patient.encounters.find_by_encounter_type(EncounterType.find_by_name('ART_INITIAL').id)
      latest_hiv_program = [] ; patient.patient_programs.collect{ | p |next unless p.program_id == 1 ; latest_hiv_program << p } 
      if latest_hiv_program.last.closed?
        task.url = '/patients/programs/{patient}' ; task.encounter_type = 'Program enrolment'
        return task
      end rescue nil
    end

    return task if task.url == "/patients/show/{patient}"

    art_encounters = ['ART_INITIAL','HIV RECEPTION','VITALS','HIV STAGING','ART VISIT','ART ADHERENCE','TREATMENT','DISPENSING']

    #if the following happens - that means the patient is a transfer in and the reception are trying to stage from the transfer in sheet
    if task.encounter_type == 'HIV STAGING' and location.name.match(/RECEPTION/i)
      return task 
    end

    #if the following happens - that means the patient was refered to see a clinician
    if task.description.match(/REFER/i) and location.name.match(/Clinician/i)
      return task 
    end

    if patient.encounters.find_by_encounter_type(EncounterType.find_by_name(art_encounters[0]).id).blank? and task.encounter_type != art_encounters[0]
      task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
      task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[0].gsub(' ','_')}") 
      return task
    elsif patient.encounters.find_by_encounter_type(EncounterType.find_by_name(art_encounters[0]).id).blank? and task.encounter_type == art_encounters[0]
      return task
    end
    
    hiv_reception = Encounter.find(:first,
                                   :conditions =>["patient_id = ? AND encounter_type = ? AND DATE(encounter_datetime) = ?",
                                   patient.id,EncounterType.find_by_name(art_encounters[1]).id,session_date],
                                   :order =>'encounter_datetime DESC')

    if hiv_reception.blank? and task.encounter_type != art_encounters[1]
      task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
      task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[1].gsub(' ','_')}") 
      return task
    elsif hiv_reception.blank? and task.encounter_type == art_encounters[1]
      return task
    end



    reception = Encounter.find(:first,:conditions =>["patient_id = ? AND DATE(encounter_datetime) = ? AND encounter_type = ?",
                        patient.id,session_date,EncounterType.find_by_name(art_encounters[1]).id]).observations.to_s rescue ''
    
    if reception.match(/PATIENT PRESENT FOR CONSULTATION: YES/)
      vitals = Encounter.find(:first,
                              :conditions =>["patient_id = ? AND encounter_type = ? AND DATE(encounter_datetime) = ?",
                              patient.id,EncounterType.find_by_name(art_encounters[2]).id,session_date],
                              :order =>'encounter_datetime DESC')

      if vitals.blank? and task.encounter_type != art_encounters[2]
        task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
        task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[2].gsub(' ','_')}") 
        return task
      elsif vitals.blank? and task.encounter_type == art_encounters[2]
        return task
      end
    end


    if patient.encounters.find_by_encounter_type(EncounterType.find_by_name(art_encounters[3]).id).blank? and task.encounter_type != art_encounters[3]
      task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
      task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[3].gsub(' ','_')}") 
      return task
    elsif patient.encounters.find_by_encounter_type(EncounterType.find_by_name(art_encounters[3]).id).blank? and task.encounter_type == art_encounters[3]
      return task
    end

    art_visit = Encounter.find(:first,
                                   :conditions =>["patient_id = ? AND encounter_type = ? AND DATE(encounter_datetime) = ?",
                                   patient.id,EncounterType.find_by_name(art_encounters[4]).id,session_date],
                                   :order =>'encounter_datetime DESC',:limit => 1)

    if art_visit.blank? and task.encounter_type != art_encounters[4]
      task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
      task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[4].gsub(' ','_')}") 
      return task
    elsif art_visit.blank? and task.encounter_type == art_encounters[4]
      return task
    end

    unless patient.drug_given_before(session_date).blank?
      art_adherance = Encounter.find(:first,
                                     :conditions =>["patient_id = ? AND encounter_type = ? AND DATE(encounter_datetime) = ?",
                                     patient.id,EncounterType.find_by_name(art_encounters[5]).id,session_date],
                                     :order =>'encounter_datetime DESC',:limit => 1)
      
      if art_adherance.blank? and task.encounter_type != art_encounters[5]
        task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
        task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[5].gsub(' ','_')}") 
        return task
      elsif art_adherance.blank? and task.encounter_type == art_encounters[5]
        return task
      end
    end

    if patient.prescribe_arv_this_visit(session_date)
      art_treatment = Encounter.find(:first,
                                     :conditions =>["patient_id = ? AND encounter_type = ? AND DATE(encounter_datetime) = ?",
                                     patient.id,EncounterType.find_by_name(art_encounters[6]).id,session_date],
                                     :order =>'encounter_datetime DESC',:limit => 1)
      if art_treatment.blank? and task.encounter_type != art_encounters[6]
        task.url = "/patients/summary?patient_id={patient}&skipped={encounter_type}" 
        task.url = task.url.gsub(/\{encounter_type\}/, "#{art_encounters[6].gsub(' ','_')}") 
        return task
      elsif art_treatment.blank? and task.encounter_type == art_encounters[6]
        return task
      end
    end

    task
  end 
end