# frozen_string_literal: true

module MalawiHivProgramReports
  module Pepfar
    class TxMl
      attr_reader :start_date, :end_date, :location

      include Utils
      include MalawiHivProgramReports::Utils::CommonSqlQueryUtils
      include MalawiHivProgramReports::Adapters::Moh::Custom

      def initialize(start_date:, end_date:, **kwargs)
        @start_date = start_date.to_date.strftime('%Y-%m-%d 00:00:00')
        @end_date = end_date.to_date.strftime('%Y-%m-%d 23:59:59')
        @occupation = kwargs[:occupation]
        @location = kwargs[:location]
        @adapter = ActiveRecord::Base.connection.adapter_name.downcase
      end

      def find_report
        tx_ml
      end

      private

      def tx_ml
        data = {}
        tx_curr = potential_tx_ml_clients
        tx_new  = new_potential_tx_ml_clients
        patient_ids = []
        earliest_start_dates = {}

        (tx_curr || []).each do |pat|
          patient_id = pat['patient_id'].to_i
          patient_ids << patient_id
          earliest_start_dates[patient_id] = begin
            pat['earliest_start_date'].to_date
          rescue StandardError
            pat['date_enrolled'].to_date
          end
        end

        (tx_new || []).each do |pat|
          patient_id = pat['patient_id'].to_i
          patient_ids << patient_id
          patient_ids = patient_ids.uniq
          earliest_start_dates[patient_id] = begin
            pat['earliest_start_date'].to_date
          rescue StandardError
            pat['date_enrolled'].to_date
          end
          patient_ids << pat['patient_id']
          patient_ids = patient_ids.uniq
        end

        return [] if patient_ids.blank?

        filtered_patients = ActiveRecord::Base.connection.select_all <<~SQL
          SELECT
            p.person_id patient_id, birthdate, gender,
            #{function_manager(function: 'pepfar_patient_outcome', location: @location, args: "p.person_id::int, '#{end_date.to_date}'::date, #{@location}::int")} outcome,
            #{function_manager(function: 'disaggregated_age_group', location: @location, args: "p.birthdate::date, '#{end_date.to_date}::date'")} age_group
          FROM person p
          WHERE #{in_manager(column: 'p.person_id', values: patient_ids)}
          #{site_manager(operator: 'AND', column: 'p.site_id', location: @location)}
          GROUP BY p.person_id #{group_by_columns('p.birthdate, p.gender')}
        SQL

        (filtered_patients || []).each do |pat|
          outcome = pat['outcome']
          next if outcome == 'On antiretrovirals'

          patient_id = pat['patient_id'].to_i
          gender = begin
            pat['gender'].first.upcase
          rescue StandardError
            'Unknown'
          end
          age_group = pat['age_group']

          if data[age_group].blank?
            data[age_group] = {}
            data[age_group][gender] = [[], [], [], [], [], []]
          elsif data[age_group][gender].blank?
            data[age_group][gender] = [[], [], [], [], [], []]
          end

          case outcome
          when 'Defaulted'
            def_months = defaulter_period(patient_id, earliest_start_dates[patient_id])
            if def_months < 3
              data[age_group][gender][1] << patient_id
            elsif def_months <= 5
              data[age_group][gender][2] << patient_id
            elsif def_months > 5
              data[age_group][gender][3] << patient_id
            end
          when 'Patient died'
            data[age_group][gender][0] << patient_id
          when /Stopped/i
            data[age_group][gender][5] << patient_id
          when 'Patient transferred out'
            data[age_group][gender][4] << patient_id
          end
        rescue StandardError => e
          Rails.logger.error(e.message)
        end

        data
      end

      def potential_tx_ml_clients
        ActiveRecord::Base.connection.select_all <<~SQL
          SELECT
            p.patient_id AS patient_id,
            pe.birthdate,
            pe.gender,
            #{function_manager(function: 'patient_date_enrolled', location: @location, args: "p.patient_id::int, #{@location}::int")} AS date_enrolled,
            #{function_manager(function: 'date_antiretrovirals_started', location: @location, args: "p.patient_id::int, MIN(s.start_date)::date, #{@location}::int")} AS earliest_start_date
          FROM patient_program p
            INNER JOIN person pe ON pe.person_id = p.patient_id AND pe.voided = 0
            #{site_manager(operator: 'AND', column: 'pe.site_id', location: @location)}
            INNER JOIN patient_state s ON p.patient_program_id = s.patient_program_id AND s.voided = 0 AND s.state = 7
            #{site_manager(operator: 'AND', column: 's.site_id', location: @location)}
            LEFT JOIN (#{current_occupation_query}) a ON a.person_id = p.patient_id
            WHERE p.program_id = 1 #{%w[Military Civilian].include?(@occupation) ? 'AND' : ''} #{occupation_filter(occupation: @occupation, field_name: 'value', table_name: 'a', include_clause: false)}
              AND DATE(s.start_date) < '#{start_date.to_date}'
              #{site_manager(operator: 'AND', column: 'p.site_id', location: @location)}
              AND #{function_manager(function: 'pepfar_patient_outcome', location: @location, args: "p.patient_id::int, '#{start_date.to_date}'::date, #{@location}::int")} = 'On antiretrovirals'
              AND pe.person_id NOT IN (#{drug_refills_and_external_consultation_list})
            GROUP BY p.patient_id
            HAVING date_enrolled IS NOT NULL AND DATE(date_enrolled) < '#{start_date.to_date}';
        SQL
      end

      def new_potential_tx_ml_clients
        ActiveRecord::Base.connection.select_all <<~SQL
          SELECT
            p.patient_id AS patient_id,
            pe.birthdate,
            pe.gender,
            #{function_manager(function: 'patient_date_enrolled', location: @location, args: "p.patient_id::int, #{@location}::int")} AS date_enrolled,
            #{function_manager(function: 'date_antiretrovirals_started', location: @location, args: "p.patient_id::int, MIN(s.start_date)::date, #{@location}::int")} AS earliest_start_date
          FROM patient_program p
            INNER JOIN person pe ON pe.person_id = p.patient_id AND pe.voided = 0
            #{site_manager(operator: 'AND', column: 'pe.site_id', location: @location)}
            INNER JOIN patient_state s ON p.patient_program_id = s.patient_program_id AND s.voided = 0 AND s.state = 7
            #{site_manager(operator: 'AND', column: 's.site_id', location: @location)}
            LEFT JOIN (#{current_occupation_query}) a ON a.person_id = p.patient_id
            WHERE p.program_id = 1 #{%w[Military Civilian].include?(@occupation) ? 'AND' : ''} #{occupation_filter(occupation: @occupation, field_name: 'value', table_name: 'a', include_clause: false)}
              AND DATE(s.start_date) BETWEEN DATE('#{start_date}') AND DATE('#{end_date}')
              AND pe.person_id NOT IN (#{drug_refills_and_external_consultation_list})
            #{site_manager(operator: 'AND', column: 'p.site_id', location: @location)}
            GROUP BY p.patient_id
            HAVING date_enrolled IS NOT NULL AND date_enrolled BETWEEN DATE('#{start_date}') AND DATE('#{end_date}');
        SQL
      end

      def defaulter_period(patient_id, earliest_start_date)
        defaulter_date = ActiveRecord::Base.connection.select_one <<~SQL
          SELECT #{function_manager(function: 'current_pepfar_defaulter_date', location: @location, args: "#{patient_id}::int, '#{end_date}'::date, #{@location}::int")}
        SQL

        defaulter_date = begin
          defaulter_date['def_date'].to_date
        rescue StandardError
          end_date.to_date
        end

        raise 'Defaulted outside the reporting period' if defaulter_date > end_date.to_date
        raise 'Defaulted outside the reporting period' if defaulter_date < start_date.to_date

        days_gone = ActiveRecord::Base.connection.select_one <<~SQL
          SELECT TIMESTAMPDIFF(MONTH, DATE('#{earliest_start_date}'), DATE('#{defaulter_date}')) months;
        SQL

        days_gone['months'].to_i
      end
    end
  end
end