CLASS {{p}}care_visit_checker DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    TYPES:
      BEGIN OF ty_visit,
        visit_id   TYPE string,
        client_id  TYPE string,
        carer_id   TYPE string,
        start_hour TYPE i,
        end_hour   TYPE i,
      END OF ty_visit,
      tt_visit TYPE STANDARD TABLE OF ty_visit WITH EMPTY KEY.

    METHODS check_visit
      IMPORTING is_visit TYPE ty_visit
                it_plan  TYPE tt_visit
      RAISING   {{p}}cx_care_visit.

  PRIVATE SECTION.
    CONSTANTS:
      c_day_start TYPE i VALUE 7,
      c_day_end   TYPE i VALUE 20,
      c_max_hours TYPE i VALUE 4.

    METHODS validate_fields
      IMPORTING is_visit TYPE ty_visit
      RAISING   {{p}}cx_care_visit.

    METHODS validate_times
      IMPORTING is_visit TYPE ty_visit
      RAISING   {{p}}cx_care_visit.

    METHODS has_carer_overlap
      IMPORTING is_visit          TYPE ty_visit
                it_plan           TYPE tt_visit
      RETURNING VALUE(rv_overlap) TYPE abap_bool.

    METHODS has_client_overlap
      IMPORTING is_visit          TYPE ty_visit
                it_plan           TYPE tt_visit
      RETURNING VALUE(rv_overlap) TYPE abap_bool.

    METHODS periods_overlap
      IMPORTING is_visit          TYPE ty_visit
                is_other          TYPE ty_visit
      RETURNING VALUE(rv_overlap) TYPE abap_bool.

    METHODS raise_reason
      IMPORTING iv_reason   TYPE {{p}}if_care_reason=>ty_reason
                iv_visit_id TYPE string
      RAISING   {{p}}cx_care_visit.
ENDCLASS.


CLASS {{p}}care_visit_checker IMPLEMENTATION.
  METHOD check_visit.
    validate_fields( is_visit ).
    validate_times( is_visit ).

    IF has_carer_overlap( is_visit = is_visit it_plan = it_plan ).
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-carer_overlap
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.

    IF has_client_overlap( is_visit = is_visit it_plan = it_plan ).
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-client_overlap
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.
  ENDMETHOD.

  METHOD validate_fields.
    IF is_visit-visit_id IS INITIAL.
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-no_visit_id
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.

    IF is_visit-client_id IS INITIAL.
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-no_client
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.

    IF is_visit-carer_id IS INITIAL.
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-no_carer
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.
  ENDMETHOD.

  METHOD validate_times.
    IF is_visit-start_hour < c_day_start OR is_visit-end_hour > c_day_end.
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-outside_hours
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.

    IF is_visit-end_hour <= is_visit-start_hour.
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-bad_duration
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.

    IF is_visit-end_hour - is_visit-start_hour > c_max_hours.
      raise_reason( iv_reason   = {{p}}if_care_reason=>c_reason-too_long
                    iv_visit_id = is_visit-visit_id ).
    ENDIF.
  ENDMETHOD.

  METHOD has_carer_overlap.
    LOOP AT it_plan INTO DATA(ls_plan) WHERE carer_id = is_visit-carer_id.
      IF periods_overlap( is_visit = is_visit is_other = ls_plan ).
        rv_overlap = abap_true.
        RETURN.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD has_client_overlap.
    LOOP AT it_plan INTO DATA(ls_plan) WHERE client_id = is_visit-client_id.
      IF periods_overlap( is_visit = is_visit is_other = ls_plan ).
        rv_overlap = abap_true.
        RETURN.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD periods_overlap.
    rv_overlap = xsdbool( is_visit-start_hour < is_other-end_hour
                      AND is_other-start_hour < is_visit-end_hour ).
  ENDMETHOD.

  METHOD raise_reason.
    RAISE EXCEPTION TYPE {{p}}cx_care_visit
      EXPORTING
        iv_reason   = iv_reason
        iv_visit_id = iv_visit_id.
  ENDMETHOD.
ENDCLASS.