Codeunit 4691 Recurrence Schedule Impl. in 24

// ------------------------------------------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See License.txt in the project root for license information.
// ------------------------------------------------------------------------------------------------

namespace System.DateTime;

using System.Utilities;

codeunit 4691 "Recurrence Schedule Impl."
{
    Access = Internal;
    InherentEntitlements = X;
    InherentPermissions = X;
    Permissions = tabledata Date = r,
                  tabledata "Recurrence Schedule" = rim;

    var
        MinDateTime: DateTime;
        MinDateTimeSet: Boolean;
        RecurrenceDisplayTxt: Label 'Recurring %1 starting %2', Comment = '%1 = it recurrence pattern like Daily, Weekly, Monthly..., %2 = The date the recurrence starts';
        RecurrenceMaximumCalculateLimitTxt: Label 'Exceeded maximum calculation limit for recurrence. Change start date to be today.';

    procedure SetMinDateTime(DateTime: DateTime)
    begin
        MinDateTime := DateTime;
        MinDateTimeSet := true;
    end;

    local procedure GetMinDateTime(): DateTime
    begin
        if MinDateTimeSet then
            exit(MinDateTime);
        exit(CurrentDateTime());
    end;

    local procedure IsAfterOrEqualToMinDateTime(RecurrenceSchedule: Record "Recurrence Schedule"; NextDate: Date): Boolean
    begin
        if NextDate = 0D then
            exit(true);
        exit(CreateDateTime(NextDate, RecurrenceSchedule."Start Time") >= GetMinDateTime());
    end;

    procedure CalculateNextOccurrence(RecurrenceID: Guid; LastOccurrence: DateTime): DateTime
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        NextDate: Date;
        Counter: Integer;
    begin
        RecurrenceSchedule.Get(RecurrenceID);
        NextDate := DT2Date(LastOccurrence);

        repeat
            case RecurrenceSchedule.Pattern of
                RecurrenceSchedule.Pattern::Daily:
                    NextDate := CalculateDaily(RecurrenceSchedule, NextDate);
                RecurrenceSchedule.Pattern::Weekly:
                    NextDate := CalculateWeekly(RecurrenceSchedule, NextDate);
                RecurrenceSchedule.Pattern::Monthly:
                    NextDate := CalculateMonthly(RecurrenceSchedule, NextDate);
                RecurrenceSchedule.Pattern::Yearly:
                    NextDate := CalculateYearly(RecurrenceSchedule, NextDate);
            end;

            Counter := Counter + 1;
            if Counter >= 500 then
                Error(RecurrenceMaximumCalculateLimitTxt);
        until IsAfterOrEqualToMinDateTime(RecurrenceSchedule, NextDate);

        if NextDate = 0D then
            exit(0DT);

        exit(CheckForEndDateTime(RecurrenceSchedule, CreateDateTime(NextDate, RecurrenceSchedule."Start Time")));
    end;

    local procedure CalculateDaily(RecurrenceSchedule: Record "Recurrence Schedule"; LastOccurrence: Date): Date
    var
        NextDate: Date;
    begin
        if LastOccurrence = 0D then
            NextDate := RecurrenceSchedule."Start Date"
        else
            NextDate := LastOccurrence + RecurrenceSchedule."Recurs Every";

        exit(NextDate);
    end;

    local procedure CalculateWeekly(RecurrenceSchedule: Record "Recurrence Schedule"; LastOccurrence: Date): Date
    var
        NextWeekDay: Integer;
        NextDate: Date;
        NextWeekDayDateFormulaLbl: Label '<-CW+%1D>', Comment = '%1 - Next week day in integer', Locked = true;
        NextWeekDayDateFormulaPassedLbl: Label '<-CW+%1D+%2W>', Comment = 'If the weekday has passed, this formula is used instead. %1 - Next week day in integer, %2 - Occurs every number of weeks', Locked = true;
    begin
        if (RecurrenceSchedule."Start Date" = 0D) or (not AnyWeekDaysSelected(RecurrenceSchedule)) then
            exit(0D);

        if LastOccurrence = 0D then begin
            LastOccurrence := RecurrenceSchedule."Start Date";
            NextWeekDay := GetNextWeekDay(RecurrenceSchedule, Date2DWY(LastOccurrence, 1) - 1)
        end else
            NextWeekDay := GetNextWeekDay(RecurrenceSchedule, Date2DWY(LastOccurrence, 1));

        if NextWeekDay > 0 then
            NextDate := CalcDate(StrSubstNo(NextWeekDayDateFormulaLbl, NextWeekDay - 1), LastOccurrence)
        else
            NextDate := CalcDate(StrSubstNo(NextWeekDayDateFormulaPassedLbl, GetNextWeekDay(RecurrenceSchedule, 0) - 1, RecurrenceSchedule."Recurs Every"), LastOccurrence);

        exit(NextDate);
    end;

    local procedure AnyWeekDaysSelected(RecurrenceSchedule: Record "Recurrence Schedule"): Boolean
    begin
        exit(
              RecurrenceSchedule."Recurs on Monday" or
              RecurrenceSchedule."Recurs on Tuesday" or
              RecurrenceSchedule."Recurs on Wednesday" or
              RecurrenceSchedule."Recurs on Thursday" or
              RecurrenceSchedule."Recurs on Friday" or
              RecurrenceSchedule."Recurs on Saturday" or
              RecurrenceSchedule."Recurs on Sunday");
    end;

    local procedure GetNextWeekDay(RecurrenceSchedule: Record "Recurrence Schedule"; CurrentWeekDay: Integer): Integer
    begin
        if CurrentWeekDay < 0 then
            CurrentWeekDay := 0;

        repeat
            case CurrentWeekDay of
                0:
                    if RecurrenceSchedule."Recurs on Monday" then
                        exit(CurrentWeekDay + 1);
                1:
                    if RecurrenceSchedule."Recurs on Tuesday" then
                        exit(CurrentWeekDay + 1);
                2:
                    if RecurrenceSchedule."Recurs on Wednesday" then
                        exit(CurrentWeekDay + 1);
                3:
                    if RecurrenceSchedule."Recurs on Thursday" then
                        exit(CurrentWeekDay + 1);
                4:
                    if RecurrenceSchedule."Recurs on Friday" then
                        exit(CurrentWeekDay + 1);
                5:
                    if RecurrenceSchedule."Recurs on Saturday" then
                        exit(CurrentWeekDay + 1);
                6:
                    if RecurrenceSchedule."Recurs on Sunday" then
                        exit(CurrentWeekDay + 1);
            end;
            CurrentWeekDay += 1;
        until CurrentWeekDay >= 7;

        exit(0);
    end;

    local procedure CalculateMonthly(RecurrenceSchedule: Record "Recurrence Schedule"; LastOccurrence: Date): Date
    var
        MonthlyPattern: Enum "Recurrence - Monthly Pattern";
        MonthlySpecificDayFirstTimeDateFormulaLbl: Label '<-CM+%1D>', Comment = '%1 - Occurence day', Locked = true;
        MonthlySpecificDayDateFormulaLbl: Label '<-CM+%1M+%2D>', Comment = '%1 - occurs every number of months, %2 - Occurence day', Locked = true;
        MonthlyByWeekdayDateFormulaLbl: Label '<-CM+%1M>', Comment = '%1 - Occurs every number of months', Locked = true;
    begin
        if LastOccurrence = 0D then begin
            case RecurrenceSchedule."Monthly Pattern" of
                MonthlyPattern::"By Weekday":
                    exit(CalculateMonthlyByWeekDay(RecurrenceSchedule, RecurrenceSchedule."Start Date"));
                MonthlyPattern::"Specific Day":
                    if Date2DMY(RecurrenceSchedule."Start Date", 1) <= RecurrenceSchedule."Recurs on Day" then
                        exit(CalcDate(StrSubstNo(MonthlySpecificDayFirstTimeDateFormulaLbl, RecurrenceSchedule."Recurs on Day" - 1), RecurrenceSchedule."Start Date"));
            end;

            LastOccurrence := RecurrenceSchedule."Start Date";
        end;

        case RecurrenceSchedule."Monthly Pattern" of
            MonthlyPattern::"By Weekday":
                exit(CalculateMonthlyByWeekDay(RecurrenceSchedule, CalcDate(StrSubstNo(MonthlyByWeekdayDateFormulaLbl, RecurrenceSchedule."Recurs Every"), LastOccurrence)));
            MonthlyPattern::"Specific Day":
                exit(CalcDate(StrSubstNo(MonthlySpecificDayDateFormulaLbl, RecurrenceSchedule."Recurs Every", RecurrenceSchedule."Recurs on Day" - 1), LastOccurrence));
        end
    end;

    local procedure CalculateMonthlyByWeekDay(RecurrenceSchedule: Record "Recurrence Schedule"; LastOccurrence: Date): Date
    var
        DayOfWeek: Enum "Recurrence - Day of Week";
    begin
        case RecurrenceSchedule.Weekday of
            DayOfWeek::Day:
                exit(FindDayInMonth(LastOccurrence, RecurrenceSchedule."Ordinal Recurrence No.", DayOfWeek::Monday.AsInteger(), DayOfWeek::Sunday.AsInteger()));
            DayOfWeek::Weekday:
                exit(FindDayInMonth(LastOccurrence, RecurrenceSchedule."Ordinal Recurrence No.", DayOfWeek::Monday.AsInteger(), DayOfWeek::Friday.AsInteger()));
            DayOfWeek::"Weekend Day":
                exit(FindDayInMonth(LastOccurrence, RecurrenceSchedule."Ordinal Recurrence No.", DayOfWeek::Saturday.AsInteger(), DayOfWeek::Sunday.AsInteger()))
            else
                exit(FindDayInMonth(LastOccurrence, RecurrenceSchedule."Ordinal Recurrence No.",
                    RecurrenceSchedule.Weekday.AsInteger(), RecurrenceSchedule.Weekday.AsInteger()))
        end;
    end;

    local procedure FindDayInMonth(CurrDate: Date; WhatToFind: Enum "Recurrence - Ordinal No."; StartWeekDay: Integer; EndWeekDay: Integer): Date
    var
        DatesInMonth: Record Date;
        RecurrenceOrdinalNo: Enum "Recurrence - Ordinal No.";
    begin
        DatesInMonth.SetRange("Period Type", DatesInMonth."Period Type"::Date);
        DatesInMonth.SetRange("Period Start", CalcDate('<-CM>', CurrDate), CalcDate('<+CM>', CurrDate));
#pragma warning disable AA0210
        DatesInMonth.SetRange("Period No.", StartWeekDay, EndWeekDay);
#pragma warning restore AA0210

        if WhatToFind = RecurrenceOrdinalNo::Last then begin
            DatesInMonth.FindLast();
            exit(DatesInMonth."Period Start");
        end;

        DatesInMonth.FindSet();
        if WhatToFind = RecurrenceOrdinalNo::First then
            exit(DatesInMonth."Period Start");

        DatesInMonth.Next(WhatToFind.AsInteger());
        exit(DatesInMonth."Period Start");
    end;

    local procedure CalculateYearly(RecurrenceSchedule: Record "Recurrence Schedule"; LastOccurrence: Date): Date
    var
        MonthlyPattern: Enum "Recurrence - Monthly Pattern";
        WeekdayDateFormulaTxt: Label '<-CM+%1Y>', Comment = '%1 - Number of years', Locked = true;
        SpecificDateDateFormulaTxt: Label '<-CM+%1Y+%2D>', Comment = '%1 - Number of years, %2 - Number of days', Locked = true;
    begin
        if LastOccurrence = 0D then
            case RecurrenceSchedule."Monthly Pattern" of
                MonthlyPattern::"By Weekday":
                    exit(CalculateMonthlyByWeekDay(RecurrenceSchedule, DMY2Date(1, RecurrenceSchedule.Month.AsInteger(), Date2DMY(RecurrenceSchedule."Start Date", 3))));
                MonthlyPattern::"Specific Day":
                    exit(DMY2Date(RecurrenceSchedule."Recurs on Day", RecurrenceSchedule.Month.AsInteger(), Date2DMY(RecurrenceSchedule."Start Date", 3)));
            end;

        case RecurrenceSchedule."Monthly Pattern" of
            MonthlyPattern::"By Weekday":
                exit(CalculateMonthlyByWeekDay(RecurrenceSchedule, CalcDate(StrSubstNo(WeekdayDateFormulaTxt, RecurrenceSchedule."Recurs Every"), LastOccurrence)));
            MonthlyPattern::"Specific Day":
                exit(CalcDate(StrSubstNo(SpecificDateDateFormulaTxt, RecurrenceSchedule."Recurs Every", RecurrenceSchedule."Recurs on Day" - 1), LastOccurrence));
        end;
    end;

    local procedure CheckForEndDateTime(RecurrenceSchedule: Record "Recurrence Schedule"; PlannedDateTime: DateTime): DateTime
    begin
        if RecurrenceSchedule."End Date" <> 0D then
            if PlannedDateTime > CreateDateTime(RecurrenceSchedule."End Date", RecurrenceSchedule."Start Time") then
                exit(0DT);

        exit(PlannedDateTime);
    end;

    procedure CreateDaily(StartTime: Time; StartDate: Date; EndDate: Date; DaysBetween: Integer): Guid
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        RecurrencePattern: Enum "Recurrence - Pattern";
    begin
        RecurrenceSchedule.Pattern := RecurrencePattern::Daily;
        RecurrenceSchedule."Start Time" := StartTime;
        RecurrenceSchedule."Start Date" := StartDate;
        RecurrenceSchedule."End Date" := EndDate;
        RecurrenceSchedule."Recurs Every" := DaysBetween;
        RecurrenceSchedule.Insert(true);
        exit(RecurrenceSchedule.ID);
    end;

    procedure CreateWeekly(StartTime: Time; StartDate: Date; EndDate: Date; WeeksBetween: Integer; Monday: Boolean; Tuesday: Boolean; Wednesday: Boolean; Thursday: Boolean; Friday: Boolean; Saturday: Boolean; Sunday: Boolean): Guid
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        RecurrencePattern: Enum "Recurrence - Pattern";
    begin
        RecurrenceSchedule.Pattern := RecurrencePattern::Weekly;
        RecurrenceSchedule."Start Time" := StartTime;
        RecurrenceSchedule."Start Date" := StartDate;
        RecurrenceSchedule."End Date" := EndDate;
        RecurrenceSchedule."Recurs Every" := WeeksBetween;
        RecurrenceSchedule."Recurs on Monday" := Monday;
        RecurrenceSchedule."Recurs on Tuesday" := Tuesday;
        RecurrenceSchedule."Recurs on Wednesday" := Wednesday;
        RecurrenceSchedule."Recurs on Thursday" := Thursday;
        RecurrenceSchedule."Recurs on Friday" := Friday;
        RecurrenceSchedule."Recurs on Saturday" := Saturday;
        RecurrenceSchedule."Recurs on Sunday" := Sunday;
        RecurrenceSchedule.Insert(true);
        exit(RecurrenceSchedule.ID);
    end;

    procedure CreateMonthlyByDay(StartTime: Time; StartDate: Date; EndDate: Date; MonthsBetween: Integer; DayOfMonth: Integer): Guid
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        RecurrenceMonthlyPattern: Enum "Recurrence - Monthly Pattern";
        RecurrencePattern: Enum "Recurrence - Pattern";
    begin
        RecurrenceSchedule.Pattern := RecurrencePattern::Monthly;
        RecurrenceSchedule."Monthly Pattern" := RecurrenceMonthlyPattern::"Specific Day";
        RecurrenceSchedule."Start Time" := StartTime;
        RecurrenceSchedule."Start Date" := StartDate;
        RecurrenceSchedule."End Date" := EndDate;
        RecurrenceSchedule."Recurs Every" := MonthsBetween;
        RecurrenceSchedule."Recurs on Day" := DayOfMonth;
        RecurrenceSchedule.Insert(true);
        exit(RecurrenceSchedule.ID);
    end;

    procedure CreateMonthlyByDayOfWeek(StartTime: Time; StartDate: Date; EndDate: Date; MonthsBetween: Integer; InWeek: Enum "Recurrence - Ordinal No."; DayOfWeek: Enum "Recurrence - Day of Week"): Guid
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        RecurrenceMonthlyPattern: Enum "Recurrence - Monthly Pattern";
        RecurrencePattern: Enum "Recurrence - Pattern";
    begin
        RecurrenceSchedule.Pattern := RecurrencePattern::Monthly;
        RecurrenceSchedule."Monthly Pattern" := RecurrenceMonthlyPattern::"By Weekday";
        RecurrenceSchedule."Start Time" := StartTime;
        RecurrenceSchedule."Start Date" := StartDate;
        RecurrenceSchedule."End Date" := EndDate;
        RecurrenceSchedule."Recurs Every" := MonthsBetween;
        RecurrenceSchedule."Ordinal Recurrence No." := InWeek;
        RecurrenceSchedule.Weekday := DayOfWeek;
        RecurrenceSchedule.Insert(true);
        exit(RecurrenceSchedule.ID);
    end;

    procedure CreateYearlyByDay(StartTime: Time; StartDate: Date; EndDate: Date; YearsBetween: Integer; DayOfMonth: Integer; Month: Enum "Recurrence - Month"): Guid
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        RecurrenceMonthlyPattern: Enum "Recurrence - Monthly Pattern";
        RecurrencePattern: Enum "Recurrence - Pattern";
    begin
        RecurrenceSchedule.Pattern := RecurrencePattern::Yearly;
        RecurrenceSchedule."Monthly Pattern" := RecurrenceMonthlyPattern::"Specific Day";
        RecurrenceSchedule."Start Time" := StartTime;
        RecurrenceSchedule."Start Date" := StartDate;
        RecurrenceSchedule."End Date" := EndDate;
        RecurrenceSchedule."Recurs Every" := YearsBetween;
        RecurrenceSchedule."Recurs on Day" := DayOfMonth;
        RecurrenceSchedule.Month := Month;
        RecurrenceSchedule.Insert(true);
        exit(RecurrenceSchedule.ID);
    end;

    procedure CreateYearlyByDayOfWeek(StartTime: Time; StartDate: Date; EndDate: Date; YearsBetween: Integer; OrdinalNumber: Enum "Recurrence - Ordinal No."; DayOfWeek: Enum "Recurrence - Day of Week"; Month: Enum "Recurrence - Month"): Guid
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        RecurrenceMonthlyPattern: Enum "Recurrence - Monthly Pattern";
        RecurrencePattern: Enum "Recurrence - Pattern";
    begin
        RecurrenceSchedule.Pattern := RecurrencePattern::Yearly;
        RecurrenceSchedule."Monthly Pattern" := RecurrenceMonthlyPattern::"By Weekday";
        RecurrenceSchedule."Start Time" := StartTime;
        RecurrenceSchedule."Start Date" := StartDate;
        RecurrenceSchedule."End Date" := EndDate;
        RecurrenceSchedule."Recurs Every" := YearsBetween;
        RecurrenceSchedule."Ordinal Recurrence No." := OrdinalNumber;
        RecurrenceSchedule.Weekday := DayOfWeek;
        RecurrenceSchedule.Month := Month;
        RecurrenceSchedule.Insert(true);
        exit(RecurrenceSchedule.ID);
    end;

    procedure OpenRecurrenceSchedule(var RecurrenceID: Guid)
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
        TempRecurrenceSchedule: Record "Recurrence Schedule" temporary;
    begin
        if not IsNullGuid(RecurrenceID) and RecurrenceSchedule.Get(RecurrenceID) then
            TempRecurrenceSchedule.Copy(RecurrenceSchedule)
        else begin
            TempRecurrenceSchedule."Start Time" := Time();
            TempRecurrenceSchedule."Start Date" := Today();
        end;

        TempRecurrenceSchedule.Insert();

        if Page.RunModal(Page::"Recurrence Schedule Card", TempRecurrenceSchedule) = Action::LookupOK then begin
            RecurrenceSchedule.Copy(TempRecurrenceSchedule);
            if IsNullGuid(RecurrenceID) then
                RecurrenceSchedule.Insert(true)
            else
#pragma warning disable AA0214
                RecurrenceSchedule.Modify(true);
#pragma warning restore
            RecurrenceID := RecurrenceSchedule.ID;
            exit;
        end;

        if not TempRecurrenceSchedule.Get(RecurrenceID) and RecurrenceSchedule.Get(RecurrenceID) then begin
            RecurrenceSchedule.Delete();
            Clear(RecurrenceID);
        end;
    end;

    procedure RecurrenceDisplayText(RecurrenceID: Guid): Text
    var
        RecurrenceSchedule: Record "Recurrence Schedule";
    begin
        if IsNullGuid(RecurrenceID) or not RecurrenceSchedule.Get(RecurrenceID) then
            exit('');

        exit(StrSubstNo(RecurrenceDisplayTxt, RecurrenceSchedule.Pattern, RecurrenceSchedule."Start Date"));
    end;
}