feat: Scheduling Multiple shifts and Auto Attendance

[ruchamahabal]

Problem

• Earlier, only 1 Shift Type could be assigned to an employee for one day.
• However, in some organizations, employees could be working in multiple shifts (Morning Shift, Evening Shift) on the same day.

What Changes?

Schedule multiple shifts

• Users can make multiple non-overlapping Shift Assignments for the same employee on the same day

Shift Request

• Users can make multiple non-overlapping Shift Requests for the same employee on the same day

Fetching shift in Employee Check In

• When employee check-ins are logged via biometric or manually, the exact shift based on the timestamp is fetched. Before, shifts used to be fetched based on date. Now they are timestamp specific.
• Handles shifts spanning over 2 different days (eg: 23:00 - 2:00), midnight shifts.
• Shift fetching used to fail on timing boundaries, this is fixed.
• Handles 2 consecutive shifts if they are overlapping within grace periods.

Attendance

• Earlier, only 1 attendance record could be marked for 1 day.
• Now multiple attendance records can be marked for each shift. Eg: employee can be absent for one shift, present for another on the same day
• Auto Attendance now, takes care of marking shift specific attendance and not for the whole day
• Earlier, employees with no attendance records on a specific date used to be marked absent via Auto Attendance. Now, this also checks for shift-wise attendance records along with the date. So, only if attendance is not marked for a particular shift/for the whole day, the employee will be marked absent.

Attendance Reports

• Added shift-wise attendance against employees
• Added legend for status abbr with full form and color.
• Formatter for data to quickly identify cells with lesser cognitive load.
• Refactored Monthly Attendance Sheet code. Can still be better but will leave it for the next iteration.

Before:

After:

Impact on Payroll

If there are multiple attendance records marked for a single day with separate shifts, each record will be considered as 1 Payment Day in payroll. So if an employee works 2 shifts in a single day this contributes to 2 payment days in Payroll. No code level changes are done for this

Documentation: Added docs for Monthly Attendance Sheet only since others are mostly backend changes: https://docs.erpnext.com/docs/v14/user/manual/en/human-resources/human-resources-reports#3-monthly-attendance-sheet
Also closes #29210

ToDo

• Allow scheduling multiple shifts
• Shift fetching in employee check-ins
• Multiple attendance records for the same day
• Auto Attendance for multiple shifts
• Handle impact on attendance reports
• Refactor Shift Request Overlapping validation
• Test cases
• Documentation

[codecov]

Codecov Report

Merging #30588 (7ba66b0) into develop (f1fd4e5) will increase coverage by 0.30%.
The diff coverage is 94.35%.

@@             Coverage Diff             @@
##           develop   #30588      +/-   ##
===========================================
+ Coverage    60.92%   61.22%   +0.30%     
===========================================
  Files         1083     1083              
  Lines        69224    69356     +132     
===========================================
+ Hits         42173    42466     +293     
+ Misses       27051    26890     -161     

Impacted Files	Coverage Δ
erpnext/hr/doctype/shift_type/shift_type.py	86.07% <87.09%> (+64.55%)	⬆️
...xt/hr/doctype/shift_assignment/shift_assignment.py	75.72% <89.14%> (+26.34%)	⬆️
...nthly_attendance_sheet/monthly_attendance_sheet.py	95.60% <96.26%> (+33.21%)	⬆️
erpnext/hr/doctype/attendance/attendance.py	71.52% <100.00%> (+9.13%)	⬆️
...xt/hr/doctype/employee_checkin/employee_checkin.py	93.63% <100.00%> (+8.58%)	⬆️
erpnext/hr/doctype/shift_request/shift_request.py	93.24% <100.00%> (+7.52%)	⬆️
erpnext/accounts/doctype/bank/bank.py	71.42% <0.00%> (-14.29%)	⬇️
...em_wise_sales_register/item_wise_sales_register.py	51.58% <0.00%> (-11.32%)	⬇️
...urity_shortfall/process_loan_security_shortfall.py	93.75% <0.00%> (-6.25%)	⬇️
...pnext/accounts/report/gross_profit/gross_profit.py	81.48% <0.00%> (-5.77%)	⬇️
... and 37 more

[mohsinalimat]

Could you please support v13 as well.