[Appointments +] Set the weekly calendar time slots based on worker start hours for each day

app-workers-weekly-hours.php

<?php
/*
Plugin Name: [Appointments] - Workers weekly hours
Plugin URI: https://premium.wpmudev.org/
Description: Sets the weekly calendar time slots based on worker start hours for each day
Author: Panos Lyrakis @ WPMUDEV
Author URI: https://premium.wpmudev.org/
License: GPLv2 or later
*/

add_filter( 'appointments_get_weekly_schedule_slots', function( $slots, $now, $service_id, $worker_id, $location_id ){

	$appointments = appointments();

	if ( ! $now ) {
		$now = current_time( 'timestamp' );
	}

	// Get the start/end hours
	$hour_start = 8;
	$hour_end = 18;
	if ( $min_max = $appointments->min_max_wh() ) {
		$hour_start = $min_max["min"];
		$hour_end = $min_max["max"];
	}

	if ( $hour_start > $hour_end ) {
		$hour_start = $min_max["max"];
		$hour_end = $min_max["min"];
	}

	$hour_start = apply_filters( 'app_schedule_starting_hour', $hour_start, $now, 'week' );
	$hour_end = apply_filters( 'app_schedule_ending_hour', $hour_end, $now, 'week' );

	$step = $appointments->get_min_time() * 60; // Timestamp increase interval to one cell below
	if ( ! appointments_use_legacy_duration_calculus() ) {
		$service = appointments_get_service( $service_id );
		if ( $service ) {
			$step = $service->duration * 60;
		}
	}

	// Allow direct step increment manipulation,
	// mainly for service duration based calculus start/stop times
	$step = apply_filters( 'app-timetable-step_increment', $step, 'week' );

	// Get the last day that was a start of week. We'll start from there
	$week_start = appointments_week_start();
	$week_start_string = appointments_number_to_weekday( $week_start );

	$now_weekday = absint( date( 'N', $now ) );

	// By default we'll start the schedule by today
	$day_start = date( 'Y-m-d', $now );
	if ( $week_start != $now_weekday ) {
		// Today is not the same day that the week start
		// Get the latest start weekday
		$day_start = date( 'Y-m-d', strtotime( 'Last ' . $week_start_string, $now ) );
	}

	// Timestamps to start and end each day

	$day_start_timestamp = strtotime( $day_start . ' ' . zeroise( $hour_start, 2 ) . ':00:00' );
	$day_end_timestamp = strtotime( $day_start . ' ' . zeroise( $hour_end, 2 ) . ':00:00' );

	$the_week = array();
	for ( $day = $day_start_timestamp; $day < ( $day_start_timestamp + ( 24 * 3600 * 7 ) ); $day = $day + ( 24 * 3600 ) ) {
		// Increase one day in every loop until we completed 7 days
		$the_week[] = date( 'Y-m-d', $day );
	}

	$time_slots = $start_hours = array();

	if( $worker_id && appointments_is_worker( $worker_id ) ){

		$start_hours = wpmudev_appointments_get_worker_weekly_start_hours( $service_id, $worker_id, $location_id );

	}else{

		if( $service_id ){
			$workers = appointments_get_workers_by_service( $service_id );
		}
		else{
			$workers = appointments_get_all_workers();
		}

		foreach ( $workers as $worker ) {
			$start_hours = array_merge( $time_slots , wpmudev_appointments_get_worker_weekly_start_hours( $service_id, $worker_id, $location_id ) );
		}
		
	}

	if( ! empty( $start_hours ) ){
		sort( $start_hours );
		foreach ( $start_hours as $start_time ) {
			$start_dt = strtotime( $start_time );
			$end_time = date("H:i", strtotime('+' . $step . ' seconds', $start_dt));

			if( apply_filters( 'appointments_get_weekly_schedule_slots/skip_after_midnight', true ) ){
				if( $end_time < $start_time ){
					continue;
				}
			}

			$time_slots[] = array(
				'from' => $start_time,
				'to' => $end_time
			);
		}

	}
	
	return array(
		'the_week' => $the_week,
		'time_slots' => $time_slots
	);

}, 20, 5 );


function wpmudev_appointments_get_worker_weekly_start_hours( $service_id = 0, $worker_id = 0, $location_id = 0 ){

	if( ! $worker_id || ! appointments_is_worker( $worker_id  ) ){
		return array();
	}

	$appointments = appointments();
	$step = $duration = $appointments->get_min_time() * 60;

	$worker = appointments_get_worker( $worker_id );

	$service = appointments_get_service( $service_id );
	if ( $service ) {
		$duration = $service->duration * 60;
	}

	$worker_working_hours = appointments_get_worker_working_hours( 'open', $worker_id, $location_id );

	if( ! empty( $worker_working_hours ) && isset( $worker_working_hours->hours ) && ! empty( $worker_working_hours->hours ) ){

		$slot_starts = array();

		//The starting hours set in Working Hours settings page
		foreach( $worker_working_hours->hours as $dayname => $open_hours )	{

			if( $open_hours['active'] != 'yes' ){
				continue;
			}

			//We make a loop using the $step set in General > Time base settings page
			for ( $start_time = $open_hours['start']; $start_time < $open_hours['end']; $start_time = date("H:i", strtotime('+' . $step . ' seconds', strtotime( $start_time ) )) ) {

				$end_slot = date("H:i", strtotime('+' . $duration . ' seconds', strtotime( $start_time ) ) );
				if( $end_slot > $open_hours['end'] ){
					break;
				}

				if( ! in_array( $start_time, $slot_starts ) ){
					$slot_starts[] = $start_time;
				}

			}
			
		}

		return $slot_starts;

	}

}