path: root/time.odin

package main

import math "core:math"
import "core:fmt"
import "core:os"
import "core:strings"
import "core:strconv"
import "core:slice"
import "core:sort"

//
// --- STRUCTURES ---
//

Weekday :: enum{
	Monday,
	Tuesday,
	Wednesday,
	Thursday,
	Friday,
	Saturday,
	Sunday,
}

Delta :: struct {
	minutes : int,
	hours   : int,
	days    : int,
}

Moment :: struct {
	minutes : int,
	hours   : int,
	day     : int,
	month   : int,
	year    : int,
}

Timeblock :: struct {
	start : Moment,
	end   : Moment,
	value : f32,
	reason : string,
}

Fractionpair :: struct {
	start : f32,
	end : f32,
}


Workday :: struct {
	call		 : Moment,
	wrap		 : Moment,
	planned_wrap : Moment,

	// blocks is over 12,
	// because lunch breaks
	// cause more blocks
	blocks : [16]Timeblock,

	// Fractions store how long
	// since the workday's
	// preceding midnight
	// a timesplit occurs.
	// They're pairs so they
	// can exactly map to each
	// timeblock's start and end
	fractions : [16]Fractionpair,
	total_timeblocks : int,
	price: f32,
}


//
// --- MAJOR PROCEDURES ---
//

new_workday :: proc(previous_wrap    : Moment,
					calltime         : Moment,
					wraptime         : Moment,
					planned_wraptime : Moment) -> (workday: Workday) {
	
	workday.call = calltime
	workday.wrap = wraptime
	workday.planned_wrap = planned_wraptime
	
	using workday
	
	initial_block: Timeblock = {call,
								// Paragraph 6.7 says that up to 2 hours of unused warned overtime counts as worktime,
								// though so that at least one hour of the unused overtime is not counted.
								// (It's unclear if an 8-hour day that ends 3 hours in counts as having 5 hours of unused overtime)
								time_max(time_clamp(sub(planned_wrap, {0, 1, 0}), wrap, add(wrap, {0, 2, 0})),
									add(call, {0, 4, 0})), 1, ""}
									//  ^ Minimum 4 hour day ^
									
									// BUG: I think this is causing a bug where if the day ends at 6 and gets extended,
									//      it doesn't split the day at 6 and set the work-time before that to be extra expensive
	
	sp_length :: 11
	splitpoints:= [sp_length]Moment{ // --$-- Points where the price may change --$-- //
		
		// TODO: Replace this terribleness with a system for parsing simple, user-editable rulseset-files
		
		add(previous_wrap, {0, 10, 0}), // Sleepbreach, 10 hours after previous wrap, aka. turnover
		{0, 5, call.day, call.month, call.year}, // 2 hours before 7, aka 5
		{0, 6, call.day, call.month, call.year}, // 6 in the morning
		add(call, {0, 8, 0}), // Normal 8 hours of work
		add(call, {0, 9, 0}), // 1st hour of overtime is over
		add(call, {0, 11, 0}), // 3rd hour of overtime is over
		planned_wraptime, // End of warned overtime
		add(call, {0, 14, 0}), // The 14-hour mark
		{0, 22, call.day, call.month, call.year}, // 22:00 in the evening
		add({0, 23, call.day, call.month, call.year}, {0, 1, 0}), // Midnight
		add({0, 23, call.day, call.month, call.year}, {0, 7, 0}), // 06:00 the next morning
	}
	
	// Eliminate planned wrap, if it occurs within normal 8-hour period.
	// This is to make sure the first period of time becomes a pure 8 hours,
	// which makes detecting the main section of the workday easier.
	if sortable(splitpoints[6]) < sortable(splitpoints[3]) {
		splitpoints[6] = splitpoints[3];
	}
	
	splitpoints_sorted: [sp_length]Moment = splitpoints
	slice.sort_by(splitpoints_sorted[:], lessMoment)

	for each_point, i in splitpoints_sorted {
		fmt.printf("Splitpoint %2i: %s\n", i+1, toString(each_point))
	}
	
	working_block: Timeblock = initial_block
	fmt.println("working_block: ", toString(working_block))
	
	j: int = 0
	for each_point in splitpoints_sorted {
		// If each splitpoint moment is within the workday, and is not equal to the start of the current block
		if sortable(each_point) > sortable(call) && // vvvvvvvvvvvvvvvvvvvvvvvv this complication is here to cover
		   sortable(each_point) < sortable(time_max(wrap, add(call, {0, 4, 0}))) && // for the 4-hour minimum day.
		   each_point != working_block.start {

			blocks[j], working_block = timesplit(working_block, each_point)
			j += 1
			//fmt.println("Split and wrote:", j)
		}
	}
	blocks[j] = working_block
	j += 1
	total_timeblocks = j
	
	// This line is commented out because it shouldn't be needed.
	//slice.sort_by(blocks[:], lessTimeblock)
	
	
	fmt.println(total_timeblocks)

	for block, i in &blocks {
		if i >= total_timeblocks do break
		
		//using Weekday
		
		if lessEq(block.end, splitpoints[0]) do upvalue(&block, 3, "Sleep-breach") // +200% for sleep-breach
		if block.start.hours >= 22 do upvalue(&block, 2, "Night")				  // Work at night, aka. between 22:00 and 06:00
		if (block.end.hours == 6 && block.end.minutes == 0) || block.end.hours <= 5 do upvalue(&block, 2, "Night") // is +100%
		if greatEq(block.start, splitpoints[3]) {
			upvalue(&block, 1.5, "Overtime")
			if getweekday(block.start) == .Saturday do upvalue(&block, 2, "Saturday Overtime")
		}
		if greatEq(block.start, splitpoints[5]) do upvalue(&block, 2, "Overtime") // End of 3-hour cheap planned overtime
		if greatEq(block.start, planned_wrap) && greatEq(block.start, splitpoints[4]) do upvalue(&block, 2, "Overtime") // Unwarned OT
		if greatEq(block.start, splitpoints[7]) do upvalue(&block, 3, "Far overtime") // +200% beyond 14th hours            is +100%
		if getweekday(block.start) == .Saturday do upvalue(&block, 1.5, "Saturday") // Saturdays are +50%
		if getweekday(block.start) == .Sunday do upvalue(&block, 2, "Sunday") // Sundays are +100%
		
		if !(less(call, Moment{0, 7, call.day, call.month, call.year}) &&
			less(time_min(add(call, Delta{0,8,0}), wrap), Moment{0, 17, call.day, call.month, call.year} )) {
				// This was added for rule 6.11c, but in a world without a defined normal workday,
				// that rule is already covered already by 6.11g, so this is empty.
			}
		
		
		// Holidays!
		if (block.start.day==1) && (block.start.month==1) { upvalue(&block, 2, "New year"); continue}
		if (block.start.day==1) && (block.start.month==5) { upvalue(&block, 2, "1st of May"); continue}
		if (block.start.day==17) && (block.start.month==5) { upvalue(&block, 2, "17th of May"); continue}
		if (block.start.day==25 || block.start.day==26) && block.start.month==12 { upvalue(&block, 2, "Christmas"); continue}
		easter: Moment = gaussEaster(block.start.year)
		if (block.start.day == sub(easter, {0,0,3}).day) && block.start.month == sub(easter, {0,0,3}).month { upvalue(&block, 2, "Maundy Thursday"); continue}
		if (block.start.day == sub(easter, {0,0,2}).day) && block.start.month == sub(easter, {0,0,2}).month { upvalue(&block, 2, "Good Friday"); continue}
		if (block.start.day == easter.day) && (block.start.month == easter.month) { upvalue(&block, 2, "Easter"); continue}
		if (block.start.day == add(easter, {0,0,1}).day) && (block.start.month == add(easter, {0,0,1}).month) { upvalue(&block, 2, "Easter"); continue}
		if (block.start.day == add(easter, {0,0,39}).day) && (block.start.month == add(easter, {0,0,39}).month) { upvalue(&block, 2, "Feast of the Ascension"); continue}
		if (block.start.day == add(easter, {0,0,49}).day) && (block.start.month == add(easter, {0,0,49}).month) { upvalue(&block, 2, "Pentecost"); continue}
		if (block.start.day == add(easter, {0,0,50}).day) && (block.start.month == add(easter, {0,0,50}).month) { upvalue(&block, 2, "Pentecost Monday"); continue}
	}
	
	for each_block, i in blocks {
		fmt.printf("Block %2i: %s $f: %i%% %s\n", i+1, toString(each_block), int((each_block.value-1)*100), each_block.reason)
		price += f32(f64(dayrate/7.5) * f64(hourcount(each_block)) * f64(each_block.value))
	}
	
	return
}

lunch :: proc(workday: ^Workday, lunch_start: Moment, lunch_end: Moment) {

	//
	//    This basically cuts out part of the workday
	//
	// |-------|---|-------|----|---------|--------------|
	//                  |--lunch--|
	// |-------|---|----|         |-------|--------------|
	//               This ^ works now!

	if lunch_start == lunch_end do return
	assert(less(lunch_start, lunch_end), "ERROR: Bad Lunch! Lunch ends before it starts")

	start_index: int
	end_index: int
	for block, i in workday.blocks {
		if (great(lunch_start, block.start) && less(lunch_start, block.end)) || (block.start == lunch_start) {
			start_index = i
		}
		if (great(lunch_end, block.start) && less(lunch_end, block.end)) || (block.end == lunch_end) {
			end_index = i
		}
	}

	assert(start_index <= end_index, "ERROR: Bad Lunch! start_index greater than end_index")

	span: int = end_index - start_index

	// TODO: This is bad and can definitely be simplified and done in a more principled way
	// But right now it works perfectly, and is much better than it used to be in the C++ version
	switch span {
		case 0:
			fmt.println("Start and end are in the same block")
			switch {
				case (lunch_start == workday.blocks[start_index].start) && (lunch_end == workday.blocks[end_index].end):
					popBlock(workday, start_index)
				case lunch_start == workday.blocks[start_index].start:
					workday.blocks[start_index].start = lunch_end
				case lunch_end == workday.blocks[end_index].end:
					workday.blocks[end_index].end = lunch_start
				case:
					growBlocks(workday, start_index)
					end_index += 1
					workday.blocks[start_index].end = lunch_start
					workday.blocks[end_index].start = lunch_end
			}

		case 1:
			fmt.println("Start and end span one gap")
			switch {
				case (lunch_start == workday.blocks[start_index].start) && (lunch_end == workday.blocks[end_index].end):
					popBlock(workday, start_index, 2)
				case lunch_start == workday.blocks[start_index].start:
					workday.blocks[end_index].start = lunch_end
					popBlock(workday, start_index)
				case lunch_end == workday.blocks[end_index].end:
					workday.blocks[start_index].end = lunch_start
					popBlock(workday, end_index)
				case:
					workday.blocks[end_index].start = lunch_end
					workday.blocks[start_index].end = lunch_start
			}

		case 2..=len(workday.blocks):
			fmt.println("Start and end span more than one gap")
			switch {
				case (lunch_start == workday.blocks[start_index].start) && (lunch_end == workday.blocks[end_index].end):
					popBlock(workday, start_index, span+1)
				case lunch_start == workday.blocks[start_index].start:
					workday.blocks[end_index].start = lunch_end
					popBlock(workday, start_index, span)
				case lunch_end == workday.blocks[end_index].end:
					workday.blocks[start_index].end = lunch_start
					popBlock(workday, start_index+1, span)
				case:
					workday.blocks[end_index].start = lunch_end
					workday.blocks[start_index].end = lunch_start
					popBlock(workday, start_index+1, span-1)
				}
	}
}

windIndividual :: proc(input_moment: ^Moment,
			 minutes:	int,
			 hours: 	int,
			 days:		int) {
	
	// Adding minutes
	input_moment.minutes += minutes
	for input_moment.minutes > 59 {
		input_moment.minutes -= 60
		input_moment.hours += 1
	}
	for input_moment.minutes < 0 {
		input_moment.minutes += 60
		input_moment.hours -= 1
	}
	
	// Adding hours
	input_moment.hours += hours
	for input_moment.hours > 23 {
		input_moment.hours -= 24
		input_moment.day += 1
	}
	for input_moment.hours < 0 {
		input_moment.hours += 24
		input_moment.day -= 1
	}
	
	// Adding days
	input_moment.day += days
	current_month_length: int = days_in(input_moment.month, input_moment.year)
	
	for input_moment.day > current_month_length {
		input_moment.day -= current_month_length
		input_moment.month += 1
		if input_moment.month > 12 {
			input_moment.month -= 12
			input_moment.year += 1
		}
		current_month_length = days_in(input_moment.month, input_moment.year)
	}
	
	for input_moment.day < 1 {
		input_moment.month -= 1
		if input_moment.month < 1 {
			input_moment.month += 12
			input_moment.year -= 1
		}
		current_month_length = days_in(input_moment.month, input_moment.year)
		input_moment.day += current_month_length
	}
	
	return
}
windByDelta :: proc(moment: ^Moment, delta: Delta) {
	using delta
	wind(moment, minutes, hours, days)
	return
}
wind :: proc{windIndividual, windByDelta}

timesplit :: proc(block: Timeblock, splitpoint: Moment) -> (first_half: Timeblock, second_half: Timeblock) {
	// Splits a timeblock at splitpoint.
	
	if  sortable(splitpoint) < sortable(block.start) ||
		sortable(splitpoint) > sortable(block.end) ||
		splitpoint == block.start || splitpoint == block.end {
			fmt.println("WHOOPS: Splitpoint is outside timeblock range!")
			fmt.println("Timeblock:", toString(block))
			fmt.println("Splitpoint:", toString(splitpoint))
			second_half = block
			return
		}
	
	first_half = {block.start, splitpoint, block.value, block.reason}
	second_half = {splitpoint, block.end, block.value, block.reason}
	
	return
}

upvalue :: proc(input_block: ^Timeblock, value: f32, reason: string) {
	block: ^Timeblock = input_block
	if value > block.value {
		block.value = value
		block.reason = reason
	}
}

importICS :: proc(path: string, verbose: bool = false) -> ([dynamic]Timeblock, bool) {
	output: [dynamic]Timeblock

	c : Timeblock

	raw, ok := os.read_entire_file_from_filename(path)
	content := string(raw)

	i := 1
	line_nr := 1

	if !ok {
		// TODO: Actually check the content to see if it is an ICS file.
		fmt.eprintf("ERROR: No file found at: \"%v\"", path)
		return output, false
	}

	for line in strings.split_lines_iterator(&content) {

		// BUG: This assumes that there will never be a line shorter than 10.
		//      That means this will try reading out of bounds at some point.

		if line[0:10]=="DTSTART;TZ" {
			// grab the timestamp from the end of the line, and set start to it

			ll := len(line)
			if verbose do fmt.println("Found a DTSTART!")
			if verbose do fmt.println("length of line:", ll)
			if verbose do fmt.println(line)
			date_start : int

			if verbose do fmt.printf("Time: %s:%s\n", line[ll-6:ll-4], line[ll-4:ll-2])

			if verbose do fmt.printf("Hours: %s\n", line[ll-6:ll-4])
			c.start.hours = strconv.atoi(line[ll-6:ll-4])

			if verbose do fmt.printf("Minutes: %s\n", line[ll-4:ll-2])
			c.start.minutes = strconv.atoi(line[ll-4:ll-2])

			if verbose do fmt.printf("Day: %s\n", line[ll-9:ll-7])
			c.start.day = strconv.atoi(line[ll-9:ll-7])

			if verbose do fmt.printf("Month: %s\n", line[ll-11:ll-9])
			c.start.month = strconv.atoi(line[ll-11:ll-9])

			if verbose do fmt.printf("Year: %s\n", line[ll-15:ll-11])
			c.start.year = strconv.atoi(line[ll-15:ll-11])
		}
		if line[0:5]=="DTEND" {
			// grab the timestamp from the end of the line, and set end to it
			ll := len(line)
			if verbose do fmt.println("Found a DTEND!")
			if verbose do fmt.println(line)


			if verbose do fmt.printf("Time: %s:%s\n", line[ll-6:ll-4], line[ll-4:ll-2])

			if verbose do fmt.printf("Hours: %s\n", line[ll-6:ll-4])
			c.end.hours = strconv.atoi(line[ll-6:ll-4])

			if verbose do fmt.printf("Minutes: %s\n", line[ll-4:ll-2])
			c.end.minutes = strconv.atoi(line[ll-4:ll-2])

			if verbose do fmt.printf("Day: %s\n", line[ll-9:ll-7])
			c.end.day = strconv.atoi(line[ll-9:ll-7])

			if verbose do fmt.printf("Month: %s\n", line[ll-11:ll-9])
			c.end.month = strconv.atoi(line[ll-11:ll-9])

			if verbose do fmt.printf("Year: %s\n", line[ll-15:ll-11])
			c.end.year = strconv.atoi(line[ll-15:ll-11])

		}

		// TODO: This is checking if the years are 0 to make sure it hasn't read from
		//       from a line containing "DTSTART;VALUE" instead of "DTSTART;TZID"
		//       VALUE days are events that are set to last the entire day, 
		//       as opposed to having a defined start and end point.
		//
		//       This should eventually not be needed, because these days
		//       should also be imported based on the session's default-day settings

		if line=="END:VEVENT" && (c.end.year != 0) && (c.start.year != 0) {
			if verbose do fmt.println(line)
			c.value = 1
			append(&output, c)

			blank_timeblock: Timeblock
			c = blank_timeblock

			if verbose do fmt.println("\n\n", i, line_nr, "\n\n")
			i += 1
		}
		line_nr += 1
	}
	return output, true
}


//
// --- BASIC OPERATIONS ---
//

add :: proc(moment: Moment, delta: Delta) -> (output: Moment) {
	output = moment
	wind(&output, delta)
	return
}
sub :: proc(moment: Moment, delta: Delta) -> (output: Moment) {
	output = moment
	using delta
	wind(&output, minutes*-1, hours*-1, days*-1)
	return
}
maxMoment :: proc(moment_a: Moment, moment_b: Moment) -> Moment {
	if sortable(moment_a) > sortable(moment_b) do return moment_a
	return moment_b
}
maxDelta :: proc(delta_a: Delta, delta_b: Delta) -> Delta {
	if sortable(delta_a) > sortable(delta_b) do return delta_a
	return delta_b
}
time_max :: proc{maxDelta, maxMoment}

minMoment :: proc(moment_a: Moment, moment_b: Moment) -> Moment {
	if sortable(moment_a) < sortable(moment_b) do return moment_a
	return moment_b
}
minDelta :: proc(delta_a: Delta, delta_b: Delta) -> Delta {
	if sortable(delta_a) < sortable(delta_b) do return delta_a
	return delta_b
}
time_min :: proc{minDelta, minMoment}

clampMoment :: proc(moment: Moment, moment_min: Moment, moment_max: Moment) -> Moment {
	return time_min(time_max(moment, moment_min), moment_max)
}
clampDelta :: proc(delta: Delta, delta_min: Delta, delta_max: Delta) -> Delta {
	return time_min(time_max(delta, delta_min), delta_max)
}
time_clamp :: proc{clampMoment, clampDelta}

greatMoment :: proc(moment_a: Moment, moment_b: Moment) -> bool {
	return bool(sortable(moment_a) > sortable(moment_b))
}
greatDelta :: proc(delta_a: Delta, delta_b: Delta) -> bool {
	return bool(sortable(delta_a) > sortable(delta_b))
}
great :: proc{greatMoment, greatDelta}

lessMoment :: proc(moment_a: Moment, moment_b: Moment) -> bool {
	return bool(sortable(moment_a) < sortable(moment_b))
}
lessDelta :: proc(delta_a: Delta, delta_b: Delta) -> bool {
	return bool(sortable(delta_a) < sortable(delta_b))
}
lessTimeblock :: proc(block_a: Timeblock, block_b: Timeblock) -> bool {
	if block_b.start == {0, 0, 0, 0, 0} do return true
	if block_a.start == {0, 0, 0, 0, 0} do return false
	return bool(sortable(block_a.start) < sortable(block_b.start))
}
lessWorkday :: proc(day_a: Workday, day_b: Workday) -> bool {
	return bool(sortable(day_a.call) < sortable(day_b.call))
}
lessWorkdayPtr :: proc(day_a: ^Workday, day_b: ^Workday) -> bool {
	return bool(sortable(day_a.call) < sortable(day_b.call))
}
less :: proc{lessMoment, lessDelta, lessTimeblock, lessWorkday}

lessEqMoment :: proc(moment_a: Moment, moment_b: Moment) -> bool {
	return moment_a==moment_b || less(moment_a, moment_b)
}
lessEq :: proc{lessEqMoment}

greatEqMoment :: proc(moment_a: Moment, moment_b: Moment) -> bool {
	return moment_a == moment_b || great(moment_a, moment_b)
}
greatEq :: proc{greatEqMoment}


diff :: proc(moment_a: Moment, moment_b: Moment) -> (acc: Delta) {
	// FIXME: This seems to cause either infinite loops or crashes sometimes
	
	// Uses what I call an accumulator-decumulator design
	// Count how long it takes to approach a benchmark,
	// and that count is the difference
	
	acc = {0, 0, 0}
	if moment_a == moment_b do return
	
	// smallest operand becomes benchmark to approach
	reverse: bool = sortable(moment_a) < sortable(moment_b)
	bench : Moment
	dec : Moment
	if reverse {
		bench = moment_a
		dec = moment_b
	} else {
		bench = moment_b
		dec = moment_a
	}
	
	// It is possible to write something that does this in months at a time, instead of days,
	// which would be faster, but I am not expecting to have to do this with such
	// long periods of time, so screw that.
	for ((dec.year  - bench.year)  > 1 ||
		 (dec.month - bench.month) > 1 ||
		 (dec.day   - bench.day)   > 1) {
		wind(&dec, 0, 0, -1)
		acc.days += 1
	}
	
	for (dec.hours - bench.hours > 1) {
		wind(&dec, 0, -1, 0)
		acc.hours += 1
	}
	for acc.hours > 23 {
		acc.hours -= 24
		acc.days  += 1
	}
	
	for dec != bench {
		wind(&dec, -1, 0, 0)
		acc.minutes += 1
	}
	for acc.minutes > 59 {
		acc.minutes -= 60
		acc.hours   += 1
	}
	
	// Repeating this is a little bit ugly, but it works
	for acc.hours > 23 {
		acc.hours -= 24
		acc.days  += 1
	}
	
	return
}

sortableTimeDelta :: proc(delta: Delta) -> (output: u64) {
	using delta
	output, _ = strconv.parse_u64(fmt.tprintf("1%3i%2i%2i", days, hours, minutes))
	return
}
sortableTimeMoment :: proc(moment: Moment) -> (output: u64) {
	using moment
	output, _ = strconv.parse_u64(fmt.tprintf("%4i%2i%2i%2i%2i", year, month, day, hours, minutes))
	return
}
sortable :: proc{sortableTimeMoment, sortableTimeDelta}

deltaToString :: proc(delta: Delta) -> (output: string) {
	using delta
	
	if hours == 0 &&
	   days == 0 &&
	   minutes == 0 {
			return "None"
	   }
	
	cat_array : [dynamic]string
	printed_prev : bool = false
	
	if days>0 {
		buf: [5]byte
		append(&cat_array, fmt.tprint(days))
		if days < 2 {
			append(&cat_array, " day")
		} else {
			append(&cat_array, " days")
		}
		printed_prev = true
	}
	
	if hours>0 {
		
		if printed_prev do append(&cat_array, ", ")
		
		buf: [5]byte
		append(&cat_array, fmt.tprint(hours))
		if hours < 2 {
			append(&cat_array, " hour")
		} else {
			append(&cat_array, " hours")
		}
		printed_prev = true
	}
	
	if minutes>0 {
		
		if printed_prev do append(&cat_array, ", ")
		
		buf: [5]byte
		append(&cat_array, fmt.tprint(minutes))
		if minutes < 2 {
			append(&cat_array, " minute")
		} else {
			append(&cat_array, " minutes")
		}
	}
	
	output = strings.concatenate(cat_array[:])
	return
}


momentToString :: proc(moment: Moment) -> (output: string) {
	using moment
	
	cat_array: [dynamic]string
	
	output = fmt.tprintf("%4i-%2i-%2i %2i:%2i", year, month, day, hours, minutes)
	
	return
}
timeblockToString :: proc(block: Timeblock) -> (output: string) {
	using block
	s: [3]string = {toString(start), " -> ", toString(end)}
	output = strings.concatenate(s[:])
	return
}
toString :: proc{deltaToString, momentToString, timeblockToString}



clockprintMoment :: proc(moment: Moment) -> string {
	using moment
	return fmt.tprintf("%2i:%2i", hours, minutes)
}
clockprintTimeblock :: proc(block: Timeblock) -> string {
	using block
	return fmt.tprintf("%s -> %s", clockprint(start), clockprint(end))
}
clockprint :: proc{clockprintTimeblock, clockprintMoment}

dayprintMoment :: proc(moment: Moment) -> string {
	using moment
	return fmt.tprintf("%4i-%2i-%2i", year, month, day)
}
dayprintTimeblock :: proc(block: Timeblock) -> string {
	using block
	return fmt.tprintf("%s -> %s", dayprint(start), dayprint(end))
}
dayprint :: proc{dayprintTimeblock, dayprintMoment}

popBlock :: proc(workday: ^Workday, index: int, count: int = 1) {
	using workday
	when ODIN_DEBUG do fmt.printf("popBlock() running to remove %i block(s) from index %i\n", count, index)
	for i in index..<len(blocks)-count {
		when ODIN_DEBUG do fmt.printf("Putting the contents of %i/%i into %i\n", i+count, len(blocks)-1, i)
		blocks[i] = blocks[i+count]
	}
	for i in len(blocks)-count-1..<len(blocks) {
		blocks[i] = {{0, 0, 0, 0, 0}, {0, 0, 0, 0, 0}, 0, ""}
	}
	total_timeblocks -= count
}

growBlocks :: proc(workday: ^Workday, index: int, count: int = 1) {
	using workday
	fmt.printf("growBlocks() running to make space for %i block(s) at index %i\n", count, index)
	for i: int = len(blocks)-1-count; i>=index; i-=1 {
		fmt.printf("Putting the contents of %i/%i into %i\n", i+count, len(blocks)-1, i)
		blocks[i+count] = blocks[i]
	}
	//for i in index..<index+count {
	//	blocks[i] = {{0, 0, 0, 0, 0}, {0, 0, 0, 0, 0}, 0, ""}
	//}
	total_timeblocks += count
}

getweekday :: proc(moment: Moment) -> Weekday {
	y: int = moment.year
	t: []int = { 0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 }
	y -= int(moment.month < 3)
	return Weekday((y + y / 4 - y / 100 + y / 400 + t[moment.month - 1] + moment.day - 1) % 7)
}

hourcount :: proc(block: Timeblock) -> f32 {
	using block
	delta: Delta = diff(end, start)
	using delta
	return f32(f32(minutes)/60 + 
	           f32(hours) +
	           f32(days) * 24)
}

daycount :: proc(delta: Delta) -> f32 {
	using delta
	assert(delta != {0,0,0})
	return f32(f32(minutes)/60/24 +
	           f32(hours)/24 +
	           f32(days) )
}

days_in :: proc(month: int, year: int) -> int {
	switch month {
		case 1:
			return 31;
		case 2:
			if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)){
				return 29;
			}
			return 28;
		case 3:
			return 31;
		case 4:
			return 30;
		case 5:
			return 31;
		case 6:
			return 30;
		case 7:
			return 31;
		case 8:
			return 31;
		case 9:
			return 30;
		case 10:
			return 31;
		case 11:
			return 30;
		case 12:
			return 31;
	}
	fmt.printf("You just found month nr: %i. Something is very wrong.\n", month)
	fmt.assertf(month < 13 &&  month > 0, "You tried to get the days in month %i!\n", month)
	return 30
}

gaussEaster :: proc(year: int) -> Moment {
	// Thanks to Carl Friedrich Gauss for the algorythm
	// Thanks rahulhegde97, bansal_rtk_, code_hunt, sanjoy_62, simranarora5sos
	// and aashutoshparoha on GeeksForGeeks for the implementation I based this on.
    A, B, C, P, Q, M, N, D, E: f64
    easter_month: int = 0
    easter_day: int = 0
    
    A = f64(year % 19)
    B = f64(year % 4)
    C = f64(year % 7)
    P = f64(math.floor(f64(year / 100.0)))
    
    Q = math.floor((13 + 8 * P) / 25.0)
 
    M = f64(int(15 - Q + P - math.floor(f64(P / 4))) % 30)
 
    N = f64(int(4 + P - math.floor(P / 4)) % 7)
 
    D = f64(int(19 * A + M) % 30)
 
    E = f64(int(2 * B + 4 * C + 6 * D + N) % 7)
    
    days: int = int(22 + D + E)
	easter_day = days
	
    if (D == 29) && (E == 6) {
	    // A corner case when D is 29
		easter_month = 4
		easter_day = 19
    } else if (D == 28) && (E == 6) {
	    // Another corner case, when D is 28
		easter_month = 4
		easter_day = 18
    } else {
        // If days > 31, move to April
        // April = 4th Month
        if (days > 31) {
			easter_month = 04
			easter_day = days-31
        } else {
            // Otherwise, stay on March
            // March = 3rd Month
			easter_month = 03
        }
    }
    
	return {0, 0, easter_day, easter_month, year}
}