local gpu = require("component").gpu
local buffer = require("doubleBuffering")
local unicode = require("unicode")
local syntax = {}

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--Стандартные цветовые схемы
syntax.colorSchemes = {
	midnight = {
		recommendedBackground = 0x262626,
		text = 0xffffff,
		strings = 0xff2024,
		loops = 0xffff98,
		comments = 0xa2ffb7,
		boolean = 0xffcc66,
		logic = 0xffcc66,
		numbers = 0x24c0ff,
		functions = 0xffcc66,
		compares = 0xffff98,
	},
	sunrise = {
		recommendedBackground = 0xffffff,
		text = 0x262626,
		strings = 0x880000,
		loops = 0x24c0ff,
		comments = 0xa2ffb7,
		boolean = 0x19c0cc,
		logic = 0x880000,
		numbers = 0x24c0ff,
		functions = 0x24c0ff,
		compares = 0x880000,
	},
}

--Текущая цветовая схема
local currentColorScheme = {}
--Шаблоны поиска
local patterns
--Размер массива шаблонов поиска
local sPatterns

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--Пересчитать цвета шаблонов
--Приоритет поиска шаблонов снижается сверху вниз
local function definePatterns()
	patterns = {
		--Комментарии
		{ pattern = "%-%-.*", color = currentColorScheme.comments, cutFromLeft = 0, cutFromRight = 0 },
		
		--Строки
		{ pattern = "\"[^\"\"]*\"", color = currentColorScheme.strings, cutFromLeft = 0, cutFromRight = 0 },
		
		--Циклы, условия, объявления
		{ pattern = "while ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "do$", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "do ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "end$", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "end ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "for ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = " in ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "repeat ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "if ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "then", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "until ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "return", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "local ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "function ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "else$", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "else ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = "elseif ", color = currentColorScheme.loops, cutFromLeft = 0, cutFromRight = 1 },

		--Состояния переменной
		{ pattern = "true", color = currentColorScheme.boolean, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "false", color = currentColorScheme.boolean, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "nil", color = currentColorScheme.boolean, cutFromLeft = 0, cutFromRight = 0 },
				
		--Функции
		{ pattern = "%s([%a%d%_%-%.]*)%(", color = currentColorScheme.functions, cutFromLeft = 0, cutFromRight = 1 },
		
		--And, or, not, break
		{ pattern = " and ", color = currentColorScheme.logic, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = " or ", color = currentColorScheme.logic, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = " not ", color = currentColorScheme.logic, cutFromLeft = 0, cutFromRight = 1 },
		{ pattern = " break$", color = currentColorScheme.logic, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "^break", color = currentColorScheme.logic, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = " break ", color = currentColorScheme.logic, cutFromLeft = 0, cutFromRight = 0 },

		--Числа
		{ pattern = "%s(0x)(%w*)", color = currentColorScheme.numbers, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "(%s)([%d%.]*)", color = currentColorScheme.numbers, cutFromLeft = 0, cutFromRight = 0 },
		
		--Сравнения и мат. операции
		{ pattern = "<=", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = ">=", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "<", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = ">", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "==", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "~=", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "=", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "%+", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "%-", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "%*", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "%/", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "%.%.", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "%#", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
		{ pattern = "#^", color = currentColorScheme.compares, cutFromLeft = 0, cutFromRight = 0 },
	}

	--Ну, и размер массива шаблонов тоже
	sPatterns = #patterns
end

--Костыльная замена обычному string.find()
--Работает медленнее, но хотя бы поддерживает юникод
function unicode.find(str, pattern, init, plain)
	-- checkArg(1, str, "string")
	-- checkArg(2, pattern, "string")
	-- checkArg(3, init, "number", "nil")
	if init then
		if init < 0 then
			init = -#unicode.sub(str,init)
		elseif init > 0 then
			init = #unicode.sub(str,1,init-1)+1
		end
	end
	
	a, b = string.find(str, pattern, init, plain)
	
	if a then
		local ap,bp = str:sub(1,a-1), str:sub(a,b)
		a = unicode.len(ap)+1
		b = a + unicode.len(bp)-1
		return a,b
	else
		return a
	end
end

--Проанализировать строку и создать на ее основе цветовую карту
function syntax.highlight(x, y, text, limit)
	--Кароч вооот, хыыы
	local searchFrom, starting, ending
	--Загоняем в буффер всю строку базового цвета
	buffer.text(x, y, currentColorScheme.text, limit and unicode.sub(text, 1, limit) or text)
	limit = limit or math.huge

	--Перебираем шаблоны
	for i = #patterns, 1, -1 do
		searchFrom = 1
		--Перебираем весь текст, а то мало ли шаблон дохуя раз встречается
		while true do
			starting, ending = unicode.find(text, patterns[i].pattern, searchFrom)
			if starting and ending then
				if ending <= limit then
					buffer.text(x + starting - 1, y, patterns[i].color, unicode.sub(text, starting, ending - patterns[i].cutFromRight))
					searchFrom = ending + 1
				else
					buffer.text(x + starting - 1, y, patterns[i].color, unicode.sub(text, starting, limit))
					break
				end
			else
				break
			end
		end
	end
end

--Объявить новую цветовую схему
function syntax.setColorScheme(colorScheme)
	--Выбранная цветовая схема
	currentColorScheme = colorScheme
	--Пересчитываем шаблоны
	definePatterns()
end

--Открыть файл для чтения и отобразить первые строки из него, чтобы чекнуть, как работает подсветка
function syntax.highlightFileForDebug(pathToFile)
	--Получаем размер экрана
	local xSize, ySize = gpu.getResolution()
	--Очищаем экран рекомендуемым цветом
	buffer.square(1, 1, xSize, ySize, currentColorScheme.recommendedBackground, currentColorScheme.text, " ")
	buffer.draw(true)
	--Открываем файлик
	local file = io.open(pathToFile, "r")
	--Счетчик строк
	local lineCounter = 1
	--Читаем строки
	for line in file:lines() do
		--Подсвечиваем строку и рисуем
		syntax.highlight(2, lineCounter + 1, line)
		--Счетчик в плюс
		lineCounter = lineCounter + 1
		--Разрываем цикл, если кол-во строк превысило высоту экрана
		if lineCounter > ySize then break end
		--ecs.wait()
	end
	--Закрываем файл
	file:close()

	buffer.draw()
end

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--Стартовое объявление цветовой схемы при загрузке библиотеки
syntax.setColorScheme(syntax.colorSchemes.midnight)

--Епты бля!
--syntax.highlightFileForDebug("MineOS/Applications/Highlight.app/Resources/TestFile.txt", "midnight")

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return syntax