local color = require("Color")
local screen = require("Screen")
local GUI = require("GUI")
local event = require("Event")
local filesystem = require("Filesystem")
local system = require("System")
local paths = require("Paths")

--------------------------------------------------------------------------------

local configPath = paths.user.applicationData .. "MultiScreen/Config.cfg"
local elementWidth = 48
local baseResolutionWidth = 146
local baseResolutionHeight = 54
local GPUProxy = screen.getGPUProxy()
local mainScreenAddress = GPUProxy.getScreen()

local config = {
	backgroundColor = 0x0,
}

--------------------------------------------------------------------------------

if filesystem.exists(configPath) then
	config = filesystem.readTable(configPath)
end

local function saveConfig()
	filesystem.writeTable(configPath, config, true)
end

local workspace, window = system.addWindow(GUI.filledWindow(1, 1, 68, 40, 0x2D2D2D))

local layout = window:addChild(GUI.layout(1, 1, window.width, window.height, 1, 1))

local function addButton(text)
	local button = layout:addChild(GUI.button(1, 1, elementWidth, 3, 0x4B4B4B, 0xD2D2D2, 0xD2D2D2, 0x4B4B4B, text))
	button.colors.disabled.background = 0x3C3C3C
	button.colors.disabled.text = 0x5A5A5A

	return button
end

local function addTextBox(lines)
	local textBox = layout:addChild(GUI.textBox(1, 1, elementWidth, 16, nil, 0x969696, lines, 1, 0, 0, true, true))
	textBox.eventHandler = nil

	return textBox
end

local function mainMenu(force)
	layout:removeChildren()

	local lines = {
		{color = 0xE1E1E1, text = "Welcome to MultiScreen software"},
		" ",
		"You can combine multiple screens into a single cluster and draw huge images saved in OCIF5 format. Image converter converter can be downloaded from it's repository:",
		"github.com/IgorTimofeev/OCIFImageConverter",
		" ",
		"There's some useful tips for best experience:",
		"• Use maximum size constructions for each screen (8x6 blocks)",
		"• Connect more power sources to screens if they're blinking",
		" "
	}

	if config.map then
		table.insert(lines, {color = 0xE1E1E1, text = "Current cluster properties:"})
		table.insert(lines, " ")
		local width, height = #config.map[1], #config.map
		table.insert(lines, width .. "x" .. height .. " screen blocks")
		table.insert(lines, width * baseResolutionWidth .. "x" .. height * baseResolutionHeight .. " OpenComputers pixels")
		-- table.insert(lines, width * baseResolutionWidth * 2 .. "x" .. height * baseResolutionHeight * 4 .. " pixels using Braille font")
	else
		table.insert(lines, {color = 0xFF4940, text = "Calibrate your system before starting"})
	end

	addTextBox(lines)

	local actionComboBox = layout:addChild(GUI.comboBox(1, 1, elementWidth, 3, 0xEEEEEE, 0x2D2D2D, 0x3C3C3C, 0x888888))
	actionComboBox:addItem("Draw image")
	actionComboBox:addItem("Calibrate")

	local filesystemChooser = layout:addChild(GUI.filesystemChooser(1, 1, elementWidth, 3, 0xE1E1E1, 0x888888, 0x3C3C3C, 0x888888, nil, "Open", "Cancel", "Choose file", "/"))
	filesystemChooser:setMode(GUI.IO_MODE_OPEN, GUI.IO_MODE_FILE)
	filesystemChooser:addExtensionFilter(".pic")
	filesystemChooser.path = config.lastPath

	local colorSelector = layout:addChild(GUI.colorSelector(2, 2, elementWidth, 3, config.backgroundColor, "Background color"))

	local actionButton = addButton("Next")

	actionComboBox.onItemSelected = function()
		filesystemChooser.hidden = actionComboBox.selectedItem ~= 1
		colorSelector.hidden = actionComboBox.selectedItem ~= 1
		actionButton.disabled = actionComboBox.selectedItem == 1 and (not filesystemChooser.path or not config.map)
	end

	filesystemChooser.onSubmit = function()
		actionComboBox.onItemSelected()
		workspace:draw()
	end

	actionButton.onTouch = function()
		if actionComboBox.selectedItem == 1 then
			local file = filesystem.open(filesystemChooser.path, "rb")

			local signature = file:readString(4)
			if signature == "OCIF" then
				local encodingMethod = file:readBytes(1)
				if encodingMethod == 5 then
					local width, height, maxWidth, maxHeight, oldWidth, oldHeight, widthLimit, heightLimit, monitorCornerImageX, monitorCornerImageY, background, foreground, symbol = 
						file:readBytes(2),
						file:readBytes(2),
						baseResolutionWidth * #config.map[1],
						baseResolutionHeight * #config.map,
						screen.getResolution()

					local function skipPixels(count)
						local trigger = 10000
						for i = 1, count do
							-- Seek тут смысла не имеет, т.к. буферное чтение куда быстрее
							file:readString(3)
							file:readUnicodeChar()

							-- Иначе может впасть в TLWY на тормознутых серваках
							if i > trigger then
								computer.pullSignal(0)
								trigger = trigger + 10000
							end
						end
					end

					-- Сейвим ебанину в конфиг
					config.lastPath = filesystemChooser.path
					config.backgroundColor = colorSelector.color
					saveConfig()

					-- Биндим гпуху к первому монику. Фишка в том, что смена резолюшна не должна затрагивать главный моник
					screen.bind(config.map[1][1], false)
					-- Сеттим разрешение разово. Все равно оно сохраняется даже при бинде
					screen.setResolution(baseResolutionWidth, baseResolutionHeight)

					for yMonitor = 1, #config.map do
						monitorCornerImageY = (yMonitor - 1) * baseResolutionHeight

						for xMonitor = 1, #config.map[yMonitor] do
							monitorCornerImageX = (xMonitor - 1) * baseResolutionWidth

							local lastMonitorPosition = file:seek("cur", 0)

							-- Биндим гпуху к выбранному монику
							screen.bind(config.map[yMonitor][xMonitor], false)
							-- Чистим вилочкой буфер
							screen.clear(config.backgroundColor)

							-- Если коорды моника в пикче воообще дотягивают до размеров самой пикчи
							if monitorCornerImageX < width and monitorCornerImageY < height then
								-- Число пикселей, которые мы можем прочесть до окончания пикчи на данном монике (вдруг она заканчивается посередине?)
								widthLimit, heightLimit =
									math.min(width - monitorCornerImageX, baseResolutionWidth),
									math.min(height - monitorCornerImageY, baseResolutionHeight)


								-- Читаем ебучие пиксели
								for yImage = 1, heightLimit do
									for xImage = 1, widthLimit do
										background, foreground = color.to24Bit(file:readBytes(1)), color.to24Bit(file:readBytes(1))
										file:readString(1)
										symbol = file:readUnicodeChar()

										screen.set(
											xImage,
											yImage,
											background,
											foreground,
											symbol
										)
									end

									-- Скипаем пиксели вплоть до начала следующего сканлайна на ДАННОМ монике
									if yImage < heightLimit then
										skipPixels(width - widthLimit)
									end
								end

								-- Если мы рассматриваем любой не последний моник в ряду
								if xMonitor < #config.map[yMonitor] then
									-- Когда все пиксели для рассматриваемого моника прочтены, надо вернуться на позицию этого моника в файле
									file:seek("set", lastMonitorPosition)
									-- А затем скипнуть пиксели шириной с этот моник вплоть до следующего моника
									skipPixels(widthLimit)
								-- Если же это последний моник в ряду
								else
									-- Считаем коорду в пикче следующего моника
									local next = xMonitor * baseResolutionWidth
									-- Если она втискивается в пикчу, то скипаем до первого моника в следующей строке
									if next < width then
										skipPixels(width - next)
									end
								end
							end							

							-- Рисуем всю хуйню с буфера
							screen.update()
						end
					end

					file:close()
					
					screen.bind(mainScreenAddress, false)
					screen.setResolution(oldWidth, oldHeight)
				else
					file:close()
					GUI.alert("Wrong encodingMethod: " .. tostring(encodingMethod))
				end
			else
				file:close()
				GUI.alert("Wrong signature: " .. tostring(signature))
			end
		else
			layout:removeChildren()	 

			addTextBox({
				{color = 0xE1E1E1, text = "Screen cluster calibration"},
				" ",
				"Specify required count of screens (not screen blocks, screens!) by horizontal and vertical"
			})

			local hSlider = layout:addChild(GUI.slider(1, 1, elementWidth, 0x66DB80, 0x0, 0xFFFFFF, 0xAAAAAA, 1, 10, 5, false, "Screens by horizontal: ", ""))
			hSlider.roundValues = true
			hSlider.height = 2

			local vSlider = layout:addChild(GUI.slider(1, 1, elementWidth, 0x66DB80, 0x0, 0xFFFFFF, 0xAAAAAA, 1, 10, 4, false, "Screens by vertical: ", ""))
			vSlider.roundValues = true
			vSlider.height = 2

			addButton("Next").onTouch = function()
				local connectedCount = -1
				for address in component.list("screen") do
					connectedCount = connectedCount + 1
				end
				
				hSlider.value, vSlider.value = math.floor(hSlider.value), math.floor(vSlider.value)
				local specifiedCount = hSlider.value * vSlider.value

				if specifiedCount <= connectedCount then
					layout:removeChildren()

					addTextBox({
						{color = 0xE1E1E1, text = "Screen cluster calibration"},
						" ",
						"Touch highlighted screen with your hand once. After touching all of screens calibration will be finished"
					})

					local SSX, SSY = 1, 1
					local function screenObjectDraw(object)
						screen.drawRectangle(object.x, object.y, object.width, object.height, (SSX == object.SX and SSY == object.SY) and 0x22FF22 or 0xE1E1E1, 0x0, " ")
					end

					local function newScreen(SX, SY)
						local object = GUI.object(1, 1, 8, 3)
						object.draw = screenObjectDraw
						object.SX = SX
						object.SY = SY

						return object
					end

					local function newScreenLine(SY)
						local lineLayout = GUI.layout(1, 1, layout.width, 3, 1, 1)
						lineLayout:setDirection(1, 1, GUI.DIRECTION_HORIZONTAL)
						lineLayout:setSpacing(1, 1, 2)

						for SX = 1, hSlider.value do
							lineLayout:addChild(newScreen(SX, SY))
						end

						return lineLayout
					end

					for SY = 1, vSlider.value do
						layout:addChild(newScreenLine(SY))
					end

					workspace:draw()

					config.map = {}
					local hue, hueStep = 0, 360 / specifiedCount
					while true do
						local e1, e2 = event.pull()
						if e1 == "touch" then
							if e2 ~= mainScreenAddress then
								GPUProxy.bind(e2, false)
								GPUProxy.setDepth(8)
								GPUProxy.setResolution(baseResolutionWidth, baseResolutionHeight)
								GPUProxy.setBackground(color.HSBToInteger(hue, 1, 1))
								GPUProxy.setForeground(0x0)
								GPUProxy.fill(1, 1, baseResolutionWidth, baseResolutionHeight, " ")

								local text = "Screen " .. SSX .. "x" .. SSY .. " has been calibrated"
								GPUProxy.set(math.floor(baseResolutionWidth / 2 - unicode.len(text) / 2), math.floor(baseResolutionHeight / 2), text)
								
								GPUProxy.bind(mainScreenAddress, false)

								config.map[SSY] = config.map[SSY] or {}
								config.map[SSY][SSX] = e2

								SSX, hue = SSX + 1, hue + hueStep
								if SSX > hSlider.value then
									SSX, SSY = 1, SSY + 1
									if SSY > vSlider.value then
										saveConfig()
										break
									end
								end

								workspace:draw()
							end
						end
					end

					mainMenu()
				else
					GUI.alert("Invalid count of connected screens. You're specified " .. specifiedCount .. " of screens, but there's " .. connectedCount .. " connected screens")
				end
			end

			workspace:draw()
		end
	end

	actionComboBox.onItemSelected()
	workspace:draw(force)
end

window.onResize = function(width, height)
	window.backgroundPanel.width = width
	window.backgroundPanel.height = height

	layout.width = width
	layout.height = height
end

--------------------------------------------------------------------------------

window:resize(window.width, window.height)
mainMenu(true)
workspace:draw()