#include "ui_defs.lua"

Ui.ContentLayout = {}
Ui.ContentLayout.Vertical =
{
	Top = 123,
	Bottom = 1233,
	Middle = 123333
}


Ui.ContentLayout.Horizontal = 
{
	Left = 1111,
	Right = 22222,
	Center = 33333
}

Ui.ContentLayout.EndFrameScaled = function()

	local w, h = UiEndFrame()
	local sx, sy = UiGetScale()

	local sw = (sx ~= 0) and w / sx or 0
	local sh = (sy ~= 0) and h / sy or 0

	return sw, sh
end

function CreateUiWindow()
	local LayoutUiWindow = {}
	setmetatable(LayoutUiWindow,
	{
		__call = function(self, w, h)
			local cx, cy = UiGetCursorPos()
			local obj = {
				x = cx,
				y = cy,
				w = w,
				h = h
			}
			setmetatable(obj, {__index = LayoutUiWindow})
			return obj
		end
	})

	function LayoutUiWindow:TranslateToCenter(offsetX, offsetY)
		offsetX = offsetX or 0
		offsetY = offsetY or 0
	
		local cx = UiGetCursorPos()
		local sx = UiGetScale()
		local wc = self.x + self.w * sx / 2
		local delta = (sx ~= 0) and ((wc - cx) / sx) or 0
	
		UiTranslate(delta + offsetX, offsetY)
	end
	

	function LayoutUiWindow:TranslateToMiddle(offsetX, offsetY)
		offsetX = offsetX or 0
		offsetY = offsetY or 0
	
		local _, cy = UiGetCursorPos()
		local _, sy = UiGetScale()
		local hc = self.y + self.h * sy / 2
		local delta = (sy ~= 0) and ((hc - cy) / sy) or 0
	
		UiTranslate(offsetX, delta + offsetY)
	end


	function LayoutUiWindow:TranslateToRightEdge(offsetX, offsetY)
		offsetX = offsetX or 0
		offsetY = offsetY or 0
	
		local cx = UiGetCursorPos()
		local sx = UiGetScale()
		local wx = self.x + self.w * sx
		local delta = (sx ~= 0) and ((wx - cx) / sx) or 0
	
		UiTranslate(delta + offsetX, offsetY)
	end
	

	function LayoutUiWindow:TranslateToLeftEdge(offsetX, offsetY)
		offsetX = offsetX or 0
		offsetY = offsetY or 0
	
		local cx = UiGetCursorPos()
		local wx = self.x
	
		UiTranslate((wx - cx) + offsetX, offsetY)
	end
	

	function LayoutUiWindow:TranslateToTopEdge(offsetX, offsetY)
		offsetX = offsetX or 0
		offsetY = offsetY or 0
	
		local _, cy = UiGetCursorPos()
		local wy = self.y
	
		UiTranslate(offsetX, (wy - cy) + offsetY)
	end


	function LayoutUiWindow:TranslateToBottomEdge(offsetX, offsetY)
		offsetX = offsetX or 0
		offsetY = offsetY or 0
	
		local _, cy = UiGetCursorPos()
		local _, sy = UiGetScale()
		local wy = self.y + self.h * sy
		local delta = (sy ~= 0) and ((wy - cy) / sy) or 0
	
		UiTranslate(offsetX, delta + offsetY)
	end

	function LayoutUiWindow:IsInRect(x, y)
		return (x > self.x) and (x < (self.x + self.w)) and
			(y > self.y) and (y < (self.y + self.h))
	end

	function LayoutUiWindow:FullyVisible(x, y, w, h)
		return (x > self.x) and (y > self.y) and 
			((self.x + self.w) > (x + w)) and ((self.y + self.h) > (y + h))
	end
	
	return LayoutUiWindow
end

function Ui.Frame(obj)

	local FrameUiWindow  = CreateUiWindow()

	local frame = Ui.Object:new {
		x = 0,
		y = 0,
		padding = { top = 0, left = 0, bottom = 0, right = 0 },

		draw = function(self)
			UiPush()
				UiAlign("top left")
				
				self.window = FrameUiWindow (self.w, self.h)
				for child in filter(self.children, function(it) return it.visible end) do

					local cw, ch = child:getSize()
                    child.actualSize = { w = cw, h = ch }

					UiPush()
						self:_translateAligned(child)
						UiPush()
							child:draw()
						UiPop()
						if self.debug then
							UiPush()
								UiFrameSkipItem(true)
								UiColor(1,0,0)
								UiRect(cw, 2)
								UiTranslate(cw - 2, 0)
								UiRect(2, ch)
								UiTranslate(-cw, ch - 2)
								UiRect(cw, 2)
								UiTranslate(0, -ch + 2)
								UiRect(2, ch)
							UiPop()
						end
					UiPop()
				end
	  		UiPop()
		end,
		
		getSize = function(self)
			UiPush()
				for child in filter(self.children, function(it) return it.visible end) do
					child:getSize()
				end
			UiPop()
			return self.w, self.h
		end,

		_translateAligned = function(self, obj)
			local hAlign = obj.hAlign or Ui.ContentLayout.Horizontal.Left
			local vAlign = obj.vAlign or Ui.ContentLayout.Vertical.Top

			if hAlign == Ui.ContentLayout.Horizontal.Left then
				self.window:TranslateToLeftEdge(self.padding.left + obj.margin.left, 0)
			elseif hAlign == Ui.ContentLayout.Horizontal.Right then
				self.window:TranslateToRightEdge(-(obj.actualSize.w + self.padding.right + obj.margin.right), 0)
			elseif hAlign == Ui.ContentLayout.Horizontal.Center then
				self.window:TranslateToCenter(-obj.actualSize.w / 2, 0)
			end

			if vAlign == Ui.ContentLayout.Vertical.Top then
				self.window:TranslateToTopEdge(0, self.padding.top + obj.margin.top)
			elseif vAlign == Ui.ContentLayout.Vertical.Bottom then
				self.window:TranslateToBottomEdge(0, -(obj.actualSize.h + self.padding.bottom + obj.margin.bottom))
			elseif vAlign == Ui.ContentLayout.Vertical.Middle then
				self.window:TranslateToMiddle(0, -obj.actualSize.h / 2)
			end
		end
	}

	return frame:new(obj)
end


function Ui.VerticalLayout(obj)
	local VerticalLayoutUiWindow = CreateUiWindow()
	local vLayout = Ui.Object:new {
		padding = 0,
		alignment = Ui.ContentLayout.Horizontal.Left,

		draw = function(self)
            UiPush()
                UiAlign("top left")
                self:getSize()
                self.window = VerticalLayoutUiWindow(self.w, self.h)
                local nextOffset = 0
                for child in filter(self.children, function(it) return it.visible end) do
					UiTranslate(0, nextOffset)

                    self:_translateAligned(child)

					UiPush()
						child:draw()
					UiPop()
					if self.debug then
                        local cw = child.actualSize.w
                        local ch = child.actualSize.h
						UiPush()
							UiFrameSkipItem(true)
							UiColor(1,1,0)
							UiRect(cw, 2)
							UiTranslate(cw - 2, 0)
							UiRect(2, ch)
							UiTranslate(-cw, ch - 2)
							UiRect(cw, 2)
							UiTranslate(0, -ch + 2)
							UiRect(2, ch)
						UiPop()
					end
					UiTranslate(0, child.actualSize.h)
					nextOffset = child.margin.bottom + self.padding
                end
            UiPop()
        end,

        getSize = function(self)
			local maxW = 0
			local totalH = 0
			for child in filter(self.children, function(it) return it.visible end) do
				local cw, ch = child:getSize()
                child.actualSize = { w = cw, h = ch }
				maxW = math.max(maxW, cw + child.margin.left + child.margin.right)
				totalH = totalH + ch + child.margin.top + child.margin.bottom + self.padding
			end
			totalH = totalH - self.padding
			self.w, self.h = maxW, totalH
            return self.w, self.h
        end,

		_translateAligned = function(self, obj)
			--override hlayout alignment if a child has specified alignment explicitly
			local align = (self.alignment == obj.hAlign or (not obj.hAlign)) and self.alignment or obj.hAlign

			if align == Ui.ContentLayout.Horizontal.Left then
				self.window:TranslateToLeftEdge(obj.margin.left, obj.margin.top)
			elseif align == Ui.ContentLayout.Horizontal.Right then
				self.window:TranslateToRightEdge(-(obj.actualSize.w + obj.margin.right), obj.margin.top)
			elseif align == Ui.ContentLayout.Horizontal.Center then
				self.window:TranslateToCenter(-obj.actualSize.w / 2 + obj.margin.left - obj.margin.right, obj.margin.top)
			end
		end
	}

	return vLayout:new(obj)
end


function Ui.HorizontalLayout(obj)
	local HorizontalLayoutUiWindow = CreateUiWindow()
	local hLayout = Ui.Object:new {
		padding = 0,
		alignment = Ui.ContentLayout.Vertical.Top,

        draw = function(self)
            UiPush()
                UiAlign("top left")
                self:getSize()
                self.window = HorizontalLayoutUiWindow(self.w, self.h)
                local nextOffset = 0
                for child in filter(self.children, function(it) return it.visible end) do
                    UiTranslate(nextOffset, 0)
                    self:_translateAligned(child)
                   
					UiPush()
						child:draw()
					UiPop()
					if self.debug then
                        local cw = child.actualSize.w
                        local ch = child.actualSize.h
						UiPush()
							UiFrameSkipItem(true)
							UiColor(1,1,0)
							UiRect(cw, 2)
							UiTranslate(cw - 2, 0)
							UiRect(2, ch)
							UiTranslate(-cw, ch - 2)
							UiRect(cw, 2)
							UiTranslate(0, -ch + 2)
							UiRect(2, ch)
						UiPop()
					end
                    UiTranslate(child.actualSize.w, 0)
                    nextOffset = child.margin.right + self.padding
                end
            UiPop()
        end,

        getSize = function(self)
			local maxH = 0
			local totalW = 0
			for child in filter(self.children, function(it) return it.visible end) do
				local cw, ch = child:getSize()
                child.actualSize = { w = cw, h = ch }
				maxH = math.max(maxH, ch + child.margin.top + child.margin.bottom)
				totalW = totalW + cw + child.margin.left + child.margin.right + self.padding
			end
			totalW = totalW - self.padding
			self.w, self.h = totalW, maxH
            return self.w, self.h
        end,

		_translateAligned = function(self, obj)
			--override vlayout alignment if a child has specified alignment explicitly
			local align = (self.alignment == obj.vAlign or (not obj.vAlign)) and self.alignment or obj.vAlign

			if align == Ui.ContentLayout.Vertical.Top then
				self.window:TranslateToTopEdge(obj.margin.left, obj.margin.top)
			elseif align == Ui.ContentLayout.Vertical.Bottom then
				self.window:TranslateToBottomEdge(obj.margin.left, -(obj.actualSize.h + obj.margin.bottom))
			elseif align == Ui.ContentLayout.Vertical.Middle then
				self.window:TranslateToMiddle(obj.margin.left, -obj.actualSize.h / 2 + obj.margin.top - obj.margin.bottom)
			end
		end
	}

	return hLayout:new(obj)
end