require "rendertext"
require "keys"
require "graphics"

FontChooser = {
	-- font for displaying file/dir names
	face = freetype.newBuiltinFace("sans", 25),
	fhash = "s25",
	-- font for page title
	tface = freetype.newBuiltinFace("Helvetica-BoldOblique", 32),
	tfhash = "hbo32",
	-- font for paging display
	sface = freetype.newBuiltinFace("sans", 16),
	sfhash = "s16",
	-- title height
	title_H = 45,
	-- spacing between lines
	spacing = 40,
	-- foot height
	foot_H = 27,

	-- state buffer
	fonts = {"sans", "cjk", "mono", 
		"Courier", "Courier-Bold", "Courier-Oblique", "Courier-BoldOblique",
		"Helvetica", "Helvetica-Oblique", "Helvetica-BoldOblique",
		"Times-Roman", "Times-Bold", "Times-Italic", "Times-BoldItalic",},
	items = 14,
	page = 1,
	current = 2,
	oldcurrent = 1,
}

function FontChooser:init()
	self.items = #self.fonts
	table.sort(self.fonts)
end


function FontChooser:choose(ypos, height)
	local perpage = math.floor(height / self.spacing) - 2
	local pagedirty = true
	local markerdirty = false

	local prevItem = function ()
		if self.current == 1 then
			if self.page > 1 then
				self.current = perpage
				self.page = self.page - 1
				pagedirty = true
			end
		else
			self.current = self.current - 1
			markerdirty = true
		end
	end

	local nextItem = function ()
		if self.current == perpage then
			if self.page < (self.items / perpage) then
				self.current = 1
				self.page = self.page + 1
				pagedirty = true
			end
		else
			if self.page ~= math.floor(self.items / perpage) + 1
				or self.current + (self.page-1)*perpage < self.items then
				self.current = self.current + 1
				markerdirty = true
			end
		end
	end


	while true do
		if pagedirty then
			fb.bb:paintRect(0, ypos, fb.bb:getWidth(), height, 0)

			-- draw menu title
			renderUtf8Text(fb.bb, 30, ypos + self.title_H, self.tface, self.tfhash,
				"[ Fonts Menu ]", true)

			local c
			for c = 1, perpage do
				local i = (self.page - 1) * perpage + c 
				if i <= self.items then
					y = ypos + self.title_H + (self.spacing * c)
					renderUtf8Text(fb.bb, 50, y, self.face, self.fhash, self.fonts[i], true)
				end
			end
			y = ypos + self.title_H + (self.spacing * perpage) + self.foot_H
			x = (fb.bb:getWidth() / 2) - 50
			renderUtf8Text(fb.bb, x, y, self.sface, self.sfhash,
				"Page "..self.page.." of "..(math.floor(self.items / perpage)+1), true)
			markerdirty = true
		end

		if markerdirty then
			if not pagedirty then
				if self.oldcurrent > 0 then
					y = ypos + self.title_H + (self.spacing * self.oldcurrent) + 10
					fb.bb:paintRect(30, y, fb.bb:getWidth() - 60, 3, 0)
					fb:refresh(1, 30, y, fb.bb:getWidth() - 60, 3)
				end
			end
			-- draw new marker line
			y = ypos + self.title_H + (self.spacing * self.current) + 10
			fb.bb:paintRect(30, y, fb.bb:getWidth() - 60, 3, 15)
			if not pagedirty then
				fb:refresh(1, 30, y, fb.bb:getWidth() - 60, 3)
			end
			self.oldcurrent = self.current
			markerdirty = false
		end

		if pagedirty then
			fb:refresh(0, 0, ypos, fb.bb:getWidth(), height)
			pagedirty = false
		end

		local ev = input.waitForEvent()
		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
			if ev.code == KEY_FW_UP then
				prevItem()
			elseif ev.code == KEY_FW_DOWN then
				nextItem()
			elseif ev.code == KEY_PGFWD then
				if self.page < (self.items / perpage) then
					if self.current + self.page*perpage > self.items then
						self.current = self.items - self.page*perpage
					end
					self.page = self.page + 1
					pagedirty = true
				else
					self.current = self.items - (self.page-1)*perpage
					markerdirty = true
				end
			elseif ev.code == KEY_PGBCK then
				if self.page > 1 then
					self.page = self.page - 1
					pagedirty = true
				else
					self.current = 1
					markerdirty = true
				end
			elseif ev.code == KEY_ENTER or ev.code == KEY_FW_PRESS then
				local newface = self.fonts[perpage*(self.page-1)+self.current]
				return newface
			elseif ev.code == KEY_BACK then
				return nil
			end
		end
	end
end