local awful = require("awful")
local wibox = require("wibox")
local gears = require("gears")
local beautiful = require("beautiful")
local menubar = require("menubar")
local cairo = require("lgi").cairo
local Rsvg = require("lgi").Rsvg
local longpress = require("awesome-longpress")
local launcherpopup = {
 buttonsize = 128,
 spacing = 5,
 iconPath = gears.filesystem.get_configuration_dir() .. "/awesome-launcherpopup/",
 updateOnSpawn = true,
 applications = {},
 allInstances = {}
}

function launcherpopup.update()
 menubar.menu_gen.generate(function(rv)
  launcherpopup.applications = rv
  for k,v in pairs(launcherpopup.allInstances) do
   if k and v then
    w,e = pcall(v.populateMenu)
   end
  end
 end)
end

function launcherpopup.new(s)
 local menuStart = 1
 local launcherWidget = wibox.widget{
   layout = wibox.layout.fixed.vertical,
   spacing = launcherpopup.spacing
 }
 local launcher = awful.popup{
   layout = wibox.layout.fixed.vertical,
   widget = launcherWidget,
   border_color = beautiful.border_focus,
   border_width = 2,
   ontop        = true,
   placement    = awful.placement.centered,
   visible = false,
   screen = s,
 }
 local launcherButtons = wibox.widget{
   layout = wibox.layout.grid.vertical,
   spacing = launcherpopup.spacing
 }
 local launcherNav = wibox.widget{
   layout = wibox.layout.ratio.horizontal,
   forced_width = math.floor((s.geometry.width) / (launcherpopup.buttonsize + launcherpopup.spacing * 2)) * (launcherpopup.buttonsize + launcherpopup.spacing)
 }
 local launcherList = wibox.widget{
   layout = wibox.layout.grid,
   spacing = launcherpopup.spacing
 }
 launcherWidget:add(launcherList)
 launcherWidget:add(launcherNav)
 local launcherNextPage = wibox.widget{
  widget = wibox.widget.imagebox,
  image = launcherpopup.iconPath .. "/next.svg",
  forced_width=launcherpopup.buttonsize * 0.75,
  forced_height=launcherpopup.buttonsize * 0.75
 }
 local launcherPreviousPage = wibox.widget{
  widget = wibox.widget.imagebox,
  image = launcherpopup.iconPath .. "/previous.svg",
  forced_width=launcherpopup.buttonsize * 0.75,
  forced_height=launcherpopup.buttonsize * 0.75
 }
 launcherNav:add(
  wibox.container.place(launcherPreviousPage,"left","top"),
  wibox.container.place(launcherNextPage,"right","top"))
 local function fillMenu()
  launcherList:reset()
  local maxRows = math.floor(s.geometry.height / (launcherpopup.buttonsize * 1.5 + launcherpopup.spacing * 2)) - 2
  local maxColumns = math.floor((s.geometry.width) / (launcherpopup.buttonsize + launcherpopup.spacing * 2))
  local maxEntries = maxRows * maxColumns
  local x,y = 1,1
  for y = 1, maxRows do
   for x = 1, maxColumns do
    local dentry = launcherpopup.applications[(menuStart - 1) + (y-1)*maxColumns + x]
    if not dentry then dentry = {icon="",name=""} end
    local mwidget = wibox.widget{
     layout = wibox.layout.fixed.vertical
    }
    local mwicon = wibox.widget{
     image = dentry.icon or launcherpopup.iconPath .. "/default.svg",
     widget = wibox.widget.imagebox,
     forced_width = launcherpopup.buttonsize,
     forced_height = launcherpopup.buttonsize
    }
    mwidget:add(mwicon)
    local mwtext = wibox.container.constraint(wibox.widget{
     widget = wibox.widget.textbox,
     valign = "top",
     align = "center",
     text = dentry.name
    },"exact",launcherpopup.buttonsize,launcherpopup.buttonsize * 0.5)
    mwidget:add(mwtext)
    longpress.add(mwidget,function()
     if dentry.cmdline then
      awful.spawn(dentry.cmdline)
      launcher:hide()
     end
    end)
    launcherList:add_widget_at(wibox.container.constraint(mwidget,"max",launcherpopup.buttonsize,launcherpopup.buttonsize*1.5),y,x)
   end
  end
 end
 local function goToEntry(n)
  local maxRows = math.floor(s.geometry.height / (launcherpopup.buttonsize * 1.5 + launcherpopup.spacing * 2)) - 2
  local maxColumns = math.floor((s.geometry.width) / (launcherpopup.buttonsize + launcherpopup.spacing * 2))
  local maxEntries = maxRows * maxColumns
  menuStart = n
  if menuStart < 1 then menuStart = (math.floor(#launcherpopup.applications / maxEntries) * maxEntries) + 1 end
  if menuStart > #launcherpopup.applications then menuStart = 1 end
  fillMenu()
 end
 longpress.add(launcherNextPage,function()
  goToEntry(menuStart + ((math.floor(s.geometry.height / (launcherpopup.buttonsize * 1.5 + launcherpopup.spacing * 2)) - 2) * math.floor((s.geometry.width) / (launcherpopup.buttonsize + launcherpopup.spacing * 2))))
 end,
 function()
  goToEntry(#launcherpopup.applications)
 end)
 longpress.add(launcherPreviousPage,function()
  goToEntry(menuStart - ((math.floor(s.geometry.height / (launcherpopup.buttonsize * 1.5 + launcherpopup.spacing * 2)) - 2) * math.floor((s.geometry.width) / (launcherpopup.buttonsize + launcherpopup.spacing * 2))))
 end,
 function()
  goToEntry(1)
 end)
 function launcher.populateMenu()
  fillMenu()
 end
 function launcher.addButton(icon, fn)
  local newButton = awful.widget.button{
   image = launcherpopup.iconPath .. "/" .. icon
  }
  newButton:set_forced_width(launcherpopup.buttonsize)
  newButton:set_forced_height(launcherpopup.buttonsize)
  newButton:buttons(gears.table.join(
   newButton:buttons(),
   awful.button({}, 1, nil, function()
    fn()
    launcher:hide()
   end)
  ))
  launcherButtons:add(newButton)
 end

 function launcher.show(self)
  self.visible = true
 end
 function launcher.hide(self)
  self.visible = false
 end
 function launcher.toggle(self)
  self.visible = not self.visible
 end
 launcherpopup.allInstances[#launcherpopup.allInstances+1] = launcher
 launcherpopup.update()
 return launcher
end

return launcherpopup