-- push.lua v0.2

-- Copyright (c) 2017 Ulysse Ramage
-- Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
-- The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

local push = {
  
  defaults = {
    fullscreen = false,
    resizable = false,
    pixelperfect = false,
    highdpi = true,
    canvas = true
  }
  
}
setmetatable(push, push)

--TODO: multiple canvas w/ shaders + rendering resolution?
--TODO: clean up code

function push:applySettings(settings)
  for k, v in pairs(settings) do
    self["_" .. k] = v
  end
end

function push:resetSettings() return self:applySettings(self.defaults) end

function push:setupScreen(WWIDTH, WHEIGHT, RWIDTH, RHEIGHT, settings)

  settings = settings or {}

  self._WWIDTH, self._WHEIGHT = WWIDTH, WHEIGHT
  self._RWIDTH, self._RHEIGHT = RWIDTH, RHEIGHT

  self:applySettings(self.defaults) --set defaults first
  self:applySettings(settings) --then fill with custom settings
  
  love.window.setMode( self._RWIDTH, self._RHEIGHT, {
    fullscreen = self._fullscreen,
    resizable = self._resizable,
    highdpi = self._highdpi
  } )

  self:initValues()

  if self._canvas then
    self.canvas = love.graphics.newCanvas(self._WWIDTH, self._WHEIGHT)
  end --self.canvas = actual canvas, self._canvas = use canvas?

  self._borderColor = {0, 0, 0}

  self._drawFunctions = {
    ["start"] = self.start,
    ["end"] = self.finish
  }
end

function push:initValues()
  self._PSCALE = self._highdpi and love.window.getDPIScale() or 1
  
  self._SCALE = {
    x = self._RWIDTH/self._WWIDTH * self._PSCALE,
    y = self._RHEIGHT/self._WHEIGHT * self._PSCALE
  }
  
  if self._stretched then --if stretched, no need to apply offset
    self._OFFSET = {x = 0, y = 0}
  else
    local scale = math.min(self._SCALE.x, self._SCALE.y)
    if self._pixelperfect then scale = math.floor(scale) end
    
    self._OFFSET = {x = (self._SCALE.x - scale) * (self._WWIDTH/2), y = (self._SCALE.y - scale) * (self._WHEIGHT/2)}
    self._SCALE.x, self._SCALE.y = scale, scale --apply same scale to X and Y
  end
  
  self._GWIDTH = self._RWIDTH * self._PSCALE - self._OFFSET.x * 2
  self._GHEIGHT = self._RHEIGHT * self._PSCALE - self._OFFSET.y * 2
end

function push:setShader(shader)
  self._shader = shader
end

--[[ DEPRECATED ]]--
function push:apply(operation, shader)
  if operation == "start" then
    self:start()
  elseif operation == "finish" or operation == "end" then
    self:finish(shader)
  end
end

function push:start()
  if self._canvas then
    love.graphics.push()
    love.graphics.setCanvas(self.canvas)
  else
    love.graphics.translate(self._OFFSET.x, self._OFFSET.y)
    love.graphics.setScissor(self._OFFSET.x, self._OFFSET.y, self._WWIDTH*self._SCALE.x, self._WHEIGHT*self._SCALE.y)
    love.graphics.push()
    love.graphics.scale(self._SCALE.x, self._SCALE.y)
  end
end

function push:finish(shader)
  love.graphics.setBackgroundColor(unpack(self._borderColor))
  if self._canvas then
    love.graphics.pop()
    love.graphics.setCanvas()

    love.graphics.translate(self._OFFSET.x, self._OFFSET.y)
    love.graphics.setColor(love.math.colorFromBytes(255, 255, 255))
    love.graphics.setShader(shader or self._shader)
    love.graphics.draw(self.canvas, 0, 0, 0, self._SCALE.x, self._SCALE.y)
    love.graphics.setCanvas(self.canvas)
    love.graphics.clear()
    love.graphics.setCanvas()
    love.graphics.setShader()
  else
    love.graphics.pop()
    love.graphics.setScissor()
  end
end

function push:setBorderColor(color, g, b)
  self._borderColor = g and {color, g, b} or color
end

function push:toGame(x, y)
  x, y = x - self._OFFSET.x, y - self._OFFSET.y
  local normalX, normalY = x / self._GWIDTH, y / self._GHEIGHT
  
  x = (x >= 0 and x <= self._WWIDTH * self._SCALE.x) and normalX * self._WWIDTH or nil
  y = (y >= 0 and y <= self._WHEIGHT * self._SCALE.y) and normalY * self._WHEIGHT or nil
  
  return x, y
end

--doesn't work - TODO
function push:toReal(x, y)
  return x+self._OFFSET.x, y+self._OFFSET.y
end

function push:switchFullscreen(winw, winh)
  self._fullscreen = not self._fullscreen
  local windowWidth, windowHeight = love.window.getDesktopDimensions()
  
  if self._fullscreen then --save windowed dimensions for later
    self._WINWIDTH, self._WINHEIGHT = self._RWIDTH, self._RHEIGHT
  elseif not self._WINWIDTH or not self._WINHEIGHT then
    self._WINWIDTH, self._WINHEIGHT = windowWidth * .5, windowHeight * .5
  end
  
  self._RWIDTH = self._fullscreen and windowWidth or winw or self._WINWIDTH
  self._RHEIGHT = self._fullscreen and windowHeight or winh or self._WINHEIGHT
  
  self:initValues()
  
  love.window.setFullscreen(self._fullscreen, "desktop")
  if not self._fullscreen and (winw or winh) then
    love.window.setMode(self._RWIDTH, self._RHEIGHT) --set window dimensions
  end
end

function push:resize(w, h)
  local pixelScale = love.window.getDPIScale()
  if self._highdpi then w, h = w / pixelScale, h / pixelScale end
  self._RWIDTH = w
  self._RHEIGHT = h
  self:initValues()
end

function push:getWidth() return self._WWIDTH end
function push:getHeight() return self._WHEIGHT end
function push:getDimensions() return self._WWIDTH, self._WHEIGHT end

return push
