-- camera.lua :: a basic camera adapted to the asset/world system.
-- Use hump.camera as the view backend.

--[[
  Copyright © 2019 Kazhnuz

  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 cwd   = (...):gsub('%.camera$', '') .. "."

local CameraSystem  = Object:extend()
local View          = require(cwd .. "libs.hump.camera")

local SPLITSCREEN_ISVERTICAL  = false
local SCREEN_LIMIT            = 4

-- INIT FUNCTIONS
-- Initialize the camera system

function CameraSystem:new(world)
  self.scene = world.scene
  self.world = world

  self.verticalSplit = SPLITSCREEN_ISVERTICAL

  self:initViews()
end

function CameraSystem:initViews()
  self.views = {}

  self.views.list   = {}
  self.views.width, self.views.height   = core.screen:getDimensions()
end

-- INFO FUNCTIONS
-- Get informations from the camera system

function CameraSystem:getViewNumber()
  return #self.views.list
end

function CameraSystem:haveView()
  return (self:getViewNumber() == 0)
end

-- WRAPPER and UTILS
-- Access data from the views

function CameraSystem:addView(x, y)
  if (#self.views.list < SCREEN_LIMIT) then
    local view = {}

    view.cam    = View(x, y, 1, 0, true)
    -- TODO: add a target system in order to make a camera able
    -- to target a specific object

    table.insert(self.views.list, view)
  end
end

function CameraSystem:getView(id)
  return self.views.list[id]
end

function CameraSystem:getViewCam(id)
  local view = self:getView(id)

  return view.cam
end

function CameraSystem:attachView(id)
  if (id ~= nil) then
    local cam = self:getViewCam(id)

    cam:attach()
  end
end

function CameraSystem:detachView(id)
  if (id ~= nil) then
    local cam = self:getViewCam(id)

    cam:detach()
  end
end

return CameraSystem