--
-- Driver class - manage driver execution
--


-- Class definition
Driver = {}
Driver.__index = Driver

setmetatable(Driver, {
	__call = function(c, ...)
		return c.new(...)
	end,
})


-- private functions
local function driver_setup(self, driver)
	self.name = driver
	self.driver = entity_ai.registered_drivers[driver]
	self.properties = table.copy(self.object.script.properties)
	local driver_script = self.object.script[driver]
	if driver_script.properties then
		for k, v in pairs(driver_script.properties) do
			self.properties[k] = v
		end
	end
end

local function driver_start(self)
	local script = self.object.script
	local sounds = script[self.name].sounds
	if sounds and sounds.start then
		local spec = script.sounds[sounds.start][1]
		local params = {max_hear_distance = script.sounds[sounds.start][2].max_hear_distance,
				object = self.object.object}
		minetest.sound_play(spec, params)
	end
	--print("Calling driver start for driver " .. self.name)
	self.driver.start(self.object)
end


local function driver_stop(self)
	--print("Calling driver stop for driver " .. self.name)
	self.driver.stop(self.object)
end


--- constructor
function Driver.new(object, driver)
	local self = setmetatable({}, Driver)
	self.object = object
	driver_setup(self, driver)
	return self
end


-- public functions
function Driver:switch(driver)
	driver_stop(self)
	driver_setup(self, driver)
	driver_start(self)
end

function Driver:start()
	driver_start(self)
end

function Driver:step(dtime)
	local script = self.object.script
	local sounds = script[self.name].sounds
	if math.random(1, 200) == 1 and sounds and sounds.random then
		local spec = script.sounds[sounds.random][1]
		local params = {max_hear_distance = script.sounds[sounds.random][2].max_hear_distance,
				object = self.object.object}
		minetest.sound_play(spec, params)
	end
	self.driver.step(self.object, dtime)
end

function Driver:stop()
	driver_stop(self)
end

function Driver:get_property(property)
	return self.properties[property]
end