WIP StateMachine

----------------------------
--- STATE MACHINE DEFINITION & FUNCTIONS
---------------------------
fsm = {}

-- The format of the states table is as follows:
--
--  states = {
--      state1_name = {
--          name    = state1_name,
--          enter   = func_enterState1,
--          update  = func_updateState1,
--          exit    = func_exitState1
--      },
--      state2_name = {
--          name    = state2_name,
--          enter   = func_enterState2,
--          update  = func_updateState2,
--          exit    = func_exitState2
--      },
--      state3_name = {
--          name    = state3_name,
--          enter   = func_enterState3,
--          update  = func_updateState3,
--          exit    = func_exitState3
--      }
--  }
--
--  func_enterState1 =  function(self)
--                          must have a self object as argument
--                          things to run when entering state 1
--                      end
--  func_updateState1 = function(self) -- to be run in the game loop
--                          must have a self object as argument
--                          things to run when updating state 1 with one step
--                      end
--  func_exitState1 =   function(self)
--                          must have a self object as argument
--                          things to run when exiting state 1
--                      end
--
--  in the func_updateState1() check for an event that triggers another state, let's say state2_name
--  if such event occurs then use self:setState(states[state2_name]) to switch states
--
--

function fsm:setState(newstate)
    assert(type(newstate.name) == 'string', "fsm:setState(): newstate.name must be string" )
    assert(type(newstate.enter) == 'function' or newstate.enter == nil, "fsm:setState(): newstate.enter must be a function or nil" )
    assert(type(newstate.update) == 'function' or newstate.update == nil, "fsm:setState(): newstate.update must be a function or nil" )
    assert(type(newstate.exit) == 'function' or newstate.exit == nil, "fsm:setState(): newstate.exit must be a function or nil" )
    self:doExit()
    self.state = newstate.name
    self.updateStateFunc = newstate.update
    self.exitStateFunc = newstate.exit
    if newstate.enter then
        debug.log(self.name.." - entering state:"..self.state)
        return newstate.enter(self)
    end
end

--[[
function fsm:addState(_name, _enterStateFunc, _updateStateFunc, _exitStateFunc)
    assert(type(_name) == 'string', "fsm:addState(): _name must be string" )
    assert(type(_enterStateFunc) == 'function' or _enterStateFunc == nil, "fsm:addState(): _enterStateFunc must be a function or nil" )
    assert(type(_updateStateFunc) == 'function' or _updateStateFunc == nil, "fsm:addState(): _updateStateFunc must be a function or nil" )
    assert(type(_exitStateFunc) == 'function' or _exitStateFunc == nil, "fsm:addState(): _exitStateFunc must be a function or nil" )
    assert(self.states[_name] == nil, "fsm:addState() - state already exists")
    self.states[_name] = {
        name = _name,
        enterStateFunc = _enterStateFunc,
        updateStateFunc = _updateStateFunc,
        exitStateFunc = _exitStateFunc
    }
end
--]]

function fsm:update()
    if self.updateStateFunc then
        debug.log(self.name.." - updating state:"..self.state)
        self:updateStateFunc()
    end
end

function fsm:doExit()
    if self.exitStateFunc then
        debug.log(self.name.." - exiting state:"..self.state)
        self:exitStateFunc()
    end
end

function fsm:new(states)--, state)
    local newfsm = {}
    -- use the kew table as a metatable for the new queue object
    setmetatable(newfsm, self)
    self.__index = self
    self.name = "state machine"
    newfsm.states = states or {}
    print(newfsm.states)
    --[[
    if state then
        newfsm:setState(state)
    elseif states then
        newfsm:setState(states[1])
    end --]]
    return newfsm
end