local ParentObject = require "scenes.battlesystem.actors.parent"
local Movable = ParentObject:extend()

local MOVEMENT_NONE = "none"
local MOVEMENT_MOTION = "motion"
local MOVEMENT_TARGET = "target"

local ZGRAVITY = 12

local MIDDLE_ARENA = 6

function Movable:new(world, x, y, z)
    Movable.super.new(self, world, x, y, z)
    self.direction = utils.math.sign(MIDDLE_ARENA - x)

    self.start = {}
    self.start.x = x
    self.start.y = y
    self.start.z = z
    self.start.direction = self.direction

    self:resetMovement()
end

-- MOVE FUNCTIONS
-- All functions handling the moving

function Movable:resetMovement()
  self:resetMotion()
  self:resetJump()
  self:resetDirection()
  self:resetTarget()
end

function Movable:resetMovementType()
    self.movementType = MOVEMENT_NONE
end

function Movable:stopMoving()
  self:resetMotion()
  self:finishAction("goTo")
end

function Movable:updateMovement(dt)
  self:updateMotion(dt)
  self:updateDirection()
  self:updatePreviousPosition()
end

function Movable:updatePreviousPosition()
  self.xprevious = self.x
  self.yprevious = self.y
  self.zprevious = self.z
end

-- GoTo movement functions

function Movable:goTo(dx, dy, duration)
  self:resetMotion()
  self:setTarget(dx, dy)
  local speed = utils.math.pointDistance(self.x, self.y, dx, dy) / duration
  self:setMotionToPoint(speed, dx, dy)

  self.movementType = MOVEMENT_TARGET
end

function Movable:goTo3D(dx, dy, dz, duration)
  self:resetMotion()
  self:resetJump()
  self:setTarget(dx, dy, dz)
  local speed = utils.math.pointDistance3D(self.x, self.y, self.z, dx, dy, dz) / duration
  self:setMotionToPoint(speed, dx, dy, dz)

  self.movementType = MOVEMENT_TARGET
end

-- MOTION HANDLING

function Movable:resetMotion()
  self.speed, self.angle = 0, 0

  self:updatePreviousPosition()
  self:resetMovementType()
end

function Movable:setMotion(speed, angle, vertAngle)
  self.speed = speed
  self.angle = angle
  self.motion3D = (vertAngle ~= nil)
  if (self.motion3D) then
    self.vertAngle = vertAngle
  end
  self.movementType = MOVEMENT_MOTION
end

function Movable:setMotionToPoint(speed, dx, dy, dz)
    local angle = utils.math.pointDirection(self.x, self.y, dx, dy)
    local vertAngle = nil
    if (dz ~= nil) then
        local distance2D = utils.math.pointDistance(self.x, self.y, dx, dy)
        vertAngle = utils.math.pointDirection(0, self.z, distance2D, dz)
    end
    self:setMotion(speed, angle, vertAngle)
end

function Movable:updateMotion(dt)
  self:checkTarget(dt)
  self.xspeed, self.yspeed, self.zspeed = self:getMotionCoord()
  self.x = self.x + (self.xspeed) * dt
  self.y = self.y + (self.yspeed) * dt
  self.z = self.z + (self.zspeed) * dt

  self:checkGround()
end

function Movable:getMotionCoord()
    local gspeed, xspeed, yspeed, zspeed
    if (self.motion3D) then
        gspeed, zspeed = utils.math.lengthdir(self.speed, self.vertAngle)
        xspeed, yspeed = utils.math.lengthdir(gspeed, self.angle)
    else
        xspeed, yspeed = utils.math.lengthdir(self.speed, self.angle)
        zspeed = self:getJumpMotion()
    end

    return xspeed, yspeed, zspeed
end

-- Target handling

function Movable:setTarget(x, y, z)
    self.target = {}
    self.target.x = x
    self.target.y = y
    self.target.z = z
end

function Movable:isTargetActive()
    return (self.target ~= nil)
end

function Movable:resetTarget()
    self.target = nil
end

function Movable:isNearTarget(distance)
    if (not self:isTargetActive()) then
        return false
    end

    if (self.target.z == nil) then
        return (utils.math.pointDistance(self.x, self.y, self.target.x, self.target.y) <= distance)
    else
        return (utils.math.pointDistance3D(self.x, self.y, self.z, self.target.x, self.target.y, self.target.z) <= distance)
    end
end

function Movable:checkTarget(dt)
    if (self:isTargetActive()) then
        local isNearTarget = self:isNearTarget(self.speed * dt)
        if (isNearTarget) then
            self:finishTarget()
        end
    end
end

function Movable:finishTarget()
    -- TODO: add a one-time signal to target handling
    if (self.movementType == MOVEMENT_TARGET) then
        self.x = self.target.x
        self.y = self.target.y
        if (self.target.z ~= nil) then
            self.z = self.target.z
        end
        self:stopMoving()
    end
    self:resetTarget()
end

-- Direction handling

function Movable:resetDirection()
  self.direction = self.start.direction
  self.directionPrevious = self.start.direction
  self.directionLocked = false
end

function Movable:updateDirection()
  -- Handle direction
  if math.abs(self.xspeed) >= 0.01 then
    if (self.directionLocked == false) then
      self.direction = utils.math.sign(self.xspeed)
    end
  end
end

-- Jump system

function Movable:resetJump()
  self.jump = {}
  self.jump.useDefaultAnimation  = true
  self.jump.isJumping = false
  self.jump.bounceNumber = 0
  self.jump.stopWhenLanding = false

  self.zspeed = 0
  self.motion3D = false
  self.vertAngle = 0
end

function Movable:stopJumping()
  self:resetJump()
  self:finishAction("jump")
  if (self.jump.stopWhenLanding) then
    self:resetMotion()
  end
  self:changeAnimation("idle")
end

function Movable:setJump(power, bounceNumber, useDefaultAnimation)
  self.zspeed = (power * 60)
  self.jump.useDefaultAnimation = useDefaultAnimation
  self.jump.bounceNumber = bounceNumber
  self.jump.isJumping = true
end

function Movable:jumpTo(dx, dy, height, speed, useDefaultAnimation)
  height = height or 4
  self:setMotionToPoint(speed, dx, dy)

  self:setJump(height, 0, useDefaultAnimation)
  self.jump.stopWhenLanding = true
end

function Movable:jumpBack(height, speed)
  self:jumpTo(self.start.x, self.start.y, height, speed, true)
end

function Movable:getJumpMotion()
    if (self.jump.isJumping) then
        return self.zspeed - ZGRAVITY
    else
        return 0
    end
end

function Movable:checkGround()
    if (self.z <= 0 and self.jump.isJumping) then
        if (self.jump.bounceNumber > 0) then
            self.zspeed = self.zspeed * -0.5
            self.jump.bounceNumber = self.jump.bounceNumber - 1
        else
            self:stopJumping()
        end
    end
end

return Movable