-- Base skill class
BaseSkill = {}
BaseSkill.__index = BaseSkill

function BaseSkill:new(asset, combatant)
  self = setmetatable({}, BaseSkill)
  self.asset = asset
  self.combatant = combatant
  self.context = combatant.context
  self.timer = 0
  self.duration = 0.5
  self.multiplier = 1
  self.config = asset.config or {}
  self.imageLoader = asset.imageLoader
  self.weapon = combatant and combatant.weapon
  self.power = self.config.power or 1
  return self
end

function BaseSkill:calcDamage(source, target)
  if target.invincible then return 0 end
  local atk = (source.stats and source.stats.atk or 5) * self.power * self.multiplier
  local lck = source.stats and source.stats.lck or 0
  local def = target.stats and target.stats.def or 0
  local maxDmg = atk - def
  if maxDmg < lck then maxDmg = lck end
  return math.random(lck, maxDmg)
end

function BaseSkill:getOpponents()
  return Utils.filterCombatantsByOpposingTeams(self.context.combatants, self.combatant.team)
end

function BaseSkill:getAllies()
  return Utils.filterCombatantsByTeam(self.context.combatants, self.combatant.team)
end

function BaseSkill:getNearestCombatant(combatants)
  return Utils.findNearestCombatant(combatants, (self.combatant.x + self.combatant.width / 2),
    (self.combatant.y + self.combatant.height / 2))
end

function BaseSkill:getCombatantsInRange(combatants, range)
  return Utils.findCombatantsWithinRange(combatants, (self.combatant.x + self.combatant.width / 2),
    (self.combatant.y + self.combatant.height / 2), range)
end

function BaseSkill:isInFront(target, range)
  local attCX = self.combatant.x + self.combatant.width / 2
  local attCY = self.combatant.y + self.combatant.height / 2
  local tgtCX = target.x + target.width / 2
  local tgtCY = target.y + target.height / 2
  local dx = tgtCX - attCX
  local dy = tgtCY - attCY
  if self.combatant.facing == 1 and dx < 0 then return false end
  if self.combatant.facing == -1 and dx > 0 then return false end
  local dist = math.sqrt(dx * dx + dy * dy)
  return not range or dist <= range
end

function BaseSkill:getWeapon()
  return self.combatant and self.combatant.weapon
end

function BaseSkill:getWeaponSprite()
  return self.combatant and self.combatant.weapon and self.combatant.weapon.sprite
end

function BaseSkill:updateWeaponSprite(dt)
  local sprite = self:getWeaponSprite()
  if sprite then
    sprite:update(dt)
  end
end

function BaseSkill:drawWeaponSpriteAnimation(x, y, options)
  local sprite = self:getWeaponSprite()
  if sprite then
    sprite:drawAnimationFrame(x, y, options)
  end
end

function BaseSkill:drawWeaponSpriteFrame(x, y, frame, options)
  local sprite = self:getWeaponSprite()
  if sprite then
    sprite:drawFrame(x, y, frame, options)
  end
end

function BaseSkill:update(dt)
end

function BaseSkill:draw()
end

return BaseSkill