--- @alias ImpactType "physic"|"magic"

--- Представляет из себя некое "взаимодействие", которое мы должны применить к персонажу в зависимости от контекста,
--- например, нанести урон.
--- @class Impact
--- @field intensity integer
--- @field impactType ImpactType
local impact = {}
impact.__index = impact

--- @param other Impact
function impact:__add(other)
    assert(self.impactType == other.impactType, "Impact types not equals each other!")
    local newImpact = Impact(self.intensity + other.intensity, self.impactType)
    return newImpact
end

--- @param other Impact
function impact:__sub(other)
    assert(self.impactType == other.impactType, "Impact types not equals each other!")
    local newImpact = Impact(self.intensity - other.intensity, self.impactType)
    return newImpact
end

--- @param intensity integer
--- @param impactType ImpactType
function Impact(intensity, impactType)
    return setmetatable({ intensity = intensity, impactType = impactType }, impact)
end

return Impact