client_side_blocking.lua

-- [SERVER] The attack generation.
local _attack_gen = 0

-- [SERVER] When the attack animation is initiated, also request an attack ACK.
mod:hook_safe(BTAttackAction, "enter", function(self, unit, bb, t)
    if bb.action.unblockable then return end
    local mob_id = Managers.state.unit_storage:go_id(unit)
    local atk_id = _attack_gen
    mod:network_send("request_attack_ack", mob_id, atk_id)
    bb._csb_needs_ack, bb._csb_mob_id, bb._csb_atk_id = true, mob_id, atk_id
    _attack_gen = (atk_id+1) % 0x10000
end

-- [CLIENT] Attacks that require an acknowledgement.
local _client_ack_attacks = {}

-- [CLIENT] Keep track of attacks that should be confirmed.
mod:network_register("request_attack_ack", function(_, mob_id, atk_id, fatigue_type, attack_direction)
    _client_ack_attacks[mob_id] = { atk_id, fatigue_type, attack_direction }
end)

-- [SERVER] Buffer attacks that connect and require an ACK.
mod:hook(AnimationCallbackTemplates.server, "anim_cb_damage", function(func, unit, param)
    local bb = BLACKBOARDS[unit]
    local needs_ack = bb._csb_needs_ack
    if needs_ack then mod:hook_enable(DamageUtils, "add_damage_network") end
    func(unit, param)
    if needs_ack then mod:hook_disable(DamageUtils, "add_damage_network") end
    bb._csb_needs_ack = false
end

-- [CLIENT] Confirm damage at the damage point on clients.
AnimationCallbackTemplates.client.anim_cb_damage = function(unit, param)
    if Managers.player.is_server then return end
    local unit_storage = Managers.state.unit_storage
    local mob_id = unit_storage:go_id(unit)
    local atk_data = _client_ack_attacks[mob_id]
    local target_unit = Managers.player:local_player().player_unit
    if atk_id and not DamageUtils.check_block(unit, target_unit, action.fatigue_type, attack_direction) then
        mod:network_send("attack_confirm_damage", mob_id, atk_id)
    end
    _client_ack_attacks[mob_id] = nil
end

-- [SERVER] Damage buffering handling.
mod:hook_origin(DamageUtils, "add_damage_network", function(target_unit, attacker_unit, ...)
    BLACKBOARDS[attacker_unit]._csb_dmg_data = {
        n = select("#", ...), target_unit, attacker_unit, ...
    }
end
mod:hook_disable(DamageUtils, "add_damage_network")

-- [SERVER] Apply the buffered damage on a confirmation.
mod:network_register("attack_confirm_damage", function(_, mob_id, atk_id)
    local mob = Managers.state.unit_storage:unit(mob_id)
    local bb = BLACKBOARDS[mob]
    local data = bb._csb_dmg_data
    if data and data.atk_id == atk_id then
        DamageUtils.add_damage_network(unpack(data, 1, data.n))
    end
    _attacks[mob_id] = nil
end)