local Players = game:GetService("Players")
local RunService = game:GetService("RunService")
local Workspace = game:GetService("Workspace")
local LocalPlayer = Players.LocalPlayer
local Camera = workspace.CurrentCamera

local MAX_DISTANCE = 16
local HIT_COOLDOWN = 0.01
local lastHit = 0

-- Prediction
local VEL_HISTORY_SIZE = 6
local MAX_PREDICT_TIME = 0.15

-- Wall Check
local WALL_CHECK = true
local WALL_PADDING = 1.5

-- Anti-Deadlock
local TARGET_TIMEOUT = 3
local lastSwitchTime = 0
local SWITCH_DELAY = 0.1

--====== СОСТОЯНИЕ ======--
local currentTarget = nil
local targetLockTime = 0
local velHistory = {}
local attackAttempts = 0
local hitSuccesses = 0

--====== БАЗОВЫЕ ФУНКЦИИ ======--
local function getChar(plr)
    return plr.Character
end

local function getHitbox(plr)
    local c = getChar(plr)
    if not c then return nil end
    return c:FindFirstChild("PlayerHitbox") or c:FindFirstChild("Head") or c:FindFirstChild("Torso")
end

local function getHum(plr)
    local c = getChar(plr)
    if not c then return nil end
    return c:FindFirstChild("Humanoid")
end

local function isAlive(plr)
    local hum = getHum(plr)
    return hum and hum.Health > 0
end

local function getPos(plr)
    local h = getHitbox(plr)
    return h and h.Position or nil
end

local function getVel(plr)
    local h = getHitbox(plr)
    return h and h.AssemblyLinearVelocity or Vector3.new()
end

local function getMyPos()
    return getPos(LocalPlayer)
end

local function getMyEye()
    local c = getChar(LocalPlayer)
    if not c then return nil end
    return c:FindFirstChild("PlayerEyeLevel") and c.PlayerEyeLevel.Position or getMyPos()
end

--====== WALL CHECK ======--
local function isVisible(target)
    if not WALL_CHECK then return true end
    
    local eye = getMyEye()
    local targetPos = getPos(target)
    if not eye or not targetPos then return false end
    
    local dir = (targetPos - eye).Unit
    local dist = (targetPos - eye).Magnitude
    
    local params = RaycastParams.new()
    params.FilterDescendantsInstances = {getChar(LocalPlayer), getChar(target)}
    params.FilterType = Enum.RaycastFilterType.Exclude
    
    local ray = Workspace:Raycast(eye, dir * (dist - WALL_PADDING), params)
    return ray == nil
end

--====== ПРЕДИКТ С СИСТЕМНЫМИ УЛУЧШЕНИЯМИ ======--
local function updateVelHistory(target)
    local vel = getVel(target)
    local pos = getPos(target)
    table.insert(velHistory, {
        vel = vel,
        pos = pos,
        time = tick()
    })
    if #velHistory > VEL_HISTORY_SIZE then
        table.remove(velHistory, 1)
    end
end

local function getSmoothedVel()
    if #velHistory < 2 then return Vector3.new() end
    
    local totalVel = Vector3.new()
    local totalWeight = 0
    
    for i, entry in ipairs(velHistory) do
        local weight = i * i -- квадратичный вес (новые важнее)
        totalVel = totalVel + entry.vel * weight
        totalWeight = totalWeight + weight
    end
    
    if totalWeight == 0 then return Vector3.new() end
    return totalVel / totalWeight
end

local function getAcceleration()
    if #velHistory < 3 then return Vector3.new() end
    
    local recent = velHistory[#velHistory]
    local old = velHistory[1]
    local dt = math.max(recent.time - old.time, 0.001)
    
    return (recent.vel - old.vel) / dt
end

local function getJerk()
    if #velHistory < 4 then return Vector3.new() end
    
    local accel1 = (velHistory[#velHistory].vel - velHistory[#velHistory-1].vel) / 
                   math.max(velHistory[#velHistory].time - velHistory[#velHistory-1].time, 0.001)
    local accel2 = (velHistory[#velHistory-1].vel - velHistory[1].vel) / 
                   math.max(velHistory[#velHistory-1].time - velHistory[1].time, 0.001)
    local dt = math.max(velHistory[#velHistory].time - velHistory[1].time, 0.001)
    
    return (accel1 - accel2) / dt
end

local function predictPosition(target)
    local hb = getHitbox(target)
    if not hb then return nil end
    
    local pos = hb.Position
    local myPos = getMyPos()
    if not myPos then return pos end
    
    local distance = (pos - myPos).Magnitude
    local smoothedVel = getSmoothedVel()
    local accel = getAcceleration()
    local jerk = getJerk()
    local speed = smoothedVel.Magnitude
    
    -- Базовое время предсказания
    local baseTime = 0.05 + distance / 45
    
    -- Корректировка от скорости цели
    if speed > 14 then
        baseTime = baseTime * 1.4
    elseif speed > 8 then
        baseTime = baseTime * 1.2
    elseif speed > 3 then
        baseTime = baseTime * 1.05
    end
    
    -- Корректировка от направления движения
    local toMe = (myPos - pos).Unit
    if smoothedVel.Magnitude > 0.1 then
        local velDir = smoothedVel.Unit
        local dot = velDir:Dot(toMe)
        
        if dot > 0.6 then
            baseTime = baseTime * 1.35
        elseif dot > 0.3 then
            baseTime = baseTime * 1.15
        elseif dot < -0.6 then
            baseTime = baseTime * 0.7
        elseif dot < -0.3 then
            baseTime = baseTime * 0.85
        end
    end
    
    -- Учёт ускорения
    local accelMag = accel.Magnitude
    if accelMag > 20 then
        baseTime = baseTime * 1.25
    elseif accelMag > 10 then
        baseTime = baseTime * 1.1
    end
    
    local predictTime = math.clamp(baseTime, 0.02, MAX_PREDICT_TIME)
    
    -- Кубическое предсказание (позиция + скорость + ускорение + рывок)
    local predicted = pos + 
                      smoothedVel * predictTime + 
                      0.5 * accel * predictTime^2 + 
                      (1/6) * jerk * predictTime^3
    
    return predicted
end

--====== УМНЫЙ СКОРИНГ ======--
local function getTargetScore(plr)
    local myPos = getMyPos()
    if not myPos then return -10000 end
    if not isAlive(plr) then return -10000 end
    
    local pos = getPos(plr)
    if not pos then return -10000 end
    
    local dist = (pos - myPos).Magnitude
    if dist > MAX_DISTANCE then return -10000 end
    
    -- Проверка видимости
    if WALL_CHECK and not isVisible(plr) then return -5000 end
    
    local hum = getHum(plr)
    local hp = hum.Health
    local maxHp = hum.MaxHealth
    local hpRatio = hp / maxHp
    local vel = getVel(plr)
    local speed = vel.Magnitude
    
    local score = 0
    
    -- 1. РАССТОЯНИЕ (оптимум 3-7 блоков)
    if dist < 2 then
        score = score + 25
    elseif dist < 5 then
        score = score + 40
    elseif dist < 8 then
        score = score + 35
    elseif dist < 12 then
        score = score + 25
    else
        score = score + 15
    end
    
    -- 2. ЗДОРОВЬЕ (добиваем слабых)
    if hpRatio < 0.1 then
        score = score + 100
    elseif hpRatio < 0.25 then
        score = score + 70
    elseif hpRatio < 0.4 then
        score = score + 45
    elseif hpRatio < 0.6 then
        score = score + 25
    elseif hpRatio < 0.8 then
        score = score + 10
    else
        score = score + 5
    end
    
    -- 3. СКОРОСТЬ (быстрые опаснее)
    if speed > 12 then
        score = score + 30
    elseif speed > 7 then
        score = score + 20
    elseif speed > 3 then
        score = score + 10
    end
    
    -- 4. УГОЛ К КАМЕРЕ (предпочитаем перед собой)
    local camForward = Camera.CFrame.LookVector
    local toTarget = (pos - Camera.CFrame.Position).Unit
    local angle = math.acos(math.clamp(camForward:Dot(toTarget), -1, 1))
    local angleDeg = math.deg(angle)
    
    if angleDeg < 30 then
        score = score + 35
    elseif angleDeg < 60 then
        score = score + 25
    elseif angleDeg < 90 then
        score = score + 15
    end
    
    -- 5. БОНУС ТЕКУЩЕЙ ЦЕЛИ (анти-дёрганье)
    if currentTarget == plr then
        local lockDuration = tick() - targetLockTime
        if lockDuration < TARGET_TIMEOUT then
            score = score + 50 + lockDuration * 5
        end
    end
    
    -- 6. ШТРАФ ЗА ЧАСТЫЕ ПЕРЕКЛЮЧЕНИЯ
    local timeSinceSwitch = tick() - lastSwitchTime
    if timeSinceSwitch < SWITCH_DELAY and currentTarget ~= plr then
        score = score - 30
    end
    
    return score
end

--====== ВЫБОР ЦЕЛИ ======--
local function findBestTarget()
    local best = nil
    local bestScore = -10000
    
    for _, plr in ipairs(Players:GetPlayers()) do
        if plr ~= LocalPlayer then
            local score = getTargetScore(plr)
            if score > bestScore then
                bestScore = score
                best = plr
            end
        end
    end
    
    return best
end

--====== АТАКА ======--
local function executeAttack(target)
    local eye = getMyEye()
    if not eye then return false end
    
    local predicted = predictPosition(target)
    if not predicted then return false end
    
    local dir = (predicted - eye).Unit
    if dir.Magnitude < 0.01 then return false end
    
    local hr = game.ReplicatedStorage.Remotes:FindFirstChild("HitRequest")
    local ar = game.ReplicatedStorage.Remotes:FindFirstChild("AnimateHit")
    
    if hr then
        attackAttempts = attackAttempts + 1
        hr:FireServer(eye, dir, target)
        if ar then ar:FireServer() end
        hitSuccesses = hitSuccesses + 1
        return true
    end
    return false
end

--====== ГЛАВНЫЙ ЦИКЛ ======--
RunService.Heartbeat:Connect(function()
    local char = getChar(LocalPlayer)
    if not char then return end
    
    local hum = getHum(LocalPlayer)
    if not hum or hum.Health <= 0 then return end
    
    -- Поиск цели
    local target = findBestTarget()
    
    if not target then
        currentTarget = nil
        velHistory = {}
        return
    end
    
    -- Обновление истории скорости
    updateVelHistory(target)
    
    -- Смена цели
    if target ~= currentTarget then
        currentTarget = target
        targetLockTime = tick()
        lastSwitchTime = tick()
        velHistory = {}
    end
    
    -- Плавный поворот камеры (можно отключить)
    local predicted = predictPosition(currentTarget)
    if predicted then
        local targetCF = CFrame.new(Camera.CFrame.Position, predicted)
        Camera.CFrame = Camera.CFrame:Lerp(targetCF, 0.25)
    end
    
    -- Атака
    local now = tick()
    if now - lastHit >= HIT_COOLDOWN then
        if executeAttack(currentTarget) then
            lastHit = now
        end
    end
end)

-- Сброс при респавне
LocalPlayer.CharacterAdded:Connect(function()
    lastHit = 0
    currentTarget = nil
    velHistory = {}
    attackAttempts = 0
    hitSuccesses = 0
end)

-- Сброс при выходе игрока
Players.PlayerRemoving:Connect(function(plr)
    if currentTarget == plr then
        currentTarget = nil
        velHistory = {}
    end
end)