if not TowBarMod then TowBarMod = {} end
TowBarMod.Wrecker = TowBarMod.Wrecker or {}

local Wrecker = TowBarMod.Wrecker

Wrecker.MaxAttachDistance = 0.6
Wrecker.HeightStep = 0.30
Wrecker.MinHeightLevel = 0
Wrecker.MaxHeightLevel = 2
Wrecker.ScanRadius = 8

local SupportedWreckers = {
    -- KI5 '76 Chevrolet K Series (Workshop 3161951724)
    ["Base.76chevyC30CCwrecker"] = true,
    ["Base.76chevyC30SCwrecker"] = true,
    ["Base.76chevyK30CCwrecker"] = true,
    ["Base.76chevyK30SCwrecker"] = true,

    -- KI5 '93 Chevrolet Suburban / Silverado (Workshop 3152529790).
    -- The mechanic variant inherits the K3500 wrecker template.
    ["Base.93chevySilveradoK3500wrecker"] = true,
    ["Base.93chevySilveradoK3500mechanic"] = true,

    -- KI5 '78 AM General M35 Series Trucks (Workshop 2799152995).
    ["Base.78amgeneralM62"] = true
}

local HeightAttachmentIds = {
    [0] = "towbarWreckerHookLow",
    [1] = "towbarWreckerHookMid",
    [2] = "towbarWreckerHookHigh"
}

local function getScriptFullName(script)
    if not script then return nil end
    local ok, fullName = pcall(function() return script:getFullName() end)
    if ok and fullName then return tostring(fullName) end
    local name = script:getName()
    return name and ("Base." .. tostring(name)) or nil
end

function Wrecker.isSupportedWrecker(vehicle)
    if not vehicle then return false end
    local script = vehicle:getScript()
    local fullName = getScriptFullName(script)
    return SupportedWreckers[fullName] == true
        and vehicle:attachmentExist("hook")
end

function Wrecker.getHeightAttachmentId(level)
    return HeightAttachmentIds[Wrecker.normalizeHeightLevel(level)]
end

function Wrecker.normalizeHeightLevel(level)
    local numeric = tonumber(level) or Wrecker.MinHeightLevel
    numeric = math.floor(numeric + 0.5)
    return math.max(Wrecker.MinHeightLevel, math.min(Wrecker.MaxHeightLevel, numeric))
end

function Wrecker.nextHeightLevel(currentLevel, direction)
    local current = Wrecker.normalizeHeightLevel(currentLevel)
    local delta = tonumber(direction)
    if delta ~= -1 and delta ~= 1 then return nil end
    return math.max(Wrecker.MinHeightLevel, math.min(Wrecker.MaxHeightLevel, current + delta))
end

local function distanceSquared(pointA, pointB)
    if not pointA or not pointB then return nil end
    local dx = pointA:x() - pointB:x()
    local dy = pointA:y() - pointB:y()
    return dx * dx + dy * dy
end

local function forEachVehicle(collection, callback)
    if not collection then return end
    if type(collection) == "table" then
        for _, vehicle in ipairs(collection) do callback(vehicle) end
        return
    end

    local ok, iterator = pcall(function() return collection:iterator() end)
    if ok and iterator then
        while iterator:hasNext() do callback(iterator:next()) end
        return
    end

    local sizeOk, size = pcall(function() return collection:size() end)
    if not sizeOk then return end
    for index = 0, size - 1 do callback(collection:get(index)) end
end

local function isTargetEligible(wrecker, vehicle)
    if not vehicle or vehicle == wrecker then return false end
    if vehicle:getVehicleTowing() or vehicle:getVehicleTowedBy() then return false end
    if wrecker:getVehicleTowing() or wrecker:getVehicleTowedBy() then return false end
    local script = vehicle:getScript()
    if not script then return false end
    local name = string.lower(tostring(script:getName() or ""))
    return not string.find(name, "trailer", 1, true)
end

function Wrecker.resolveNearestTarget(wrecker, candidates)
    if not Wrecker.isSupportedWrecker(wrecker) then return nil end
    local hookPoint = wrecker:getAttachmentWorldPos("hook", Vector3f.new())
    if not hookPoint then return nil end

    local best
    local maxDistanceSquared = Wrecker.MaxAttachDistance * Wrecker.MaxAttachDistance
    forEachVehicle(candidates, function(vehicle)
        if not isTargetEligible(wrecker, vehicle) then return end
        for _, attachmentId in ipairs({ "trailerfront", "trailer" }) do
            if vehicle:attachmentExist(attachmentId) then
                local targetPoint = vehicle:getAttachmentWorldPos(attachmentId, Vector3f.new())
                local score = distanceSquared(hookPoint, targetPoint)
                if score and score <= maxDistanceSquared then
                    local vehicleId = vehicle:getId()
                    if not best or score < best.distanceSquared
                            or (score == best.distanceSquared and vehicleId < best.vehicle:getId()) then
                        best = {
                            vehicle = vehicle,
                            attachment = attachmentId,
                            distanceSquared = score
                        }
                    end
                end
            end
        end
    end)
    return best
end

function Wrecker.getWorldVehicles()
    local cell = getCell()
    return cell and cell:getVehicles() or nil
end

local function registerHookAttachments()
    local manager = getScriptManager()
    if not manager then return end
    for fullName in pairs(SupportedWreckers) do
        local script = manager:getVehicle(fullName)
        local baseAttachment = script and script:getAttachmentById("hook") or nil
        local baseOffset = baseAttachment and baseAttachment:getOffset() or nil
        if baseOffset then
            for level = Wrecker.MinHeightLevel, Wrecker.MaxHeightLevel do
                local attachmentId = HeightAttachmentIds[level]
                if script:getAttachmentById(attachmentId) == nil then
                    local attachment = ModelAttachment.new(attachmentId)
                    attachment:getOffset():set(
                        baseOffset:x(),
                        baseOffset:y() + level * Wrecker.HeightStep,
                        baseOffset:z()
                    )
                    attachment:setUpdateConstraint(false)
                    script:addAttachment(attachment)
                end
            end
        end
    end
end

Wrecker.registerHookAttachments = registerHookAttachments
Events.OnGameBoot.Add(registerHookAttachments)