-- AD Smart Pickup
-- Gør AutoDrives mappe-rotation for pålæsning vare-bevidst: i stedet for
-- "næste markør i mappen" vælges den markør, hvis silo har den valgte vare —
-- og blandt dem den med MINDST i (så rester tømmes først og siloer frigives).
-- Findes ingen silo med varen, bruges AutoDrives originale rotation uændret.
--
-- Behovsstyret forsyning: er der valgt FLERE varer i AutoDrive, ses de som
-- ingredienser til aflæsningsmålet (fx en TMR-blander). Pr. tur hentes den
-- ingrediens målet mangler mest, fra en silo hvor som helst på kortet.

ADSmartPickup = {}

-- Markøren er dér hvor trækkerens næse stopper; læssetriggeren ligger et
-- vogntog bagved. Siloer tættere end dette regnes som "markørens silo".
ADSmartPickup.MAX_MARKER_TO_TRIGGER_DISTANCE = 40
-- Under dette niveau regnes siloen som tom (undgår ture efter støv-rester).
ADSmartPickup.MIN_USEFUL_LITERS = 1
ADSmartPickup.LOG_PREFIX = "ADSmartPickup: "

local LOAD_TRIGGER_NODE_FIELDS = {"triggerNode"}
local UNLOAD_TRIGGER_NODE_FIELDS = {"exactFillRootNode", "triggerNode", "aiNode"}

local isHooked = false
-- køretøj -> {ingredients, narrowedTo}. AutoDrive roterer selv vare ved triggeren
-- når flere er valgt, så valget indsnævres til én pr. tur; listen huskes her.
local supplyState = setmetatable({}, {__mode = "k"})

-- Cross-mod adgang: FS25-mods er sandboxede; AutoDrives globals ligger
-- i den globale tabel FS25_AutoDrive (zip-navnet).
local function getAutoDriveEnv()
    if FS25_AutoDrive ~= nil and FS25_AutoDrive.ADMultipleTargetsManager ~= nil then
        return FS25_AutoDrive
    end
    return nil
end

local function getFarmId(vehicle)
    if vehicle.getOwnerFarmId ~= nil then
        local farmId = vehicle:getOwnerFarmId()
        if farmId ~= nil and farmId > 0 then
            return farmId
        end
    end
    if vehicle.spec_aiVehicle ~= nil and vehicle.spec_aiVehicle.startedFarmId ~= nil and vehicle.spec_aiVehicle.startedFarmId > 0 then
        return vehicle.spec_aiVehicle.startedFarmId
    end
    return nil
end

local function getWantedFillTypes(driver)
    local wanted = {}
    local selected = driver.ad.stateModule:getSelectedFillTypes()
    if type(selected) == "table" then
        for _, fillType in pairs(selected) do
            table.insert(wanted, fillType)
        end
    end
    if #wanted == 0 then
        local fillType = driver.ad.stateModule:getFillType()
        if fillType ~= nil then
            table.insert(wanted, fillType)
        end
    end
    return wanted
end

local function getDistanceToTriggers(triggers, nodeFields, x, z)
    local closest = math.huge
    for _, trigger in pairs(triggers or {}) do
        for _, field in ipairs(nodeFields) do
            local node = trigger[field]
            if node ~= nil and entityExists(node) then
                local tx, _, tz = getWorldTranslation(node)
                closest = math.min(closest, MathUtil.vector2Length(x - tx, z - tz))
            end
        end
    end
    return closest
end

local function getClosestStation(candidateStations, triggersField, nodeFields, wayPoint, farmId)
    local bestStation = nil
    local bestDistance = ADSmartPickup.MAX_MARKER_TO_TRIGGER_DISTANCE
    for _, station in pairs(candidateStations) do
        if g_currentMission.accessHandler:canFarmAccess(farmId, station) then
            local distance = getDistanceToTriggers(station[triggersField], nodeFields, wayPoint.x, wayPoint.z)
            if distance < bestDistance then
                bestDistance = distance
                bestStation = station
            end
        end
    end
    return bestStation
end

local function getLoadStationAtMarker(wayPoint, farmId)
    return getClosestStation(g_currentMission.storageSystem:getLoadingStations(), "loadTriggers", LOAD_TRIGGER_NODE_FIELDS, wayPoint, farmId)
end

local function getUnloadStationAtMarker(wayPoint, farmId)
    return getClosestStation(g_currentMission.storageSystem:getUnloadingStations(), "unloadTriggers", UNLOAD_TRIGGER_NODE_FIELDS, wayPoint, farmId)
end

-- Siloens EGET indhold. Udvidelses-siloer (isExtension) deler lager med naboer
-- inden for storageRadius, så stationens niveau er en nabo-sum — eget lager er
-- det tal spilleren ser på siloen og giver en præcis "mindst først"-rangering.
local function getOwnStorageLevel(station, fillTypes)
    local placeable = station.owningPlaceable
    local storages = placeable ~= nil and placeable.spec_silo ~= nil and placeable.spec_silo.storages or nil
    if storages == nil then
        return 0
    end
    local total = 0
    for _, storage in pairs(storages) do
        for _, fillType in ipairs(fillTypes) do
            total = total + (storage:getFillLevel(fillType) or 0)
        end
    end
    return total
end

-- Returnerer niveau + om det er siloens eget lager (true) eller kun nabo-lagre (false).
local function getStationFillLevel(station, fillTypes, farmId)
    local ownLevel = getOwnStorageLevel(station, fillTypes)
    if ownLevel >= ADSmartPickup.MIN_USEFUL_LITERS then
        return ownLevel, true
    end
    -- intet i eget lager: stationen kan stadig læsse fra nabo-lagre
    local total = 0
    for _, fillType in ipairs(fillTypes) do
        total = total + (station:getFillLevel(fillType, farmId) or 0)
    end
    return total, false
end

-- Parrer markører med deres læssestation (markører uden station udelades).
-- excludedPlaceable: aflæsningsmålets egen placeable må ikke være kilde.
local function collectMarkerStations(adEnv, candidateMarkers, farmId, excludedPlaceable)
    local markerStations = {}
    for _, marker in pairs(candidateMarkers) do
        local wayPoint = adEnv.ADGraphManager:getWayPointById(marker.id)
        local station = wayPoint ~= nil and getLoadStationAtMarker(wayPoint, farmId) or nil
        local isExcluded = station ~= nil and excludedPlaceable ~= nil and station.owningPlaceable == excludedPlaceable
        if station ~= nil and not isExcluded then
            table.insert(markerStations, {marker = marker, station = station})
        end
    end
    return markerStations
end

-- Mindst fyldte silo der har varen; siloer med varen i EGET lager går altid
-- forud for dem der kun kan låne fra naboer. Returnerer et valg eller nil.
local function findLeastFilled(markerStations, fillTypes, farmId)
    local best = {[true] = {level = math.huge}, [false] = {level = math.huge}}
    for _, entry in ipairs(markerStations) do
        local level, isOwn = getStationFillLevel(entry.station, fillTypes, farmId)
        if level >= ADSmartPickup.MIN_USEFUL_LITERS and level < best[isOwn].level then
            best[isOwn] = {level = level, marker = entry.marker}
        end
    end

    local choice = best[true].marker ~= nil and best[true] or best[false]
    if choice.marker == nil then
        return nil
    end
    return {
        markerIndex = choice.marker.markerIndex,
        markerName = choice.marker.name,
        group = choice.marker.group,
        level = choice.level,
    }
end

-- Mappe-logik: mappens mindst fyldte silo der har den/de valgte varer, ellers nil.
function ADSmartPickup.findLeastFilledPickup(adEnv, driver)
    local firstMarker = driver.ad.stateModule:getFirstMarker()
    if firstMarker == nil or firstMarker.group == nil or firstMarker.group == "All" then
        return nil
    end
    local farmId = getFarmId(driver)
    local fillTypes = getWantedFillTypes(driver)
    if farmId == nil or #fillTypes == 0 then
        return nil
    end
    local groupMarkers = adEnv.ADGraphManager:getMapMarkersInGroup(firstMarker.group)
    return findLeastFilled(collectMarkerStations(adEnv, groupMarkers, farmId, nil), fillTypes, farmId)
end

-- Lagrene bag aflæsningsstationen; produktionspunkter uden targetStorages læses direkte.
local function getTargetStorages(station)
    if station.targetStorages ~= nil and next(station.targetStorages) ~= nil then
        return station.targetStorages
    end
    local placeable = station.owningPlaceable
    local productionPoint = placeable ~= nil and placeable.spec_productionPoint ~= nil and placeable.spec_productionPoint.productionPoint or nil
    if productionPoint ~= nil and productionPoint.storage ~= nil then
        return {productionPoint.storage}
    end
    return {}
end

-- Niveau + kapacitet pr. ingrediens i aflæsningsmålets lager.
local function getTargetNeeds(station, ingredients, farmId)
    local needs = {}
    local storages = getTargetStorages(station)
    for _, fillType in ipairs(ingredients) do
        if station.getIsFillTypeSupported == nil or station:getIsFillTypeSupported(fillType) then
            local level, freeSpace = 0, 0
            for _, storage in pairs(storages) do
                level = level + (storage:getFillLevel(fillType) or 0)
                freeSpace = freeSpace + (storage:getFreeCapacity(fillType) or 0)
            end
            if level + freeSpace <= 0 and station.getFreeCapacity ~= nil then
                -- ukendt lagertype: brug stationens egen opgørelse af fri plads
                level, freeSpace = 0, station:getFreeCapacity(fillType, farmId) or 0
            end
            table.insert(needs, {fillType = fillType, level = level, capacity = level + freeSpace})
        end
    end
    return needs
end

-- Behovsstyret: den ingrediens aflæsningsmålet mangler mest, som også findes i en silo.
function ADSmartPickup.findSupplyPickup(adEnv, driver, ingredients)
    local secondMarker = driver.ad.stateModule:getSecondMarker()
    local farmId = getFarmId(driver)
    if secondMarker == nil or farmId == nil then
        return nil
    end
    local targetWayPoint = adEnv.ADGraphManager:getWayPointById(secondMarker.id)
    local target = targetWayPoint ~= nil and getUnloadStationAtMarker(targetWayPoint, farmId) or nil
    if target == nil then
        return nil
    end

    local allMarkers = adEnv.ADGraphManager:getMapMarkers()
    local markerStations = collectMarkerStations(adEnv, allMarkers, farmId, target.owningPlaceable)
    for _, need in ipairs(ADSupplyPlanner.rankNeeds(getTargetNeeds(target, ingredients, farmId))) do
        local choice = findLeastFilled(markerStations, {need.fillType}, farmId)
        if choice ~= nil then
            return {
                markerIndex = choice.markerIndex,
                markerName = choice.markerName,
                group = choice.group,
                level = choice.level,
                fillType = need.fillType,
                need = need,
            }
        end
    end
    return nil
end

local function applySupplyChoice(driver, ingredients, choice)
    local stateModule = driver.ad.stateModule
    stateModule:setFillType(choice.fillType)
    stateModule.selectedFillTypes = {choice.fillType}
    stateModule:raiseDirtyFlag()
    supplyState[driver] = {ingredients = ingredients, narrowedTo = choice.fillType}
end

-- Samlet valg: behovsstyret når flere varer er valgt, ellers mappe-logik. nil = AutoDrives original.
function ADSmartPickup.choosePickup(adEnv, driver)
    local selected = driver.ad.stateModule:getSelectedFillTypes()
    local ingredients = ADSupplyPlanner.resolveIngredients(supplyState[driver], selected)
    if ingredients == nil then
        supplyState[driver] = nil
        return ADSmartPickup.findLeastFilledPickup(adEnv, driver)
    end

    local choice = ADSmartPickup.findSupplyPickup(adEnv, driver, ingredients)
    if choice == nil then
        return ADSmartPickup.findLeastFilledPickup(adEnv, driver)
    end
    applySupplyChoice(driver, ingredients, choice)
    return choice
end

local function describeChoice(choice)
    if choice.fillType == nil then
        return string.format("%.0f l", choice.level)
    end
    local fillTypeName = g_fillTypeManager ~= nil and g_fillTypeManager:getFillTypeNameByIndex(choice.fillType) or tostring(choice.fillType)
    return string.format("%s: kilde %.0f l, målet har %.0f/%.0f l", tostring(fillTypeName), choice.level, choice.need.level, choice.need.capacity)
end

local function installHook(adEnv)
    local manager = adEnv.ADMultipleTargetsManager
    local originalGetNextPickup = manager.getNextPickup

    manager.getNextPickup = function(self, driver, forcedSkip)
        local ok, choice = pcall(ADSmartPickup.choosePickup, adEnv, driver)
        if not ok then
            Logging.warning(ADSmartPickup.LOG_PREFIX .. "fejl i silo-opslag, bruger AutoDrives rotation: %s", tostring(choice))
            return originalGetNextPickup(self, driver, forcedSkip)
        end
        if choice == nil then
            return originalGetNextPickup(self, driver, forcedSkip)
        end

        -- hold AutoDrives egen rotations-tilstand konsistent med vores valg
        self.pickups[choice.group] = self.pickups[choice.group] or {}
        self.pickups[choice.group].lastTarget = choice.markerIndex
        self.pickups[choice.group].lastVehicle = driver

        Logging.info(ADSmartPickup.LOG_PREFIX .. "'%s' -> %s (%s)", tostring(driver:getName()), tostring(choice.markerName), describeChoice(choice))
        return choice.markerIndex
    end

    Logging.info(ADSmartPickup.LOG_PREFIX .. "aktiv (mindst fyldte silo med varen; flere valgte varer = behovsstyret forsyning)")
end

-- Når AutoDrive stopper, får køretøjet hele ingredienslisten tilbage i varevalget
-- (AutoDrive gemmer valget i savegame, så listen overlever også en genindlæsning).
local function restoreStoppedVehicles()
    for vehicle, state in pairs(supplyState) do
        local stateModule = vehicle.ad ~= nil and vehicle.ad.stateModule or nil
        if stateModule == nil or not stateModule:isActive() then
            supplyState[vehicle] = nil
            local selected = stateModule ~= nil and stateModule:getSelectedFillTypes() or nil
            if type(selected) == "table" and #selected == 1 and selected[1] == state.narrowedTo then
                stateModule.selectedFillTypes = ADSupplyPlanner.copyList(state.ingredients)
                stateModule:raiseDirtyFlag()
            end
        end
    end
end

function ADSmartPickup:update(dt)
    if not isHooked then
        local adEnv = getAutoDriveEnv()
        if adEnv ~= nil and g_currentMission ~= nil and g_currentMission.storageSystem ~= nil then
            installHook(adEnv)
            isHooked = true
        end
        return
    end

    local ok, err = pcall(restoreStoppedVehicles)
    if not ok then
        Logging.warning(ADSmartPickup.LOG_PREFIX .. "kunne ikke gendanne varevalg: %s", tostring(err))
        supplyState = setmetatable({}, {__mode = "k"})
    end
end

addModEventListener(ADSmartPickup)