-- AD Field Work
-- Udsendelse og opfølgning af markflådens sæt: AutoDrive kører sættet til markens F-markør, derfra starter
-- Courseplay arbejdet (eget kursus, kopieret kursus eller multi-tool-bane), og når det er færdigt kører
-- sættet hjem. Læssevogne tømmes af AutoDrive (Hent og aflever), aflæsningsvogne under høst er Courseplays
-- combine-unloader. Beslutningen om HVAD der sendes ud ligger i ADFieldJobs.decide.

ADFieldWork = {}

ADFieldWork.ARRIVE_DISTANCE = 30
ADFieldWork.IDLE_CONFIRM_MS = 5000
ADFieldWork.START_TIMEOUT_MS = 60000
ADFieldWork.COURSE_WAIT_MS = 180000
ADFieldWork.PLAYER_DRIVING_KMH = 3
-- riven skal være udfoldet og i gang, før nedlægningsområdet måles
ADFieldWork.WINDROW_MEASURE_MS = 10000
-- mangler der sæt, prøves igen efter så lang tid (ikke hvert sekund over hele flåden)
ADFieldWork.NO_RIG_RETRY_MS = 30000
ADFieldWork.REFILL_ROLES = {seeder = true, fertilizer = true, limer = true, weeder = true}

local function log(...) ADFieldJobs.log(...) end
local function note(...) ADFieldJobs.note(...) end
local function now() return ADFieldJobs.now end

-- ---- AutoDrive ----

local function stateModule(vehicle)
    return vehicle.ad ~= nil and vehicle.ad.stateModule or nil
end

local function isAdActive(vehicle)
    local module = stateModule(vehicle)
    return module ~= nil and module:isActive()
end

local function stopAd(vehicle)
    if isAdActive(vehicle) then vehicle:stopAutoDrive() end
end

-- Parkerede køretøjer SOVER i FS25 (motoren kalder ikke onUpdate), så AutoDrives køreopgave står stille,
-- til nogen vækker dem (in-game 25/9). Samme greb som flows (applyAndStart) + raiseActive fra AI-Bonden.
local function wake(vehicle, kick)
    if vehicle.raiseActive ~= nil then vehicle:raiseActive() end
    if kick and vehicle.isServer and SpecializationUtil ~= nil and SpecializationUtil.raiseEvent ~= nil then
        SpecializationUtil.raiseEvent(vehicle, "onUpdate", 16, false, false, false)
    end
end

local function enableParkAtJobFinished(vehicle)
    local setting = vehicle.ad.settings ~= nil and vehicle.ad.settings.enableParkAtJobFinished or nil
    if setting ~= nil then
        setting.current = 2
        setting.new = 2
    end
end

local function helperCp(adEnv)
    return adEnv.ADStateModule ~= nil and adEnv.ADStateModule.HELPER_CP or 1
end

local function startAd(adEnv, vehicle, mode, firstId, secondId)
    local module = stateModule(vehicle)
    stopAd(vehicle)
    module:setMode(mode)
    module:setFirstMarkerByWayPointId(firstId)
    if secondId ~= nil then module:setSecondMarkerByWayPointId(secondId) end
    module:setStartHelper(false)
    if module.setActualFarmId ~= nil then module:setActualFarmId(vehicle:getOwnerFarmId()) end
    module:raiseDirtyFlag()
    local current = module:getCurrentMode()
    if current ~= nil and current.start ~= nil then
        current:start(adEnv.AutoDrive.USER_PLAYER or 1)
    else
        vehicle:startAutoDrive()
    end
    wake(vehicle, true)
end

-- AD-parkering: sidder på redskabet og kopieres af AD til traktorens stateModule (markør-INDEKS).
local function parkMarkerId(adEnv, vehicle)
    local module = stateModule(vehicle)
    local index = module ~= nil and module.getParkDestinationAtJobFinished ~= nil and module:getParkDestinationAtJobFinished() or nil
    if index == nil or index < 1 then return nil end
    local marker = adEnv.ADGraphManager:getMapMarkerById(index)
    return marker ~= nil and marker.id or nil
end

local function restLoad(adEnv, vehicle)
    local ok, level = pcall(function()
        return (adEnv.AutoDrive.getAllFillLevels(adEnv.AutoDrive.getAllUnits(vehicle)))
    end)
    return ok and tonumber(level) or 0
end

local function vehiclePosition(vehicle)
    local x, _, z = getWorldTranslation(vehicle.rootNode)
    return x, z
end

local function isControlledByPlayer(vehicle)
    return (vehicle.getIsControlled ~= nil and vehicle:getIsControlled()) or false
end

-- ---- flåde ----

function ADFieldWork.getRigs(adEnv)
    local rigs = {}
    local state = ADFieldJobs.state
    for _, vehicle in ipairs(ADRunsController.getFarmVehicles(adEnv)) do
        local specs = ADCpBridge.getSpecs(vehicle)
        local role = ADFieldFleet.roleFromSpecs(specs)
        local id = ADRunsController.getVehicleId(vehicle)
        if role ~= nil and id ~= nil then
            local x, z = vehiclePosition(vehicle)
            local rig = {
                id = id, vehicle = vehicle, role = role, label = ADRuns.vehicleLabel(vehicle),
                enabled = ADFieldFleet.isEnabled(state.fleetMode, state.fleet, id),
                -- optaget: vores egen opgave, et Smart Pickup-flow, eller AutoDrive/Courseplay kører den allerede
                -- (fx spillerens egen parkeringstur) — den må ikke kapres midt i en anden kørsel
                busy = state.assignments[id] ~= nil or ADRunsController.getRunForVehicle(vehicle) ~= nil
                    or isAdActive(vehicle) or ADCpBridge.isWorking(vehicle),
                controlled = isControlledByPlayer(vehicle),
                width = ADCpBridge.getWorkWidth(vehicle), x = x, z = z,
            }
            if role == "harvester" then rig.fruits = ADCpBridge.getHarvestFruits(vehicle) or {} end
            if role == "seeder" then
                rig.seedFruits = ADCpBridge.getSeedFruits(vehicle)
                rig.hasSeeds = ADCpBridge.hasSeeds(vehicle)
            end
            if role == "weeder" then rig.mechanical = ADCpBridge.isMechanicalWeeder(vehicle) end
            table.insert(rigs, rig)
        end
    end
    return rigs
end

-- ---- lager ----

-- Gårdens gæringssiloer for markens skår, nærmest marken først (produktioner skår -> SILAGE).
function ADFieldWork.getFermenters(adEnv, farmId, windrowFillType, x, z)
    local silage = g_fillTypeManager ~= nil and g_fillTypeManager:getFillTypeIndexByName("SILAGE") or nil
    local result = {}
    for _, building in ipairs(ADBuildings.list(adEnv, farmId)) do
        local spec = building.kind == "factory" and building.placeable ~= nil and building.placeable.spec_productionPoint or nil
        local point = spec ~= nil and spec.productionPoint or nil
        if point ~= nil and ADFieldModel.isFermenter(point.productions, windrowFillType, silage) then
            local bx, _, bz = getWorldTranslation(building.placeable.rootNode)
            table.insert(result, {building = building, distance = (bx - (x or bx)) ^ 2 + (bz - (z or bz)) ^ 2})
        end
    end
    table.sort(result, function(a, b) return a.distance < b.distance end)
    local buildings = {}
    for _, entry in ipairs(result) do table.insert(buildings, entry.building) end
    return buildings
end

local function unloadMarkerIds(buildings)
    local markerIds = {}
    for _, building in ipairs(buildings) do
        for _, marker in ipairs(ADBuildings.getMarkers(building, "unload") or {}) do
            table.insert(markerIds, marker.id)
        end
    end
    return markerIds
end

-- Hvilken vare markens trin fører til lager: skår (ensilage), tørskår (hø) eller høstet afgrøde.
function ADFieldWork.storeFillType(field, info)
    if field.stage == "harvesting" then return info.harvestFillType end
    if field.stage == "strawCollecting" or field.stage == "baling" or field.stage == "baleCollecting" then
        return g_fillTypeManager:getFillTypeIndexByName("STRAW")
    end
    local product = ADFieldModel.product(field.plan, field.kind or info.kind)
    return product == "hay" and info.hay or info.windrow
end

-- Tvunget lager -> de valgte; ensilage -> gæringssiloer før almindelige siloer (in-game 25/9: græs endte
-- i en Farma-silo); hø og høst -> kun siloer (gæringssiloer laver også hø om til ensilage).
function ADFieldWork.chooseStore(adEnv, field, info, vehicle, fillType)
    local isReachable = function(markerId) return ADUnloadWait.hasRouteTo(adEnv, vehicle, markerId) end
    local farmId = vehicle:getOwnerFarmId()
    if #field.plan.storeBuildingIds > 0 then
        local buildings = {}
        for _, buildingId in ipairs(field.plan.storeBuildingIds) do
            local building = ADBuildings.find(adEnv, farmId, buildingId)
            if building ~= nil then table.insert(buildings, building) end
        end
        return ADLoadSwap.findForcedDumpMarker(adEnv, vehicle, fillType, 1, unloadMarkerIds(buildings), isReachable)
    end
    local product = ADFieldModel.product(field.plan, field.kind or info.kind)
    if field.stage == "collecting" and product == "silage" then
        local fermenters = ADFieldWork.getFermenters(adEnv, farmId, fillType, info.x, info.z)
        if #fermenters > 0 then
            local store, why = ADLoadSwap.findForcedDumpMarker(adEnv, vehicle, fillType, 1, unloadMarkerIds(fermenters), isReachable)
            if store ~= nil then return store end
            log(field.id, "ingen gæringssilo kan tage græsset (%s) — bruger almindelig silo", tostring(why))
        end
    end
    return ADLoadSwap.findDumpMarker(adEnv, vehicle, fillType, 1, info.markerId, isReachable, nil, nil, false)
end

-- ---- kurser ----

local function coursesOf(fieldId)
    ADFieldJobs.courses[fieldId] = ADFieldJobs.courses[fieldId] or {}
    return ADFieldJobs.courses[fieldId]
end

-- Kurset et trin skal genbruge ("mower"/"rake"/"harvester"): gemt kopi, ellers maskinens nuværende kursus.
local function sourceCourse(adEnv, field, source)
    local saved = coursesOf(field.id)[source]
    if saved ~= nil then return saved end
    local vehicleIds = {mower = field.mowVehicleId, rake = field.rakeVehicleId, harvester = field.harvestVehicleId}
    local vehicleId = vehicleIds[source]
    if vehicleId == nil then return nil end
    for _, vehicle in ipairs(ADRunsController.getFarmVehicles(adEnv)) do
        if ADRunsController.getVehicleId(vehicle) == vehicleId then return ADCpBridge.getCourse(vehicle) end
    end
    return nil
end

local function copyCourse(course)
    if course ~= nil and course.copy ~= nil then
        local ok, copy = pcall(course.copy, course)
        if ok and copy ~= nil then return copy end
    end
    return course
end

local function rememberCourse(field, key, vehicle)
    coursesOf(field.id)[key] = copyCourse(ADCpBridge.getCourse(vehicle))
end

-- ---- udsendelse ----

local function restoreToolOffset(assignment)
    if assignment.restoreToolOffset ~= nil then
        ADCpBridge.setToolOffset(assignment.vehicle, assignment.restoreToolOffset)
        assignment.restoreToolOffset = nil
    end
end

function ADFieldWork.release(assignment, phase)
    restoreToolOffset(assignment)
    if assignment.handle ~= nil then assignment.handle.cancelled = true end
    assignment.phase = phase or "released"
    ADFieldJobs.state.assignments[assignment.vehicleId] = nil
end

local function fail(fieldId, text)
    note(fieldId, {retryAt = now() + ADFieldModel.RETRY_MS, reason = {text = tostring(text)}})
    log(fieldId, "%s", tostring(text))
    ADFieldJobs.notify(string.format("F%s: %s", tostring(fieldId), tostring(text)), true)
end

-- Hvad et sæt skal kunne ud over rollen (afgrøde, frø, ukrudtets størrelse).
local function acceptFor(field, info, role)
    if role == "harvester" then
        local fruit = info.fruitIndex
        return function(candidate) return fruit ~= nil and candidate.fruits ~= nil and candidate.fruits[fruit] == true end
    elseif role == "seeder" then
        local fruitIndex = ADFieldWork.sowFruitIndex(field)
        return function(candidate) return candidate.hasSeeds and fruitIndex ~= nil and candidate.seedFruits[fruitIndex] == true end
    elseif role == "weeder" then
        local large = (info.weed or 0) > ADFieldModel.WEED_MECHANICAL_MAX
        return function(candidate) return not (large and candidate.mechanical) end
    end
    return nil
end

function ADFieldWork.sowFruitIndex(field)
    local name = ADFieldModel.sowFruit(field)
    if name == nil or g_fruitTypeManager == nil then return nil end
    local fruit = g_fruitTypeManager:getFruitTypeByName(name)
    return fruit ~= nil and fruit.index or nil
end

-- Kan trinnet overhovedet begynde? (såning: afgrøde valgt og i såperioden)
local function preflight(field, role)
    if role == "seeder" then
        local fruitIndex = ADFieldWork.sowFruitIndex(field)
        if fruitIndex == nil then return false, {key = "spu_field_reason_noSowFruit"} end
        if not ADCpBridge.isPlantableNow(fruitIndex) then
            return false, {key = "spu_field_reason_notPlantable", name = ADFieldModel.sowFruit(field)}
        end
    end
    return true
end

function ADFieldWork.dispatch(adEnv, field, info, decision)
    local role = decision.role
    local ok, reason = preflight(field, role)
    if not ok then
        note(field.id, {retryAt = now() + ADFieldModel.RETRY_MS, reason = reason})
        return
    end
    local candidates = ADFieldWork.getRigs(adEnv)
    local required = ADFieldModel.requiredWidth(field, role)
    local accept = acceptFor(field, info, role)
    local rigs, why, args
    if (decision.count or 1) > 1 then
        rigs, why, args = ADFieldFleet.pickMany(candidates, role, decision.count, info.x, info.z, required, accept)
    else
        local rig
        rig, why, args = ADFieldFleet.pick(candidates, role, info.x, info.z, required, accept)
        rigs = rig ~= nil and {rig} or nil
    end
    if rigs == nil then
        note(field.id, {reason = {key = "spu_field_reason_" .. tostring(why), role = role, args = args}, retryAt = now() + ADFieldWork.NO_RIG_RETRY_MS})
        return
    end
    local count = #rigs
    local lanes = ADFieldModel.lanePositions(count)
    for index, rig in ipairs(rigs) do
        local assignment = {
            vehicleId = rig.id, vehicle = rig.vehicle, fieldId = field.id, role = role, stage = field.stage,
            helper = decision.helper == true, phase = "driving", since = now(), width = rig.width,
            groupSize = decision.helper and 1 or count, lane = count > 1 and lanes[index] or nil, leader = index == 1,
            fillType = decision.helper and info.harvestFillType or nil,
        }
        ADFieldJobs.state.assignments[rig.id] = assignment
        startAd(adEnv, rig.vehicle, adEnv.AutoDrive.MODE_DRIVETO, info.markerId, nil)
        log(field.id, "%s '%s' sendt til %s (%.1f m%s)", role, rig.label, tostring(info.markerName), rig.width or 0,
            assignment.lane ~= nil and string.format(", bane %d", assignment.lane) or "")
    end
    note(field.id, {reason = false})
end

-- Læssevogn: AutoDrive overtager ved "fuld" (Hent og aflever F -> lager, hjælper = Courseplay).
local function prepareCollector(adEnv, field, info, assignment)
    local vehicle = assignment.vehicle
    local store, why = ADFieldWork.chooseStore(adEnv, field, info, vehicle, ADFieldWork.storeFillType(field, info))
    if store == nil then
        ADFieldWork.release(assignment)
        fail(field.id, "intet lager: " .. tostring(why))
        return false
    end
    assignment.storeId = store.id
    local module = stateModule(vehicle)
    module:setMode(adEnv.AutoDrive.MODE_PICKUPANDDELIVER)
    module:setFirstMarkerByWayPointId(info.markerId)
    module:setSecondMarkerByWayPointId(store.id)
    module:setStartHelper(true)
    module.usedHelper = helperCp(adEnv)
    enableParkAtJobFinished(vehicle)
    module:raiseDirtyFlag()
    log(field.id, "læssevogn '%s' aflæsser i %s", ADRuns.vehicleLabel(vehicle), tostring(store.name))
    return true
end

-- Nærmeste påfyldning af varen: en læssestation gården har adgang til, med varen på lager, en AutoDrive-
-- markør ved triggeren og vej fra traktoren. (AutoDrives eget "automatiske påfyldningsmål" er slået fra i
-- AutoDrive — AutoDrive.automaticPickupTarget = false — så vi finder stedet selv, som silovalget.)
function ADFieldWork.findRefillMarker(adEnv, vehicle, fillType, x, z)
    local farmId = vehicle:getOwnerFarmId()
    local best, bestDistance = nil, math.huge
    local ok = pcall(function()
        for _, station in pairs(g_currentMission.storageSystem:getLoadingStations()) do
            local supported = station.getAISupportedFillTypes ~= nil and station:getAISupportedFillTypes() or {}
            if g_currentMission.accessHandler:canFarmAccess(farmId, station) and supported[fillType]
                and (station:getFillLevel(fillType, farmId) or 0) > 0 then
                local wayPointId = adEnv.ADTriggerManager:getMarkerAtStation(station, vehicle, 10)
                local wayPoint = wayPointId ~= nil and wayPointId > 0 and adEnv.ADGraphManager:getWayPointById(wayPointId) or nil
                if wayPoint ~= nil then
                    local distance = (wayPoint.x - x) ^ 2 + (wayPoint.z - z) ^ 2
                    if distance < bestDistance and ADUnloadWait.hasRouteTo(adEnv, vehicle, wayPointId) then
                        best, bestDistance = wayPointId, distance
                    end
                end
            end
        end
    end)
    return ok and best or nil
end

-- Påfyldning undervejs (såmaskine/sprøjte/spreder): AutoDrive LOAD med hjælper = Courseplay. Når CP melder
-- tom (onCpEmpty), kører AD til påfyldningen (2. markør), fylder op, kører tilbage til F-markøren (1. markør)
-- og genstarter CP. Findes ingen påfyldning, stopper sættet når det er tomt ("tom for …", se finish).
local function prepareRefill(adEnv, field, info, assignment)
    local vehicle = assignment.vehicle
    local fillType = ADCpBridge.getRefillFillType(vehicle)
    if fillType == nil then return end
    assignment.refillFillType = fillType
    local name = g_fillTypeManager ~= nil and g_fillTypeManager:getFillTypeNameByIndex(fillType) or tostring(fillType)
    local refillId = ADFieldWork.findRefillMarker(adEnv, vehicle, fillType, info.x, info.z)
    if refillId == nil then
        log(field.id, "ingen påfyldning af %s med AutoDrive-markør fundet — '%s' stopper når den er tom", tostring(name), ADRuns.vehicleLabel(vehicle))
        return
    end
    local module = stateModule(vehicle)
    local ok = pcall(function()
        module:setMode(adEnv.AutoDrive.MODE_LOAD)
        module:setFirstMarkerByWayPointId(info.markerId)
        module:setSecondMarkerByWayPointId(refillId)
        module:setFillType(fillType)
        module:setStartHelper(true)
        module.usedHelper = helperCp(adEnv)
        enableParkAtJobFinished(vehicle)
        module:raiseDirtyFlag()
    end)
    if ok then
        assignment.adHandlesEnd = true
        local marker = adEnv.ADGraphManager:getMapMarkerByWayPointId(refillId)
        log(field.id, "'%s' fyldes op med %s ved %s af AutoDrive når den er tom", ADRuns.vehicleLabel(vehicle), tostring(name), tostring(marker ~= nil and marker.name or refillId))
    end
end

-- Aflæsningsvogn under høst: Courseplays combine-unloader med stationen fra silovalget.
local function beginUnloader(adEnv, field, info, assignment)
    local vehicle = assignment.vehicle
    local fillType = assignment.fillType or info.harvestFillType
    local store, why = ADFieldWork.chooseStore(adEnv, field, info, vehicle, fillType)
    if store == nil then
        ADFieldWork.release(assignment)
        fail(field.id, "intet lager til høsten: " .. tostring(why))
        return
    end
    assignment.storeId = store.id
    local station = ADSmartPickup.getUnloadStationAtWayPointId(adEnv, store.id, vehicle:getOwnerFarmId())
    local markerPoint = adEnv.ADGraphManager:getWayPointById(info.markerId)
    local point = info.points[1] or {x = info.x, z = info.z}
    assignment.phase = "starting"
    assignment.since = now()
    local handle, err = ADCpBridge.startUnloader(vehicle, point.x, point.z, markerPoint ~= nil and markerPoint.x or point.x,
        markerPoint ~= nil and markerPoint.z or point.z, station, function(ok, reason)
            if ok then
                assignment.phase = "working"
                assignment.since = now()
                log(field.id, "aflæsningsvogn '%s' følger høsteren -> %s", ADRuns.vehicleLabel(vehicle), tostring(store.name))
            else
                ADFieldWork.release(assignment)
                fail(field.id, "aflæsningsvogn: " .. tostring(reason))
            end
        end)
    if handle == nil then
        ADFieldWork.release(assignment)
        fail(field.id, "aflæsningsvogn: " .. tostring(err))
        return
    end
    assignment.handle = handle
end

-- Ballesamler: Courseplays ballefinder; fuld vogn tømmes af AutoDrive i nærmeste ballelager (palleskur der
-- tager halmballer), som læssevognen. Uden lager stopper den når den er fuld.
local function beginBaleCollector(adEnv, field, info, assignment)
    local vehicle = assignment.vehicle
    local farmId = vehicle:getOwnerFarmId()
    local straw = g_fillTypeManager:getFillTypeIndexByName("STRAW")
    local isReachable = function(markerId) return ADUnloadWait.hasRouteTo(adEnv, vehicle, markerId) end
    local store = ADSources.findPalletStore(adEnv, vehicle, straw, nil, isReachable, farmId)
    if store ~= nil then
        pcall(function()
            local module = stateModule(vehicle)
            module:setMode(adEnv.AutoDrive.MODE_PICKUPANDDELIVER)
            module:setFirstMarkerByWayPointId(info.markerId)
            module:setSecondMarkerByWayPointId(store.wayPointId)
            module:setStartHelper(true)
            module.usedHelper = helperCp(adEnv)
            enableParkAtJobFinished(vehicle)
            module:raiseDirtyFlag()
        end)
        assignment.adHandlesEnd = true
        log(field.id, "ballesamler '%s' kører fulde læs til %s", ADRuns.vehicleLabel(vehicle), tostring(store.name))
    else
        log(field.id, "intet ballelager med plads og vej fundet — ballesamleren stopper når den er fuld")
    end
    local point = info.points[1] or {x = info.x, z = info.z}
    assignment.phase = "starting"
    assignment.since = now()
    local handle, err = ADCpBridge.startBaleFinder(vehicle, point.x, point.z, function(ok, reason)
        if ok then
            assignment.phase = "working"
            assignment.since = now()
            log(field.id, "Courseplay startet (ballesamler)")
        else
            ADFieldWork.release(assignment)
            fail(field.id, "ballesamler: " .. tostring(reason))
        end
    end)
    if handle == nil then
        ADFieldWork.release(assignment)
        fail(field.id, "ballesamler: " .. tostring(err))
        return
    end
    assignment.handle = handle
end

-- Multi-tool: følgere venter på lederens kursus for trinnet og kopierer det med deres bane.
local function courseOptions(adEnv, field, assignment)
    local source = ADFieldModel.courseSource(field, assignment.role)
    if source ~= nil then
        local course = sourceCourse(adEnv, field, source)
        if course == nil then
            log(field.id, "intet %s-kursus kendt — Courseplay laver et nyt kursus til %s", source, assignment.role)
        end
        return {course = course, lane = assignment.lane}, source
    end
    if (assignment.groupSize or 1) > 1 then
        if assignment.leader then
            return {multiTools = assignment.groupSize, lane = assignment.lane}, nil
        end
        local shared = coursesOf(field.id)[field.stage]
        if shared == nil then return nil, nil end
        return {course = shared, lane = assignment.lane}, "multi"
    end
    return {}, nil
end

local function beginWork(adEnv, field, info, assignment)
    local vehicle = assignment.vehicle
    if assignment.role == "unloader" then return beginUnloader(adEnv, field, info, assignment) end
    if assignment.role == "baleCollector" then return beginBaleCollector(adEnv, field, info, assignment) end
    -- høsteren: halmskår efter planen (hakkes = fra; samles op/presses = skår)
    if assignment.role == "harvester" then
        local keepStraw = field.plan.straw == "collect" or field.plan.straw == "bale"
        ADCpBridge.setStrawSwath(vehicle, keepStraw)
    end
    local opts, source = courseOptions(adEnv, field, assignment)
    if opts == nil then
        -- følger uden lederens kursus endnu
        if assignment.phase ~= "waitingCourse" then
            assignment.phase = "waitingCourse"
            assignment.since = now()
        end
        return
    end
    if assignment.role == "collector" then
        if not prepareCollector(adEnv, field, info, assignment) then return end
        assignment.adHandlesEnd = true
    elseif assignment.role == "seeder" or assignment.role == "fertilizer" or assignment.role == "limer" or assignment.role == "weeder" then
        prepareRefill(adEnv, field, info, assignment)
    end
    if assignment.role == "seeder" then
        local okSeed, seedError = ADCpBridge.setSeedFruit(vehicle, ADFieldWork.sowFruitIndex(field))
        if not okSeed then
            ADFieldWork.release(assignment)
            fail(field.id, "såmaskine: " .. tostring(seedError))
            return
        end
    end
    if source == "rake" and field.windrowOffset ~= nil and math.abs(field.windrowOffset) > 0.05 then
        local own = ADCpBridge.getToolOffset(vehicle)
        local target = ADFieldModel.collectorOffset(own, field.windrowOffset)
        if ADCpBridge.setToolOffset(vehicle, target) then
            assignment.restoreToolOffset = own
            log(field.id, "skår ligger %.1f m %s for rivens linje -> læssevognens forskydning %.1f m (var %.1f m)",
                math.abs(field.windrowOffset), field.windrowOffset > 0 and "til venstre" or "til højre", target, own)
        end
    end
    local point = info.points[1] or {x = info.x, z = info.z}
    assignment.phase = "starting"
    assignment.since = now()
    local handle, err = ADCpBridge.start(vehicle, point.x, point.z, function(ok, reason)
        if ok then
            assignment.phase = "working"
            assignment.since = now()
            if assignment.role == "mower" then
                note(field.id, {mowWidth = assignment.width, mowVehicleId = assignment.vehicleId})
                rememberCourse(field, "mower", vehicle)
            elseif assignment.role == "rake" then
                note(field.id, {rakeVehicleId = assignment.vehicleId})
                rememberCourse(field, "rake", vehicle)
            elseif assignment.role == "harvester" then
                note(field.id, {harvestVehicleId = assignment.vehicleId})
                rememberCourse(field, "harvester", vehicle)
            end
            if assignment.leader and (assignment.groupSize or 1) > 1 then
                rememberCourse(field, field.stage, vehicle)
            end
            log(field.id, "Courseplay startet (%s%s%s)", assignment.role,
                reason == "copied" and (", " .. tostring(source) .. "-kursus kopieret") or "",
                assignment.lane ~= nil and string.format(", bane %d", assignment.lane) or "")
        else
            ADFieldWork.release(assignment)
            fail(field.id, "Courseplay fejlede: " .. tostring(reason))
        end
    end, opts)
    if handle == nil then
        ADFieldWork.release(assignment)
        fail(field.id, "Courseplay kunne ikke startes: " .. tostring(err))
        return
    end
    assignment.handle = handle
end

-- Sættet er færdigt: rest til lager (læsse-/aflæsningsvogn), ellers parkering.
local function finishAssignment(adEnv, assignment)
    local vehicle = assignment.vehicle
    -- tom såmaskine/sprøjte der ikke blev fyldt op: arbejdet er IKKE færdigt — marken må ikke gå videre
    if assignment.refillFillType ~= nil and ADCpBridge.getRefillLevel(vehicle, assignment.refillFillType) <= 0 then
        local name = g_fillTypeManager ~= nil and g_fillTypeManager:getFillTypeNameByIndex(assignment.refillFillType) or "?"
        ADFieldWork.release(assignment)
        fail(assignment.fieldId, string.format("'%s' er tom for %s — fyld op, så fortsætter marken", ADRuns.vehicleLabel(vehicle), tostring(name)))
        return
    end
    log(assignment.fieldId, "%s '%s' færdig", assignment.role, ADRuns.vehicleLabel(vehicle))
    -- læssevogn/påfyldte sæt parkeres af AutoDrive selv (onCpFinished med parkering sat)
    local park = not assignment.adHandlesEnd and parkMarkerId(adEnv, vehicle) or nil
    if park ~= nil then startAd(adEnv, vehicle, adEnv.AutoDrive.MODE_DRIVETO, park, nil) end
    restoreToolOffset(assignment)
    assignment.phase = "finished"
    table.insert(ADFieldJobs.finished, assignment)
    ADFieldJobs.state.assignments[assignment.vehicleId] = nil
end

local function followWorking(adEnv, field, assignment)
    local vehicle = assignment.vehicle
    if assignment.role == "rake" and field.windrowOffset == nil and now() - assignment.since >= ADFieldWork.WINDROW_MEASURE_MS
        and ADCpBridge.isWorking(vehicle) then
        local offset = ADCpBridge.getWindrowOffset(vehicle)
        note(assignment.fieldId, {windrowOffset = offset or 0})
        log(assignment.fieldId, offset ~= nil and "river lægger skåret %.1f m fra sin kursuslinje (venstre +)" or "river: nedlægningsområde ikke fundet — regner med midten (%.1f m)", offset or 0)
    end
    if ADCpBridge.isWorking(vehicle) or isAdActive(vehicle) then
        assignment.idleSince = nil
        return
    end
    assignment.idleSince = assignment.idleSince or now()
    if now() - assignment.idleSince < ADFieldWork.IDLE_CONFIRM_MS then return end
    local rest = assignment.storeId ~= nil and not assignment.deliveredRest and restLoad(adEnv, vehicle) or 0
    if rest > 0 then
        -- CP færdig/stoppet med læs på: AD tømmer kun selv med parkering sat, så vi sender resten til lager
        assignment.deliveredRest = true
        assignment.idleSince = nil
        startAd(adEnv, vehicle, adEnv.AutoDrive.MODE_DELIVERTO, assignment.storeId, nil)
        log(assignment.fieldId, "'%s' kører rest-læs (%.0f l) til lager", ADRuns.vehicleLabel(vehicle), rest)
        return
    end
    finishAssignment(adEnv, assignment)
end

function ADFieldWork.follow(adEnv, assignment)
    local vehicle = assignment.vehicle
    -- Kun når spilleren selv KØRER (bevæger sig uden Courseplay/AutoDrive) slippes sættet — at sidde i
    -- førersædet og kigge må ikke slippe det (in-game 25/9).
    local steeredByAi = ADCpBridge.isWorking(vehicle) or isAdActive(vehicle) or assignment.phase == "starting"
    local speed = vehicle.getLastSpeed ~= nil and vehicle:getLastSpeed() or 0
    if isControlledByPlayer(vehicle) and not steeredByAi and speed > ADFieldWork.PLAYER_DRIVING_KMH then
        log(assignment.fieldId, "'%s' frigivet — spilleren kører det", ADRuns.vehicleLabel(vehicle))
        return ADFieldWork.release(assignment)
    end
    local field = ADFieldJobs.getField(assignment.fieldId)
    local info = ADFields.getInfo(assignment.fieldId)
    wake(vehicle)
    if assignment.phase == "driving" then
        if not isAdActive(vehicle) and now() - assignment.since > 2000 then
            local x, z = vehiclePosition(vehicle)
            local wayPoint = info ~= nil and adEnv.ADGraphManager:getWayPointById(info.markerId) or nil
            local distance = wayPoint ~= nil and math.sqrt((wayPoint.x - x) ^ 2 + (wayPoint.z - z) ^ 2) or math.huge
            if distance <= ADFieldWork.ARRIVE_DISTANCE then
                beginWork(adEnv, field, info, assignment)
            else
                ADFieldWork.release(assignment)
                fail(assignment.fieldId, string.format("%s nåede ikke %s (%.0f m væk)", ADRuns.vehicleLabel(vehicle), tostring(info ~= nil and info.markerName or "?"), distance))
            end
        end
    elseif assignment.phase == "waitingCourse" then
        if now() - assignment.since > ADFieldWork.COURSE_WAIT_MS then
            ADFieldWork.release(assignment)
            fail(assignment.fieldId, "multi-tool: lederens kursus kom ikke (3 min)")
        elseif coursesOf(field.id)[field.stage] ~= nil then
            beginWork(adEnv, field, info, assignment)
        end
    elseif assignment.phase == "starting" then
        if now() - assignment.since > ADFieldWork.START_TIMEOUT_MS then
            ADFieldWork.release(assignment)
            fail(assignment.fieldId, "Courseplay svarede ikke (60 s)")
        end
    elseif assignment.phase == "working" then
        followWorking(adEnv, field, assignment)
    end
end

-- Høsten er færdig: aflæsningsvognene stoppes; har de rest, kører den til lager, ellers parkering.
function ADFieldWork.windDownHelpers(adEnv, fieldId, stage)
    for _, assignment in ipairs(ADFieldJobs.assignmentsFor(fieldId)) do
        if assignment.helper and assignment.stage == stage then
            if assignment.handle ~= nil then assignment.handle.cancelled = true end
            ADCpBridge.stop(assignment.vehicle)
            assignment.phase = "working"
            assignment.idleSince = nil
            log(fieldId, "aflæsningsvogn '%s' stoppes — høsten er færdig", ADRuns.vehicleLabel(assignment.vehicle))
        end
    end
end

function ADFieldWork.stopAll(adEnv, fieldId)
    for _, assignment in ipairs(ADFieldJobs.assignmentsFor(fieldId)) do
        pcall(stopAd, assignment.vehicle)
        ADCpBridge.stop(assignment.vehicle)
        ADFieldWork.release(assignment)
    end
end