-- AD Flow Wagons
-- Flows ejer deres vogne, men traktor og vogn er ikke låst sammen: den vogn der hænger på en flow-traktor huskes
-- (run.wagons = {[traktorId] = vognId}). Starter flowet med en solo-traktor, henter den sin vogn ved "Connect <vognens
-- parkering>". Stoppes/slettes flowet, eller er dets bygning væk, sættes vognen på plads og traktoren kører hjem —
-- så er begge ledige i maskinpuljen (en stoppet flows vogn må lånes; en kørende flows aldrig).

ADFlowWagons = {}
ADFlowWagons.LOG_PREFIX = "ADSmartPickup: flow-vogne: "
ADFlowWagons.REMEMBER_MS = 10000     -- husk vogne / prøv ventende starter igen
ADFlowWagons.BUILDING_CHECK_MS = 60000
ADFlowWagons.MISSING_CHECKS = 2      -- så mange tjek i træk før en bygning regnes for væk

-- ---- ren logik ----

ADFlowWagons.serialize = function(wagons) return ADRuns.serializeWagons(wagons) end
ADFlowWagons.parse = function(text) return ADRuns.parseWagons(text) end

-- Husk traktorens vogn: ny tabel ved ændring, samme tabel når intet ændres.
function ADFlowWagons.remember(wagons, tractorId, wagonId)
    if (wagons or {})[tractorId] == wagonId then return wagons end
    local copy = ADRuns.copyWagons(wagons)
    copy[tractorId] = wagonId
    return copy
end

-- s = {hasRear, wagonId, wagonExists, hasConnect, wagonAttached, wagonBusy} -> "start" | "fetch" | "wait"
function ADFlowWagons.startAction(s)
    if s.hasRear or s.wagonId == nil or not s.wagonExists or not s.hasConnect then return "start" end
    if s.wagonAttached or s.wagonBusy then return "wait" end
    return "fetch"
end

function ADFlowWagons.ownerOf(runs, wagonId)
    for _, run in ipairs(runs or {}) do
        for _, id in pairs(run.wagons or {}) do
            if id == wagonId then return run end
        end
    end
    return nil
end

-- Holdes vognen af et flow der ikke er stoppet? (så må puljen ikke låne den)
function ADFlowWagons.isHeld(runs, wagonId)
    local run = ADFlowWagons.ownerOf(runs, wagonId)
    return run ~= nil and not run.stopped
end

-- Et tjek af om bygningen mangler: -> ny tæller, væk?
function ADFlowWagons.missingStep(count, missingNow)
    if not missingNow then return 0, false end
    local next = (count or 0) + 1
    return next, next >= ADFlowWagons.MISSING_CHECKS
end

-- Flowets bygnings-id'er der ikke findes i exists = {[id] = true}.
function ADFlowWagons.missingBuildings(run, exists)
    local missing = {}
    for _, key in ipairs({"sourceBuildingIds", "targetBuildingIds", "storeBuildingIds"}) do
        for _, id in ipairs(run[key] or {}) do
            if not exists[id] then table.insert(missing, id) end
        end
    end
    return missing
end

-- ---- spil ----

local waiting = setmetatable({}, {__mode = "k"})   -- traktor -> runId (venter på sin vogn)
local fetching = setmetatable({}, {__mode = "k"})  -- traktor -> runId (henter sin vogn)
local missingCount = {}                            -- runId -> tjek i træk
local rememberTimer, buildingTimer = 0, 0

local function runs()
    return ADRunsController.store ~= nil and ADRunsController.store.runs or {}
end

local function findAnyVehicle(id)
    for _, vehicle in pairs(g_currentMission.vehicleSystem.vehicles) do
        if ADRunsController.getVehicleId(vehicle) == id then return vehicle end
    end
    return nil
end

local function connectOf(adEnv, wagon)
    local index = wagon.advd ~= nil and wagon.advd.parkDestination or nil
    local park = type(index) == "number" and index >= 1 and adEnv.ADGraphManager:getMapMarkerById(index) or nil
    if park == nil then return nil end
    local marker = ADPool.connectFor(park.name, adEnv.ADGraphManager:getMapMarkers())
    return marker ~= nil and marker.id or nil
end

-- Traktorer i stoppede flows er ledige i puljen; traktorer i kørende flows aldrig.
function ADFlowWagons.isFreeTractor(vehicle)
    local run = ADRunsController.getRunForVehicle(vehicle)
    return run == nil or run.stopped == true
end

function ADFlowWagons.hasWagonFor(run, tractorId)
    return (run.wagons or {})[tractorId] ~= nil
end

function ADFlowWagons.isHeldWagon(wagonId)
    return ADFlowWagons.isHeld(runs(), wagonId)
end

-- Før en flow-traktor startes: hent sin vogn / vent på den. -> håndteret, resultat (som startVehicle)
function ADFlowWagons.beforeStart(adEnv, run, vehicle)
    local tractorId = ADRunsController.getVehicleId(vehicle)
    if fetching[vehicle] ~= nil then return true, {vehicle = vehicle, ok = true, reason = "fetchingWagon"} end
    local wagonId = (run.wagons or {})[tractorId]
    local wagon = wagonId ~= nil and findAnyVehicle(wagonId) or nil
    local connectId = wagon ~= nil and connectOf(adEnv, wagon) or nil
    local action = ADFlowWagons.startAction({
        hasRear = #ADHitch.rearImplementsOf(vehicle) > 0, wagonId = wagonId, wagonExists = wagon ~= nil,
        hasConnect = connectId ~= nil,
        wagonAttached = wagon ~= nil and wagon.getAttacherVehicle ~= nil and wagon:getAttacherVehicle() ~= nil,
        wagonBusy = wagonId ~= nil and ADPool.isReserved(wagonId),
    })
    if action == "start" then return false end
    ADRunsController.runningRuns[run.id] = true
    if action == "wait" then
        if waiting[vehicle] == nil then
            Logging.info(ADFlowWagons.LOG_PREFIX .. "flow '%s': '%s' venter på sin vogn (i brug andetsteds)", tostring(run.name),
                tostring(ADRuns.vehicleLabel(vehicle)))
        end
        waiting[vehicle] = run.id
        return true, {vehicle = vehicle, ok = true, reason = "waitingWagon"}
    end
    waiting[vehicle] = nil
    fetching[vehicle] = run.id
    local runId = run.id
    ADHitch.fetch(adEnv, vehicle, connectId, function(tractor, ok, detail)
        fetching[tractor] = nil
        local current = ADRuns.getRun(ADRunsController.store, runId)
        if current == nil or current.stopped then
            ADHitch.returnHome(adEnv, tractor)
            return
        end
        if ok then
            ADRunsController.startVehicle(adEnv, current, tractor)
        else
            Logging.warning(ADFlowWagons.LOG_PREFIX .. "flow '%s': '%s' kunne ikke hente sin vogn (%s)", tostring(current.name),
                tostring(ADRuns.vehicleLabel(tractor)), tostring(detail))
        end
    end)
    Logging.info(ADFlowWagons.LOG_PREFIX .. "flow '%s': '%s' henter sin vogn", tostring(run.name), tostring(ADRuns.vehicleLabel(vehicle)))
    return true, {vehicle = vehicle, ok = true, reason = "fetchingWagon"}
end

-- Stop/slet/bygning væk: vognen på plads, traktoren hjem.
function ADFlowWagons.sendHome(adEnv, run)
    for _, vehicleId in ipairs(run.vehicleIds or {}) do
        local vehicle = ADRunsController.findVehicleById(adEnv, vehicleId)
        if vehicle ~= nil then
            waiting[vehicle] = nil
            if fetching[vehicle] ~= nil then
                fetching[vehicle] = nil
                ADHitch.cancel(vehicle)
            end
            local okHome, pooled = pcall(ADHitch.returnHome, adEnv, vehicle)
            if not (okHome and pooled) then
                local park = ADFieldWork.parkMarkerId(adEnv, vehicle)
                if park ~= nil then pcall(ADFieldWork.startAd, adEnv, vehicle, adEnv.AutoDrive.MODE_DRIVETO, park, nil) end
            end
        end
    end
end

local function rememberAll(adEnv)
    for _, run in ipairs(runs()) do
        if not run.stopped then
            for _, vehicleId in ipairs(run.vehicleIds or {}) do
                local vehicle = ADRunsController.findVehicleById(adEnv, vehicleId)
                local rear = vehicle ~= nil and ADHitch.rearImplementsOf(vehicle) or {}
                local wagonId = rear[1] ~= nil and ADRunsController.getVehicleId(rear[1].object) or nil
                if wagonId ~= nil then
                    local updated = ADFlowWagons.remember(run.wagons, vehicleId, wagonId)
                    if updated ~= run.wagons then
                        run.wagons = updated
                        Logging.info(ADFlowWagons.LOG_PREFIX .. "flow '%s': '%s' har vognen '%s'", tostring(run.name),
                            tostring(ADRuns.vehicleLabel(vehicle)), tostring(ADRuns.vehicleLabel(rear[1].object)))
                    end
                end
            end
        end
    end
end

local function retryWaiting(adEnv)
    local list = {}
    for vehicle, runId in pairs(waiting) do table.insert(list, {vehicle = vehicle, runId = runId}) end
    for _, item in ipairs(list) do
        waiting[item.vehicle] = nil
        local run = ADRuns.getRun(ADRunsController.store, item.runId)
        if run ~= nil and not run.stopped then pcall(ADRunsController.startVehicle, adEnv, run, item.vehicle) end
    end
end

local function checkBuildings(adEnv)
    local exists = {}
    local placeables = g_currentMission.placeableSystem ~= nil and g_currentMission.placeableSystem.placeables or {}
    for _, placeable in pairs(placeables) do
        local id = ADBuildings.getId(placeable)
        if id ~= nil then exists[id] = true end
    end
    if next(exists) == nil then return end -- listen er ikke klar: sig intet
    for _, run in ipairs(runs()) do
        if not run.stopped then
            local missing = ADFlowWagons.missingBuildings(run, exists)
            local count, gone = ADFlowWagons.missingStep(missingCount[run.id], #missing > 0)
            missingCount[run.id] = count
            if gone then
                missingCount[run.id] = 0
                Logging.warning(ADFlowWagons.LOG_PREFIX .. "flow '%s': bygning findes ikke længere (%s) — stoppet, traktorer kørt hjem",
                    tostring(run.name), table.concat(missing, ", "))
                ADRunsController.stopRun(adEnv, run.id)
                if ADFieldJobs ~= nil and ADFieldJobs.notify ~= nil then
                    pcall(ADFieldJobs.notify, string.format("Flow '%s': bygning findes ikke længere — stoppet, traktorer kørt hjem", tostring(run.name)), true)
                end
            end
        end
    end
end

-- Én gang efter indlæsning: et stoppet flows traktor der holder stille med sin vogn (gemt midt i hjemturen — AD
-- kørte den færdig, men afkoblingen er glemt) køres hjem. Ikke løbende: spilleren kan selv have koblet på.
ADFlowWagons.AFTER_LOAD_MS = 120000
local sinceLoad, cleanedUp = 0, false

local function cleanupAfterLoad(adEnv)
    for _, run in ipairs(runs()) do
        if run.stopped then
            for _, vehicleId in ipairs(run.vehicleIds or {}) do
                local vehicle = ADRunsController.findVehicleById(adEnv, vehicleId)
                local module = vehicle ~= nil and vehicle.ad ~= nil and vehicle.ad.stateModule or nil
                local controlled = vehicle ~= nil and vehicle.getIsControlled ~= nil and vehicle:getIsControlled()
                if module ~= nil and not module:isActive() and not controlled and #ADHitch.poolParkIds(adEnv, vehicle) > 0 then
                    Logging.info(ADFlowWagons.LOG_PREFIX .. "flow '%s' er stoppet: '%s' sætter sin vogn på plads", tostring(run.name),
                        tostring(ADRuns.vehicleLabel(vehicle)))
                    pcall(ADHitch.returnHome, adEnv, vehicle)
                end
            end
        end
    end
end

function ADFlowWagons.tick(adEnv, dt)
    if adEnv == nil or ADRunsController.store == nil then return end
    if not cleanedUp then
        sinceLoad = sinceLoad + dt
        if sinceLoad >= ADFlowWagons.AFTER_LOAD_MS then
            cleanedUp = true
            local ok, err = pcall(cleanupAfterLoad, adEnv)
            if not ok then Logging.warning(ADFlowWagons.LOG_PREFIX .. "oprydning efter indlæsning: %s", tostring(err)) end
        end
    end
    rememberTimer = rememberTimer + dt
    buildingTimer = buildingTimer + dt
    if rememberTimer >= ADFlowWagons.REMEMBER_MS then
        rememberTimer = 0
        rememberAll(adEnv)
        retryWaiting(adEnv)
    end
    if buildingTimer >= ADFlowWagons.BUILDING_CHECK_MS then
        buildingTimer = 0
        checkBuildings(adEnv)
    end
end