require "__core__/lualib/util"
require "__TheFatController__/TickTable"
require "__TheFatController__/Alerts"
require "__TheFatController__/TrainList"
require "__TheFatController__/GUI"

local v = require "__TheFatController__/semver"

MOD_NAME = "TheFatController" --luacheck: allow defined top

update_rate = 60 --luacheck: allow defined top
update_rate_manual = 90 --luacheck: allow defined top

-- myevent = game.generateeventname()
-- the name and tick are filled for the event automatically
-- this event is raised with extra parameter foo with value "bar"
--game.raiseevent(myevent, {foo="bar"})
events = {} --luacheck: allow defined top
events["on_player_opened"] = script.generate_event_name()
events["on_player_closed"] = script.generate_event_name()

local on_player_switched_from_train = nil

function getOrLoadSwitchedEvent() --luacheck: allow defined top
    if on_player_switched_from_train == nil then
        on_player_switched_from_train = script.generate_event_name()
    end
    return on_player_switched_from_train
end

function generateEvents() --luacheck: allow defined top
    getOrLoadSwitchedEvent()
end

defaults = {stationDuration = 10, signalDuration = 2} --luacheck: allow defined top

defaultGuiSettings = {--luacheck: allow defined top
    alarm = {noPath = true, noFuel = false, timeAtSignal = true, timeToStation = true},
    displayCount = 10,
    fatControllerButtons = {},
    fatControllerGui = {},
    page = 1,
    pageCount = 5,
    filter_page = 1,
    filter_pageCount = 1,
    filtered_trains = false,
    filter_alarms = false,
    automatedCount = 0,
    stopButton_state = false,
    displayed_trains = {},
    renameTrains = false,
    show_names = false,
    indicators = false,
    renameTrain = {}
}

-- character_blacklist = { ["orbital-uplink"] = true, ["yarm-remote-viewer"] = true, }

function debugDump(var, force) --luacheck: allow defined top
    if false or force then
        local msg
        if type(var) == "string" then
            msg = var
        else
            msg = serpent.dump(var, {name = "var", comment = false, sparse = false, sortkeys = true})
        end
        for _, player in pairs(game.players) do
            player.print(msg)
        end
    end
end

function pauseError(err) --luacheck: allow defined top
    if game then
        debugDump("Error in FatController " .. serpent.line(global.version, {comment = false}), true)
        debugDump(err, true)
    else
        log("Error in FatController " .. serpent.line(global.version, {comment = false}))
        log(serpent.line(global.version, {comment = false}) .. " " .. err)
    end
end

function register_events() --luacheck: allow defined top
    script.on_event(defines.events.on_gui_click, GUI.onguiclick)
    script.on_event(defines.events.on_gui_checked_state_changed, GUI.on_gui_checked_state_changed)
end

local function init_global()
    global = global or {}
    global.gui = global.gui or {}
    global.trainsByForce = global.trainsByForce or {}
    global.character = global.character or {}
    global.unlocked = global.unlocked or false
    global.unlockedByForce = global.unlockedByForce or {}
    global.updateEntities = global.updateEntities or false
    global.updateTrains = global.updateTrains or {}
    global.updateManual = global.updateManual or {}
    global.updateAlarms = global.updateAlarms or {}
    global.automatedCount = global.automatedCount or {}
    global.PAGE_SIZE = global.PAGE_SIZE or 60
    global.station_count = global.station_count or {}
    global.items = global.items or {}
    global.force_settings = global.force_settings or {}
end

local function init_player(player)
    global.gui[player.index] = global.gui[player.index] or util.table.deepcopy(defaultGuiSettings)
    if global.unlockedByForce[player.force.name] then
        GUI.init_gui(player)
    end
end

local function init_players()
    for _, player in pairs(game.players) do
        init_player(player)
    end
end

local function init_force(force)
    init_global()
    global.trainsByForce[force.name] = global.trainsByForce[force.name] or {}
    global.station_count[force.name] = global.station_count[force.name] or {}
    global.automatedCount[force.name] = global.automatedCount[force.name] or 0
    global.force_settings[force.name] = global.force_settings[force.name] or {signalDuration = defaults.signalDuration * 3600, stationDuration = defaults.stationDuration * 3600}
    global.unlockedByForce[force.name] = global.unlockedByForce[force.name] or false
    if force.technologies["rail-signals"].researched or force.technologies["automated-rail-transportation"].researched then
        global.unlockedByForce[force.name] = true
        global.unlocked = true
        register_events()
        for _, p in pairs(force.players) do
            init_player(p)
        end
    end
end

local function init_forces()
    for _, force in pairs(game.forces) do
        init_force(force)
    end
end

local function on_init()
    generateEvents()
    init_global()
    init_forces()
    init_players()
end

local function on_load()
    generateEvents()
    if global.unlocked then
        register_events()
    end
end

-- run once
local function on_configuration_changed(data)
    if not data or not data.mod_changes then
        return
    end
    local newVersion
    local oldVersion
    if data.mod_changes[MOD_NAME] then
        newVersion = data.mod_changes[MOD_NAME].new_version
        newVersion = v(newVersion)
        oldVersion = data.mod_changes[MOD_NAME].old_version
        if oldVersion then
            oldVersion = v(oldVersion)
            log("Updating TheFatController from " .. tostring(oldVersion) .. " to " .. tostring(newVersion))
            if oldVersion < v'5.0.0' then
                debugDump("Resetting FatController settings", true)
                local tmp = {}
                for i, _ in pairs(game.players) do
                    tmp[i] = {}
                    tmp[i].fatControllerGui = global.guiSettings[i].fatControllerGui
                    tmp[i].fatControllerButtons = global.guiSettings[i].fatControllerButtons
                end
                local tmpCharacter = global.character or {}
                global = {}
                global.character = tmpCharacter
                on_init()
                for i, _ in pairs(game.players) do
                    global.gui[i].fatControllerGui = tmp[i].fatControllerGui
                    global.gui[i].fatControllerButtons = tmp[i].fatControllerButtons
                end
            end
            on_init()

            if oldVersion < v'4.0.1' then
                for _, player in pairs(game.players) do
                    if player.character and player.vehicle and player.vehicle.get_driver() == player.character and player.character.name == "fatcontroller" then
                        player.vehicle.set_driver(nil)
                    end
                end
                findTrains(true)
                for _, gui in pairs(global.gui) do
                    GUI.refresh_gui(gui)
                end
            end
            if oldVersion < v'5.0.1' then
                findStations(true, true)
            end
            if oldVersion < v'5.1.1' then
                for _, player in pairs(game.players) do
                    if player.gui.top.fatControllerButtons and player.gui.top.fatControllerButtons.valid then
                        player.gui.top.fatControllerButtons.destroy()
                        GUI.init_gui(player, true)
                    end
                end
            end
        end
        if not oldVersion or oldVersion < v'0.4.0' then
            findTrains(true)
        end
        global.version = tostring(newVersion)
    end
    -- if data.mod_changes["GuiPlayground"] then
    --     if __DebugAdapter then
    --         __DebugAdapter.breakpoint()
    --         for i, character in pairs(global.character) do
    --             if swapPlayer(game.get_player(i), character) then
    --                 local guiSettings = global.gui[i]
    --                 global.character[i] = nil
    --                 stop_following(guiSettings)
    --             end
    --         end
    --     end
    -- end
    --reset item cache if a mod has changed
    global.items = {}
    --check for other mods
end

local function on_player_created(event)
    init_player(game.players[event.player_index])
end

local function on_pre_player_left_game(e)
    local player = game.get_player(e.player_index)
    if global.character[e.player_index] then
        if swapPlayer(player, global.character[e.player_index]) then
            global.character[e.player_index] = nil
            stop_following(global.gui[e.player_index])
        end
    end
end
script.on_event(defines.events.on_pre_player_left_game, on_pre_player_left_game)

script.on_event(defines.events.on_pre_player_removed,function(e)
    on_pre_player_left_game(e)
    global.character[e.player_index] = nil
    global.gui = global.gui or {}
    for _, force_trains in pairs(global.trainsByForce) do
        for _, t in pairs(force_trains) do
            t.opened_guis[e.player_index] = nil
            t.follower_index = nil
        end
    end
end)

local function on_force_created(event)
    init_force(event.force)
end

function on_research_finished(event)
    if event.research.name == "rail-signals" or event.research.name == "automated-rail-transportation" then
        global.unlockedByForce[event.research.force.name] = true
        global.unlocked = true
        register_events()
        for _, p in pairs(event.research.force.players) do
            init_player(p)
        end
    end
end

script.on_init(on_init)
script.on_load(on_load)
script.on_configuration_changed(on_configuration_changed)
script.on_event(defines.events.on_player_created, on_player_created)
script.on_event(defines.events.on_force_created, on_force_created)
--script.on_event(defines.events.on_forces_merging, on_forces_merging)

script.on_event(defines.events.on_research_finished,
    function(event)
        local _, err = pcall(on_research_finished, event)
        if err then
            pauseError(err, true)
        end
    end
)

function addInventoryContents(invA, invB)
    local res = {}
    for item, c in pairs(invA) do
        invB[item] = invB[item] or 0
        res[item] = c + invB[item]
        invB[item] = nil
        if res[item] == 0 then
            res[item] = nil
        end
    end
    for item, c in pairs(invB) do
        res[item] = c
        if res[item] == 0 then
            res[item] = nil
        end
    end
    return res
end

function getHighestInventoryStack(trainInfo)
    if trainInfo and trainInfo.train and trainInfo.train.valid then
        local itemsCount = 0
        local largestItem = {}
        local items = {}
        items = addInventoryContents(items, trainInfo.train.get_contents())
        local fluid_wagons = trainInfo.train.fluid_wagons
        for _, wagon in pairs(fluid_wagons) do
            local filter = wagon.fluidbox[1]
            if filter then
                if not items[filter.name] then
                    items[filter.name] = filter.amount
                else
                    items[filter.name] = items[filter.name] + filter.amount
                end
            end
        end
        for name, count in pairs(items) do
            if largestItem.count == nil or largestItem.count < count then
                largestItem.name = name
                largestItem.count = items[name]
            end
            itemsCount = itemsCount + 1
        end
        largestItem.count = largestItem.count and math.ceil(largestItem.count)
        return largestItem, itemsCount
    end
end

function getHighestInventoryCount(trainInfo)
    local inventory = ""
    local largestItem, itemsCount = getHighestInventoryStack(trainInfo)
    local name = largestItem.name
    if name ~= nil then
        local isFluid = game.fluid_prototypes[name]
        local isItem = game.item_prototypes[name]
        local prefix = isItem and "item" or isFluid and "fluid"
        local displayName = (isItem or isFluid) and "[" .. prefix .. "=" .. name .. "]" or name --isItem.localised_name or largestItem.name
        --local displayName = isItem and isItem.localised_name or largestItem.name
        local suffix = itemsCount > 1 and "..." or ""
        inventory = {"", displayName, " ", largestItem.count, suffix}
    end
    return inventory
end

function on_player_driving_changed_state(event)
    local _, err = pcall(function()
        local player = game.players[event.player_index]
        if player.vehicle and (player.vehicle.type == "locomotive" or player.vehicle.type == "cargo-wagon") then
            local ti = TrainList.get_traininfo(player.force, player.vehicle.train)
            if ti and ti.train.state == defines.train_state.manual_control then
                TrainList.add_manual(ti, player)
                global.gui[player.index].vehicle = ti.train
            end
        end
        if player.vehicle == nil then
            --log("changed_state")
            if global.gui[player.index].followEntity then
                local guiSettings = global.gui[player.index]
                if player.connected then
                    swapPlayer(game.players[player.index], global.character[player.index])
                    global.character[player.index] = nil
                    stop_following(guiSettings, player)
                    --TODO find replacement?
                    -- if player.vehicle and player.vehicle.name == "farl" then
                    --     script.raise_event(defines.events.on_player_driving_changed_state, {tick = game.tick, player_index = player.index, name = defines.events.on_player_driving_changed_state})
                    -- end
                else
                    if not global.to_swap then
                        global.to_swap = {}
                    end
                    table.insert(global.to_swap, {index = player.index, character = global.character[player.index]})
                end
            end
            TrainList.remove_invalid(player.force, true)
            TrainList.reset_manual(global.gui[player.index].vehicle)
            global.gui[player.index].vehicle = false
        --log("changed_state2")
        end
    end)
    if err then
        pauseError(err)
        GUI.revalidate(game.get_player(event.player_index))
    end
end
script.on_event(defines.events.on_player_driving_changed_state, on_player_driving_changed_state)

function on_tick(event)
    local _, err = pcall(function()
        local tick = event.tick
        if global.updateEntities then
            for _, ent in pairs(global.updateEntities) do
                --debugDump("updateEnt"..i,true)
                if ent == true then
                    TrainList.removeAlarms()
                elseif ent.valid then
                    TrainList.add_train(ent.train)
                end
            end
            global.updateEntities = false
        --script.on_event(defines.events.on_tick, nil)
        end

        if global.dead_players then
            for i, character in pairs(global.dead_players) do
                if not character.valid then
                    debugDump(game.players[i].name .. " died while remote controlling", true)
                    debugDump("Killing " .. game.players[i].name .. " softly", true)
                    game.players[i].character.die()
                    global.gui[i].followEntity = nil
                end
            end
            global.dead_players = nil
        end

        if global.updateManual[tick] then
            for _, ti in pairs(global.updateManual[tick]) do
                if ti and ti.train.valid then
                    Alerts.check_noFuel(ti)
                    --debugDump("updateManual",true)
                    GUI.update_single_traininfo(ti, true)
                    if (ti.passenger and (ti.train.state == defines.train_state.manual_control or ti.train.state == defines.train_state.manual_control_stop or ti.train.state == defines.train_state.no_path)) or (ti.train.state == defines.train_state.manual_control and ti.train.speed == 0) then
                        TickTable.insert(tick + update_rate_manual, "updateManual", ti)
                    end
                end
            end
            global.updateManual[tick] = nil
        end

        if global.updateTrains[tick] then
            local fuel_status_changed = false
            for _, ti in pairs(global.updateTrains[tick]) do
                if ti.train and ti.train.valid then
                    fuel_status_changed = fuel_status_changed or Alerts.check_noFuel(ti, true)
                    if ti.last_state == defines.train_state.wait_station then
                        GUI.update_single_traininfo(ti, true)
                        TickTable.insert(tick + update_rate, "updateTrains", ti)
                    else
                        GUI.update_single_traininfo(ti, true)
                        ti.depart_at = false
                    end
                end
            end
            if fuel_status_changed then
                for _, force in pairs(game.forces) do
                    GUI.refreshAllTrainInfoGuis(force)
                end
            end
            global.updateTrains[tick] = nil
        end

        if global.updateAlarms[tick] then
            for _, ti in pairs(global.updateAlarms[tick]) do
                if ti.train and ti.train.valid then
                    if Alerts.check_alerts(ti) then
                        GUI.update_single_traininfo(ti)
                    end
                end
            end
            global.updateAlarms[tick] = nil
        end

    end)
    if err then
        pauseError(err)
    end
end

script.on_event(defines.events.on_tick, on_tick)

function on_built_entity(event)
    local status, err = pcall(function()
        local ent = event.created_entity
        local ctype = ent.type
        if ctype == "locomotive" or ctype == "cargo-wagon" then
            -- can be a new train or added to an existing one
            if #ent.train.carriages == 1 and ctype == "locomotive" then
                local ti = TrainList.add_train(ent.train, true)
                if ent.type == "locomotive" then
                    Alerts.check_noFuel(ti)
                end
            else
                local added = false
                if ctype == "locomotive" then
                    local train = ent.train
                    local c = #train.locomotives.front_movers + #train.locomotives.back_movers
                    if c == 1 then
                        TrainList.add_train(ent.train, true)
                        added = true
                    end
                end
                if not added then
                    --added to existing one: revalidate
                    --debugDump("add to existing",true)
                    TrainList.remove_invalid(ent.force, true)
                end
            end
        elseif ctype == "train-stop" then
            increaseStationCount(ent)
        end
    end)
    if not status then
        pauseError(err, "on_built_entity")
    end
end

function on_preplayer_mined_item(event)
    local status, err = pcall(function()
        local ent = event.entity
        local ctype = ent.type
        if ctype == "locomotive" or ctype == "cargo-wagon" then
            local driver = ent.get_driver()
            local player_index
            if driver and driver.name == "fatcontroller" then
                for pi, pdata in pairs(global.gui) do
                    if pdata.followEntity == ent then
                        player_index = pi
                        break
                    end
                end
            end
            if player_index then
                if global.gui[player_index].followEntity then
                    local guiSettings = global.gui[player_index]
                    local player = game.get_player(player_index)
                    if player.connected then
                        swapPlayer(game.players[player_index], global.character[player_index])
                        global.character[player_index] = nil
                        stop_following(guiSettings, player)
                    else
                        if not global.to_swap then
                            global.to_swap = {}
                        end
                        table.insert(global.to_swap, {index = player.index, character = global.character[player.index]})
                    end
                end
            end
            local oldTrain = ent.train
            -- an existing train can be shortened or split in two trains or be removed completely
            local length = #oldTrain.carriages
            if not global.updateEntities then
                global.updateEntities = {}
            end
            if length == 1 then
                --debugDump("removing train", true)
                TrainList.remove_train(ent.train)
                table.insert(global.updateEntities, true)
                return
            end
            local ownPos
            for i, carriage in pairs(ent.train.carriages) do
                if ent == carriage then
                    ownPos = i
                    break
                end
            end
            local before = ownPos > 1 and ent.train.carriages[ownPos - 1] or false
            local after = ownPos < length and ent.train.carriages[ownPos + 1] or false
            if before then
                --debugDump("before",true)
                table.insert(global.updateEntities, before)
            end
            if after then
                --debugDump("after",true)
                table.insert(global.updateEntities, after)
            end
        elseif ctype == "train-stop" then
            decreaseStationCount(ent, ent.backer_name)
        end
    end)
    if not status then
        pauseError(err, "on_pre_player_mined_item")
        if event.player_index then
            GUI.revalidate(game.get_player(event.player_index))
        end
    end
end

function on_robot_built_entity(event)
    if event.created_entity.type == "train-stop" then
        increaseStationCount(event.created_entity)
    end
end

script.on_event(defines.events.on_robot_mined_entity, on_preplayer_mined_item)
script.on_event(defines.events.on_robot_built_entity, on_robot_built_entity)
script.on_event(defines.events.on_pre_player_mined_item, on_preplayer_mined_item)
script.on_event(defines.events.on_built_entity, on_built_entity)

function getKeyByValue(tableA, value)--luacheck: ignore
    for i, c in pairs(tableA) do
        if c == value then
            return i
        end
    end
end

function on_train_changed_state(event)
    --debugDump("state:"..event.train.state,true)
    local train_states = defines.train_state
    local tick = event.tick
    --log(game.tick .. " " .. event.train.state .. " " .. getKeyByValue(defines.train_state, event.train.state))
    local _, err = pcall(function()
        local train = event.train
        local force = train.carriages[1].force
        --debugDump(game.tick.." state:"..train.state,true)
        local trainInfo = TrainList.get_traininfo(force, train)
        if not trainInfo or not trainInfo.train.valid then
            TrainList.remove_invalid(force)
            if not TrainList.get_traininfo(force, train) then
                trainInfo = TrainList.add_train(train)
            end
        end
        if trainInfo then
            local unf = {}
            unf.previous_state = trainInfo.unfiltered_state.last_state
            unf.previous_tick = trainInfo.unfiltered_state.last_tick
            unf.last_state = train.state
            unf.last_tick = tick
            trainInfo.unfiltered_state = unf
            -- skip update if:
            --  going from wait_signal to on_the_path after 300 ticks
            --  going from on_the_path to wait_signal after 1 tick
            --  arrive_signal
            local diff = tick - unf.previous_tick
            if train.state == train_states.arrive_signal or (unf.previous_state == train_states.wait_signal and train.state == train_states.on_the_path and diff == 300) or (unf.previous_state == train_states.on_the_path and train.state == train_states.wait_signal and diff == 1) then
                --debugDump(game.tick.." Skipped",true)
                return
            end
            trainInfo.previous_state = trainInfo.last_state
            trainInfo.previous_state_tick = trainInfo.last_state_tick
            trainInfo.last_state = train.state
            trainInfo.last_state_tick = tick

            local old_auto = trainInfo.automated
            trainInfo.automated = (train.state ~= train_states.manual_control and train.state ~= train_states.manual_control_stop)
            if old_auto ~= trainInfo.automated then
                local change = trainInfo.automated and 1 or -1
                global.automatedCount[force.name] = global.automatedCount[force.name] + change
                for i, player in pairs(game.players) do
                    local guiSettings = global.gui[i]
                    if player.connected and guiSettings.activeFilterList and guiSettings.filteredIndex[trainInfo.mainIndex] then
                        guiSettings.automatedCount = guiSettings.automatedCount + change
                        if guiSettings.automatedCount < 0 then
                            guiSettings.automatedCount = 0
                        end
                        if guiSettings.automatedCount == 0 or guiSettings.automatedCount == #guiSettings.filtered_trains then
                            GUI.set_toggleButtonCaption(guiSettings, player)
                        end
                    end
                end
                --log("count:"..global.automatedCount[force.name])
                if global.automatedCount[force.name] < 0 then
                    global.automatedCount[force.name] = 0
                end
                if global.automatedCount[force.name] == 0 or global.automatedCount[force.name] == #global.trainsByForce[force.name] then
                    GUI.refreshAllTrainInfoGuis(force)
                end
            end

            if trainInfo.alarm.active and trainInfo.alarm.type == "noPath" then
                Alerts.reset_alarm(trainInfo)
            end
            local update_cargo = false
            if train.state == train_states.wait_signal then
                trainInfo.alarm.arrived_at_signal = tick
                local nextUpdate = tick + global.force_settings[force.name].signalDuration
                TickTable.insert(nextUpdate, "updateAlarms", trainInfo)
            elseif (train.state == train_states.on_the_path or train.state == train_states.manual_control_stop) and trainInfo.previous_state == train_states.wait_station then
                trainInfo.alarm.left_station = tick
                update_cargo = true
                --log("left_station")
                --log(serpent.block(trainInfo.alarm, {comment=false}))
                local nextUpdate = tick + global.force_settings[force.name].stationDuration
                TickTable.insert(nextUpdate, "updateAlarms", trainInfo)
            elseif train.state == train_states.on_the_path then
                if trainInfo.previous_state == train_states.wait_signal then
                    if trainInfo.alarm.type and trainInfo.alarm.type == "timeAtSignal" then
                        trainInfo.alarm.active = false
                        trainInfo.alarm.type = false
                    end
                    if trainInfo.alarm.arrived_at_signal then
                        TickTable.remove_from_tick(trainInfo.alarm.arrived_at_signal + global.force_settings[force.name].signalDuration, "updateAlarms", trainInfo.train)
                        trainInfo.alarm.arrived_at_signal = false
                    end
                end
            elseif train.state == train_states.wait_station then
                local depart_at = false
                local conditions = train.schedule and train.schedule.records[train.schedule.current].wait_conditions
                if conditions then
                    for _, condition in pairs(conditions) do
                        if condition.type == "time" then
                            depart_at = tick + condition.ticks
                            break
                        end
                    end
                end

                trainInfo.depart_at = depart_at
                if train.schedule and #train.schedule.records < 2 then
                    trainInfo.depart_at = false
                end
                local station = train.station
                if station and not global.station_count[force.name][station.backer_name] then
                    increaseStationCount(station)
                end
                update_cargo = true
                TickTable.insert(tick + update_rate, "updateTrains", trainInfo)
            elseif train.state == train_states.arrive_station then
                if trainInfo.alarm.left_station then
                    local stationDuration = global.force_settings[force.name].stationDuration
                    if trainInfo.alarm.left_station + stationDuration < tick then
                        Alerts.set_alert(trainInfo, "timeToStation", stationDuration / 3600)
                    else
                        TrainList.removeAlarms(train)
                    end
                end
            elseif train.state == train_states.path_lost or train.state == train_states.no_path then
                Alerts.set_alert(trainInfo, "noPath")
            elseif train.state == train_states.manual_control then
                Alerts.reset_alarm(trainInfo)
                TrainList.removeAlarms(train)
                TrainList.add_manual(trainInfo)
            elseif train.state == train_states.no_schedule then
                Alerts.reset_alarm(trainInfo)
                TrainList.removeAlarms(train)
            else
                trainInfo.depart_at = false
            end
            Alerts.check_noFuel(trainInfo)
            local records = train.schedule and train.schedule.records
            local record = (records and #records > 0) and records[train.schedule.current]
            local station = record and record.station
            if not station then
                if record and record.temporary and record.rail then
                    local wait_cond = record.wait_conditions and record.wait_conditions[1]
                    if wait_cond and wait_cond.type == "time" then
                        if wait_cond.ticks == 0 then
                            local next_stop = records[train.schedule.current + 1]
                            station = next_stop and next_stop.station or "Temporary"
                        else
                            station = "Temporary"
                        end
                    end
                else
                    station = "Temporary"
                end
            end

            trainInfo.current_station = station
            GUI.update_single_traininfo(trainInfo, update_cargo)
        else
            --debugDump("You should never ever see this! Look away!",true)
            --debugDump("no traininfo",true)
            TrainList.remove_invalid(force)
            if not TrainList.get_traininfo(force, train) then
                TrainList.add_train(train)
            end
        end
    end)
    if err then
        pauseError(err)
    end
end

script.on_event(defines.events.on_train_changed_state, on_train_changed_state)

function decreaseStationCount(station, name)
    local force = station.force.name
    if not global.station_count[force][name] then
        global.station_count[force][name] = 1
    end
    global.station_count[force][name] = global.station_count[force][name] - 1
    return global.station_count[force][name]
end

function increaseStationCount(station)
    local name = station.backer_name
    local force = station.force.name
    if not global.station_count[force][name] or global.station_count[force][name] < 0 then
        global.station_count[force][name] = 0
    end
    global.station_count[force][name] = global.station_count[force][name] + 1
    return global.station_count[force][name]
end

function on_station_rename(event)
    if event.entity.type == "train-stop" then
        local _, err = pcall(function()
            local station, oldName = event.entity, event.old_name
            local oldc = decreaseStationCount(station, oldName)
            increaseStationCount(station)
            if oldc == 0 then
                global.station_count[station.force.name][oldName] = nil
            end
        end)
        if err then
            pauseError(err, true)
            findStations(true, true)
        end
    end
end

-- function on_player_opened(event)
--     if event.entity.valid and game.players[event.player_index].valid then
--         if event.entity.type == "locomotive" and event.entity.train then
--             --TODO do something here?
--             return
--         elseif event.entity.type == "cargo-wagon" and event.entity.train then
--             --TODO do something here?
--             return
--         end
--     end
-- end

function on_player_closed(event)
    if event.entity and event.entity.valid and game.players[event.player_index].valid then
        if event.entity.type == "locomotive" and event.entity.train then
            local ti = TrainList.get_traininfo(event.entity.force, event.entity.train)
            if not ti then
                ti = TrainList.add_train(event.entity.train)
            end
            TrainList.update_stations(ti)
            Alerts.check_noFuel(ti)
            GUI.update_single_traininfo(ti)
        elseif event.entity.type == "cargo-wagon" and event.entity.train then
            local ti = TrainList.get_traininfo(event.entity.force, event.entity.train)
            if not ti then
                TrainList.add_train(event.entity.train)
            else
                GUI.update_single_traininfo(ti, true)
            end
        end
    end
end

--script.on_event(events.on_player_opened, on_player_opened)
script.on_event(defines.events.on_gui_closed, on_player_closed)
script.on_event(defines.events.on_entity_renamed, on_station_rename)

function getPageCount(guiSettings, player)
    local trains = (guiSettings.activeFilterList or guiSettings.filter_alarms) and guiSettings.filtered_trains or global.trainsByForce[player.force.name]
    if not trains then error("no trains", 2) end
    local trainCount = 0
    for i, t in pairs(trains) do
        if t.train.valid then
            trainCount = trainCount + 1
        else
            table.remove(trains, i)
        end
    end

    local p = math.floor((trainCount - 1) / guiSettings.displayCount) + 1
    p = p > 0 and p or 1
    guiSettings.page = guiSettings.page > p and p or guiSettings.page
    return p
end

function update_pageCount(force) --luacheck: allow defined top
    for _, p in pairs(force.players) do
        local guiSettings = global.gui[p.index]
        guiSettings.pageCount = getPageCount(guiSettings, p)
    end
end

function get_filter_PageCount(force)
    local stationCount = 0
    for _, _ in pairs(global.station_count[force.name]) do
        stationCount = stationCount + 1
    end
    local p = math.floor((stationCount - 1) / (global.PAGE_SIZE)) + 1
    p = p > 0 and p or 1
    return p
end

on_entity_died = function(event)
    if event.entity.type == "locomotive" or event.entity.type == "cargo-wagon" then
        local ent = event.entity
        local oldTrain = ent.train
        -- an existing train can be shortened or split in two trains or be removed completely
        local length = #oldTrain.carriages
        if length == 1 then
            TrainList.remove_train(oldTrain)
            return
        end
        local ownPos
        for i, carriage in pairs(ent.train.carriages) do
            if ent == carriage then
                ownPos = i
                break
            end
        end
        if ent.train.carriages[ownPos - 1] ~= nil then
            if not global.updateEntities then global.updateEntities = {} end
            table.insert(global.updateEntities, ent.train.carriages[ownPos - 1])
        --script.on_event(defines.events.on_tick, on_tick)
        end
        if ent.train.carriages[ownPos + 1] ~= nil then
            if not global.updateEntities then global.updateEntities = {} end
            table.insert(global.updateEntities, ent.train.carriages[ownPos + 1])
        --script.on_event(defines.events.on_tick, on_tick)
        end
        return
    end
    if event.entity.type == "character" and event.entity.name ~= "fatcontroller" then
        -- game.print(game.tick .. " " .. event.entity.type)
        -- player died
        for i, guiSettings in pairs(global.gui) do
            -- check if character is still valid next tick for players remote controlling a train
            if guiSettings.followEntity then
                -- if event.entity == global.character[i] then
                --   game.print("Player " .. game.players[i].name .. " died!")
                --   game.print(util.distance(game.players[i].position, event.entity.position))
                -- end
                global.dead_players = global.dead_players or {}
                global.dead_players[i] = global.character[i]
            end
        end
    end
end

script.on_event(defines.events.on_entity_died, on_entity_died)

--function on_pre_player_died(event)
--game.print("pre " .. serpent.line(event))
--if event.cause then
--game.print(serpent.line(event.cause.type))
--end
--end

--script.on_event(defines.events.on_pre_player_died, on_pre_player_died)

function swapPlayer(player, character)
    if not player.connected then return end
    if player.walking_state.walking then
        player.walking_state = {walking = false, direction = player.walking_state.direction}
    end
    if player.character ~= nil and player.character.valid and player.character.name == "fatcontroller" then
        player.character.destroy()
    end

    if character and character.valid and character ~= player.character then
        player.character = character
        return true
    end
end

function newFatControllerEntity(player)
    --assert(not global.character[player.index])
    return player.surface.create_entity({name = "fatcontroller", position = player.position, force = player.force})
end

function tableIsEmpty(tableA)
    if tableA ~= nil then
        return next(tableA) == nil
    end
    return true
end

function pairsByKeys(t, f)
    local a = {}
    for n in pairs(t) do
        table.insert(a, n)
    end
    table.sort(a, f)
    local i = 0 -- iterator variable
    -- iterator function
    local iter = function()
        i = i + 1
        if a[i] == nil then
            return nil
        else
            return a[i], t[a[i]]
        end
    end
    return iter
end

function saveVar(var, name, varname)
    local n = name or ""
    game.write_file("FAT" .. n .. ".lua", serpent.block(var or global, {name = varname or "global"}))
end

function findStations(show, reset)
    local surface = game.surfaces["nauvis"]

    if show then
        debugDump("Searching stations..", true)
    end
    if reset then
        for force, _ in pairs(game.forces) do
            global.station_count[force] = {}
        end
    end
    local count = 0
    for _, station in pairs(surface.find_entities_filtered {type = "train-stop"}) do
        count = count + 1
        increaseStationCount(station)
    end

    if show then
        debugDump("Found " .. count .. " stations", true)
    end
end

function findTrains(show)
    local surface = game.surfaces["nauvis"]

    if show then
        debugDump("Searching trains..", true)
    end
    local trains = surface.get_trains()
    for _, train in pairs(trains) do
        if not TrainList.get_traininfo(train.carriages[1].force, train) then
            local trainInfo = TrainList.add_train(train)
            if train.state == defines.train_state.wait_station then
                TickTable.insert(game.tick + update_rate, "updateTrains", trainInfo)
            end
        end
    end
    TrainList.reset_manual()
    if show then
        debugDump("Found " .. TrainList.count() .. " trains", true)
    end
    findStations(show)
end

--if remote.interfaces.buttons then
--local buttons = remote.interfaces.buttons
--buttons.registerButton('fatController', 'main', {})
--end

interface = {
    mess_up = function()
        global.gui[game.player.index].fatControllerGui = nil
    end,
    mess_up2 = function()
        global.gui[game.player.index].fatControllerGui.destroy()
    end,
    mess_up3 = function()
        global.gui[game.player.index].fatControllerButtons = nil
    end,
    mess_up4 = function()
        global.gui[game.player.index].fatControllerButtons.destroy()
    end,
    get_player_switched_event = function()
        return getOrLoadSwitchedEvent()
    end,
    saveVar = function(name)
        saveVar(global, name)
    end,
    remove_invalid_players = function()
        local delete = {}
        for i, _ in pairs(global.gui) do
            if not game.players[i] then
                delete[i] = true
            end
        end
        for j, _ in pairs(delete) do
            global.gui[j] = nil
        end
    end,
    init = function()
        global.PAGE_SIZE = 60
        for pi, g in pairs(global.gui) do
            g.filter_page = 1
            g.filter_pageCount = get_filter_PageCount(game.players[pi].force)
            g.stopButton_state = false
            GUI.refresh_gui(g)
        end
        init_forces()
    end,
    rescan_trains = function()
        for i, guiSettings in pairs(global.gui) do
            if guiSettings.fatControllerGui.trainInfo ~= nil then
                guiSettings.fatControllerGui.trainInfo.destroy()
                if global.character[i] then
                    swapPlayer(game.players[i], global.character[i])
                end
            end
        end
        for _, trains in pairs(global.trainsByForce) do
            local c = #trains
            for i = c, 1, -1 do
                if not trains[i].train.valid then
                    trains[i] = nil
                end
            end
        end
        findTrains()
    end,
    page_size = function(size)
        global.PAGE_SIZE = tonumber(size)
    end,
    find_trains = function()
        global.station_count = nil
        on_init()
        findTrains(true)
    end,
    find_stations = function()
        global.station_count = nil
        on_init()
        findStations(true)
    end,
    fixCharacter = function()
        local index = game.player.index
        if global.character[index] then
            game.player.character = global.character[index]
            global.character.index = nil
        else
            game.player.print("No character found.")
        end
    end
}

commands.add_command("fat_fix_character", "Try to return control to the player after a FatController error.", interface.fixCharacter)
remote.add_interface("fat", interface)