local EXPORTER_NAME = "signal-exporter"
local EXPORT_INTERVAL = 1800 -- Ticks between file writes (1800 = 30s at 60 UPS)

local function init_global()
    global.exporters = global.exporters or {}
    global.open_guis = global.open_guis or {}
end

script.on_init(init_global)
script.on_configuration_changed(init_global)

local function export_combinator(unit_number, data)
    local entity = data.entity
    if not (entity and entity.valid) then
        global.exporters[unit_number] = nil
        return
    end

    local signals = {
        game_tick = game.tick,
        circuit_network = {
            red = {},
            green = {}
        },
        logistic_network = {}
    }

    local wires = {
        [defines.wire_type.red] = "red",
        [defines.wire_type.green] = "green"
    }

    for wire_type, color in pairs(wires) do
        local network = entity.get_circuit_network(wire_type)
        if network and network.signals then
            for _, signal in ipairs(network.signals) do
                local name = signal.signal.name
                if name then
                    signals.circuit_network[color][name] = (signals.circuit_network[color][name] or 0) + signal.count
                end
            end
        end
    end

    local logistic_network = entity.surface.find_logistic_network_by_position(entity.position, entity.force)
    if logistic_network then
        local contents = logistic_network.get_contents()
        for name, count in pairs(contents) do
            signals.logistic_network[name] = count
        end
    end

    local json_string = game.table_to_json(signals)
    game.write_file("signal_export/" .. data.name .. ".json", json_string, false)
end

local function on_created(event)
    local entity = event.created_entity or event.entity or event.destination
    if not (entity and entity.valid) then return end

    if entity.name == EXPORTER_NAME then
        global.exporters[entity.unit_number] = {
            entity = entity,
            name = "combinator_" .. tostring(entity.unit_number)
        }
    end
end

local function on_destroyed(event)
    local entity = event.entity
    if not (entity and entity.valid) then return end

    if entity.name == EXPORTER_NAME then
        global.exporters[entity.unit_number] = nil
    end
end

local build_events = {
    defines.events.on_built_entity,
    defines.events.on_robot_built_entity,
    defines.events.script_raised_built,
    defines.events.script_raised_revive
}
for _, e in ipairs(build_events) do
    script.on_event(e, on_created)
end

local destroy_events = {
    defines.events.on_player_mined_entity,
    defines.events.on_robot_mined_entity,
    defines.events.on_entity_died,
    defines.events.script_raised_destroy
}
for _, e in ipairs(destroy_events) do
    script.on_event(e, on_destroyed)
end

script.on_nth_tick(EXPORT_INTERVAL, function()
    for unit_number, data in pairs(global.exporters) do
        export_combinator(unit_number, data)
    end
end)

script.on_event(defines.events.on_gui_opened, function(event)
    local entity = event.entity
    if entity and entity.valid and entity.name == EXPORTER_NAME then
        local player = game.players[event.player_index]
        local data = global.exporters[entity.unit_number]
        if not data then return end

        local screen = player.gui.screen
        if screen["signal_exporter_gui"] then
            screen["signal_exporter_gui"].destroy()
        end

        local frame = screen.add{type = "frame", name = "signal_exporter_gui", caption = "Configure Signal Exporter", direction = "vertical"}
        frame.force_auto_center()

        local name_flow = frame.add{type = "flow", name = "name_flow", direction = "horizontal"}
        name_flow.style.vertical_align = "center"
        name_flow.style.bottom_margin = 8
        name_flow.add{type = "label", caption = "Combinator Name: "}
        name_flow.add{type = "textfield", name = "exporter_name_input", text = data.name}

        local button_flow = frame.add{type = "flow", name = "button_flow", direction = "horizontal"}
        button_flow.add{type = "button", name = "exporter_save_button", caption = "Save & Close"}
        button_flow.add{type = "button", name = "exporter_refresh_button", caption = "Export Now"}

        player.opened = frame
        global.open_guis[player.index] = entity.unit_number
    end
end)

script.on_event(defines.events.on_gui_click, function(event)
    local element = event.element
    if element.name == "exporter_save_button" or element.name == "exporter_refresh_button" then
        local player = game.players[event.player_index]
        local unit_number = global.open_guis[player.index]

        if unit_number and global.exporters[unit_number] then
            local frame = player.gui.screen["signal_exporter_gui"]
            if frame then
                local new_name = frame.name_flow.exporter_name_input.text
                global.exporters[unit_number].name = new_name
            end

            if element.name == "exporter_refresh_button" then
                export_combinator(unit_number, global.exporters[unit_number])
                player.print("Data manually exported to signals_" .. global.exporters[unit_number].name .. ".json")
            end
        end

        if element.name == "exporter_save_button" then
            if player.gui.screen["signal_exporter_gui"] then
                player.gui.screen["signal_exporter_gui"].destroy()
            end
            global.open_guis[player.index] = nil
        end
    end
end)

script.on_event(defines.events.on_gui_closed, function(event)
    if event.element and event.element.name == "signal_exporter_gui" then
        event.element.destroy()
        global.open_guis[event.player_index] = nil
    end
end)

local function export_item_names_csv(event)
    local player = game.players[event.player_index]
    local csv_lines = { '"item_key","localised_name"' }

    local function escape_csv_field(value)
        if value == nil then return "" end
        return string.gsub(tostring(value), '"', '""')
    end

    for _, item_prototype in pairs(game.item_prototypes) do
        local key = item_prototype.name
        local resolved_name = player.localise(item_prototype.localised_name)
        local escaped_key = escape_csv_field(key)
        local escaped_name = escape_csv_field(resolved_name)
        table.insert(csv_lines, '"' .. escaped_key .. '","' .. escaped_name .. '"')
    end

    local csv_content = table.concat(csv_lines, "\n")
    game.write_file("item_names.csv", csv_content, false, player.index)
    player.print("Export complete. File saved to 'script-output/item_names.csv'.")
end

commands.add_command(
    "export-item-names",
    "Exports the internal name (key) and localised name for all game items to a CSV file.",
    export_item_names_csv
)