local cache_size

function on_load()
    -- Get the system's total memory in MB
    local mem_total = tonumber(io.popen("free -m | awk '/Mem:/ {print $2}'"):read())

    -- Calculate the cache size based on total memory
    cache_size = math.floor(mem_total / 32) -- 128MB for 4GB RAM, increase proportionally

    -- Set initial cache properties
    mp.set_property_number("demuxer-max-bytes", tostring(cache_size * 1024 * 1024))  -- Set cache size in bytes
    mp.set_property("demuxer-readahead-secs", "20")  -- Set read-ahead in seconds, adjust as needed
end

function on_pause_change(name, value)
    if value then
        -- Force caching when paused and free backwards cache
        mp.set_property("demuxer-max-back-bytes", "0")  -- Free backwards cache
        mp.command("script-message-to cache flush")
        mp.command("script-message-to cache prefill")
    else
        -- Reset cache properties when playback resumes
        mp.set_property("demuxer-max-back-bytes", tostring(cache_size * 1024 * 1024))  -- Reset backwards cache size
    end
end

mp.register_event("file-loaded", on_load)
mp.observe_property("pause", "bool", on_pause_change)