-- probe2.lua -- marker + X-server client-table telemetry.
local machine = manager.machine
local dir = os.getenv("MSG_DIR") or "."
local trigger = os.getenv("MSG_TRIGGER") or (dir .. "/trigger")
local screen = nil
for _, s in pairs(machine.screens) do screen = s; break end
local cpu = machine.devices[':maincpu']
local space = cpu.spaces['program']
local frame = 0
local job = nil

local function consume_trigger()
    local fh = io.open(trigger, "r")
    if not fh then return end
    local text = fh:read("*a") or ""
    fh:close(); os.remove(trigger)
    local prefix, count, stride = text:match("(%S+)%s+(%d+)%s+(%d+)")
    if not prefix then return end
    job = { prefix = prefix, left = tonumber(count), stride = tonumber(stride), next = frame }
    print(string.format("probe2: frame %d job %s x%d every %d", frame, prefix, job.left, job.stride))
end

local function u32(a)
    local ok, v = pcall(function() return space:read_u32(a) end)
    if ok then return v end
    return 0xdeadbeef
end

emu.register_frame_done(function()
    frame = frame + 1
    consume_trigger()
    if job and frame >= job.next and screen then
        local out = string.format("%s/%s_frame%05d.png", dir, job.prefix, frame)
        pcall(function() return screen:snapshot(out) end)
        print(string.format("probe2: frame %d %s", frame, out))
        job.left = job.left - 1
        job.next = frame + job.stride
        if job.left <= 0 then job = nil end
    end
    if frame % 25 == 0 then
        print(string.format("probe2: f=%d PC=%08X st=%d disp=%08X win=%08X xclients=%d strlen=%d",
            frame, cpu.state['PC'].value, u32(0x01850140), u32(0x01850100),
            u32(0x01850120), u32(0x1b8620), u32(0x01850160)))
    end
end, "vt1200-gui-probe2")

if machine.debugger then machine.debugger.execution_state = 'run' end