"""Display and heartbeat phase of the request-local streaming monitor."""

import time
from types import SimpleNamespace

from agent.model_metadata import is_local_endpoint


class StreamingWaitMonitor:
    def _poll_local_load_notice(self, now: float) -> bool:
        """Managed local server: surface a cold model's weight-load progress
        instead of the 60s "provider may be slow" copy. Polled ~1s only while no
        REAL chunk arrived for 2s+ (never during healthy token flow); in-memory,
        no network. True while loading = heartbeat liveness, skip the rest of
        this iteration (the stale detector's local floor dwarfs any load)."""
        from agent.chat_completion_helpers import _managed_local_load_notice

        m = self._mon
        if now - self.last_chunk_time["t"] < 2.0 or now - m.last_load_poll < 1.0:
            return False
        m.last_load_poll = now
        _load_notice = _managed_local_load_notice(self.agent, self.api_kwargs)
        if _load_notice is not None:
            m.wait_notice_started_ts = None  # The local loader now owns the display.
            self.agent._emit_wait_notice(_load_notice)
            self.agent._touch_activity("local model loading")
            m.load_notice_shown, m.load_notice_misses, m.last_heartbeat = True, 0, now  # loading IS liveness
            return True
        if m.load_notice_shown:
            # One missed sample is routine (probe timeout under load); clearing on it strobed the line.
            m.load_notice_misses += 1
            if m.load_notice_misses >= 3:
                m.load_notice_shown, m.load_notice_misses = False, 0
                self.agent._emit_wait_notice("")
        return False

    def _heartbeat(self, waiting_secs: int) -> None:
        """Gateway inactivity heartbeat: the start-to-first-chunk gap (thinking,
        local prefill) can exceed the gateway timeout."""
        if waiting_secs >= 60.0:
            # No chunks for 60s+: say WHAT the wait is and WHEN recovery kicks in.
            stale = self._stream_stale_timeout
            _recovery = f"; auto-reconnect at {int(stale)}s" if stale is not None and stale != float("inf") else ""
            self._mon.wait_notice_started_ts = self._mon.last_heartbeat
            self.agent._emit_wait_notice(
                f"⏳ waiting on {self.api_kwargs.get('model', 'the provider')} — no stream output for {waiting_secs}s "
                f"(provider may be slow or overloaded, or the model is thinking{_recovery})")
        else:
            # Chunks are flowing — keep the tracker fresh, leave the display alone.
            self.agent._touch_activity(f"waiting for stream response ({waiting_secs}s, no chunks yet)")

    def _monitor_loop(self) -> None:
        _HEARTBEAT_INTERVAL = 30.0  # seconds between gateway activity touches
        self._mon = SimpleNamespace(
            last_heartbeat=time.time(), last_load_poll=0.0,
            load_notice_shown=False, load_notice_misses=0, wait_notice_started_ts=None,
        )
        _is_local_base = bool(self.agent.base_url) and is_local_endpoint(self.agent.base_url)
        while not self._call_done.is_set():
            self._call_done.wait(timeout=0.3)
            _hb_now = time.time()
            if _is_local_base and self._poll_local_load_notice(_hb_now):
                continue
            # Reasoning callbacks do not clear the classic CLI spinner. The empty
            # protocol payload resets status without adding synthetic reasoning.
            if (self._mon.wait_notice_started_ts is not None
                    and self.last_chunk_time["t"] > self._mon.wait_notice_started_ts):
                self.agent._emit_wait_notice("")
                self._mon.wait_notice_started_ts = None
            if _hb_now - self._mon.last_heartbeat >= _HEARTBEAT_INTERVAL:
                self._mon.last_heartbeat = _hb_now
                self._heartbeat(int(_hb_now - self.last_chunk_time["t"]))
            _stale_elapsed = time.time() - self.last_chunk_time["t"]
            if _stale_elapsed > self._stream_stale_timeout:
                self._mon.wait_notice_started_ts = None  # Reconnect status has its own owner.
                self._kill_stale_stream(_stale_elapsed)
            if self.agent._interrupt_requested:
                self._abort_for_interrupt(_stale_elapsed)
                return