from __future__ import annotations

import asyncio

from fastapi import APIRouter, WebSocket, WebSocketDisconnect

import config
from log_tail import LogTailer
from routers.system import build_status

router = APIRouter()

STATUS_PUSH_HZ = 1.0  # slowed from 2.0 — paired with health.py's wider RATE_WINDOW,
                      # the operator asked for a calmer/more trustworthy number over a
                      # snappier one (2026-08-06).
LOG_POLL_HZ = 4.0


@router.websocket("/ws/status")
async def ws_status(ws: WebSocket):
    await ws.accept()
    period = 1.0 / STATUS_PUSH_HZ
    try:
        while True:
            await ws.send_json(build_status(ws.app))
            await asyncio.sleep(period)
    except WebSocketDisconnect:
        pass


@router.websocket("/ws/pointcloud")
async def ws_pointcloud(ws: WebSocket, profile: str = "desktop"):
    """M3 live scan view — binary-framed decimated point cloud, see
    pointcloud_codec.py for the wire format. `profile` picks desktop vs.
    phone point/Hz budgets rather than trusting client-supplied numbers
    directly (a client could otherwise ask for an unbounded frame size)."""
    await ws.accept()
    prof = config.POINTCLOUD_PROFILES.get(profile, config.POINTCLOUD_PROFILES["desktop"])
    period = 1.0 / prof["hz"]
    ros = ws.app.state.ros
    try:
        while True:
            await ws.send_bytes(ros.pointcloud.encode_frame(max_points=prof["max_points"]))
            await asyncio.sleep(period)
    except WebSocketDisconnect:
        pass


@router.websocket("/ws/logs")
async def ws_logs(ws: WebSocket):
    """Unified log tail — mirrors the old PyQt GUIs' single scrollback pane.
    Sends recent backlog once on connect, then only newly-appended lines."""
    await ws.accept()
    tailer = LogTailer({
        "lidar": config.LIDAR_LOG_PATH,
        "camera": config.CAMERA_LOG_PATH,
        "recording": config.RECORDING_LOG_PATH,
        "fastlio": config.FASTLIO_LOG_PATH,
    })
    backlog = []
    for tag in ("lidar", "camera", "recording", "fastlio"):
        backlog += [{"tag": tag, "line": ln} for ln in tailer.read_tail(tag, max_lines=80)]
    if backlog:
        await ws.send_json({"backlog": backlog})

    period = 1.0 / LOG_POLL_HZ
    try:
        while True:
            new_lines = [{"tag": tag, "line": line} for tag, line in tailer.read_new()]
            if new_lines:
                await ws.send_json({"lines": new_lines})
            await asyncio.sleep(period)
    except WebSocketDisconnect:
        pass