#!/usr/bin/env python3
# test_bluetooth_peripheral.py
# 设备(MaixCAM)作为 BLE 从机(Peripheral/GATT Server)广播给手机连接。
# 参考: https://wiki.sipeed.com/maixpy/doc/zh/modules/bluetooth.html
#
# 用法:
#   python test_bluetooth_peripheral.py [广播名字]     # 默认 shoot
#
# 依赖:
#   1. 使能蓝牙:  bluetoothctl power on
#   2. 安装依赖:  pip install bless
#   3. 部分 BlueZ 需要 experimental 模式才支持 GATT Server:
#      编辑 /etc/bluetooth/main.conf 保证有 Experimental = true
#      然后 systemctl restart bluetooth && bluetoothctl power on
#
# 手机端: 用 nRF Connect / 任意 BLE 调试 App 搜索广播名连接，
#         读写 characteristic 并订阅 notify，每 2 秒会收到计数通知。
#
# 实现:
#   - GATT 服务由 bless 注册到 BlueZ
#   - 广播由常驻 bluetoothctl 子进程控制 (menu advertise / name / advertise on)，
#     这是已验证手机能搜到的路径; 若 bluetoothctl 不可用则回退到 btmgmt adv on

import asyncio
import shutil
import subprocess
import sys
import time

try:
    from bless import (
        BlessServer,
        GATTCharacteristicProperties,
        GATTAttributePermissions,
    )
except ImportError:
    print("ModuleNotFoundError: No module named 'bless'")
    print("请先在设备上安装依赖:")
    print("  pip install bless")
    print("并使能蓝牙:")
    print("  bluetoothctl power on")
    raise SystemExit(1)

DEVICE_NAME = sys.argv[1] if len(sys.argv) > 1 else "shoot"
SERVICE_UUID = "A07498CA-AD5B-474E-940D-16F1FBE7E8CD"
CHAR_UUID = "51FF12BB-3ED8-46E5-B4F9-D64E2FEC021B"
BTCTL_LOG = "/tmp/btctl_adv.log"

# 不同 bless 版本枚举名不同: writeable / writable
try:
    WRITE_PERMISSION = GATTAttributePermissions.writeable
except AttributeError:
    WRITE_PERMISSION = GATTAttributePermissions.writable

_btctl = None


def on_read(characteristic, request):
    print(f"[GATT] read {characteristic.uuid}")
    return characteristic.value


def on_write(characteristic, value, request):
    characteristic.value = value
    print(f"[GATT] write {characteristic.uuid} = {bytes(value)}")


def on_subscribe(characteristic, session):
    print(f"[GATT] client subscribed: {characteristic.uuid}")


def on_unsubscribe(characteristic, session):
    print(f"[GATT] client unsubscribed: {characteristic.uuid}")


def _run(cmd):
    try:
        r = subprocess.run(cmd, capture_output=True, text=True, timeout=10)
        out = ((r.stdout or "") + (r.stderr or "")).strip()
        if out:
            print(f"[adv] {' '.join(cmd)} -> {out}")
        return r.returncode == 0
    except FileNotFoundError:
        print(f"[adv] {cmd[0]} not found")
        return False
    except Exception as e:
        print(f"[adv] {' '.join(cmd)} failed: {e}")
        return False


def adv_start(name):
    """启动广播: 优先 bluetoothctl (常驻子进程), 失败则回退 btmgmt"""
    global _btctl

    if shutil.which("bluetoothctl") is not None:
        try:
            log = open(BTCTL_LOG, "w")
            _btctl = subprocess.Popen(
                ["bluetoothctl"],
                stdin=subprocess.PIPE,
                stdout=log,
                stderr=subprocess.STDOUT,
                text=True,
                bufsize=1,
            )
        except Exception as e:
            print(f"[adv] start bluetoothctl failed: {e}")
            _btctl = None

        if _btctl is not None:
            for cmd in (
                "menu advertise",
                f"name {name}",
                "discoverable on",
                "menu main",
                "advertise on",
            ):
                try:
                    _btctl.stdin.write(cmd + "\n")
                    _btctl.stdin.flush()
                except Exception as e:
                    print(f"[adv] write '{cmd}' failed: {e}")
                    break
                time.sleep(0.3)

            time.sleep(1.0)
            if _btctl.poll() is None:
                print(f"[adv] bluetoothctl advertising on (log: {BTCTL_LOG})")
                return True
            print("[adv] bluetoothctl exited early, fallback to btmgmt")

    # 回退: mgmt 传统广播
    if shutil.which("btmgmt") is None:
        print("[adv] bluetoothctl/btmgmt 均不可用")
        return False
    _run(["btmgmt", "le", "on"])
    _run(["btmgmt", "connectable", "on"])
    return _run(["btmgmt", "adv", "on"])


def adv_stop():
    global _btctl
    if _btctl is not None:
        try:
            _btctl.stdin.write("advertise off\n")
            _btctl.stdin.flush()
            time.sleep(0.3)
            _btctl.terminate()
        except Exception:
            pass
        _btctl = None
    elif shutil.which("btmgmt") is not None:
        _run(["btmgmt", "adv", "off"])


async def run():
    gatt = {
        SERVICE_UUID: {
            CHAR_UUID: {
                "Properties": (
                    GATTCharacteristicProperties.read
                    | GATTCharacteristicProperties.write
                    | GATTCharacteristicProperties.notify
                ),
                "Permissions": (
                    GATTAttributePermissions.readable | WRITE_PERMISSION
                ),
                "Value": bytearray(b"hello from maixcam"),
            }
        }
    }

    server = BlessServer(
        name=DEVICE_NAME,
        on_read=on_read,
        on_write=on_write,
        on_subscribe=on_subscribe,
        on_unsubscribe=on_unsubscribe,
    )

    print("Adding GATT ...")
    await server.add_gatt(gatt)

    print(f"Starting BLE peripheral, name = '{DEVICE_NAME}' ...")
    try:
        await server.start()
    except Exception as e:
        print(f"start() failed: {e}")
        print("排查:")
        print("  1. 蓝牙是否上电:  bluetoothctl power on  (bluetoothctl show 看 Powered)")
        print("  2. /etc/bluetooth/main.conf 加 Experimental = true 后重启:")
        print("       systemctl restart bluetooth && bluetoothctl power on")
        print("  3. 依赖: pip install -U bless dbus-next bleak")
        return

    adv = await server.is_advertising()
    print("=" * 60)
    print(f"'{DEVICE_NAME}' advertising status: {adv}")

    print("Starting advertising ...")
    if not adv_start(DEVICE_NAME):
        print("广播启动失败，请手动执行: bluetoothctl -> advertise on")

    print("手机用 nRF Connect 等 App 搜索并连接，")
    print(f"服务 {SERVICE_UUID}")
    print(f"特征 {CHAR_UUID}  (read/write/notify)")
    print("Ctrl+C 退出")
    print("=" * 60)

    try:
        # 每 2 秒向订阅者推送一次计数
        counter = 0
        while True:
            counter += 1
            try:
                char = server.get_characteristic(CHAR_UUID)
                if char is not None:
                    char.value = bytearray(str(counter).encode())
                    server.update_value(SERVICE_UUID, CHAR_UUID)
            except Exception as e:
                # 没有客户端订阅时可能失败，忽略
                print(f"notify failed: {e}")

            if counter % 10 == 0:
                try:
                    print(f"[status] advertising={await server.is_advertising()} "
                          f"connected={await server.is_connected()}")
                except Exception:
                    pass
            await asyncio.sleep(2)
    finally:
        adv_stop()


if __name__ == "__main__":
    try:
        asyncio.run(run())
    except KeyboardInterrupt:
        print("\nStopped.")