import sys
import os
import threading
import time
import pytest

# Ensure project root is on sys.path when running tests directly
ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
if ROOT not in sys.path:
    sys.path.insert(0, ROOT)

from pymsc.core.monitor import MonitorBuffer, MonDecoded, MonitorInfo
from pymsc.core.app_controller import AppController


def make_entry(sa=11, tr=0, payload=b'\x01\x02'):
    return MonDecoded(
        cw_raw=0x1234,
        sw=0x0000,
        error_code=0x0000,
        sa=sa,
        tr=tr,
        rt=20,
        wc=len(payload)//2,
        data=payload,
        timetag=time.time()
    )


def test_append_and_get_raw_buffer():
    buf = MonitorBuffer(buf_size=10)
    # append 3 entries
    for i in range(3):
        buf.append(make_entry(sa=11 + i))

    snap = buf.get_raw_buffer()
    assert isinstance(snap, MonitorInfo)
    assert snap.total_message == 3
    assert len(snap.buffer) == 3
    # After get_raw_buffer the buffer must be cleared
    snap2 = buf.get_raw_buffer()
    assert snap2.total_message == 0
    assert len(snap2.buffer) == 0


def test_isr_invoked_when_threshold_reached():
    called = threading.Event()
    captured = {}

    def isr(snapshot: MonitorInfo):
        captured['n'] = snapshot.total_message
        called.set()

    buf = MonitorBuffer(buf_size=8, isr_threshold=3)
    buf.set_isr(isr)
    buf.enable_isr(True)

    # Append two entries: below threshold
    buf.append(make_entry(sa=12))
    buf.append(make_entry(sa=13))
    assert not called.is_set()

    # Third append should trigger ISR (runs in daemon thread)
    buf.append(make_entry(sa=14))

    # Wait briefly for ISR to run
    assert called.wait(1.0), "ISR was not invoked within 1s"
    assert captured.get('n', 0) >= 3


def test_appcontroller_integration_monitor_delegation():
    ctrl = AppController()
    # Ensure monitor exists and is instance of MonitorBuffer
    assert hasattr(ctrl, 'monitor')

    ev = threading.Event()
    def cb(snapshot):
        # just set event
        ev.set()

    ctrl.set_mon_isr(cb)
    ctrl.enableMonitorIsr(True)
    # Append via controller.monitor
    ctrl.monitor.append(make_entry(sa=15))
    ctrl.monitor.append(make_entry(sa=15))
    ctrl.monitor.append(make_entry(sa=15))

    # ISR threshold default is 256 (buf_size 512 -> threshold 256) but MonitorBuffer in controller was created with 512
    # temporarily set a low threshold on controller.monitor for this test
    ctrl.monitor._isr_threshold = 2
    # append one more to reach threshold
    ctrl.monitor.append(make_entry(sa=15))

    assert ev.wait(1.0), "Controller monitor ISR not invoked"