import logging
import subprocess
import sys

from django.conf import settings
from django.http import FileResponse, Http404
from django.shortcuts import get_object_or_404, redirect, render
from django.urls import reverse
from django.views.decorators.http import require_POST

from .models import Camera, TimelapseJob
from .services.cameras import (
    create_cameras_from_candidates,
    discover_camera_candidates,
    get_camera_lastsnap_path,
    is_storage_available,
    list_active_cameras,
)

logger = logging.getLogger('camlaps')


def index(request):
    cameras = list_active_cameras()
    context = {
        'cameras': cameras,
        'storage_available': is_storage_available(),
        'added': request.GET.get('added'),
    }
    return render(request, 'camlaps/index.html', context)


@require_POST
def discover_cameras(request):
    cameras = list_active_cameras()
    candidates = discover_camera_candidates()
    context = {
        'cameras': cameras,
        'storage_available': is_storage_available(),
        'discovered_candidates': candidates,
        'discovered_count': len(candidates),
    }
    return render(request, 'camlaps/index.html', context)


@require_POST
def apply_discovered_cameras(request):
    selected_paths = request.POST.getlist('selected_storage_paths')
    created = create_cameras_from_candidates(selected_paths)
    return redirect(f"{reverse('camlaps:index')}?added={created}")


def camera_preview(request, camera_id: int):
    camera = get_object_or_404(Camera, pk=camera_id, is_active=True)
    path = get_camera_lastsnap_path(camera)
    if not path:
        raise Http404
    return FileResponse(path.open('rb'), content_type='image/jpeg')


def job_list(request):
    qs = TimelapseJob.objects.select_related('camera').all()
    camera_id = request.GET.get('camera')
    if camera_id:
        qs = qs.filter(camera_id=camera_id)
    jobs = qs.order_by('-created_at')[:200]
    return render(request, 'camlaps/job_list.html', {'jobs': jobs, 'queue_started': request.GET.get('started')})


@require_POST
def start_queue(request):
    logger.info('queue:start_request:start')

    has_planned = TimelapseJob.objects.filter(status=TimelapseJob.Status.PLANNED).exists()
    if not has_planned:
        logger.info('queue:start_request:done no_planned_jobs=true')
        return redirect(f"{reverse('camlaps:job_list')}?started=none")

    cmd = [sys.executable, 'manage.py', 'run_timelapse_worker', '--once']

    kwargs = {
        'cwd': settings.BASE_DIR,
        'stdout': subprocess.DEVNULL,
        'stderr': subprocess.DEVNULL,
    }

    if sys.platform.startswith('win'):
        kwargs['creationflags'] = subprocess.DETACHED_PROCESS | subprocess.CREATE_NEW_PROCESS_GROUP

    try:
        subprocess.Popen(cmd, **kwargs)
        logger.info('queue:start_request:done worker_started=true')
        return redirect(f"{reverse('camlaps:job_list')}?started=worker")
    except Exception:
        logger.exception('queue:start_request:error')
        return redirect(f"{reverse('camlaps:job_list')}?started=error")


def job_detail(request, job_id: int):
    job = get_object_or_404(TimelapseJob.objects.select_related('camera'), pk=job_id)
    video_url = None
    if job.output_rel_path:
        rel = job.output_rel_path.lstrip('/')
        if rel.startswith('timelapses/'):
            video_url = '/' + rel
        else:
            video_url = '/timelapses/' + rel.split('/')[-1]

    return render(request, 'camlaps/job_detail.html', {'job': job, 'video_url': video_url})


def job_create(request, camera_id: int):
    from .forms import TimelapseJobCreateForm

    camera = get_object_or_404(Camera, pk=camera_id, is_active=True)

    if request.method == 'POST':
        form = TimelapseJobCreateForm(request.POST)
        if form.is_valid():
            job = form.save(commit=False)
            job.camera = camera
            job.save()
            return redirect(reverse('camlaps:job_detail', kwargs={'job_id': job.id}))
    else:
        form = TimelapseJobCreateForm()

    sampling_choices = TimelapseJob.SamplingPreset.choices
    sampling_max = len(TimelapseJob.SAMPLING_PRESET_MINUTES) - 1

    return render(
        request,
        'camlaps/job_create.html',
        {
            'camera': camera,
            'form': form,
            'sampling_choices': sampling_choices,
            'sampling_max': sampling_max,
        },
    )