from django.shortcuts import render, redirect

_SESSION_KEYS = [
    'identify_matches', 'identify_image_paths', 'identify_selected',
    'identify_vpc_results', 'identify_vpc_idx',
]


def _clear_session(request):
    for key in _SESSION_KEYS:
        request.session.pop(key, None)


def identify_upload(request):
    if request.method == 'POST':
        return redirect('identify_confirm')
    return render(request, 'plants/identify_upload.html')


def identify_confirm(request):
    if 'identify_matches' not in request.session:
        return redirect('identify_upload')
    if request.method == 'POST':
        return redirect('identify_fields')
    return render(request, 'plants/identify_confirm.html', {
        'matches': request.session.get('identify_matches', []),
    })


def identify_fields(request):
    if 'identify_selected' not in request.session:
        return redirect('identify_upload')
    if request.method == 'POST':
        _clear_session(request)
        return redirect('plant_list')
    return render(request, 'plants/identify_fields.html', {
        'selected': request.session.get('identify_selected', {}),
        'vpc_results': request.session.get('identify_vpc_results', []),
        'vpc_idx': request.session.get('identify_vpc_idx', 0),
    })