import uuid
from django.shortcuts import render, redirect
from django.core.files.base import ContentFile
from django.core.files.storage import default_storage
from plants.services import plantnet
from plants.services.plantnet import PlantNetError
from plants.services.vpc import search_species as vpc_search
from plants.models import Plant, Species

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

_VALID_ORGANS = {'flower', 'leaf', 'fruit', 'bark', 'habit', 'auto'}


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


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

    files = request.FILES.getlist('images')
    organs = request.POST.getlist('organs')

    if not files:
        return render(request, 'plants/identify_upload.html',
                      {'error': 'Please select at least one photo.'})

    scan_id = uuid.uuid4().hex
    saved_paths = []
    images = []

    for i, f in enumerate(files[:5]):
        organ = organs[i] if i < len(organs) else 'auto'
        if organ not in _VALID_ORGANS:
            organ = 'auto'
        file_bytes = f.read()
        name = f'plants/temp_identify/{scan_id}_{i}.jpg'
        default_storage.save(name, ContentFile(file_bytes))
        saved_paths.append({'path': name, 'organ': organ})
        images.append((file_bytes, organ))

    try:
        matches = plantnet.identify(images)
    except PlantNetError as e:
        for p in saved_paths:
            if default_storage.exists(p['path']):
                default_storage.delete(p['path'])
        return render(request, 'plants/identify_upload.html', {'error': str(e)})

    request.session['identify_matches'] = matches
    request.session['identify_image_paths'] = saved_paths
    return redirect('identify_confirm')


def identify_confirm(request):
    if 'identify_matches' not in request.session:
        return redirect('identify_upload')

    matches = request.session['identify_matches']

    if request.method == 'POST':
        try:
            idx = int(request.POST.get('match_idx', 0))
            idx = max(0, min(idx, len(matches) - 1))
        except (ValueError, TypeError):
            idx = 0

        selected = matches[idx]
        request.session['identify_selected'] = selected

        try:
            vpc_results = vpc_search(selected['scientific_name'])[:3]
        except Exception:
            vpc_results = []
        request.session['identify_vpc_results'] = vpc_results
        request.session['identify_vpc_idx'] = 0

        return redirect('identify_fields')

    return render(request, 'plants/identify_confirm.html', {'matches': matches})


def _apply_vpc_care_fields(species, vpc_result):
    from plants.services.vpc import scrape_plant, VPCError
    slug = vpc_result.get('slug', '')
    if not slug:
        return
    try:
        data = scrape_plant(slug)
    except VPCError:
        return
    for field in ('bloom_months', 'max_height_cm', 'sunlight', 'growth_rate',
                  'description', 'api_image_url', 'frost_hardiness_c',
                  'planting_density_m2'):
        val = data.get(field)
        if val not in (None, '', []):
            setattr(species, field, val)
    species.vpc_slug = slug
    species.vpc_raw = data
    species.save()


def identify_fields(request):
    if 'identify_selected' not in request.session:
        return redirect('identify_upload')

    selected = request.session['identify_selected']
    vpc_results = request.session.get('identify_vpc_results', [])
    vpc_idx = request.session.get('identify_vpc_idx', 0)

    if request.method == 'GET' and 'vpc_idx' in request.GET:
        try:
            new_idx = int(request.GET['vpc_idx'])
            vpc_idx = max(0, min(new_idx, len(vpc_results) - 1))
            request.session['identify_vpc_idx'] = vpc_idx
        except (ValueError, TypeError):
            pass
        return redirect('identify_fields')

    vpc_match = vpc_results[vpc_idx] if vpc_results else None

    if request.method == 'POST':
        common_name_source = request.POST.get('common_name_source', 'plantnet')
        scientific_name_source = request.POST.get('scientific_name_source', 'plantnet')
        name = request.POST.get('name', '').strip() or selected['scientific_name']

        if common_name_source == 'vpc' and vpc_match:
            common_name = vpc_match['common_name']
        else:
            common_name = (selected['common_names'] or [selected['scientific_name']])[0]

        if scientific_name_source == 'vpc' and vpc_match:
            scientific_name = vpc_match['scientific_name']
        else:
            scientific_name = selected['scientific_name']

        species = Species.objects.filter(scientific_name=scientific_name).first()
        if not species:
            species = Species.objects.create(
                scientific_name=scientific_name,
                common_name=common_name,
            )
        else:
            species.common_name = common_name
            species.save(update_fields=['common_name'])

        if vpc_match:
            _apply_vpc_care_fields(species, vpc_match)

        plant = Plant.objects.create(name=name, species=species)

        try:
            for p in request.session.get('identify_image_paths', []):
                if default_storage.exists(p['path']):
                    default_storage.delete(p['path'])
        finally:
            _clear_session(request)

        return redirect('plant_detail', pk=plant.pk)

    return render(request, 'plants/identify_fields.html', {
        'selected': selected,
        'vpc_results': vpc_results,
        'vpc_idx': vpc_idx,
        'vpc_match': vpc_match,
    })