import base64
import json
from django.conf import settings
from django.contrib.auth import authenticate, login, get_user_model
from django.contrib.auth.decorators import login_required
from django.contrib.auth.forms import UserCreationForm, AuthenticationForm
from django.http import JsonResponse
from django.shortcuts import render, redirect
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_http_methods

from radio import lastfm as lastfm_module

User = get_user_model()


# ---------------------------------------------------------------------------
# Register
# ---------------------------------------------------------------------------

def register(request):
    if request.user.is_authenticated:
        return redirect('index')

    if request.method == 'POST':
        form = UserCreationForm(request.POST)
        if form.is_valid():
            user = form.save()
            login(request, user)
            return redirect('index')
    else:
        form = UserCreationForm()

    return render(request, 'accounts/register.html', {'form': form})


# ---------------------------------------------------------------------------
# Login
# ---------------------------------------------------------------------------

def login_view(request):
    if request.user.is_authenticated:
        return redirect('index')

    if request.method == 'POST':
        form = AuthenticationForm(data=request.POST)
        if form.is_valid():
            user = form.get_user()
            login(request, user)
            next_url = request.GET.get('next', '/')
            return redirect(next_url)
    else:
        form = AuthenticationForm()

    return render(request, 'accounts/login.html', {'form': form})


# ---------------------------------------------------------------------------
# Settings
# ---------------------------------------------------------------------------

@login_required
def settings_view(request):
    profile = request.user.profile

    if request.method == 'POST':
        profile.lastfm_scrobble = 'lastfm_scrobble' in request.POST
        profile.save(update_fields=['lastfm_scrobble'])
        return redirect('settings')

    context = {
        'profile': profile,
        'has_lastfm': profile.has_lastfm(),
    }
    return render(request, 'accounts/settings.html', context)


# ---------------------------------------------------------------------------
# Last.fm OAuth
# ---------------------------------------------------------------------------

@login_required
def lastfm_connect(request):
    callback_url = request.build_absolute_uri('/accounts/lastfm/callback/')
    try:
        auth_url, token = lastfm_module.get_auth_url(callback_url)
        request.session['lastfm_token'] = token
        return redirect(auth_url)
    except Exception as exc:
        return render(request, 'accounts/settings.html', {
            'profile': request.user.profile,
            'has_lastfm': request.user.profile.has_lastfm(),
            'lastfm_error': f"Could not connect to Last.fm: {exc}",
        })


@login_required
def lastfm_callback(request):
    token = request.session.get('lastfm_token')
    if not token:
        return redirect('settings')

    try:
        session_key = lastfm_module.get_session_key(token)
        username = lastfm_module.get_username(session_key)

        profile = request.user.profile
        profile.lastfm_session_key = session_key
        profile.lastfm_username = username
        profile.save(update_fields=['lastfm_session_key', 'lastfm_username'])

        # Clean up session
        del request.session['lastfm_token']
    except Exception:
        pass

    return redirect('settings')


@login_required
@csrf_exempt
@require_http_methods(['POST'])
def upload_background(request):
    try:
        body = json.loads(request.body)
    except (json.JSONDecodeError, ValueError):
        return JsonResponse({'error': 'invalid JSON'}, status=400)

    iv = body.get('iv', '').strip()
    ciphertext = body.get('ciphertext', '').strip()
    mime_type = body.get('mime_type', '').strip()
    file_size = int(body.get('file_size', 0))

    if not all([iv, ciphertext, mime_type]):
        return JsonResponse({'error': 'iv, ciphertext, mime_type required'}, status=400)

    allowed_mimes = {'image/jpeg', 'image/png', 'image/webp'}
    if mime_type not in allowed_mimes:
        return JsonResponse({'error': 'only jpeg, png, or webp allowed'}, status=400)

    if file_size > settings.BG_MAX_BYTES:
        return JsonResponse({'error': 'file too large (max 5 MB)'}, status=400)

    profile = request.user.profile
    profile.background_image_data = ''
    profile.background_encrypted = ciphertext
    profile.background_iv = iv
    profile.background_mime = mime_type
    profile.save(update_fields=['background_image_data', 'background_encrypted', 'background_iv', 'background_mime'])
    return JsonResponse({'ok': True})


@login_required
@require_http_methods(['POST'])
def delete_background(request):
    profile = request.user.profile
    profile.background_image_data = ''
    profile.background_encrypted = ''
    profile.background_iv = ''
    profile.background_mime = ''
    profile.save(update_fields=['background_image_data', 'background_encrypted', 'background_iv', 'background_mime'])
    return redirect('settings')


@login_required
@csrf_exempt
@require_http_methods(['POST'])
def save_focus_station(request):
    try:
        body = json.loads(request.body)
    except (json.JSONDecodeError, ValueError):
        return JsonResponse({'error': 'invalid JSON'}, status=400)

    url = body.get('url', '').strip()
    name = body.get('name', '').strip()

    profile = request.user.profile
    profile.focus_station_url = url
    profile.focus_station_name = name
    profile.save(update_fields=['focus_station_url', 'focus_station_name'])
    return JsonResponse({'ok': True})


@login_required
@require_http_methods(['POST'])
def lastfm_disconnect(request):
    profile = request.user.profile
    profile.lastfm_session_key = ''
    profile.lastfm_username = ''
    profile.save(update_fields=['lastfm_session_key', 'lastfm_username'])
    return redirect('settings')