import logging
from pathlib import Path

from django.apps import apps
from django.conf import settings
from django.contrib import messages
from django.core.cache import cache
from django.core.paginator import Paginator
from django.db import IntegrityError
from django.db.models import prefetch_related_objects
from django.http import HttpResponse, HttpResponseBadRequest, JsonResponse
from django.shortcuts import redirect, render
from django.urls import reverse
from django.utils import timezone
from django.utils.dateparse import parse_date
from django.utils.timezone import datetime
from django.views.decorators.http import require_GET, require_http_methods, require_POST

from app import config, helpers, history_processor
from app import statistics as stats
from app.forms import EpisodeForm, ManualItemForm, get_form_class
from app.models import TV, BasicMedia, Item, MediaTypes, Season, Sources, Status
from app.providers import manual, services, tmdb
from app.templatetags import app_tags
from users.models import HomeSortChoices, MediaSortChoices, MediaStatusChoices

logger = logging.getLogger(__name__)


@require_GET
def home(request):
    """Home page with media items in progress."""
    sort_by = request.user.update_preference("home_sort", request.GET.get("sort"))
    media_type_to_load = request.GET.get("load_media_type")
    items_limit = 14

    list_by_type = BasicMedia.objects.get_in_progress(
        request.user,
        sort_by,
        items_limit,
        media_type_to_load,
    )

    # If this is an HTMX request to load more items for a specific media type
    if request.headers.get("HX-Request") and media_type_to_load:
        context = {
            "media_list": list_by_type.get(media_type_to_load, []),
        }
        return render(request, "app/components/home_grid.html", context)

    context = {
        "list_by_type": list_by_type,
        "current_sort": sort_by,
        "sort_choices": HomeSortChoices.choices,
        "items_limit": items_limit,
    }
    return render(request, "app/home.html", context)


@require_POST
def progress_edit(request, media_type, instance_id):
    """Increase or decrease the progress of a media item from home page."""
    operation = request.POST["operation"]

    media = BasicMedia.objects.get_media_prefetch(
        request.user,
        media_type,
        instance_id,
    )

    if operation == "increase":
        media.increase_progress()
    elif operation == "decrease":
        media.decrease_progress()

    if media_type == MediaTypes.SEASON.value:
        # clear prefetch cache to get the updated episodes
        media.refresh_from_db()
        prefetch_related_objects([media], "episodes")

    context = {
        "media": media,
    }
    return render(
        request,
        "app/components/progress_changer.html",
        context,
    )


@require_GET
def media_list(request, media_type):
    """Return the media list page."""
    layout = request.user.update_preference(
        f"{media_type}_layout",
        request.GET.get("layout"),
    )
    sort_filter = request.user.update_preference(
        f"{media_type}_sort",
        request.GET.get("sort"),
    )
    status_filter = request.user.update_preference(
        f"{media_type}_status",
        request.GET.get("status"),
    )
    search_query = request.GET.get("search", "")
    page = request.GET.get("page", 1)

    # Prepare status filter for database query
    if not status_filter:
        status_filter = MediaStatusChoices.ALL

    # Get media list with filters applied
    media_queryset = BasicMedia.objects.get_media_list(
        user=request.user,
        media_type=media_type,
        status_filter=status_filter,
        sort_filter=sort_filter,
        search=search_query,
    )

    # Paginate results
    items_per_page = 32
    paginator = Paginator(media_queryset, items_per_page)
    media_page = paginator.get_page(page)

    BasicMedia.objects.annotate_max_progress(
        media_page.object_list,
        media_type,
    )

    context = {
        "media_type": media_type,
        "media_type_plural": app_tags.media_type_readable_plural(media_type).lower(),
        "media_list": media_page,
        "current_layout": layout,
        "layout_class": ".media-grid" if layout == "grid" else "tbody",
        "current_sort": sort_filter,
        "current_status": status_filter,
        "sort_choices": MediaSortChoices.choices,
        "status_choices": MediaStatusChoices.choices,
    }

    # Handle HTMX requests for partial updates
    if request.headers.get("HX-Request"):
        # Changing from empty list to a status with items
        if request.headers.get("HX-Target") == "empty_list":
            response = HttpResponse()
            response["HX-Redirect"] = reverse("medialist", args=[media_type])
            return response
        if layout == "grid":
            template_name = "app/components/media_grid_items.html"
        else:
            template_name = "app/components/media_table_items.html"
    else:
        template_name = "app/media_list.html"

    return render(request, template_name, context)


@require_GET
def media_search(request):
    """Return the media search page."""
    media_type = request.user.update_preference(
        "last_search_type",
        request.GET["media_type"],
    )
    query = request.GET["q"]
    page = int(request.GET.get("page", 1))
    layout = request.GET.get("layout", "grid")

    # only receives source when searching with secondary source
    source = request.GET.get(
        "source",
        config.get_default_source_name(media_type).value,
    )

    data = services.search(media_type, query, page, source)

    # Enrich search results with user tracking data
    if data.get("results"):
        data["results"] = helpers.enrich_items_with_user_data(request, data["results"])

    context = {
        "data": data,
        "source": source,
        "media_type": media_type,
        "layout": layout,
    }

    return render(request, "app/search.html", context)


@require_GET
def media_details(request, source, media_type, media_id, title):  # noqa: ARG001 title for URL
    """Return the details page for a media item."""
    media_metadata = services.get_media_metadata(media_type, media_id, source)
    user_medias = BasicMedia.objects.filter_media_prefetch(
        request.user,
        media_id,
        media_type,
        source,
    )
    current_instance = user_medias[0] if user_medias else None

    # Enrich related items with user tracking data
    if media_metadata.get("related"):
        for section_name, related_items in media_metadata["related"].items():
            if related_items:
                media_metadata["related"][section_name] = (
                    helpers.enrich_items_with_user_data(
                        request,
                        related_items,
                    )
                )

    context = {
        "media": media_metadata,
        "media_type": media_type,
        "user_medias": user_medias,
        "current_instance": current_instance,
    }
    return render(request, "app/media_details.html", context)


@require_GET
def season_details(request, source, media_id, title, season_number):  # noqa: ARG001 For URL
    """Return the details page for a season."""
    tv_with_seasons_metadata = services.get_media_metadata(
        "tv_with_seasons",
        media_id,
        source,
        [season_number],
    )
    season_metadata = tv_with_seasons_metadata[f"season/{season_number}"]

    user_medias = BasicMedia.objects.filter_media_prefetch(
        request.user,
        media_id,
        MediaTypes.SEASON.value,
        source,
        season_number=season_number,
    )

    current_instance = user_medias[0] if user_medias else None
    episodes_in_db = current_instance.episodes.all() if current_instance else []

    if source == Sources.MANUAL.value:
        season_metadata["episodes"] = manual.process_episodes(
            season_metadata,
            episodes_in_db,
        )
    else:
        season_metadata["episodes"] = tmdb.process_episodes(
            season_metadata,
            episodes_in_db,
        )

    # Enrich related items with user tracking data
    if season_metadata.get("related"):
        for section_name, related_items in season_metadata["related"].items():
            if related_items:
                season_metadata["related"][section_name] = (
                    helpers.enrich_items_with_user_data(
                        request,
                        related_items,
                    )
                )

    context = {
        "media": season_metadata,
        "tv": tv_with_seasons_metadata,
        "media_type": MediaTypes.SEASON.value,
        "user_medias": user_medias,
        "current_instance": current_instance,
    }
    return render(request, "app/media_details.html", context)


@require_POST
def update_media_score(request, media_type, instance_id):
    """Update the user's score for a media item."""
    media = BasicMedia.objects.get_media(
        request.user,
        media_type,
        instance_id,
    )

    score = float(request.POST.get("score"))
    media.score = score
    media.save()
    logger.info(
        "%s score updated to %s",
        media,
        score,
    )

    return JsonResponse(
        {
            "success": True,
            "score": score,
        },
    )


@require_POST
def sync_metadata(request, source, media_type, media_id, season_number=None):
    """Refresh the metadata for a media item."""
    if source == Sources.MANUAL.value:
        msg = "Manual items cannot be synced."
        messages.error(request, msg)
        return HttpResponse(
            msg,
            status=400,
            headers={"HX-Redirect": request.POST.get("next", "/")},
        )

    cache_key = f"{source}_{media_type}_{media_id}"
    if media_type == MediaTypes.SEASON.value:
        cache_key += f"_{season_number}"

    ttl = cache.ttl(cache_key)
    logger.debug("%s - Cache TTL for: %s", cache_key, ttl)

    if ttl is not None and ttl > (settings.CACHE_TIMEOUT - 3):
        msg = "The data was recently synced, please wait a few seconds."
        messages.error(request, msg)
        logger.error(msg)
    else:
        deleted = cache.delete(cache_key)
        logger.debug("%s - Old cache deleted: %s", cache_key, deleted)

        metadata = services.get_media_metadata(
            media_type,
            media_id,
            source,
            [season_number],
        )
        item, _ = Item.objects.update_or_create(
            media_id=media_id,
            source=source,
            media_type=media_type,
            season_number=season_number,
            defaults={
                "title": metadata["title"],
                "image": metadata["image"],
            },
        )
        title = metadata["title"]
        if season_number:
            title += f" - Season {season_number}"

        if media_type == MediaTypes.SEASON.value:
            metadata["episodes"] = tmdb.process_episodes(
                metadata,
                [],
            )

            # Create a dictionary of existing episodes keyed by episode number
            existing_episodes = {
                ep.episode_number: ep
                for ep in Item.objects.filter(
                    source=source,
                    media_type=MediaTypes.EPISODE.value,
                    media_id=media_id,
                    season_number=season_number,
                )
            }

            episodes_to_update = []
            episode_count = 0

            for episode_data in metadata["episodes"]:
                episode_number = episode_data["episode_number"]
                if episode_number in existing_episodes:
                    episode_item = existing_episodes[episode_number]
                    episode_item.title = metadata["title"]
                    episode_item.image = episode_data["image"]
                    episodes_to_update.append(episode_item)
                    episode_count += 1

            logger.info(
                "Found %s existing episodes to update for %s",
                episode_count,
                title,
            )

            if episodes_to_update:
                updated_count = Item.objects.bulk_update(
                    episodes_to_update,
                    ["title", "image"],
                    batch_size=100,
                )
                logger.info(
                    "Successfully updated %s episodes for %s",
                    updated_count,
                    title,
                )

        item.fetch_releases(delay=False)

        msg = f"{title} was synced to {Sources(source).label} successfully."
        messages.success(request, msg)

    if request.headers.get("HX-Request"):
        return HttpResponse(
            status=204,
            headers={
                "HX-Redirect": request.POST["next"],
            },
        )
    return helpers.redirect_back(request)


@require_GET
def track_modal(
    request,
    source,
    media_type,
    media_id,
    season_number=None,
):
    """Return the tracking form for a media item."""
    instance_id = request.GET.get("instance_id")
    if instance_id:
        media = BasicMedia.objects.get_media(
            request.user,
            media_type,
            instance_id,
        )
    elif request.GET.get("is_create"):
        media = None
    else:
        # no specific instance, try to find the first one
        user_medias = BasicMedia.objects.filter_media(
            request.user,
            media_id,
            media_type,
            source,
            season_number=season_number,
        )
        media = user_medias.first()
        if media:
            instance_id = media.id

    initial_data = {
        "media_id": media_id,
        "source": source,
        "media_type": media_type,
        "season_number": season_number,
        "instance_id": instance_id,
    }

    if media:
        title = media.item
        if media_type == MediaTypes.GAME.value:
            initial_data["progress"] = helpers.minutes_to_hhmm(media.progress)
    else:
        title = services.get_media_metadata(
            media_type,
            media_id,
            source,
            [season_number],
        )["title"]
        if media_type == MediaTypes.SEASON.value:
            title += f" S{season_number}"

    form = get_form_class(media_type)(instance=media, initial=initial_data)

    return render(
        request,
        "app/components/fill_track.html",
        {
            "title": title,
            "form": form,
            "media": media,
            "return_url": request.GET["return_url"],
        },
    )


@require_POST
def media_save(request):
    """Save or update media data to the database."""
    media_id = request.POST["media_id"]
    source = request.POST["source"]
    media_type = request.POST["media_type"]
    season_number = request.POST.get("season_number")
    instance_id = request.POST.get("instance_id")

    if instance_id:
        instance = BasicMedia.objects.get_media(
            request.user,
            media_type,
            instance_id,
        )
    else:
        metadata = services.get_media_metadata(
            media_type,
            media_id,
            source,
            [season_number],
        )
        item, _ = Item.objects.get_or_create(
            media_id=media_id,
            source=source,
            media_type=media_type,
            season_number=season_number,
            defaults={
                "title": metadata["title"],
                "image": metadata["image"],
            },
        )
        model = apps.get_model(app_label="app", model_name=media_type)
        instance = model(item=item, user=request.user)

    # Validate the form and save the instance if it's valid
    form_class = get_form_class(media_type)
    form = form_class(request.POST, instance=instance)
    if form.is_valid():
        form.save()
        logger.info("%s saved successfully.", form.instance)
    else:
        logger.error(form.errors.as_json())
        for field, errors in form.errors.items():
            for error in errors:
                messages.error(
                    request,
                    f"{field.replace('_', ' ').title()}: {error}",
                )

    return helpers.redirect_back(request)


@require_POST
def media_delete(request):
    """Delete media data from the database."""
    instance_id = request.POST["instance_id"]
    media_type = request.POST["media_type"]
    model = apps.get_model(app_label="app", model_name=media_type)

    try:
        media = BasicMedia.objects.get_media(
            request.user,
            media_type,
            instance_id,
        )
        media.delete()
        logger.info("%s deleted successfully.", media)

    except model.DoesNotExist:
        logger.warning("The %s was already deleted before.", media_type)

    return helpers.redirect_back(request)


@require_POST
def episode_save(request):
    """Handle the creation, deletion, and updating of episodes for a season."""
    media_id = request.POST["media_id"]
    season_number = int(request.POST["season_number"])
    episode_number = int(request.POST["episode_number"])
    source = request.POST["source"]

    form = EpisodeForm(request.POST)
    if not form.is_valid():
        logger.error("Form validation failed: %s", form.errors)
        return HttpResponseBadRequest("Invalid form data")

    try:
        related_season = Season.objects.get(
            item__media_id=media_id,
            item__source=source,
            item__season_number=season_number,
            item__episode_number=None,
            user=request.user,
        )
    except Season.DoesNotExist:
        tv_with_seasons_metadata = services.get_media_metadata(
            "tv_with_seasons",
            media_id,
            source,
            [season_number],
        )
        season_metadata = tv_with_seasons_metadata[f"season/{season_number}"]

        item, _ = Item.objects.get_or_create(
            media_id=media_id,
            source=Sources.TMDB.value,
            media_type=MediaTypes.SEASON.value,
            season_number=season_number,
            defaults={
                "title": tv_with_seasons_metadata["title"],
                "image": season_metadata["image"],
            },
        )
        related_season = Season.objects.create(
            item=item,
            user=request.user,
            score=None,
            status=Status.IN_PROGRESS.value,
            notes="",
        )

        logger.info("%s did not exist, it was created successfully.", related_season)

    related_season.watch(episode_number, form.cleaned_data["end_date"])

    return helpers.redirect_back(request)


@require_http_methods(["GET", "POST"])
def create_entry(request):
    """Return the form for manually adding media items."""
    if request.method == "GET":
        media_types = MediaTypes.values
        return render(request, "app/create_entry.html", {"media_types": media_types})

    # Process the form submission
    form = ManualItemForm(request.POST, user=request.user)
    if not form.is_valid():
        # Handle form validation errors
        logger.error(form.errors.as_json())
        helpers.form_error_messages(form, request)
        return redirect("create_entry")

    # Try to save the item
    try:
        item = form.save()
    except IntegrityError:
        # Handle duplicate item
        media_name = form.cleaned_data["title"]
        if form.cleaned_data.get("season_number"):
            media_name += f" - Season {form.cleaned_data['season_number']}"
        if form.cleaned_data.get("episode_number"):
            media_name += f" - Episode {form.cleaned_data['episode_number']}"

        logger.exception("%s already exists in the database.", media_name)
        messages.error(request, f"{media_name} already exists in the database.")
        return redirect("create_entry")

    # Prepare and validate the media form
    updated_request = request.POST.copy()
    updated_request.update({"source": item.source, "media_id": item.media_id})
    media_form = get_form_class(item.media_type)(updated_request)

    if not media_form.is_valid():
        # Handle media form validation errors
        logger.error(media_form.errors.as_json())
        helpers.form_error_messages(media_form, request)

        # Delete the item since the media creation failed
        item.delete()
        logger.info("%s was deleted due to media form validation failure", item)
        return redirect("create_entry")

    # Save the media instance
    media_form.instance.user = request.user
    media_form.instance.item = item

    # Handle relationships based on media type
    if item.media_type == MediaTypes.SEASON.value:
        media_form.instance.related_tv = form.cleaned_data["parent_tv"]
    elif item.media_type == MediaTypes.EPISODE.value:
        media_form.instance.related_season = form.cleaned_data["parent_season"]

    media_form.save()

    # Success message
    msg = f"{item} added successfully."
    messages.success(request, msg)
    logger.info(msg)

    return redirect("create_entry")


@require_GET
def search_parent_tv(request):
    """Return the search results for parent TV shows."""
    query = request.GET.get("q", "").strip()

    if len(query) <= 1:
        return render(request, "app/components/search_parent_tv.html")

    logger.debug(
        "%s - Searching for TV shows with query: %s",
        request.user.username,
        query,
    )

    parent_tvs = TV.objects.filter(
        user=request.user,
        item__source=Sources.MANUAL.value,
        item__media_type=MediaTypes.TV.value,
        item__title__icontains=query,
    )[:5]

    return render(
        request,
        "app/components/search_parent_tv.html",
        {"results": parent_tvs, "query": query},
    )


@require_GET
def search_parent_season(request):
    """Return the search results for parent seasons."""
    query = request.GET.get("q", "").strip()

    if len(query) <= 1:
        return render(request, "app/components/search_parent_tv.html")

    logger.debug(
        "%s - Searching for seasons with query: %s",
        request.user.username,
        query,
    )

    parent_seasons = Season.objects.filter(
        user=request.user,
        item__source=Sources.MANUAL.value,
        item__media_type=MediaTypes.SEASON.value,
        item__title__icontains=query,
    )[:5]

    return render(
        request,
        "app/components/search_parent_season.html",
        {"results": parent_seasons, "query": query},
    )


@require_GET
def history_modal(
    request,
    source,
    media_type,
    media_id,
    season_number=None,
    episode_number=None,
):
    """Return the history page for a media item."""
    user_medias = BasicMedia.objects.filter_media(
        request.user,
        media_id,
        media_type,
        source,
        season_number=season_number,
        episode_number=episode_number,
    )

    total_medias = user_medias.count()
    timeline_entries = []
    for index, media in enumerate(user_medias, start=1):
        if history := media.history.all():
            media_entry_number = total_medias - index + 1
            timeline_entries.extend(
                history_processor.process_history_entries(
                    history,
                    media_type,
                    media_entry_number,
                    request.user,
                ),
            )
    return render(
        request,
        "app/components/fill_history.html",
        {
            "media_type": media_type,
            "timeline": timeline_entries,
            "total_medias": total_medias,
            "return_url": request.GET["return_url"],
        },
    )


@require_http_methods(["DELETE"])
def delete_history_record(request, media_type, history_id):
    """Delete a specific history record."""
    try:
        historical_model = apps.get_model(
            app_label="app",
            model_name=f"historical{media_type.lower()}",
        )

        historical_model.objects.get(
            history_id=history_id,
            history_user=request.user,
        ).delete()

        logger.info(
            "Deleted history record %s",
            str(history_id),
        )

        # Return empty 200 response - the element will be removed by HTMX
        return HttpResponse()

    except historical_model.DoesNotExist:
        logger.exception(
            "History record %s not found for user %s",
            str(history_id),
            str(request.user),
        )
        return HttpResponse("Record not found", status=404)


@require_GET
def statistics(request):
    """Return the statistics page."""
    # Set default date range to last year
    timeformat = "%Y-%m-%d"
    today = timezone.localdate()
    one_year_ago = today.replace(year=today.year - 1)

    # Get date parameters with defaults
    start_date_str = request.GET.get("start-date") or one_year_ago.strftime(timeformat)
    end_date_str = request.GET.get("end-date") or today.strftime(timeformat)

    if start_date_str == "all" and end_date_str == "all":
        start_date = None
        end_date = None
    else:
        start_date = parse_date(start_date_str)
        end_date = parse_date(end_date_str)

        if start_date and end_date:
            # Convert to datetime with timezone awareness
            start_date = timezone.make_aware(
                datetime.combine(start_date, datetime.min.time()),
            )

            # End date should be end of day
            end_date = timezone.make_aware(
                datetime.combine(end_date, datetime.max.time()),
            )

    # Get all user media data in a single operation
    user_media, media_count = stats.get_user_media(
        request.user,
        start_date,
        end_date,
    )

    # Calculate all statistics from the retrieved data
    media_type_distribution = stats.get_media_type_distribution(
        media_count,
    )
    score_distribution, top_rated = stats.get_score_distribution(user_media)
    status_distribution = stats.get_status_distribution(user_media)
    status_pie_chart_data = stats.get_status_pie_chart_data(
        status_distribution,
    )
    timeline = stats.get_timeline(user_media)

    activity_data = stats.get_activity_data(request.user, start_date, end_date)

    context = {
        "start_date": start_date,
        "end_date": end_date,
        "media_count": media_count,
        "activity_data": activity_data,
        "media_type_distribution": media_type_distribution,
        "score_distribution": score_distribution,
        "top_rated": top_rated,
        "status_distribution": status_distribution,
        "status_pie_chart_data": status_pie_chart_data,
        "timeline": timeline,
    }

    return render(request, "app/statistics.html", context)


@require_GET
def service_worker():
    """Serve the service worker file."""
    sw_path = Path(settings.STATICFILES_DIRS[0]) / "js" / "serviceworker.js"
    with sw_path.open() as f:
        response = HttpResponse(f.read(), content_type="application/javascript")
        response["Service-Worker-Allowed"] = "/"
        return response
