import re
import yaml
from decimal import Decimal

from django.shortcuts import render, get_object_or_404
from django.db.models import Q
from django.http import HttpResponse, JsonResponse
from django.template.loader import render_to_string
from hub.services.models import (
    ServiceOffering,
    CloudProvider,
    Category,
    Service,
    ComputePlan,
    VSHNAppCatPrice,
    StoragePlan,
)
from collections import defaultdict
from markdownify import markdownify


def decimal_to_float(obj):
    """Convert Decimal objects to float for JSON serialization"""
    if isinstance(obj, Decimal):
        return float(obj)
    elif isinstance(obj, dict):
        return {key: decimal_to_float(value) for key, value in obj.items()}
    elif isinstance(obj, list):
        return [decimal_to_float(item) for item in obj]
    return obj


def natural_sort_key(name):
    """Extract numeric part from compute plan name for natural sorting"""
    match = re.search(r"compute-std-(\d+)", name)
    return int(match.group(1)) if match else 0


def offering_list(request):
    offerings = (
        ServiceOffering.objects.filter(disable_listing=False)
        .order_by("service")
        .select_related("service", "cloud_provider")
        .prefetch_related(
            "service__categories",
            "plans",
        )
    )

    cloud_providers = CloudProvider.objects.all()
    categories = Category.objects.filter(parent=None).prefetch_related("children")
    services = Service.objects.all().order_by("name")

    # Handle cloud provider filter
    if request.GET.get("cloud_provider"):
        provider_id = request.GET.get("cloud_provider")
        offerings = offerings.filter(cloud_provider_id=provider_id)

    # Handle category filter
    if request.GET.get("category"):
        category_id = request.GET.get("category")
        category = get_object_or_404(Category, id=category_id)
        subcategories = Category.objects.filter(parent=category)
        offerings = offerings.filter(
            Q(service__categories=category) | Q(service__categories__in=subcategories)
        ).distinct()

    # Handle service filter
    if request.GET.get("service"):
        service_id = request.GET.get("service")
        offerings = offerings.filter(service_id=service_id)

    # Handle search
    if request.GET.get("search"):
        query = request.GET.get("search")
        offerings = offerings.filter(
            Q(service__name__icontains=query)
            | Q(description__icontains=query)
            | Q(cloud_provider__name__icontains=query)
        ).distinct()

    context = {
        "offerings": offerings,
        "cloud_providers": cloud_providers,
        "categories": categories,
        "services": services,
    }
    return render(request, "services/offering_list.html", context)


def offering_detail(request, provider_slug, service_slug):
    offering = get_object_or_404(
        ServiceOffering.objects.select_related(
            "service", "cloud_provider"
        ).prefetch_related("plans"),
        cloud_provider__slug=provider_slug,
        service__slug=service_slug,
    )

    # Check if JSON pricing data is requested
    if request.GET.get("pricing") == "json":
        pricing_data = None
        if offering.msp == "VS":
            pricing_data = generate_pricing_data(offering)
            if pricing_data:
                # Convert Decimal objects to float for JSON serialization
                pricing_data = decimal_to_float(pricing_data)

        return JsonResponse(pricing_data or {})

    # Check if Exoscale marketplace YAML is requested
    if request.GET.get("exo_marketplace") == "true":
        return generate_exoscale_marketplace_yaml(offering)

    pricing_data_by_group_and_service_level = None
    price_calculator_enabled = False

    # Generate pricing data for VSHN offerings
    if offering.msp == "VS":
        try:
            appcat_price = offering.service.vshn_appcat_price.get()
            price_calculator_enabled = appcat_price.public_display_enabled

            # Only generate pricing data if public display is enabled
            if price_calculator_enabled:
                pricing_data_by_group_and_service_level = generate_pricing_data(
                    offering
                )
        except VSHNAppCatPrice.DoesNotExist:
            pass

    # Get related articles for both cloud provider and service
    provider_articles = offering.cloud_provider.articles.filter(
        is_published=True
    ).order_by("-created_at")[:3]
    service_articles = offering.service.articles.filter(is_published=True).order_by(
        "-created_at"
    )[:3]

    context = {
        "offering": offering,
        "pricing_data_by_group_and_service_level": pricing_data_by_group_and_service_level,
        "price_calculator_enabled": price_calculator_enabled,
        "provider_articles": provider_articles,
        "service_articles": service_articles,
    }
    return render(request, "services/offering_detail.html", context)


def generate_exoscale_marketplace_yaml(offering):
    """Generate YAML structure for Exoscale marketplace"""

    # Create service name slug for YAML key
    service_slug = offering.service.slug.replace("-", "")
    yaml_key = f"marketplace_PRODUCTS_servala-{service_slug}"

    # Generate product overview content from service description (convert HTML to Markdown)
    product_overview = ""
    if offering.service.description:
        product_overview = markdownify(
            offering.service.description, heading_style="ATX"
        ).strip()

    # Generate highlights content from offering description and offer_description (convert HTML to Markdown)
    highlights = ""
    if offering.description:
        highlights += markdownify(offering.description, heading_style="ATX").strip()
    if offering.offer_description:
        if highlights:
            highlights += "\n\n"
        highlights += markdownify(
            offering.offer_description.get_full_text(), heading_style="ATX"
        ).strip()

    # Build YAML structure
    yaml_structure = {
        yaml_key: {
            "page_class": "tmpl-marketplace-product",
            "html_title": f"Managed {offering.service.name} by VSHN via Servala",
            "meta_desc": "Servala is the Open Cloud Native Service Hub. It connects businesses, developers, and cloud service providers on one unique hub with secure, scalable, and easy-to-use cloud-native services.",
            "page_header_title": f"Managed {offering.service.name} by VSHN via Servala",
            "provider_key": "vshn",
            "slug": f"servala-managed-{offering.service.slug}",
            "title": f"Managed {offering.service.name} by VSHN via Servala",
            "logo": f"img/servala-{offering.service.slug}.svg",
            "list_display": [],
            "meta": [
                {"key": "exoscale-iaas", "value": True},
                {"key": "availability", "zones": "all"},
            ],
            "action_link": f"https://servala.com/offering/{offering.cloud_provider.slug}/{offering.service.slug}/?source=exoscale_marketplace",
            "action_link_text": "Subscribe now",
            "blobs": [
                {
                    "key": "product-overview",
                    "blob": (
                        product_overview.strip()
                        if product_overview
                        else "Service description not available."
                    ),
                },
                {
                    "key": "highlights",
                    "blob": (
                        highlights.strip()
                        if highlights
                        else "Offering highlights not available."
                    ),
                },
                "editor",
                {
                    "key": "pricing",
                    "blob": f"Find all the pricing information on the [Servala website](https://servala.com/offering/{offering.cloud_provider.slug}/{offering.service.slug}/?source=exoscale_marketplace#plans)",
                },
                {
                    "key": "service-and-support",
                    "blob": "Servala is operated by VSHN AG in Zurich, Switzerland.\n\nSeveral SLAs are available on request, offering support 24/7.\n\nMore details can be found in the [VSHN Service Levels Documentation](https://products.vshn.ch/service_levels.html).",
                },
                {
                    "key": "terms-of-service",
                    "blob": "- [Product Description](https://products.vshn.ch/servala/index.html)\n- [General Terms and Conditions](https://products.vshn.ch/legal/gtc_en.html)\n- [SLA](https://products.vshn.ch/service_levels.html)\n- [DPA](https://products.vshn.ch/legal/dpa_en.html)\n- [Privacy Policy](https://products.vshn.ch/legal/privacy_policy_en.html)",
                },
            ],
        }
    }

    # Generate YAML response for browser display
    yaml_content = yaml.dump(
        yaml_structure,
        default_flow_style=False,
        allow_unicode=True,
        indent=2,
        width=120,
        sort_keys=False,
        default_style=None,
    )

    # Return as plain text for browser display
    response = HttpResponse(yaml_content, content_type="text/plain")

    return response


def generate_pricing_data(offering):
    """Generate pricing data for a specific offering and its plans with multi-currency support"""
    # Fetch all plans for this offering
    plans = offering.plans.prefetch_related("plan_prices")

    pricing_data = []
    for plan in plans:
        for plan_price in plan.plan_prices.all():
            pricing_data.append({
                "plan_id": plan.id,
                "plan_name": plan.name,
                "description": plan.description,
                "currency": plan_price.currency,
                "amount": float(plan_price.amount),
            })

    return {"plans": pricing_data}