"""
Source related views.
"""
from datetime import datetime

from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.paginator import Paginator
from django.db.models import Count
from django.shortcuts import render
from django.views import View

from ..models import Source
from ..utils import parse_pagination_params


class SourceListView(LoginRequiredMixin, View):
    """
    View for displaying a list of sources (Source).
    """
    
    def get(self, request):
        # Get pagination parameters
        page_number, items_per_page = parse_pagination_params(request)
        
        # Get sorting parameters
        sort_param = request.GET.get("sort", "-created_at")
        
        # Get filter parameters
        search_query = request.GET.get("search", "").strip()
        has_coords_average = request.GET.get("has_coords_average")
        has_coords_kupsat = request.GET.get("has_coords_kupsat")
        has_coords_valid = request.GET.get("has_coords_valid")
        has_coords_reference = request.GET.get("has_coords_reference")
        objitem_count_min = request.GET.get("objitem_count_min", "").strip()
        objitem_count_max = request.GET.get("objitem_count_max", "").strip()
        date_from = request.GET.get("date_from", "").strip()
        date_to = request.GET.get("date_to", "").strip()
        
        # Get all Source objects with query optimization
        sources = Source.objects.select_related(
            'created_by__user',
            'updated_by__user'
        ).prefetch_related(
            'source_objitems',
            'source_objitems__parameter_obj',
            'source_objitems__geo_obj'
        ).annotate(
            objitem_count=Count('source_objitems')
        )
        
        # Apply filters
        # Filter by coords_average presence
        if has_coords_average == "1":
            sources = sources.filter(coords_average__isnull=False)
        elif has_coords_average == "0":
            sources = sources.filter(coords_average__isnull=True)
        
        # Filter by coords_kupsat presence
        if has_coords_kupsat == "1":
            sources = sources.filter(coords_kupsat__isnull=False)
        elif has_coords_kupsat == "0":
            sources = sources.filter(coords_kupsat__isnull=True)
        
        # Filter by coords_valid presence
        if has_coords_valid == "1":
            sources = sources.filter(coords_valid__isnull=False)
        elif has_coords_valid == "0":
            sources = sources.filter(coords_valid__isnull=True)
        
        # Filter by coords_reference presence
        if has_coords_reference == "1":
            sources = sources.filter(coords_reference__isnull=False)
        elif has_coords_reference == "0":
            sources = sources.filter(coords_reference__isnull=True)
        
        # Filter by ObjItem count
        if objitem_count_min:
            try:
                min_count = int(objitem_count_min)
                sources = sources.filter(objitem_count__gte=min_count)
            except ValueError:
                pass
        
        if objitem_count_max:
            try:
                max_count = int(objitem_count_max)
                sources = sources.filter(objitem_count__lte=max_count)
            except ValueError:
                pass
        
        # Filter by creation date range
        if date_from:
            try:
                date_from_obj = datetime.strptime(date_from, "%Y-%m-%d")
                sources = sources.filter(created_at__gte=date_from_obj)
            except (ValueError, TypeError):
                pass
        
        if date_to:
            try:
                from datetime import timedelta
                date_to_obj = datetime.strptime(date_to, "%Y-%m-%d")
                # Add one day to include entire end date
                date_to_obj = date_to_obj + timedelta(days=1)
                sources = sources.filter(created_at__lt=date_to_obj)
            except (ValueError, TypeError):
                pass
        
        # Search by ID
        if search_query:
            try:
                search_id = int(search_query)
                sources = sources.filter(id=search_id)
            except ValueError:
                # If not a number, ignore
                pass
        
        # Apply sorting
        valid_sort_fields = {
            "id": "id",
            "-id": "-id",
            "created_at": "created_at",
            "-created_at": "-created_at",
            "updated_at": "updated_at",
            "-updated_at": "-updated_at",
            "objitem_count": "objitem_count",
            "-objitem_count": "-objitem_count",
        }
        
        if sort_param in valid_sort_fields:
            sources = sources.order_by(valid_sort_fields[sort_param])
        
        # Create paginator
        paginator = Paginator(sources, items_per_page)
        page_obj = paginator.get_page(page_number)
        
        # Prepare data for display
        processed_sources = []
        for source in page_obj:
            # Format coordinates
            def format_coords(point):
                if point:
                    longitude = point.coords[0]
                    latitude = point.coords[1]
                    lon = f"{longitude}E" if longitude > 0 else f"{abs(longitude)}W"
                    lat = f"{latitude}N" if latitude > 0 else f"{abs(latitude)}S"
                    return f"{lat} {lon}"
                return "-"
            
            coords_average_str = format_coords(source.coords_average)
            coords_kupsat_str = format_coords(source.coords_kupsat)
            coords_valid_str = format_coords(source.coords_valid)
            coords_reference_str = format_coords(source.coords_reference)
            
            # Get count of related ObjItems
            objitem_count = source.objitem_count
            
            processed_sources.append({
                'id': source.id,
                'coords_average': coords_average_str,
                'coords_kupsat': coords_kupsat_str,
                'coords_valid': coords_valid_str,
                'coords_reference': coords_reference_str,
                'objitem_count': objitem_count,
                'created_at': source.created_at,
                'updated_at': source.updated_at,
                'created_by': source.created_by,
                'updated_by': source.updated_by,
            })
        
        # Prepare context for template
        context = {
            'page_obj': page_obj,
            'processed_sources': processed_sources,
            'items_per_page': items_per_page,
            'available_items_per_page': [50, 100, 500, 1000],
            'sort': sort_param,
            'search_query': search_query,
            'has_coords_average': has_coords_average,
            'has_coords_kupsat': has_coords_kupsat,
            'has_coords_valid': has_coords_valid,
            'has_coords_reference': has_coords_reference,
            'objitem_count_min': objitem_count_min,
            'objitem_count_max': objitem_count_max,
            'date_from': date_from,
            'date_to': date_to,
            'full_width_page': True,
        }
        
        return render(request, "mainapp/source_list.html", context)