from django.contrib import admin
from django.utils.translation import gettext_lazy as _
from django.utils.html import format_html
from django.contrib import messages

from unfold.admin import ModelAdmin, StackedInline, TabularInline
from unfold.decorators import display

from apps.transaction.models import TransactionParticipant, ParticipantInfo, TransactionReceipt
from apps.course.models import Participant

from utils.admin import project_admin_site

class ParticipantInfoInline(StackedInline):
    model = ParticipantInfo
    extra = 1
    fields = ['fullname', 'email', 'phone_number', 'gender', 'birthdate']
    # readonly_fields = ['email', 'phone_number']
    classes = ['collapse']
    tab = True
    show_change_link = True


class TransactionReceiptInline(TabularInline):
    model = TransactionReceipt
    extra = 0
    fields = ['file', 'description', 'uploaded_at']
    readonly_fields = ['uploaded_at']
    classes = ['collapse']
    tab = True
    show_change_link = True
    verbose_name = _('Payment Receipt')
    verbose_name_plural = _('Payment Receipts')


@admin.register(TransactionParticipant)
class TransactionParticipantAdmin(ModelAdmin):
    list_display = ('user', 'course', 'payment_status', 'price_display', 'participant_status', 'receipts_count', 'created_at', 'updated_at')
    list_filter = ('status', 'course', 'created_at')
    search_fields = ('user__email', 'course__title')
    readonly_fields = ['created_at', 'updated_at']
    inlines = [ParticipantInfoInline, TransactionReceiptInline]
    autocomplete_fields = ['user',]
    show_change_link = True
    ordering = ('-created_at',)
    
    fieldsets = (
        (None, {
            'fields': ('user', 'course', 'status', 'price')
        }),
        (_('Timestamps'), {
            'fields': ('created_at', 'updated_at'),
            'classes': ('collapse',)
        }),
    )
    
    @display(description=_("Payment Status"), ordering="status")
    def payment_status(self, obj):
        if obj.status == 'success':
            return format_html('<span class="unfold-badge unfold-badge--success">Paid</span>')
        elif obj.status == 'failed':
            return format_html('<span class="unfold-badge unfold-badge--danger">Failed</span>')
        elif obj.status == 'waiting_approval':
            return format_html('<span class="unfold-badge unfold-badge--info">Waiting Approval</span>')
        return format_html('<span class="unfold-badge unfold-badge--warning">Pending</span>')

    @display(description=_("Receipts Count"))
    def receipts_count(self, obj):
        """Display count of uploaded receipts"""
        count = obj.receipts.count()
        if count > 0:
            return format_html('<span class="unfold-badge unfold-badge--info">{} receipts</span>', count)
        return format_html('<span class="unfold-badge unfold-badge--secondary">No receipts</span>')
    
    @display(description=_("Price"), ordering="price")
    def price_display(self, obj):
        return format_html('<span class="unfold-badge unfold-badge--info">${}</span>', obj.price)
    
    @display(description=_("Course Participant Status"))
    def participant_status(self, obj):
        """نمایش وضعیت شرکت‌کننده در دوره"""
        if obj.status == TransactionParticipant.TransactionStatus.SUCCESS:
            participant_exists = Participant.objects.filter(
                student=obj.user, 
                course=obj.course
            ).exists()
            if participant_exists:
                return format_html('<span class="unfold-badge unfold-badge--success">✓ Enrolled</span>')
            else:
                return format_html('<span class="unfold-badge unfold-badge--warning">⚠ Not Enrolled</span>')
        else:
            return format_html('<span class="unfold-badge unfold-badge--secondary">- Not Applicable</span>')
    
    def save_model(self, request, obj, form, change):
        """Override save_model to show messages when participant is created"""
        if change:
            # Store the old status before saving
            old_obj = TransactionParticipant.objects.get(pk=obj.pk)
            old_status = old_obj.status
            
            # Save the object
            super().save_model(request, obj, form, change)
            
            # Check if status changed to SUCCESS
            if (old_status != TransactionParticipant.TransactionStatus.SUCCESS and 
                obj.status == TransactionParticipant.TransactionStatus.SUCCESS):
                
                participant_exists = Participant.objects.filter(
                    student=obj.user, 
                    course=obj.course
                ).exists()
                
                if participant_exists:
                    messages.success(
                        request, 
                        f"Transaction status updated to SUCCESS. User {obj.user.email} is now enrolled in course '{obj.course.title}'."
                    )
                else:
                    messages.warning(
                        request, 
                        f"Transaction status updated to SUCCESS, but there was an issue enrolling user {obj.user.email} in course '{obj.course.title}'. Please check the logs."
                    )
        else:
            super().save_model(request, obj, form, change)
    
    def get_queryset(self, request):
        # Filter out deleted transactions
        return super().get_queryset(request).filter(is_deleted=False)
    
project_admin_site.register(TransactionParticipant, TransactionParticipantAdmin)


@admin.register(TransactionReceipt)
class TransactionReceiptAdmin(ModelAdmin):
    list_display = ('transaction', 'file', 'uploaded_at', 'description_preview')
    list_filter = ('uploaded_at', 'transaction__status')
    search_fields = ('transaction__user__email', 'transaction__course__title', 'description')
    readonly_fields = ['uploaded_at']
    autocomplete_fields = ['transaction']
    ordering = ('-uploaded_at',)

    fieldsets = (
        (None, {
            'fields': ('transaction', 'file', 'description')
        }),
        (_('Timestamps'), {
            'fields': ('uploaded_at',),
            'classes': ('collapse',)
        }),
    )

    @display(description=_("Description"))
    def description_preview(self, obj):
        """Display truncated description"""
        if obj.description:
            return obj.description[:50] + '...' if len(obj.description) > 50 else obj.description
        return '-'

project_admin_site.register(TransactionReceipt, TransactionReceiptAdmin)