from django.contrib import admin
from unfold.admin import ModelAdmin, StackedInline
from django.db import models
from django.forms import widgets
from .models import Subject, Assignment, Submission, Question, Answer

@admin.register(Subject)
class SubjectAdmin(ModelAdmin):
    list_display = ('name',)
    list_display_links = ('name',)

class QuestionInline(StackedInline):
    model = Question
    extra = 1

    class Media:
        js = ('js/admin_assignment.js',)

@admin.register(Assignment)
class AssignmentAdmin(ModelAdmin):
    list_display = ('title', 'subject', 'created_at')
    list_display_links = ('title',)
    list_filter = ('subject',)
    search_fields = ('title', 'description')
    exclude = ('created_by',)
    inlines = [QuestionInline]
    actions = ['delete_selected_assignments']

    @admin.action(description="Удалить выбранные задания")
    def delete_selected_assignments(self, request, queryset):
        deleted_count = 0
        for obj in queryset:
            if self.has_delete_permission(request, obj):
                obj.delete()
                deleted_count += 1
        self.message_user(request, f"Успешно удалено {deleted_count} заданий.")

    def get_queryset(self, request):
        qs = super().get_queryset(request)
        if request.user.is_superuser or request.user.role == 'ADMIN':
            return qs
        return qs.filter(created_by=request.user)

    def save_model(self, request, obj, form, change):
        if getattr(obj, 'created_by_id', None) is None:
            obj.created_by = request.user
        super().save_model(request, obj, form, change)

    def has_delete_permission(self, request, obj=None):
        if request.user.is_superuser or request.user.role == 'ADMIN':
            return True
        if request.user.role == 'TEACHER':
            if obj is not None and obj.created_by != request.user:
                return False
            return True
        return False

from django.utils.html import format_html

class AnswerInline(StackedInline):
    model = Answer
    extra = 0
    readonly_fields = ('question', 'get_student_answer')
    fields = ('question', 'get_student_answer', 'is_correct', 'points', 'comment')
    
    def get_student_answer(self, obj):
        if not obj or not obj.pk:
            return ""
        if obj.question.question_type == 'TEXT_AUTO':
            return obj.text_answer or "Нет ответа"
        elif obj.question.question_type == 'TABLE_AUTO':
            import json
            try:
                data = json.loads(obj.text_answer)
                html = '<table style="border-collapse: collapse; margin-top: 4px;">'
                for row in data:
                    html += f'<tr><td style="border: 1px solid #e5e7eb; padding: 4px 8px;">{row[0]}</td><td style="border: 1px solid #e5e7eb; padding: 4px 8px;">{row[1]}</td></tr>'
                html += '</table>'
                return format_html(html)
            except Exception:
                return obj.text_answer or "Нет ответа"
        else:
            if obj.file_answer:
                return format_html('<a href="{}" target="_blank">Скачать файл</a>', obj.file_answer.url)
            return "Файл не прикреплен"
    get_student_answer.short_description = 'Ответ ученика'
    
    def has_add_permission(self, request, obj=None):
        return False

@admin.register(Submission)
class SubmissionAdmin(ModelAdmin):
    change_list_template = "admin/lms/submission/change_list.html"
    list_display = ('assignment', 'student', 'status', 'grade', 'submitted_at')
    list_filter = ('status', 'assignment__subject', 'student')
    search_fields = ('student__username', 'assignment__title')
    inlines = [AnswerInline]

    def get_queryset(self, request):
        qs = super().get_queryset(request)
        if request.user.is_superuser or request.user.role == 'ADMIN':
            return qs
        if request.user.role == 'TEACHER':
            return qs.filter(assignment__created_by=request.user)
        return qs.filter(student=request.user)