from django.db import models
from django.contrib.auth.models import AbstractUser
from django.urls import reverse
from django.utils.text import slugify
from unidecode import unidecode


class CustomUser(AbstractUser):
    """Расширенная модель пользователя с упрощённой регистрацией."""
    email = models.EmailField(blank=True, null=True, verbose_name='Email')
    is_verified = models.BooleanField(default=False, verbose_name='Верифицирован')
    avatar = models.ImageField(upload_to='avatars/', blank=True, null=True, verbose_name='Аватар')

    class Meta:
        verbose_name = 'Пользователь'
        verbose_name_plural = 'Пользователи'
        ordering = ['-date_joined']

    def __str__(self):
        return self.username

    def get_avatar_letter(self):
        return self.username[0].upper() if self.username else 'U'


class Category(models.Model):
    """Категории для статей блога."""
    name = models.CharField(max_length=100, verbose_name='Название')
    slug = models.SlugField(max_length=100, unique=True, verbose_name='URL')
    description = models.TextField(blank=True, verbose_name='Описание')
    icon = models.CharField(max_length=50, blank=True, default='fas fa-folder', verbose_name='Иконка')
    order = models.PositiveIntegerField(default=0, verbose_name='Порядок')

    class Meta:
        verbose_name = 'Категория'
        verbose_name_plural = 'Категории'
        ordering = ['order', 'name']

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(unidecode(self.name))
        super().save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse('blog_category', kwargs={'category_slug': self.slug})

    @property
    def articles_count(self):
        return self.articles.filter(is_published=True).count()


class Article(models.Model):
    """Модель статей блога и достижений."""
    title = models.CharField(max_length=200, verbose_name='Заголовок')
    slug = models.SlugField(max_length=200, unique=True, verbose_name='URL')
    sub_title = models.CharField(max_length=300, blank=True, verbose_name='Подзаголовок')
    excerpt = models.TextField(max_length=500, blank=True, verbose_name='Краткое описание')
    post = models.TextField(verbose_name='Содержание')
    img = models.ImageField(upload_to='articles/', blank=True, null=True, verbose_name='Изображение')
    category = models.ForeignKey(
        Category, on_delete=models.SET_NULL, null=True, blank=True,
        related_name='articles', verbose_name='Категория'
    )
    author = models.CharField(max_length=100, default='Егор Деев', verbose_name='Автор')
    date = models.DateTimeField(auto_now_add=True, verbose_name='Дата публикации')
    updated_at = models.DateTimeField(auto_now=True, verbose_name='Дата обновления')
    views = models.PositiveIntegerField(default=0, verbose_name='Просмотры')
    is_published = models.BooleanField(default=True, verbose_name='Опубликовано')
    is_achievement = models.BooleanField(default=False, verbose_name='Это достижение')
    achievement_icon = models.CharField(
        max_length=50, blank=True, default='fas fa-trophy',
        verbose_name='Иконка достижения'
    )
    achievement_date = models.DateField(blank=True, null=True, verbose_name='Дата достижения')

    class Meta:
        verbose_name = 'Статья'
        verbose_name_plural = 'Статьи'
        ordering = ['-date']

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        if not self.slug:
            base_slug = slugify(unidecode(self.title))
            slug = base_slug
            counter = 1
            while Article.objects.filter(slug=slug).exclude(pk=self.pk).exists():
                slug = f"{base_slug}-{counter}"
                counter += 1
            self.slug = slug
        if not self.excerpt and self.post:
            self.excerpt = self.post[:300] + '...' if len(self.post) > 300 else self.post
        super().save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse('article_detail', kwargs={'slug': self.slug})

    @property
    def likes_count(self):
        return self.likes.filter(is_like=True).count()

    @property
    def dislikes_count(self):
        return self.likes.filter(is_like=False).count()

    @property
    def comments_count(self):
        return self.comments.filter(is_approved=True).count()


class Project(models.Model):
    """Модель проектов портфолио."""
    STATUS_CHOICES = [
        ('completed', 'Завершён'),
        ('in_development', 'В разработке'),
        ('beta', 'Бета'),
    ]

    SIZE_CHOICES = [
        ('featured', 'Главный (большой)'),
        ('regular', 'Обычный'),
        ('small', 'Компактный'),
    ]

    title = models.CharField(max_length=200, verbose_name='Название')
    slug = models.SlugField(max_length=200, unique=True, verbose_name='URL')
    short_description = models.CharField(max_length=300, verbose_name='Краткое описание')
    description = models.TextField(verbose_name='Полное описание')
    features = models.TextField(blank=True, verbose_name='Особенности (каждая с новой строки)')
    img_main = models.ImageField(upload_to='projects/', blank=True, null=True, verbose_name='Главное изображение')
    icon = models.CharField(max_length=50, default='fas fa-code', verbose_name='Иконка проекта')
    technologies = models.CharField(max_length=500, verbose_name='Технологии (через запятую)')
    github_url = models.URLField(blank=True, verbose_name='GitHub')
    demo_url = models.URLField(blank=True, verbose_name='Демо/Ссылка')
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='completed', verbose_name='Статус')
    card_size = models.CharField(max_length=20, choices=SIZE_CHOICES, default='regular', verbose_name='Размер карточки')
    users_count = models.CharField(max_length=50, blank=True, verbose_name='Количество пользователей')
    author = models.CharField(max_length=100, default='Егор Деев', verbose_name='Автор')
    date = models.DateTimeField(auto_now_add=True, verbose_name='Дата добавления')
    order = models.PositiveIntegerField(default=0, verbose_name='Порядок отображения')
    is_visible = models.BooleanField(default=True, verbose_name='Отображать')

    class Meta:
        verbose_name = 'Проект'
        verbose_name_plural = 'Проекты'
        ordering = ['order', '-date']

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(unidecode(self.title))
        super().save(*args, **kwargs)

    def get_technologies_list(self):
        return [tech.strip() for tech in self.technologies.split(',') if tech.strip()]

    def get_features_list(self):
        if not self.features:
            return []
        return [f.strip() for f in self.features.split('\n') if f.strip()]


class Skill(models.Model):
    """Модель навыков и технологий."""
    CATEGORY_CHOICES = [
        ('backend', 'Backend'),
        ('frontend', 'Frontend'),
        ('devops', 'DevOps'),
        ('database', 'Database'),
        ('tools', 'Tools'),
    ]

    name = models.CharField(max_length=100, verbose_name='Название')
    category = models.CharField(max_length=20, choices=CATEGORY_CHOICES, verbose_name='Категория')
    icon = models.CharField(max_length=100, blank=True, verbose_name='CSS класс иконки')
    icon_svg = models.TextField(blank=True, verbose_name='SVG иконка')
    order = models.PositiveIntegerField(default=0, verbose_name='Порядок')

    class Meta:
        verbose_name = 'Навык'
        verbose_name_plural = 'Навыки'
        ordering = ['category', 'order', 'name']

    def __str__(self):
        return f"{self.name} ({self.get_category_display()})"


class Experience(models.Model):
    """Модель опыта работы."""
    title = models.CharField(max_length=200, verbose_name='Должность')
    company = models.CharField(max_length=200, verbose_name='Компания')
    company_url = models.URLField(blank=True, verbose_name='Сайт компании')
    description = models.TextField(verbose_name='Описание')
    responsibilities = models.TextField(blank=True, verbose_name='Обязанности (каждая с новой строки)')
    technologies = models.CharField(max_length=500, blank=True, verbose_name='Технологии')
    start_date = models.DateField(verbose_name='Дата начала')
    end_date = models.DateField(null=True, blank=True, verbose_name='Дата окончания')
    is_current = models.BooleanField(default=False, verbose_name='Текущее место работы')
    order = models.PositiveIntegerField(default=0, verbose_name='Порядок')

    class Meta:
        verbose_name = 'Опыт работы'
        verbose_name_plural = 'Опыт работы'
        ordering = ['order', '-start_date']

    def __str__(self):
        return f"{self.title} — {self.company}"

    def get_responsibilities_list(self):
        if not self.responsibilities:
            return []
        return [r.strip() for r in self.responsibilities.split('\n') if r.strip()]

    def get_technologies_list(self):
        if not self.technologies:
            return []
        return [t.strip() for t in self.technologies.split(',') if t.strip()]

    @property
    def duration(self):
        end = self.end_date or __import__('datetime').date.today()
        months = (end.year - self.start_date.year) * 12 + (end.month - self.start_date.month)
        years = months // 12
        remaining_months = months % 12

        parts = []
        if years:
            parts.append(f"{years} {'год' if years == 1 else 'года' if 2 <= years <= 4 else 'лет'}")
        if remaining_months:
            parts.append(
                f"{remaining_months} {'месяц' if remaining_months == 1 else 'месяца' if 2 <= remaining_months <= 4 else 'месяцев'}")
        return ' '.join(parts) if parts else 'Менее месяца'


class Education(models.Model):
    """Модель образования."""
    TYPE_CHOICES = [
        ('university', 'Высшее образование'),
        ('course', 'Курс/Сертификат'),
        ('school', 'Школа/Лицей'),
    ]

    institution = models.CharField(max_length=300, verbose_name='Учебное заведение')
    institution_short = models.CharField(max_length=100, blank=True, verbose_name='Сокращённое название')
    degree = models.CharField(max_length=200, verbose_name='Специальность/Программа')
    education_type = models.CharField(max_length=20, choices=TYPE_CHOICES, default='university', verbose_name='Тип')
    description = models.TextField(blank=True, verbose_name='Описание')
    achievements = models.TextField(blank=True, verbose_name='Достижения (каждое с новой строки)')
    start_year = models.PositiveIntegerField(verbose_name='Год начала')
    end_year = models.PositiveIntegerField(null=True, blank=True, verbose_name='Год окончания')
    is_current = models.BooleanField(default=False, verbose_name='В процессе обучения')
    certificate_number = models.CharField(max_length=100, blank=True, verbose_name='Номер сертификата')
    certificate_url = models.URLField(blank=True, verbose_name='Ссылка на сертификат')
    icon = models.CharField(max_length=50, default='fas fa-graduation-cap', verbose_name='Иконка')
    order = models.PositiveIntegerField(default=0, verbose_name='Порядок')

    class Meta:
        verbose_name = 'Образование'
        verbose_name_plural = 'Образование'
        ordering = ['order', '-start_year']

    def __str__(self):
        return f"{self.degree} — {self.institution_short or self.institution}"

    def get_achievements_list(self):
        if not self.achievements:
            return []
        return [a.strip() for a in self.achievements.split('\n') if a.strip()]


class Comment(models.Model):
    """Модель комментариев к статьям."""
    article = models.ForeignKey(
        Article, on_delete=models.CASCADE, related_name='comments', verbose_name='Статья'
    )
    user = models.ForeignKey(
        CustomUser, on_delete=models.CASCADE, related_name='comments', verbose_name='Пользователь'
    )
    parent = models.ForeignKey(
        'self', on_delete=models.CASCADE, null=True, blank=True,
        related_name='replies', verbose_name='Родительский комментарий'
    )
    content = models.TextField(max_length=2000, verbose_name='Содержание')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='Дата создания')
    updated_at = models.DateTimeField(auto_now=True, verbose_name='Дата обновления')
    is_approved = models.BooleanField(default=True, verbose_name='Одобрен')

    class Meta:
        verbose_name = 'Комментарий'
        verbose_name_plural = 'Комментарии'
        ordering = ['created_at']

    def __str__(self):
        return f'{self.user.username}: {self.content[:50]}...'

    @property
    def likes_count(self):
        return self.comment_likes.filter(is_like=True).count()

    @property
    def dislikes_count(self):
        return self.comment_likes.filter(is_like=False).count()

    @property
    def nesting_level(self):
        level = 0
        parent = self.parent
        while parent and level < 3:
            level += 1
            parent = parent.parent
        return level


class ArticleLike(models.Model):
    """Модель лайков/дизлайков статей."""
    article = models.ForeignKey(
        Article, on_delete=models.CASCADE, related_name='likes', verbose_name='Статья'
    )
    user = models.ForeignKey(
        CustomUser, on_delete=models.CASCADE, related_name='article_likes', verbose_name='Пользователь'
    )
    is_like = models.BooleanField(verbose_name='Лайк')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='Дата')

    class Meta:
        verbose_name = 'Оценка статьи'
        verbose_name_plural = 'Оценки статей'
        unique_together = ['article', 'user']


class CommentLike(models.Model):
    """Модель лайков/дизлайков комментариев."""
    comment = models.ForeignKey(
        Comment, on_delete=models.CASCADE, related_name='comment_likes', verbose_name='Комментарий'
    )
    user = models.ForeignKey(
        CustomUser, on_delete=models.CASCADE, related_name='comment_likes', verbose_name='Пользователь'
    )
    is_like = models.BooleanField(verbose_name='Лайк')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='Дата')

    class Meta:
        verbose_name = 'Оценка комментария'
        verbose_name_plural = 'Оценки комментариев'
        unique_together = ['comment', 'user']


class ContactMessage(models.Model):
    """Модель сообщений обратной связи."""
    name = models.CharField(max_length=100, verbose_name='Имя')
    email = models.EmailField(verbose_name='Email')
    subject = models.CharField(max_length=200, verbose_name='Тема')
    message = models.TextField(verbose_name='Сообщение')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='Дата')
    is_read = models.BooleanField(default=False, verbose_name='Прочитано')
    is_replied = models.BooleanField(default=False, verbose_name='Отвечено')
    admin_notes = models.TextField(blank=True, verbose_name='Заметки администратора')

    class Meta:
        verbose_name = 'Сообщение'
        verbose_name_plural = 'Сообщения'
        ordering = ['-created_at']

    def __str__(self):
        return f'{self.name}: {self.subject}'


class SiteSettings(models.Model):
    """Настройки сайта (Singleton)."""
    site_name = models.CharField(max_length=100, default='deev.space', verbose_name='Название сайта')
    site_description = models.TextField(blank=True, verbose_name='Описание сайта')
    owner_name = models.CharField(max_length=200, default='Деев Егор Викторович', verbose_name='Имя владельца')
    owner_title = models.CharField(max_length=200, default='Backend Developer', verbose_name='Должность')
    owner_bio = models.TextField(blank=True, verbose_name='О себе')
    owner_photo = models.ImageField(upload_to='site/', blank=True, null=True, verbose_name='Фото владельца')
    owner_email = models.EmailField(default='egor@deev.space', verbose_name='Email')
    owner_phone = models.CharField(max_length=20, blank=True, verbose_name='Телефон')
    owner_city = models.CharField(max_length=100, default='Москва', verbose_name='Город')
    telegram_url = models.URLField(blank=True, verbose_name='Telegram')
    github_url = models.URLField(blank=True, verbose_name='GitHub')
    vk_url = models.URLField(blank=True, verbose_name='VKontakte')
    linkedin_url = models.URLField(blank=True, verbose_name='LinkedIn')
    resume_file = models.FileField(upload_to='site/', blank=True, null=True, verbose_name='Файл резюме')
    yandex_metrika_id = models.CharField(max_length=20, blank=True, verbose_name='ID Яндекс.Метрики')
    google_analytics_id = models.CharField(max_length=20, blank=True, verbose_name='ID Google Analytics')

    class Meta:
        verbose_name = 'Настройки сайта'
        verbose_name_plural = 'Настройки сайта'

    def __str__(self):
        return self.site_name

    def save(self, *args, **kwargs):
        self.pk = 1
        super().save(*args, **kwargs)

    @classmethod
    def load(cls):
        obj, created = cls.objects.get_or_create(pk=1)
        return obj