from __future__ import annotations
from datetime import datetime
from typing import Optional
from sqlalchemy import DateTime, Enum, ForeignKey, String, UniqueConstraint, func, Text, JSON, Boolean
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.sql.sqltypes import Enum as EnumType  # Явный импорт Enum для типизации
from app.db.session import Base
from app.models.post import PostType
from enum import Enum as PyEnum

class PostStatus(str, PyEnum):
    draft = "draft"
    scheduled = "scheduled"
    sent = "sent"
    failed = "failed"

class TemplateVisibility(str, PyEnum):
    private = "private"
    org = "org"
    public = "public"

class Template(Base):
    __tablename__ = "templates"
    __table_args__ = (
        UniqueConstraint("owner_id", "name", name="uq_template_owner_name"),
    )
    
    id: Mapped[int] = mapped_column(primary_key=True)
    owner_id: Mapped[int] = mapped_column(ForeignKey("users.id"))
    name: Mapped[str] = mapped_column(String(100))
    title: Mapped[str] = mapped_column(String(200))
    description: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    content: Mapped[str] = mapped_column(Text)
    keyboard_tpl: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True)
    parse_mode: Mapped[str] = mapped_column(String(20), default="HTML")
    type: Mapped[PostType] = mapped_column(Enum(PostType))
    visibility: Mapped[TemplateVisibility] = mapped_column(
        EnumType(TemplateVisibility), 
        default=TemplateVisibility.private
    )
    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, 
        server_default=func.now(),
        onupdate=func.now()
    )
    
    @classmethod
    async def get_by_name(cls, session, name: str) -> Optional[Template]:
        """Получение шаблона по имени."""
        stmt = cls.__table__.select().where(cls.__table__.c.name == name)
        result = await session.execute(stmt)
        return result.scalar_one_or_none()
        
    async def render(self, template_vars: dict, context: dict) -> dict:
        """Рендеринг шаблона.
        
        Args:
            template_vars: Переменные для подстановки
            context: Дополнительный контекст
            
        Returns:
            Отрендеренные данные
        """
        text = self.content
        keyboard = self.keyboard_tpl
        
        # Подстановка переменных
        for key, value in template_vars.items():
            text = text.replace(f"{{${key}}}", str(value))
            
        # Подготовка данных для отправки
        return {
            "type": self.type,
            "text": text,
            "keyboard": keyboard,
            "parse_mode": self.parse_mode
        }

    id: Mapped[int] = mapped_column(primary_key=True)
    owner_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
    name: Mapped[str] = mapped_column(String(64))
    title: Mapped[Optional[str]] = mapped_column(String(128))
    type: Mapped[PostType] = mapped_column(EnumType(PostType), default=PostType.text)
    content: Mapped[str] = mapped_column(Text)
    keyboard_tpl: Mapped[Optional[list[dict]]] = mapped_column(JSON, nullable=True)
    parse_mode: Mapped[Optional[str]] = mapped_column(String(16), default="HTML")
    visibility: Mapped[TemplateVisibility] = mapped_column(EnumType(TemplateVisibility), default=TemplateVisibility.private)
    is_archived: Mapped[bool] = mapped_column(Boolean, default=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())