from typing import List, Optional

from pydantic import BaseModel, Field

from app.models.domain.articles import Article
from app.models.schemas.rwschema import RWSchema

DEFAULT_ARTICLES_LIMIT = 20
DEFAULT_ARTICLES_OFFSET = 0


class ArticleForResponse(RWSchema, Article):
    """
    返回给前端的文章结构：
    - 继承 Article（包含 cover、tags、author 等）
    - tags 字段通过 alias 暴露为 tagList，兼容前端
    """
    tags: List[str] = Field(..., alias="tagList")


class ArticleInResponse(RWSchema):
    article: ArticleForResponse


class ArticleInCreate(RWSchema):
    """
    创建文章时请求体：
    {
      "article": {
        "title": "...",
        "description": "...",
        "body": "...",
        "tagList": ["..."],
        "cover": "可选封面URL"
      }
    }
    """
    title: str
    description: str
    body: str
    tags: List[str] = Field([], alias="tagList")
    cover: Optional[str] = None


class ArticleInUpdate(RWSchema):
    """
    更新文章时请求体（全部可选）：
    - 不传的字段不改
    - cover:
        - 不传：不改
        - 传 null / ""：清空封面（配合 repo 的 cover_provided 使用）
        - 传字符串：更新为新封面
    """
    title: Optional[str] = None
    description: Optional[str] = None
    body: Optional[str] = None
    cover: Optional[str] = None
    is_top: Optional[bool] = None
    is_featured: Optional[bool] = None
    sort_weight: Optional[int] = None


class ListOfArticlesInResponse(RWSchema):
    articles: List[ArticleForResponse]
    articles_count: int


class ArticlesFilters(BaseModel):
    tag: Optional[str] = None
    tags: Optional[List[str]] = None
    author: Optional[str] = None
    favorited: Optional[str] = None
    search: Optional[str] = None
    limit: int = Field(DEFAULT_ARTICLES_LIMIT, ge=1)
    offset: int = Field(DEFAULT_ARTICLES_OFFSET, ge=0)