"""API Push 短新闻 ingest 接口的 I/O schema。"""
from __future__ import annotations

from datetime import datetime
from typing import Literal

from pydantic import BaseModel, Field, field_validator


# 长度上限(commit 1 规划)
TITLE_MAX = 200
BODY_MAX = 5000
EXTERNAL_ID_MAX = 128
SOURCE_REF_MAX = 64
AUTHOR_MAX = 255
TAGS_MAX = 10  # 最多 10 个标签
TAG_MAX_LEN = 32  # 单个标签最长


class IngestPayload(BaseModel):
    """POST /api/v1/ingest 请求体。

    必填:title + body
    推荐:external_id(幂等 key)
    可选:url / source_ref / author / published_at / tags
    """

    external_id: str | None = Field(default=None, max_length=EXTERNAL_ID_MAX)
    title: str = Field(min_length=1, max_length=TITLE_MAX)
    body: str = Field(min_length=1, max_length=BODY_MAX)
    url: str | None = Field(default=None, max_length=2048)
    source_ref: str | None = Field(default=None, max_length=SOURCE_REF_MAX)
    author: str | None = Field(default=None, max_length=AUTHOR_MAX)
    published_at: datetime | None = None
    tags: list[str] | None = Field(default=None, max_length=TAGS_MAX)

    @field_validator("title", "body")
    @classmethod
    def _strip_and_check(cls, v: str) -> str:
        v = v.strip()
        if not v:
            raise ValueError("must not be empty after strip")
        return v

    @field_validator("tags")
    @classmethod
    def _clean_tags(cls, v: list[str] | None) -> list[str] | None:
        if v is None:
            return None
        out: list[str] = []
        seen: set[str] = set()
        for t in v:
            t = t.strip()
            if not t:
                continue
            if len(t) > TAG_MAX_LEN:
                raise ValueError(f"tag too long: {t[:16]}...")
            if t in seen:
                continue
            seen.add(t)
            out.append(t)
        return out or None


class IngestResponse(BaseModel):
    """POST /api/v1/ingest 响应。"""

    article_id: int
    content_hash: str
    status: Literal["created", "duplicate"]
    # duplicate 时,告知是 L1 / L2 / L3 哪一层命中
    reason: str | None = None  # 仅 duplicate 时填充
    matched_external_id: str | None = None  # 仅 L1 命中时填充