from datetime import datetime
from typing import Literal
from uuid import UUID

from pydantic import BaseModel, Field

from app.schemas.catalog import Category, Input


class RetrievalRequest(Input):
    query: str = Field(min_length=1, max_length=500)
    mode: Literal["keyword"] = "keyword"
    top_k: int = Field(default=5, ge=1, le=20)
    category: Category | None = None


class RetrievalHit(BaseModel):
    rank: int
    knowledge_id: int
    knowledge_version: int
    document_id: int | None
    document_version: int | None
    source_id: int | None
    source_version: int | None
    source_name: str | None
    source_url: str
    title: str
    category: str
    snippet: str
    snippet_start: int
    snippet_end: int
    score: float
    matched_terms: list[str]


class RetrievalConfig(BaseModel):
    tokenizer: str
    scorer: str
    k1: float
    b: float
    title_weight: int
    stopwords_version: str


class RetrievalResponse(BaseModel):
    run_id: UUID
    query: str
    mode: Literal["keyword"]
    status: Literal["ok", "no_evidence"]
    top_k: int
    category: str | None
    query_terms: list[str]
    corpus_size: int
    corpus_fingerprint: str
    total_hits: int
    results: list[RetrievalHit]
    elapsed_ms: float
    created_at: datetime
    config: RetrievalConfig