from __future__ import annotations

from typing import Any
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel, Field

from .core import DocumentRecord, FuzzyIndex, FuzzyRetrievalConfig
from .rag import LangChainFuzzyRAG


class IngestDocument(BaseModel):
    id: str
    text: str
    title: str = ""
    source: str = ""
    authority: float = Field(0.5, ge=0.0, le=1.0)
    freshness: float = Field(0.5, ge=0.0, le=1.0)
    reliability: float = Field(0.5, ge=0.0, le=1.0)
    metadata: dict[str, Any] = Field(default_factory=dict)


class IngestRequest(BaseModel):
    documents: list[IngestDocument]
    replace: bool = True


class QueryRequest(BaseModel):
    question: str
    k: int = Field(4, ge=1, le=20)


def create_app() -> FastAPI:
    app = FastAPI(title="Fuzzy LangChain RAG API", version="1.0.0")
    holder: dict[str, Any] = {"index": FuzzyIndex(config=FuzzyRetrievalConfig())}

    @app.get("/health")
    def health():
        return {"status": "ok", "documents": len(holder["index"].documents)}

    @app.post("/ingest")
    def ingest(req: IngestRequest):
        docs: list[DocumentRecord] = []
        for d in req.documents:
            md = dict(d.metadata)
            md.update({"authority": d.authority, "freshness": d.freshness, "reliability": d.reliability})
            docs.append(DocumentRecord(d.id, d.text, d.title, d.source, md))
        if req.replace:
            holder["index"].fit(docs)
        else:
            holder["index"].add(docs)
        return {"documents": len(holder["index"].documents)}

    @app.post("/query")
    def query(req: QueryRequest):
        if not holder["index"].documents:
            raise HTTPException(status_code=400, detail="No documents ingested")
        rag = LangChainFuzzyRAG(holder["index"], k=req.k)
        return rag.invoke(req.question)

    return app


app = create_app()