"""
API HTTP do corretor de redacao ENEM.

Endpoints:
  GET  /health    -> {"status": "ok"}
  POST /corrigir  -> body {"texto": "..."}, retorna notas C1..C5 + total
"""

from __future__ import annotations

from contextlib import asynccontextmanager

from typing import Optional

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, Field

from corretor import corrigir, diagnosticar, load_models


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Pre-carrega os 5 modelos no startup para a primeira request nao pagar o custo.
    load_models()
    yield


app = FastAPI(
    title="Dissero - Corretor ENEM",
    description="API de correcao automatica de redacao ENEM (modelos kamel-usp).",
    version="0.1.0",
    lifespan=lifespan,
)

# CORS restrito: Vite local + deploys do Vercel (production + previews).
ALLOWED_ORIGINS = [
    "http://localhost:5173",
    "http://localhost:4173",
    "https://dissero.vercel.app",
    "https://dissertaai.vercel.app",
    "https://dissero-git-main-tonetos-projects.vercel.app",
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=ALLOWED_ORIGINS,
    allow_origin_regex=r"^https://dissero-[a-z0-9-]+-tonetos-projects\.vercel\.app$",
    allow_credentials=True,
    allow_methods=["POST", "GET", "OPTIONS"],
    allow_headers=["*"],
)


class RedacaoRequest(BaseModel):
    texto: str = Field(..., min_length=1, description="Texto da redacao em portugues.")


class C5Boost(BaseModel):
    de: int
    para: int
    elementos: int


class CorrecaoResponse(BaseModel):
    C1: int
    C2: int
    C3: int
    C4: int
    C5: int
    total: int
    # Metadados (transparencia da decisao)
    modelo_usado: Optional[str] = None
    jbcs_total: Optional[int] = None
    local_total: Optional[int] = None
    c5_boost: Optional[C5Boost] = None


@app.get("/health")
def health() -> dict:
    return {"status": "ok"}


@app.post("/corrigir", response_model=CorrecaoResponse)
def corrigir_endpoint(req: RedacaoRequest) -> dict:
    raw = corrigir(req.texto)
    # Mapeia underscores internos pra nomes publicos do schema
    out = {
        "C1": raw["C1"], "C2": raw["C2"], "C3": raw["C3"],
        "C4": raw["C4"], "C5": raw["C5"], "total": raw["total"],
        "modelo_usado": raw.get("_modelo_usado"),
        "jbcs_total": raw.get("_jbcs_total"),
        "local_total": raw.get("_local_total"),
    }
    boost = raw.get("_c5_heuristica_boost")
    if boost:
        out["c5_boost"] = {
            "de": boost["de"], "para": boost["para"],
            "elementos": boost["elementos"],
        }
    return out


@app.post("/debug")
def debug_endpoint(req: RedacaoRequest) -> dict:
    """Diagnostico completo: logits, softmax, e varias estrategias de decoding."""
    return diagnosticar(req.texto)