"""Configuração do backend via variáveis de ambiente."""

from __future__ import annotations

from functools import lru_cache
from pathlib import Path

from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    """Configuração lida do ambiente ou do arquivo .env."""

    model_config = SettingsConfigDict(
        env_file=(".env", "../.env"),
        env_file_encoding="utf-8",
        extra="ignore",
    )

    # Caminhos
    pdf_dir: Path = Path("/data/pdfs")
    vector_db_dir: Path = Path("/data/vector_db")

    # Provedor de LLM: ollama | openai | groq | anthropic | stub
    llm_provider: str = "ollama"
    ollama_base_url: str = "http://ollama:11434"
    ollama_model: str = "qwen2.5:1.5b"
    openai_base_url: str = "https://api.openai.com/v1"
    openai_model: str = "gpt-4o-mini"
    openai_api_key: str = ""
    groq_base_url: str = "https://api.groq.com/openai/v1"
    groq_model: str = "llama-3.3-70b-versatile"
    groq_api_key: str = ""
    anthropic_base_url: str = "https://api.anthropic.com"
    anthropic_model: str = "claude-sonnet-4-5"
    anthropic_api_key: str = ""

    # Embeddings
    embedding_model: str = "paraphrase-multilingual-MiniLM-L12-v2"
    embedding_batch_size: int = 32

    # Busca
    top_k: int = 6
    min_similarity: float = 0.35
    collection_name: str = "biblia"

    # OCR
    ocr_dpi: int = 200
    ocr_language: str = "por+eng"
    ocr_timeout: int = 120
    ocr_workers: int = 4
    min_legible_ratio: float = 0.35

    # API
    cors_origins: str = "http://localhost:8080,http://127.0.0.1:8080"
    reindex_token: str = ""
    max_message_length: int = 4000
    max_history_turns: int = 10

    # Limites de ingestão
    max_pdf_bytes: int = 200 * 1024 * 1024

    # Indexação automática na inicialização
    auto_index: bool = True

    @property
    def ocr_cache_dir(self) -> Path:
        return self.vector_db_dir / "ocr_cache"

    @property
    def manifest_path(self) -> Path:
        return self.vector_db_dir / "manifest.json"

    @property
    def book_index_path(self) -> Path:
        return self.vector_db_dir / "book_index.json"

    @property
    def cors_origin_list(self) -> list[str]:
        return [origin.strip() for origin in self.cors_origins.split(",") if origin.strip()]


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    """Devolve as settings singleton do processo."""
    return Settings()