from __future__ import annotations

from functools import lru_cache
from typing import List, Literal

from pydantic import Field, field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
        extra="ignore",
    )

    APP_NAME: str = "reconciliation-report-service"
    VERSION: str = "1.0.0"
    ENV: Literal["development", "staging", "production"] = "production"
    DEBUG: bool = False

    HOST: str = "0.0.0.0"
    PORT: int = 7860
    WORKERS: int = 4
    ALLOWED_ORIGINS: List[str] = ["*"]

    API_KEY: str = Field(default="", description="Secret key required in X-API-Key header")

    SELF_PING_ENABLED: bool = True
    SELF_PING_URL: str = "https://validops-east-2-instance-2.hf.space/ping"
    SELF_PING_INTERVAL_SECONDS: int = 300
    HF_TOKEN: str = Field(
        default="",
        description="Hugging Face Bearer token used exclusively for self-ping",
    )

    MAX_FILE_SIZE_MB: int = 50
    MAX_PAGES: int = 100

    DEFAULT_DPI: int = 200
    MAX_DPI: int = 600
    DEFAULT_FORMAT: str = "PNG"
    DEFAULT_JPEG_QUALITY: int = 95
    SUPPORTED_FORMATS: List[str] = ["PNG", "JPEG", "WEBP", "TIFF", "BMP"]

    PAGE_RENDER_WORKERS: int = 8

    PDF_UPLOAD_MODE: Literal["per_page", "merged"] = "per_page"

    UPLOAD_CONCURRENCY: int = 4
    FILE_SERVICE_TIMEOUT: float = 600.0
    FILE_SERVICE_CONNECT_TIMEOUT: float = 100.0

    OUTPUT_DIR: str = "/tmp/pdf2img_outputs"
    TEMP_DIR: str = "/tmp/pdf2img_temp"
    OUTPUT_TTL_SECONDS: int = 3600

    LOG_LEVEL: str = "info"
    LOG_FORMAT: Literal["json", "console"] = "console"

    RATE_LIMIT: int = 100
    RATE_LIMIT_WINDOW: int = 60

    REDIS_URL: str = Field(default="", description="Redis connection URL for rate limiting")

    
    FILE_SERVICE_URL: str = Field(default="https://validops-east-3-instance-2.hf.space/api/v1/files/bulk-upload", description="External file upload service endpoint")
    FILE_SERVICE_API_KEY: str = Field(default="", description="API key for external file upload service")
    FILE_SERVICE_BEARER_TOKEN: str = Field(default="", description="Bearer token for external file upload service")

    @property
    def MAX_FILE_SIZE_BYTES(self) -> int:
        return self.MAX_FILE_SIZE_MB * 1024 * 1024

    @property
    def rate_limit_redis_configured(self) -> bool:
        return bool(self.WORKERS > 1 and self.REDIS_URL)

    @field_validator("DEFAULT_FORMAT")
    @classmethod
    def normalise_format(cls, v: str) -> str:
        return v.upper()


@lru_cache
def get_settings() -> Settings:
    return Settings()


settings = get_settings()