import json
import os
from pathlib import Path

from dotenv import load_dotenv

backend_dir = Path(__file__).resolve().parent.parent
load_dotenv(backend_dir / ".env")


def _get_int_env(name: str, default: int) -> int:
    value = os.getenv(name, "").strip()
    if not value:
        return default

    try:
        return int(value)
    except ValueError:
        return default


def _get_bool_env(name: str, default: bool = False) -> bool:
    value = os.getenv(name)
    if value is None:
        return default

    return value.strip().lower() in {"1", "true", "yes", "on"}


def _get_list_env(name: str, default: list[str]) -> list[str]:
    value = os.getenv(name, "").strip()
    if not value:
        return default

    try:
        parsed = json.loads(value)
    except json.JSONDecodeError:
        parsed = None

    if isinstance(parsed, list):
        return [str(item).strip() for item in parsed if str(item).strip()]

    return [item.strip() for item in value.split(",") if item.strip()]


def _get_path_env(name: str, default: Path) -> Path:
    value = os.getenv(name, "").strip()
    if not value:
        return default.resolve()

    path = Path(value)
    if not path.is_absolute():
        path = backend_dir / path

    return path.resolve()


class Settings:
    app_name = os.getenv("APP_NAME", "HTML Knowledge API")
    api_prefix = os.getenv("API_PREFIX", "/api").rstrip("/") or "/api"
    backend_dir = backend_dir
    data_dir = backend_dir / "data"
    database_path = data_dir / "html_generator.db"
    database_url = f"sqlite:///{database_path.as_posix()}"
    allowed_origins = _get_list_env("ALLOWED_ORIGINS", ["*"])
    public_base_url = os.getenv("PUBLIC_BASE_URL", "http://localhost:8000").rstrip("/")
    html_storage_dir = _get_path_env(
        "HTML_STORAGE_DIR",
        data_dir / "generated_html",
    )
    default_retention_days = max(1, _get_int_env("DEFAULT_RETENTION_DAYS", 7))
    max_retention_days = max(
        default_retention_days,
        _get_int_env("MAX_RETENTION_DAYS", 30),
    )
    max_html_length = max(1024, _get_int_env("MAX_HTML_LENGTH", 200_000))
    api_key = os.getenv("API_KEY", "").strip()
    allow_unsafe_html = _get_bool_env("ALLOW_UNSAFE_HTML", False)
    strip_markdown_code_fence = _get_bool_env("STRIP_MARKDOWN_CODE_FENCE", True)
    enable_request_debug_log = _get_bool_env("ENABLE_REQUEST_DEBUG_LOG", True)
    request_log_max_chars = max(256, _get_int_env("REQUEST_LOG_MAX_CHARS", 10_000))


settings = Settings()