"""Application configuration loaded from environment + DB-backed admin settings."""
from __future__ import annotations

import os
import secrets
from functools import lru_cache
from typing import List

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


def _parse_cors_origins(raw: str) -> List[str]:
    """Parse a CORS_ORIGINS env value into a list of origin strings.

    Accepts (in priority order):
      - JSON array string: '["http://a","http://b"]'
      - comma-separated:   "http://a,http://b"
      - single value:      "http://a"
    Strips whitespace and drops empties. Returns the default list if input
    is empty/blank.

    This helper exists because pydantic-settings' EnvSettingsSource treats
    `List[str]` as a "complex" type and tries to JSON-decode the raw env
    value BEFORE any field validator runs — so a plain comma-separated
    string from docker-compose crashes Settings() at import time on
    older pydantic-settings versions. Storing the field as `str` sidesteps
    that entirely; this helper parses it on demand.
    """
    if not raw:
        return ["http://localhost:5173"]
    v = raw.strip()
    if not v:
        return ["http://localhost:5173"]
    if v.startswith("["):
        import json
        try:
            parsed = json.loads(v)
            if isinstance(parsed, list):
                return [str(o).strip() for o in parsed if str(o).strip()]
        except Exception:
            pass  # fall through to comma-split
    return [o.strip() for o in v.split(",") if o.strip()]


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

    # Database
    database_url: str = "postgresql+asyncpg://airpg:airpg_secret@localhost:5432/airpg"

    # Redis
    redis_url: str = "redis://localhost:6379/0"

    # Qdrant
    qdrant_url: str = "http://localhost:6333"

    # Auth
    jwt_secret: str = Field(default_factory=lambda: secrets.token_hex(32))
    jwt_algorithm: str = "HS256"
    access_token_expire_minutes: int = 60 * 24 * 7  # 7 days

    # Admin setup
    # If empty, will be generated at first run and printed to console.
    admin_setup_token: str = ""

    # CORS
    # Stored as a raw string (NOT List[str]) so pydantic-settings' env source
    # treats it as a simple scalar and never attempts JSON-decoding. The
    # parsed list is exposed via the `cors_origins_list` property below.
    # Accepts either a comma-separated string ("http://a,http://b") or a
    # JSON-array string ('["http://a","http://b"]').
    cors_origins: str = "http://localhost:5173"

    @property
    def cors_origins_list(self) -> List[str]:
        """Parsed list of allowed CORS origins (see `_parse_cors_origins`)."""
        return _parse_cors_origins(self.cors_origins)

    # Logging
    log_level: str = "INFO"

    # Default LLM (used to seed DB on first run; overridable via admin panel)
    default_llm_base_url: str = "http://localhost:1234/v1"
    default_llm_api_key: str = "dummy"
    default_llm_model: str = "local-model"

    # Default embeddings / RAG settings (overridable via admin panel)
    # provider="hash" is a deterministic offline fallback (no semantic quality).
    # Switch to "openai" and point embedding.base_url at an OpenAI-compatible /embeddings endpoint
    # for real semantic search.
    default_embedding_provider: str = "hash"
    default_embedding_base_url: str = ""  # empty = reuse llm.base_url
    default_embedding_api_key: str = ""   # empty = reuse llm.api_key
    default_embedding_model: str = "text-embedding-3-small"
    default_embedding_dim: int = 0        # 0 = auto-probe from endpoint
    default_embedding_request_timeout: int = 60

    # Context manager defaults (admin-overridable)
    default_recent_messages: int = 10
    default_compress_threshold: int = 20
    default_summary_messages: int = 10

    # Worker mode flag
    worker_mode: bool = False

    @property
    def is_worker(self) -> bool:
        return bool(os.getenv("WORKER_MODE")) or self.worker_mode


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


settings = get_settings()