"""Application configuration, loaded from the environment via pydantic-settings.

Every setting is env-driven. Model identifiers and API keys are read from the
environment with inert placeholder defaults — the operator supplies real values
in `.env`. Never hardcode real model IDs or secrets in this file.
"""
from __future__ import annotations

from functools import lru_cache
from pathlib import Path

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


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

    # -- Job source / ingestion --------------------------------------------
    job_source: str = Field(default="jobspy", description="Ingestion provider: 'jobspy' | 'apify'.")
    search_terms: list[str] = Field(default_factory=lambda: ["software engineer"])
    location: str = "United States"
    hours_old: int = 72
    batch_size: int = 20
    results_wanted: int = 50

    # -- Apify (only used when job_source == 'apify') ----------------------
    apify_token: str = "PLACEHOLDER_APIFY_TOKEN"
    apify_actor: str = "PLACEHOLDER_APIFY_ACTOR"

    # -- Website resolution (optional search API) --------------------------
    search_api_enabled: bool = False
    search_api_key: str = "PLACEHOLDER_SEARCH_API_KEY"

    # -- LLM / agent models (placeholders -- set real IDs in .env) ---------
    # NEVER hardcode real model identifiers. These are inert placeholders.
    llm_api_key: str = "PLACEHOLDER_LLM_API_KEY"
    classifier_model: str = "PLACEHOLDER_CLASSIFIER_MODEL"   # cheap model: link classification
    agent_model: str = "PLACEHOLDER_AGENT_MODEL"             # stronger model: browser agent

    # -- HTTP client -------------------------------------------------------
    http_timeout: float = 20.0
    http_max_retries: int = 3
    http_backoff_factor: float = 0.5
    user_agent: str = "JobSourceAgent/0.1 (+https://example.com)"

    # -- Storage / output --------------------------------------------------
    db_path: Path = Path("output/jobsource.db")
    output_csv: Path = Path("output/results.csv")

    # -- Browser agent (fallback tier) -------------------------------------
    enable_browser_agent: bool = True
    browser_headless: bool = True


@lru_cache
def get_settings() -> Settings:
    """Return the cached Settings singleton (call get_settings.cache_clear() in tests)."""
    return Settings()