"""Configuration management — env vars, config file, and defaults."""

from __future__ import annotations

from pathlib import Path
from typing import Optional

import toml
from platformdirs import user_config_dir
from pydantic import field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict

CONFIG_DIR = Path(user_config_dir("freepik-cli"))
CONFIG_FILE = CONFIG_DIR / "config.toml"


class FreepikConfig(BaseSettings):
    """
    Configuration with priority (highest to lowest):
      1. CLI --api-key flag (handled in commands directly)
      2. FREEPIK_* environment variables
      3. ~/.config/freepik-cli/config.toml
      4. Defaults below
    """

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

    api_key: Optional[str] = None
    base_url: str = "https://api.freepik.com"
    default_output_dir: str = "."
    default_image_model: str = "flux-2-pro"
    default_video_model: str = "kling-o1-pro"
    default_upscale_mode: str = "precision-v2"
    poll_timeout: int = 600
    poll_max_interval: int = 15
    show_banner: bool = True

    @field_validator("api_key", mode="before")
    @classmethod
    def strip_api_key(cls, v: Optional[str]) -> Optional[str]:
        return v.strip() if isinstance(v, str) else v

    @classmethod
    def load(cls) -> "FreepikConfig":
        """Load from config file, then overlay environment variables."""
        file_data: dict = {}
        if CONFIG_FILE.exists():
            try:
                file_data = toml.load(CONFIG_FILE)
            except Exception:
                pass
        return cls(**file_data)

    def save(self, exclude_keys: set[str] | None = None) -> None:
        """Persist non-sensitive config to disk."""
        exclude_keys = (exclude_keys or set()) | {"api_key"}
        CONFIG_DIR.mkdir(parents=True, exist_ok=True)
        data = self.model_dump(exclude=exclude_keys, exclude_none=True)
        # Stringify paths
        for k, v in data.items():
            if isinstance(v, Path):
                data[k] = str(v)
        with open(CONFIG_FILE, "w") as f:
            toml.dump(data, f)

    def to_display_dict(self) -> dict:
        """Return all settings as a displayable dict (keeps api_key for masking)."""
        d = self.model_dump()
        return {k: v for k, v in d.items()}

    def set_value(self, key: str, value: str) -> None:
        """Update a single config key and save."""
        allowed = {
            "base_url", "default_output_dir", "default_image_model",
            "default_video_model", "default_upscale_mode", "poll_timeout",
            "poll_max_interval", "show_banner",
        }
        if key not in allowed:
            raise ValueError(
                f"Key '{key}' is not configurable via this command. "
                f"Use the FREEPIK_API_KEY environment variable to set the API key."
            )
        current = self.model_dump()
        if key in ("poll_timeout", "poll_max_interval"):
            current[key] = int(value)
        elif key == "show_banner":
            current[key] = value.lower() in ("true", "1", "yes")
        else:
            current[key] = value
        updated = FreepikConfig(**{k: v for k, v in current.items() if v is not None})
        updated.save()