//! Small persisted app settings - currently just the TMDB API token ("Fetch Data" needs
//! it; everything else in the app works offline without any settings at all). Stored as
//! plain JSON in Tauri's per-OS app config directory (e.g.
//! `~/Library/Application Support/com.renamr.app/settings.json` on macOS,
//! `~/.config/renamr/settings.json` on Linux) - not the original FileBot's config
//! location, since that's Java Preferences-backed and OS/JVM-specific; this is Renamr's
//! own, analogous location for its own settings.

use serde::{Deserialize, Serialize};
use std::fs;
use std::path::PathBuf;
use tauri::{AppHandle, Manager};

#[derive(Debug, Default, Serialize, Deserialize)]
struct StoredSettings {
    #[serde(default)]
    tmdb_token: Option<String>,
}

fn settings_path(app: &AppHandle) -> Result<PathBuf, String> {
    let dir = app
        .path()
        .app_config_dir()
        .map_err(|e| format!("couldn't resolve the app config directory: {e}"))?;
    fs::create_dir_all(&dir).map_err(|e| format!("couldn't create {}: {e}", dir.display()))?;
    Ok(dir.join("settings.json"))
}

fn load(app: &AppHandle) -> StoredSettings {
    let Ok(path) = settings_path(app) else {
        return StoredSettings::default();
    };
    fs::read_to_string(path)
        .ok()
        .and_then(|contents| serde_json::from_str(&contents).ok())
        .unwrap_or_default()
}

fn save(app: &AppHandle, settings: &StoredSettings) -> Result<(), String> {
    let path = settings_path(app)?;
    let json = serde_json::to_string_pretty(settings).map_err(|e| e.to_string())?;
    fs::write(&path, json).map_err(|e| format!("couldn't write {}: {e}", path.display()))
}

/// Returns the stored TMDB token, or `None` if nothing (or only blank text) is saved.
pub fn tmdb_token(app: &AppHandle) -> Option<String> {
    load(app).tmdb_token.filter(|t| !t.trim().is_empty())
}

#[tauri::command]
pub fn get_tmdb_token(app: AppHandle) -> Option<String> {
    tmdb_token(&app)
}

#[tauri::command]
pub fn save_tmdb_token(app: AppHandle, token: String) -> Result<(), String> {
    let mut settings = load(&app);
    let trimmed = token.trim().to_string();
    settings.tmdb_token = if trimmed.is_empty() { None } else { Some(trimmed) };
    save(&app, &settings)
}