/**
 * Persistent settings store.
 *
 * Settings are read from data/settings.json when present, with process.env
 * values used as fallbacks. This means existing .env.local setups keep working
 * with no changes; the UI just provides an alternative way to configure them.
 */

import { readFileSync, writeFileSync, mkdirSync, existsSync } from "fs";
import { join } from "path";

const DATA_DIR = join(process.cwd(), "data");
const SETTINGS_PATH = join(DATA_DIR, "settings.json");

export interface ServiceConfig {
  url: string;
  apiKey: string;
}

export interface DiscordConfig {
  webhookUrl: string;
}

export interface AppSettings {
  radarr: ServiceConfig;
  sonarr: ServiceConfig;
  seerr: ServiceConfig;
  tautulli: ServiceConfig;
  discord: DiscordConfig;
}

interface StoredSettings {
  radarr?: Partial<ServiceConfig>;
  sonarr?: Partial<ServiceConfig>;
  seerr?: Partial<ServiceConfig>;
  tautulli?: Partial<ServiceConfig>;
  discord?: Partial<DiscordConfig>;
}

function readFile(): StoredSettings {
  try {
    return JSON.parse(readFileSync(SETTINGS_PATH, "utf-8")) as StoredSettings;
  } catch {
    return {};
  }
}

/** Returns the merged settings (file values override env vars). */
export function getSettings(): AppSettings {
  const f = readFile();
  return {
    radarr: {
      url: f.radarr?.url ?? process.env.RADARR_URL ?? "",
      apiKey: f.radarr?.apiKey ?? process.env.RADARR_API ?? "",
    },
    sonarr: {
      url: f.sonarr?.url ?? process.env.SONARR_URL ?? "",
      apiKey: f.sonarr?.apiKey ?? process.env.SONARR_API ?? "",
    },
    seerr: {
      url: f.seerr?.url ?? process.env.SEERR_URL ?? "",
      apiKey: f.seerr?.apiKey ?? process.env.SEERR_API ?? "",
    },
    tautulli: {
      url: f.tautulli?.url ?? process.env.TAUTULLI_URL ?? "",
      apiKey: f.tautulli?.apiKey ?? process.env.TAUTULLI_API ?? "",
    },
    discord: {
      webhookUrl: f.discord?.webhookUrl ?? process.env.DISCORD_WEBHOOK ?? "",
    },
  };
}

/** Returns true iff the three services required for the dashboard to function (Radarr, Sonarr, Overseerr/Jellyseerr) have both a URL and API key. */
export function isConfigured(s: AppSettings = getSettings()): boolean {
  const filled = (c: ServiceConfig) => c.url.trim() !== "" && c.apiKey.trim() !== "";
  return filled(s.radarr) && filled(s.sonarr) && filled(s.seerr);
}

/** Saves the provided settings to disk and returns the merged result. */
export function saveSettings(settings: AppSettings): AppSettings {
  if (!existsSync(DATA_DIR)) mkdirSync(DATA_DIR, { recursive: true });

  // Strip trailing slashes from URLs for consistency
  const clean: StoredSettings = {
    radarr: { url: settings.radarr.url.replace(/\/+$/, ""), apiKey: settings.radarr.apiKey },
    sonarr: { url: settings.sonarr.url.replace(/\/+$/, ""), apiKey: settings.sonarr.apiKey },
    seerr: { url: settings.seerr.url.replace(/\/+$/, ""), apiKey: settings.seerr.apiKey },
    tautulli: { url: settings.tautulli.url.replace(/\/+$/, ""), apiKey: settings.tautulli.apiKey },
    discord: { webhookUrl: settings.discord.webhookUrl.trim() },
  };

  writeFileSync(SETTINGS_PATH, JSON.stringify(clean, null, 2), "utf-8");
  return getSettings();
}