// The Lidarr API client — lidarr's own code, living in the module (novox/hq ADR 0039). Ported from
// the shared hal `arr` client, but self-contained: in nox each Servarr app owns its own copy, so a
// change to Lidarr's API rebuilds only lidarr and nothing else. Both this module's tools and its
// events entrypoint import it, and nothing outside lidarr does.

import { existsSync, readFileSync } from "node:fs";
import { join } from "node:path";

// Lidarr speaks the v1 API (Radarr/Sonarr are v3); its content is the "artist".
const API_VERSION = "v1";
const CONTENT_ENDPOINT = "artist";
const APP_NAME = "Lidarr";

export interface LidarrQueueItem {
  /** The queue record id — stable while the item is in the queue, so events can diff on it. */
  id: number;
  title: string;
  status: string;
  size: string;
  sizeleft: string;
  timeleft?: string;
}

export interface LidarrCalendarItem {
  title: string;
  date: string;
  overview?: string;
}

export interface LidarrContentItem {
  title: string;
  status?: string;
  monitored: boolean;
}

export class LidarrClient {
  readonly baseUrl: string;

  constructor(
    url: string,
    private readonly apiKey: string,
  ) {
    this.baseUrl = url.replace(/\/$/, "");
  }

  /**
   * Build from the module's resolved environment. The URL defaults to the server on this node (the
   * runtime shares its network), and the API key is read from MESH_LIDARR_API_KEY or, failing that,
   * discovered from the server's own config.xml under MESH_LIDARR_CONFIG_DIR — the same file Lidarr
   * writes it to, so a running server needs nothing configured by hand. Throws when no key can be
   * found, so the tools/events simply do not load (the harness treats the throw as "exposes
   * nothing").
   */
  static fromEnv(env: NodeJS.ProcessEnv = process.env): LidarrClient {
    const url = env.MESH_LIDARR_URL ?? `http://127.0.0.1:${env.MESH_LIDARR_PORT ?? "8686"}`;
    const configDir = env.MESH_LIDARR_CONFIG_DIR ?? "/config";
    const apiKey = env.MESH_LIDARR_API_KEY ?? LidarrClient.detectApiKey(configDir);
    if (!apiKey) {
      throw new Error("Lidarr not configured — set MESH_LIDARR_API_KEY or make the config dir readable");
    }
    return new LidarrClient(url, apiKey);
  }

  /** Discover the API key from the server's config.xml, falling back to null. Every Servarr app
   *  writes <ApiKey> into config.xml at the root of its config directory. */
  static detectApiKey(configDir: string): string | null {
    const config = join(configDir, "config.xml");
    if (existsSync(config)) {
      const match = readFileSync(config, "utf8").match(/<ApiKey>([^<]+)<\/ApiKey>/);
      if (match) return match[1];
    }
    return null;
  }

  private async get(endpoint: string, params?: Record<string, string>): Promise<unknown> {
    const url = new URL(`${this.baseUrl}/api/${API_VERSION}/${endpoint}`);
    if (params) {
      for (const [k, v] of Object.entries(params)) url.searchParams.set(k, v);
    }
    const res = await fetch(url.toString(), { headers: { "X-Api-Key": this.apiKey } });
    if (!res.ok) throw new Error(`${APP_NAME} API /${endpoint}: ${res.status} ${await res.text()}`);
    return res.json();
  }

  async getStatus(): Promise<{ appName: string; version: string }> {
    const data = (await this.get("system/status")) as { appName?: string; version?: string };
    return { appName: data.appName || APP_NAME, version: data.version ?? "unknown" };
  }

  async getContent(limit?: number): Promise<LidarrContentItem[]> {
    const data = await this.get(CONTENT_ENDPOINT);
    const items: any[] = Array.isArray(data) ? data : ((data as any)?.records ?? []);
    const mapped = items.map((item) => ({
      // Lidarr's content is an artist; its display name is artistName, not title.
      title: item.artistName ?? item.title ?? "Unknown",
      status: item.status,
      monitored: item.monitored ?? true,
    }));
    return limit ? mapped.slice(0, limit) : mapped;
  }

  /** Library search is a filter over existing content, not an indexer lookup — same as hal's. */
  async searchContent(term: string): Promise<LidarrContentItem[]> {
    const all = await this.getContent();
    const lower = term.toLowerCase();
    return all.filter((item) => item.title.toLowerCase().includes(lower));
  }

  async getQueue(): Promise<{ totalRecords: number; items: LidarrQueueItem[] }> {
    const data = (await this.get("queue", { pageSize: "50" })) as { totalRecords?: number; records?: any[] };
    const records = data.records ?? [];
    return {
      totalRecords: data.totalRecords ?? records.length,
      items: records.map((r) => ({
        id: r.id,
        title: r.title ?? r.artist?.artistName ?? r.album?.title ?? "Unknown",
        status: r.status ?? "unknown",
        size: formatBytes(r.size ?? 0),
        sizeleft: formatBytes(r.sizeleft ?? 0),
        timeleft: r.timeleft,
      })),
    };
  }

  async getCalendar(days = 7): Promise<LidarrCalendarItem[]> {
    const start = new Date().toISOString().split("T")[0];
    const end = new Date(Date.now() + days * 86400000).toISOString().split("T")[0];
    const data = await this.get("calendar", { start, end });
    const items: any[] = Array.isArray(data) ? data : [];
    return items.map((item) => ({
      // A Lidarr calendar entry is an album release.
      title: item.title ?? item.artist?.artistName ?? "Unknown",
      date: item.releaseDate ?? "",
      overview: item.overview?.slice(0, 150),
    }));
  }
}

function formatBytes(bytes: number): string {
  if (bytes === 0) return "0 B";
  const units = ["B", "KB", "MB", "GB", "TB"];
  const i = Math.floor(Math.log(bytes) / Math.log(1024));
  return `${(bytes / Math.pow(1024, i)).toFixed(1)} ${units[i]}`;
}