import { DatabaseSync } from 'node:sqlite';

/** A stored RSS source; tags are a comma-separated string in the DB, split here. */
export interface RssSource {
  name: string;
  url: string;
  tags: string[];
  createdAt: number;
}

/** Idempotent — safe to call on every open (the table lives in the shared MESH_DB_PATH file). */
export function initRssTable(db: DatabaseSync): void {
  db.exec(`CREATE TABLE IF NOT EXISTS rss_sources (
    name TEXT PRIMARY KEY,
    url TEXT NOT NULL,
    tags TEXT NOT NULL DEFAULT '',
    created_at INTEGER
  )`);
}

/** CRUD for the rss_sources table. Names are matched case-insensitively everywhere. */
export class RssStore {
  constructor(private readonly db: DatabaseSync) {
    initRssTable(db);
  }

  list(): RssSource[] {
    const rows = this.db
      .prepare(
        'SELECT name, url, tags, created_at FROM rss_sources ORDER BY name',
      )
      .all() as {
      name: string;
      url: string;
      tags: string;
      created_at: number;
    }[];
    return rows.map((r) => ({
      name: r.name,
      url: r.url,
      tags: splitTags(r.tags),
      createdAt: r.created_at,
    }));
  }

  /** Case-insensitive lookup by name. */
  get(name: string): RssSource | undefined {
    const row = this.db
      .prepare(
        'SELECT name, url, tags, created_at FROM rss_sources WHERE name = ? COLLATE NOCASE',
      )
      .get(name) as
      | { name: string; url: string; tags: string; created_at: number }
      | undefined;
    return (
      row && {
        name: row.name,
        url: row.url,
        tags: splitTags(row.tags),
        createdAt: row.created_at,
      }
    );
  }

  /** Case-insensitive duplicate check. */
  exists(name: string): boolean {
    const row = this.db
      .prepare('SELECT 1 FROM rss_sources WHERE name = ? COLLATE NOCASE')
      .get(name);
    return row !== undefined;
  }

  add(source: { name: string; url: string; tags: string[] }): void {
    this.db
      .prepare(
        'INSERT INTO rss_sources (name, url, tags, created_at) VALUES (?, ?, ?, ?)',
      )
      .run(source.name, source.url, joinTags(source.tags), Date.now());
  }

  /** Case-insensitive delete; true when a row was removed. */
  remove(name: string): boolean {
    const result = this.db
      .prepare('DELETE FROM rss_sources WHERE name = ? COLLATE NOCASE')
      .run(name);
    return Number(result.changes) > 0;
  }

  /** All distinct tags across sources, sorted. */
  allTags(): string[] {
    const set = new Set<string>();
    for (const source of this.list()) {
      for (const tag of source.tags) set.add(tag);
    }
    return [...set].sort();
  }
}

export function splitTags(raw: string): string[] {
  return raw
    .split(',')
    .map((t) => t.trim())
    .filter(Boolean);
}

export function joinTags(tags: string[]): string {
  return tags.join(',');
}