import { type DiagnosticLogEntry, DIAGNOSTIC_STORAGE_KEYS } from '../types/diagnostic';
import { type StorageManager, storage } from '../utils/storage';

const MAX_RECENT_LOGS = 300;

type DiagnosticStoreStorage = Pick<StorageManager, 'get' | 'set' | 'remove'>;

export class DiagnosticLogStore {
  private appendChain: Promise<void> = Promise.resolve();

  constructor(private readonly storageManager: DiagnosticStoreStorage = storage) {}

  async append(entry: DiagnosticLogEntry): Promise<void> {
    const runAppend = async () => {
      const recent = await this.getRecent();
      const next = [...recent, entry];

      if (next.length > MAX_RECENT_LOGS) {
        next.splice(0, next.length - MAX_RECENT_LOGS);
      }

      await this.storageManager.set(DIAGNOSTIC_STORAGE_KEYS.RECENT_LOGS, next);
    };

    const appendPromise = this.appendChain.then(runAppend, runAppend);
    this.appendChain = appendPromise.catch(() => undefined);
    return appendPromise;
  }

  async getRecent(): Promise<DiagnosticLogEntry[]> {
    const stored = await this.storageManager.get<DiagnosticLogEntry[]>(
      DIAGNOSTIC_STORAGE_KEYS.RECENT_LOGS
    );

    return Array.isArray(stored) ? stored : [];
  }

  async clear(): Promise<void> {
    await this.storageManager.remove(DIAGNOSTIC_STORAGE_KEYS.RECENT_LOGS);
  }
}