import * as plugins from '../plugins.js';
import { logger } from '../logger.js';
import type { StorageManager } from '../storage/index.js';
import type {
  IStoredApiToken,
  IApiTokenInfo,
  TApiTokenScope,
} from '../../ts_interfaces/data/route-management.js';

const TOKENS_PREFIX = '/config-api/tokens/';
const TOKEN_PREFIX_STR = 'dcr_';

export class ApiTokenManager {
  private tokens = new Map<string, IStoredApiToken>();

  constructor(private storageManager: StorageManager) {}

  public async initialize(): Promise<void> {
    await this.loadTokens();
    if (this.tokens.size > 0) {
      logger.log('info', `Loaded ${this.tokens.size} API token(s) from storage`);
    }
  }

  // =========================================================================
  // Token lifecycle
  // =========================================================================

  /**
   * Create a new API token. Returns the raw token value (shown once).
   */
  public async createToken(
    name: string,
    scopes: TApiTokenScope[],
    expiresInDays: number | null,
    createdBy: string,
  ): Promise<{ id: string; rawToken: string }> {
    const id = plugins.uuid.v4();
    const randomBytes = plugins.crypto.randomBytes(32);
    const rawPayload = `${id}:${randomBytes.toString('base64url')}`;
    const rawToken = `${TOKEN_PREFIX_STR}${rawPayload}`;

    const tokenHash = plugins.crypto.createHash('sha256').update(rawToken).digest('hex');

    const now = Date.now();
    const stored: IStoredApiToken = {
      id,
      name,
      tokenHash,
      scopes,
      createdAt: now,
      expiresAt: expiresInDays != null ? now + expiresInDays * 86400000 : null,
      lastUsedAt: null,
      createdBy,
      enabled: true,
    };

    this.tokens.set(id, stored);
    await this.persistToken(stored);
    logger.log('info', `API token '${name}' created (id: ${id})`);
    return { id, rawToken };
  }

  /**
   * Validate a raw token string. Returns the stored token if valid, null otherwise.
   * Also updates lastUsedAt.
   */
  public async validateToken(rawToken: string): Promise<IStoredApiToken | null> {
    if (!rawToken.startsWith(TOKEN_PREFIX_STR)) return null;

    const hash = plugins.crypto.createHash('sha256').update(rawToken).digest('hex');

    for (const stored of this.tokens.values()) {
      if (stored.tokenHash === hash) {
        if (!stored.enabled) return null;
        if (stored.expiresAt !== null && stored.expiresAt < Date.now()) return null;

        // Update lastUsedAt (fire and forget)
        stored.lastUsedAt = Date.now();
        this.persistToken(stored).catch(() => {});
        return stored;
      }
    }
    return null;
  }

  /**
   * Check if a token has a specific scope.
   */
  public hasScope(token: IStoredApiToken, scope: TApiTokenScope): boolean {
    return token.scopes.includes(scope);
  }

  /**
   * List all tokens (safe info only, no hashes).
   */
  public listTokens(): IApiTokenInfo[] {
    const result: IApiTokenInfo[] = [];
    for (const stored of this.tokens.values()) {
      result.push({
        id: stored.id,
        name: stored.name,
        scopes: stored.scopes,
        createdAt: stored.createdAt,
        expiresAt: stored.expiresAt,
        lastUsedAt: stored.lastUsedAt,
        enabled: stored.enabled,
      });
    }
    return result;
  }

  /**
   * Revoke (delete) a token.
   */
  public async revokeToken(id: string): Promise<boolean> {
    if (!this.tokens.has(id)) return false;
    const token = this.tokens.get(id)!;
    this.tokens.delete(id);
    await this.storageManager.delete(`${TOKENS_PREFIX}${id}.json`);
    logger.log('info', `API token '${token.name}' revoked (id: ${id})`);
    return true;
  }

  /**
   * Enable or disable a token.
   */
  public async toggleToken(id: string, enabled: boolean): Promise<boolean> {
    const stored = this.tokens.get(id);
    if (!stored) return false;
    stored.enabled = enabled;
    await this.persistToken(stored);
    logger.log('info', `API token '${stored.name}' ${enabled ? 'enabled' : 'disabled'} (id: ${id})`);
    return true;
  }

  // =========================================================================
  // Private
  // =========================================================================

  private async loadTokens(): Promise<void> {
    const keys = await this.storageManager.list(TOKENS_PREFIX);
    for (const key of keys) {
      if (!key.endsWith('.json')) continue;
      const stored = await this.storageManager.getJSON<IStoredApiToken>(key);
      if (stored?.id) {
        this.tokens.set(stored.id, stored);
      }
    }
  }

  private async persistToken(stored: IStoredApiToken): Promise<void> {
    await this.storageManager.setJSON(`${TOKENS_PREFIX}${stored.id}.json`, stored);
  }
}