export interface YonexusClientConfig {
  mainHost: string;
  identifier: string;
  notifyBotToken: string;
  adminUserId: string;
}

export class YonexusClientConfigError extends Error {
  readonly issues: string[];

  constructor(issues: string[]) {
    super(`Invalid Yonexus.Client config: ${issues.join("; ")}`);
    this.name = "YonexusClientConfigError";
    this.issues = issues;
  }
}

function isNonEmptyString(value: unknown): value is string {
  return typeof value === "string" && value.trim().length > 0;
}

function isValidWsUrl(value: string): boolean {
  try {
    const url = new URL(value);
    return url.protocol === "ws:" || url.protocol === "wss:";
  } catch {
    return false;
  }
}

export function validateYonexusClientConfig(raw: unknown): YonexusClientConfig {
  const source = raw as Record<string, unknown> | null;
  const issues: string[] = [];

  const mainHost = source?.mainHost;
  if (!isNonEmptyString(mainHost)) {
    issues.push("mainHost is required");
  } else if (!isValidWsUrl(mainHost.trim())) {
    issues.push("mainHost must be a valid ws:// or wss:// URL");
  }

  const identifier = source?.identifier;
  if (!isNonEmptyString(identifier)) {
    issues.push("identifier is required");
  }

  const notifyBotToken = source?.notifyBotToken;
  if (!isNonEmptyString(notifyBotToken)) {
    issues.push("notifyBotToken is required");
  }

  const adminUserId = source?.adminUserId;
  if (!isNonEmptyString(adminUserId)) {
    issues.push("adminUserId is required");
  }

  if (issues.length > 0) {
    throw new YonexusClientConfigError(issues);
  }

  return {
    mainHost: mainHost.trim(),
    identifier: identifier.trim(),
    notifyBotToken: notifyBotToken.trim(),
    adminUserId: adminUserId.trim()
  };
}