import {
  EMULATOR_ACCOUNT_KEY,
  EMULATOR_ACCOUNT_NAME
} from "../blob/utils/constants";
import ILogger from "../queue/generated/utils/ILogger";
import IAccountDataStore, { IAccountProperties } from "./IAccountDataStore";
import {
  AZURITE_ACCOUNTS_ENV,
  DEFAULT_ACCOUNTS_REFRESH_INTERVAL
} from "./utils/constants";

enum Status {
  Initializing,
  Initialized,
  Closing,
  Closed
}

interface IAccounts {
  [key: string]: IAccountProperties;
}

const DEFAULT_EMULATOR_ACCOUNTS: IAccounts = {
  [EMULATOR_ACCOUNT_NAME]: {
    name: EMULATOR_ACCOUNT_NAME,
    key1: EMULATOR_ACCOUNT_KEY
  }
};

export default class AccountDataStore implements IAccountDataStore {
  private status: Status = Status.Closed;
  private timer: any;
  private accounts: IAccounts = DEFAULT_EMULATOR_ACCOUNTS;

  public constructor(private readonly logger: ILogger) {}

  public getAccount(name: string): IAccountProperties | undefined {
    if (this.accounts[name] !== undefined) {
      return this.accounts[name];
    } else {
      return undefined;
    }
  }

  public async init(): Promise<void> {
    this.refresh();
    this.timer = setInterval(() => {
      this.refresh();
    }, DEFAULT_ACCOUNTS_REFRESH_INTERVAL);
    this.timer.unref();

    this.status = Status.Initialized;
  }

  public isInitialized(): boolean {
    return this.status === Status.Initialized;
  }

  public async close(): Promise<void> {
    clearInterval(this.timer);
    this.status = Status.Closed;
  }

  public isClosed(): boolean {
    return this.status === Status.Closed;
  }

  public async clean(): Promise<void> {
    /* NOOP */
  }

  private refresh() {
    // TODO: Parse environment variable from environment class
    const env = process.env[AZURITE_ACCOUNTS_ENV];
    this.logger.info(
      `AccountDataStore:init() Refresh accounts from environment variable ${AZURITE_ACCOUNTS_ENV} with value ${
        env ? "*****" : undefined
      }`
    );
    if (env) {
      try {
        this.accounts = this.parserAccountsEnvironmentString(env);
      } catch (err) {
        this.logger.error(
          `AccountDataStore:init() Fallback to default emulator account ${EMULATOR_ACCOUNT_NAME}. Refresh accounts from environment variable ${AZURITE_ACCOUNTS_ENV} failed. ${JSON.stringify(
            err
          )}`
        );
        this.accounts = DEFAULT_EMULATOR_ACCOUNTS;
      }
    } else {
      this.logger.info(
        `AccountDataStore:init() Fallback to default emulator account ${EMULATOR_ACCOUNT_NAME}.`
      );
      this.accounts = DEFAULT_EMULATOR_ACCOUNTS;
    }
  }

  private parserAccountsEnvironmentString(accounts: string): IAccounts {
    // account1:key1
    // account1:key1:key2
    // account1:key1:key2;account2:key2;
    const results: IAccounts = {};
    const accountsArray = accounts.trim().split(";");
    accountsArray.forEach(accountAndKeys => {
      if (accountAndKeys.length > 0) {
        const parts = accountAndKeys.split(":");
        if (parts.length < 2 || parts.length > 3) {
          throw RangeError(
            `AccountDataStore:parserAccountsEnvironmentString() Invalid environment string format for ${accounts}`
          );
        }
        const account = parts[0];
        const key1 = parts[1];
        const key2 = parts.length > 2 ? parts[2] : undefined;
        results[account] = {
          name: account,
          key1: Buffer.from(key1, "base64"),
          key2: key2 ? Buffer.from(key2, "base64") : undefined
        };
      }
    });

    return results;
  }
}