// SPDX-License-Identifier: MIT
// buenos_andres Compact Contracts v0.2.11 (security/Pausable.compact)

pragma language_version >= 0.18.0;

/**
 * @module Pausable
 * @description Pausable allows the implementing contract to implement
 * an emergency stop mechanism. Only circuits that call `assertPaused`
 * or `assertNotPaused` will be affected by this mechanism.
 */
module Pausable {
  import CompactStandardLibrary;

  export ledger _isPaused: Boolean;

  /**
   * @description Returns true if the contract is paused, and false otherwise.
   *
   * @circuitInfo k=10, rows=32
   *
   * @return {Boolean} True if paused.
   */
  export circuit isPaused(): Boolean {
    return _isPaused;
  }

  /**
   * @description Makes a circuit only callable when the contract is paused.
   *
   * @circuitInfo k=10, rows=31
   *
   * Requirements:
   *
   * - Contract must be paused.
   *
   * @return {[]} - Empty tuple.
   */
  export circuit assertPaused(): [] {
    assert(_isPaused, "Pausable: not paused");
  }

  /**
   * @description Makes a circuit only callable when the contract is not paused.
   *
   * @circuitInfo k=10, rows=35
   *
   * Requirements:
   *
   * - Contract must not be paused.
   *
   * @return {[]} - Empty tuple.
   */
  export circuit assertNotPaused(): [] {
    assert(!_isPaused, "Pausable: paused");
  }

  /**
   * @description Triggers a stopped state.
   *
   * @circuitInfo k=10, rows=38
   *
   * Requirements:
   *
   * - Contract must not be paused.
   *
   * @return {[]} - Empty tuple.
   */
  export circuit _pause(): [] {
    assertNotPaused();
    _isPaused = true;
  }

  /**
   * @description Lifts the pause on the contract.
   *
   * @circuitInfo k=10, rows=34
   *
   * Requirements:
   *
   * - Contract must be paused.
   *
   * @return {[]} - Empty tuple.
   */
  export circuit _unpause(): [] {
    assertPaused();
    _isPaused = false;
  }
}