api/packages/metadata/src/Metadata/MetadataVersioned.ts

// Copyright 2017-2019 @polkadot/metadata authors & contributors
// This software may be modified and distributed under the terms
// of the Apache-2.0 license. See the LICENSE file for details.

import { MetadataAll, MetadataLatest, MetadataV0, MetadataV1, MetadataV2, MetadataV3, MetadataV4, MetadataV5, MetadataV6, MetadataV7, MetadataV8, MetadataV9, MetadataV10, MetadataV11 } from '@polkadot/types/interfaces/metadata';
import { Registry } from '@polkadot/types/types';

import { createType } from '@polkadot/types/codec/create/createType';
import Struct from '@polkadot/types/codec/Struct';
import { assert } from '@polkadot/util';

import MagicNumber from './MagicNumber';
import v0ToV1 from './v0/toV1';
import v1ToV2 from './v1/toV2';
import v2ToV3 from './v2/toV3';
import v3ToV4 from './v3/toV4';
import v4ToV5 from './v4/toV5';
import v5ToV6 from './v5/toV6';
import v6ToV7 from './v6/toV7';
import v7ToV8 from './v7/toV8';
import v8ToV9 from './v8/toV9';
import v9ToV10 from './v9/toV10';
import v10ToV11 from './v10/toV11';
import { getUniqTypes, toCallsOnly } from './util';

type MetaMapped = MetadataV0 | MetadataV1 | MetadataV2 | MetadataV3 | MetadataV4 | MetadataV5 | MetadataV6 | MetadataV7 | MetadataV8 | MetadataV9 | MetadataV10 | MetadataV11;
type MetaVersions = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11;
type MetaAsX = 'asV0' | 'asV1' | 'asV2' | 'asV3' | 'asV4' | 'asV5' | 'asV6' | 'asV7' | 'asV8' | 'asV9' | 'asV10' | 'asV11';

/**
 * @name MetadataVersioned
 * @description
 * The versioned runtime metadata as a decoded structure
 */
export default class MetadataVersioned extends Struct {
  private _converted: Map<number, MetaMapped> = new Map();

  constructor (registry: Registry, value?: any) {
    super(registry, {
      magicNumber: MagicNumber,
      metadata: 'MetadataAll'
    }, value);

    registry.setMetadata(this);
  }

  private assertVersion (version: number): boolean {
    assert(this.version <= version, `Cannot convert metadata from v${this.version} to v${version}`);

    return this.version === version;
  }

  private getVersion<T extends MetaMapped, F extends MetaMapped> (version: MetaVersions, fromPrev: (registry: Registry, input: F) => T): T {
    const asCurr = `asV${version}` as MetaAsX;
    const asPrev = `asV${version - 1}` as MetaAsX;

    if (this.assertVersion(version)) {
      return this.metadata[asCurr] as T;
    }

    if (!this._converted.has(version)) {
      this._converted.set(version, fromPrev(this.registry, this[asPrev] as F));
    }

    return this._converted.get(version) as T;
  }

  /**
   * @description Returns the wrapped metadata as a limited calls-only (latest) version
   */
  public get asCallsOnly (): MetadataVersioned {
    return new MetadataVersioned(this.registry, {
      magicNumber: this.magicNumber,
      metadata: createType(this.registry, 'MetadataAll', toCallsOnly(this.registry, this.asLatest), this.version)
    });
  }

  /**
   * @description Returns the wrapped metadata as a V0 object
   */
  public get asV0 (): MetadataV0 {
    this.assertVersion(0);

    return this.metadata.asV0;
  }

  /**
   * @description Returns the wrapped values as a V1 object
   */
  public get asV1 (): MetadataV1 {
    return this.getVersion(1, v0ToV1);
  }

  /**
   * @description Returns the wrapped values as a V2 object
   */
  public get asV2 (): MetadataV2 {
    return this.getVersion(2, v1ToV2);
  }

  /**
   * @description Returns the wrapped values as a V3 object
   */
  public get asV3 (): MetadataV3 {
    return this.getVersion(3, v2ToV3);
  }

  /**
   * @description Returns the wrapped values as a V4 object
   */
  public get asV4 (): MetadataV4 {
    return this.getVersion(4, v3ToV4);
  }

  /**
   * @description Returns the wrapped values as a V5 object
   */
  public get asV5 (): MetadataV5 {
    return this.getVersion(5, v4ToV5);
  }

  /**
   * @description Returns the wrapped values as a V6 object
   */
  public get asV6 (): MetadataV6 {
    return this.getVersion(6, v5ToV6);
  }

  /**
   * @description Returns the wrapped values as a V7 object
   */
  public get asV7 (): MetadataV7 {
    return this.getVersion(7, v6ToV7);
  }

  /**
   * @description Returns the wrapped values as a V8 object
   */
  public get asV8 (): MetadataV8 {
    return this.getVersion(8, v7ToV8);
  }

  /**
   * @description Returns the wrapped values as a V9 object
   */
  public get asV9 (): MetadataV9 {
    return this.getVersion(9, v8ToV9);
  }

  /**
   * @description Returns the wrapped values as a V10 object
   */
  public get asV10 (): MetadataV10 {
    return this.getVersion(10, v9ToV10);
  }

  /**
   * @description Returns the wrapped values as a V10 object
   */
  public get asV11 (): MetadataV11 {
    return this.getVersion(11, v10ToV11);
  }

  /**
   * @description Returns the wrapped values as a latest version object
   */
  public get asLatest (): MetadataLatest {
    return this.asV11;
  }

  /**
   * @description
   */
  public get magicNumber (): MagicNumber {
    return this.get('magicNumber') as MagicNumber;
  }

  /**
   * @description the metadata wrapped
   */
  private get metadata (): MetadataAll {
    return this.get('metadata') as MetadataAll;
  }

  /**
   * @description the metadata version this structure represents
   */
  public get version (): number {
    return this.metadata.index;
  }

  public getUniqTypes (throwError: boolean): string[] {
    return getUniqTypes(this.registry, this.asLatest, throwError);
  }
}