import * as plugins from './smartstate.plugins.js';
import { StatePart } from './smartstate.classes.statepart.js';

export type TInitMode = 'soft' | 'mandatory' | 'force' | 'persistent';

/**
 * Smartstate takes care of providing state
 */
export class Smartstate<StatePartNameType extends string> {
  public statePartMap: { [key in StatePartNameType]?: StatePart<StatePartNameType, any> } = {};

  constructor() {}

  /**
   * Allows getting and initializing a new statepart
   * initMode === 'soft' it will allow existing stateparts
   * initMode === 'mandatory' will fail if there is an existing statepart
   * initMode === 'force' will overwrite any existing statepart
   * @param statePartNameArg
   * @param initialArg
   * @param initMode
   */
  public async getStatePart<PayloadType>(
    statePartNameArg: StatePartNameType,
    initialArg?: PayloadType,
    initMode?: TInitMode
  ): Promise<StatePart<StatePartNameType, PayloadType>> {
    if (this.statePartMap[statePartNameArg]) {
      if (initialArg && (!initMode || initMode !== 'soft')) {
        throw new Error(
          `${statePartNameArg} already exists, yet you try to set an initial state again`
        );
      }
      return this.statePartMap[statePartNameArg] as StatePart<StatePartNameType, PayloadType>;
    } else {
      if (!initialArg) {
        throw new Error(
          `${statePartNameArg} does not yet exist, yet you don't provide an initial state`
        );
      }
      return this.createStatePart<PayloadType>(statePartNameArg, initialArg, initMode);
    }
  }

  /**
   * Creates a statepart
   * @param statePartName
   * @param initialPayloadArg
   */
  private async createStatePart<PayloadType>(
    statePartName: StatePartNameType,
    initialPayloadArg: PayloadType,
    initMode?: TInitMode
  ): Promise<StatePart<StatePartNameType, PayloadType>> {
    const newState = new StatePart<StatePartNameType, PayloadType>(
      statePartName,
      initMode === 'persistent'
        ? {
            dbName: 'smartstate',
            storeName: statePartName,
          }
        : null
    );
    await newState.init();
    const currentState = newState.getState();
    await newState.setState({
      ...initialPayloadArg,
      ...currentState,
    });
    this.statePartMap[statePartName] = newState;
    return newState;
  }
}