angular-ngrx-pattern/src/app/ngrx/projects/projects.reducer.ts

import { ProjectActionUnion } from './projects.actions';
import { Action } from '@ngrx/store';
import { MsgState } from '../msg.state';
import { ProjectState } from './project.state';
import { ProjectActionTypes } from './project.action.types';
import { Project } from 'src/app/shared/models/project/project.model';

/** a reducer need first initial state and action to perform */

const projectInitState: ProjectState = {
  currentProject: null,
  projectsList: [],
  msgState: MsgState.INIT_STATE,
  serverErrorMsg: 'no error massage'
};

export function projectReducer(
  state: ProjectState = projectInitState,
  projectAction: Action
): ProjectState {
  switch (projectAction.type) {
    // get all projects action reducer
    case ProjectActionTypes.GET_ALL_PROJECTS:
      return {
        ...state,
        msgState: MsgState.LOADING,
      };

    case ProjectActionTypes.GET_ALL_PROJECTS_SUCCESS:
      return {
        ...state,
        msgState: MsgState.LOADED,
        projectsList: (<ProjectActionUnion>projectAction).payload,
      };

    case ProjectActionTypes.GET_ALL_PROJECTS_ERROR:
      return {
        ...state,
        msgState: MsgState.ERR,
        serverErrorMsg: (<ProjectActionUnion>projectAction).payload,
      };

    // create project form to add action reducer

    case ProjectActionTypes.CREATE_PROJECT_FORM_ADD:
      return {
        ...state,
        msgState: MsgState.FORM_LOADING,
      };

    case ProjectActionTypes.CREATE_PROJECT_FORM_ADD_SUCCESS:
      return {
        ...state,
        msgState: MsgState.FORM_LOADED,
      };

    case ProjectActionTypes.CREATE_PROJECT_FORM_ADD_ERROR:
      return {
        ...state,
        msgState: MsgState.ERR,
        serverErrorMsg: (<ProjectActionUnion>projectAction).payload,
      };

    //saving project form data

    case ProjectActionTypes.SAVE_PROJECT_FORM_DATA:
      return {
        ...state,
        msgState: MsgState.LOADING,
      };

    case ProjectActionTypes.CREATE_PROJECT_FORM_ADD_SUCCESS:
      let createdProject: Project = (<ProjectActionUnion>projectAction).payload;
      let projectsListCopy1: Project[] = [...state.projectsList];
      projectsListCopy1.push(createdProject);

      return {
        ...state,
        msgState: MsgState.ADDED,
        projectsList: projectsListCopy1,
      };

    // create form to update project
    case ProjectActionTypes.CREATE_PROJECT_FORM_UPDATE:
      return {
        ...state,
        msgState: MsgState.FORM_LOADING,
      };

    case ProjectActionTypes.CREATE_PROJECT_FORM_UPDATE_SUCCESS:
      let projectToUpdate: Project = (<ProjectActionUnion>projectAction)
        .payload;
      return {
        ...state,
        msgState: MsgState.FORM_LOADED,
        currentProject: projectToUpdate,
      };

    case ProjectActionTypes.CREATE_PROJECT_FORM_UPDATE_ERROR:
      return {
        ...state,
        msgState: MsgState.FORM_LOAD_ERR,
        serverErrorMsg: (<ProjectActionUnion>projectAction).payload,
      };

    //update project with form data

    case ProjectActionTypes.UPDATE_PROJECT_WITH_FORM_DATA:
      return {
        ...state,
        msgState: MsgState.DEFAULT_MSG,
      };

    case ProjectActionTypes.UPDATE_PROJECT_WITH_FORM_DATA_SUCCESS:
      let updatedProject: Project = (<ProjectActionUnion>projectAction).payload;
      let projectsListCopy2 = [...state.projectsList];
      projectsListCopy2 = projectsListCopy2.map((project) =>
        project.id == updatedProject.id ? updatedProject : project
      );

      return{
        ...state,
        msgState: MsgState.UPDATED,
        projectsList : projectsListCopy2
      }

      // delete project
      case ProjectActionTypes.DELETE_PROJECT:
        return {
          ...state,
          msgState: MsgState.DELETE
        }

      case ProjectActionTypes.DELETE_PROJECT_SUCCESS:
        let deletedProject = (<ProjectActionUnion> projectAction).payload;
        let deletedProjectIndex = state.projectsList.indexOf(deletedProject);
        let projectsListCopy3 : Project[] = [...state.projectsList];
        projectsListCopy3 = projectsListCopy3.splice(deletedProjectIndex);

        return{
          ...state,
          msgState: MsgState.DELETED,
          projectsList: projectsListCopy3
        };

      case ProjectActionTypes.DELETE_PROJECT_ERROR:
        return{
          ...state,
          msgState: MsgState.ERR,
          serverErrorMsg: (<ProjectActionUnion>projectAction).payload
        };

    default:
      return { ...state };
  }
}