import _ from 'lodash'
import { Action, AnyAction, ReducersMapObject } from 'redux'

export interface ShellToggleSet {
    [name: string]: boolean
}

export interface InstalledShellsState {
    readonly installedShells: ShellToggleSet
}

export interface UpdateInstalledShellsAction extends Action {
    readonly updates: ShellToggleSet
}

const UPDATE_INSTALLED_SHELLS_ACTION = '$installedShells/update'

export const contributeInstalledShellsState = (): ReducersMapObject => {
    return {
        $installedShells: installedShellsReducer
    }
}

const selectRootState = (state: any): InstalledShellsState => state.$installedShells

export const InstalledShellsSelectors = {
    getInstalledShellsSet(state: any): ShellToggleSet {
        return selectRootState(state).installedShells
    }
}

export const InstalledShellsActions = {
    updateInstalledShells: (updates: ShellToggleSet): UpdateInstalledShellsAction => {
        return {
            type: UPDATE_INSTALLED_SHELLS_ACTION,
            updates
        }
    }
}

const toggleInstalledShells = (currentlyInstalled: ShellToggleSet, updates: ShellToggleSet): ShellToggleSet =>
    _.pickBy(_.assign({}, currentlyInstalled, updates), _.identity)

export const installedShellsReducer = (state: InstalledShellsState = { installedShells: {} }, action: AnyAction): InstalledShellsState => {
    switch (action.type) {
        case UPDATE_INSTALLED_SHELLS_ACTION:
            return {
                ...state,
                installedShells: toggleInstalledShells(state.installedShells, action.updates)
            }
    }

    return state
}