reducers.js

import { combineReducers } from 'redux'
import { MOVE_LEFT, MOVE_TO, SET_X, SET_VIEWPORT_WIDTH } from './runtime/actions'
import { NAVIGATE, TOGGLE_EXPAND, UPDATE_SETTINGS } from './actions'
import getViewportWidth from './runtime/get-viewport-width'

function apps(state = { byName: {}, items: [] }, action) {
  if (action.type === NAVIGATE &&
      action.sequence.type === 'next' &&
      action.payload.apps.items.length) {
    return {
      byName: {
        ...state.byName,
        ...action.payload.apps.byName
      },
      items: [
        ...state.items,
        ...action.payload.apps.items
      ]
    }
  } else {
    return state
  }
}

function panels(state = { byId: {}, items: [] }, action) {
  if (action.type === NAVIGATE &&
      action.sequence.type === 'next' &&
      action.payload.panels.items.length) {
    return {
      byId: {
        ...state.byId,
        ...action.payload.panels.byId
      },
      items: [
        ...state.items,
        ...action.payload.panels.items
      ]
    }
  } else if (action.type === UPDATE_SETTINGS) {
    return {
      ...state,
      byId: action.payload.nextPanelsById
    }
  } else {
    return state
  }
}

function router(state = { isLoading: true, routes: { byContext: {}, items: [] } }, action) {
  switch (action.type) {
    case NAVIGATE:
      if (action.sequence.type === 'start') {
        return {
          ...state,
          isLoading: true,
          uri: action.meta.uri
        }
      } else if (action.sequence.type === 'next') {
        return {
          ...state,
          ...action.payload.router,
          isLoading: false
        }
      }
      break

    case SET_VIEWPORT_WIDTH:
    case TOGGLE_EXPAND:
      return {
        ...state,
        routes: {
          items: state.routes.items,
          byContext: action.payload.routesByContext
        }
      }
      break

    case UPDATE_SETTINGS:
      if (action.payload.nextPosition) {
        return {
          ...state,
          routes: {
            items: state.routes.items,
            byContext: action.payload.nextPosition.routesByContext
          }
        }
      } else {
        return state
      }
      break

    default: return state
  }
}

export const MOBILE_THRESHOLD = 720

// TODO REVERT!
const preferredSnapPoint = window.panels && typeof window.panels.preferredSnapPoint === 'number' ? window.panels.preferredSnapPoint : 90
const viewportWidth = getViewportWidth()
const shouldGoMobile = viewportWidth < MOBILE_THRESHOLD
const snapPoint = shouldGoMobile ? 0 : preferredSnapPoint

const RUNTIME_DEFAULT_STATE = {
  maxFullPanelWidth: viewportWidth - snapPoint,
  preferredSnapPoint,
  snappedAt: 0,
  snapPoint,
  shouldGoMobile,
  x: 0,
  viewportWidth,
  width: viewportWidth,
  widths: []
}

function runtime(state = RUNTIME_DEFAULT_STATE, action) {
  switch (action.type) {
    // TODO normalise
    case MOVE_LEFT:
    case MOVE_TO:
    case SET_X:
      return {
        ...state,
        snappedAt: action.payload.snappedAt,
        x: action.payload.x
      }
      break

    case NAVIGATE:
      if (action.sequence.type === 'next') {
        return {
          ...state,
          maxFullPanelWidth: action.payload.runtime.maxFullPanelWidth,
          regions: action.payload.runtime.regions,
          snappedAt: action.payload.runtime.snappedAt,
          width: action.payload.runtime.width,
          widths: action.payload.runtime.widths,
          x: action.payload.runtime.x
        }
      } else {
        return state
      }
      break

    case SET_VIEWPORT_WIDTH:
      return {
        ...state,
        maxFullPanelWidth: action.payload.maxFullPanelWidth,
        shouldGoMobile: action.payload.shouldGoMobile,
        snapPoint: action.payload.snapPoint,
        viewportWidth: action.payload.viewportWidth,
        width: action.payload.width,
        widths: action.payload.widths,
        x: action.payload.x
      }
      break

    case TOGGLE_EXPAND:
      return {
        ...state,
        width: action.payload.width,
        widths: action.payload.widths,
        x: action.payload.x
      }
      break

    case UPDATE_SETTINGS:
      if (action.payload.nextPosition) {
        return {
          ...state,
          width: action.payload.nextPosition.width,
          widths: action.payload.nextPosition.widths,
          x: action.payload.nextPosition.x
        }
      } else {
        return state
      }
      break

    default: return state
  }
}

export default combineReducers({
  apps,
  panels,
  router,
  runtime
})