Generated by XState Viz: https://xstate.js.org/viz

machine.js

function buildVibrationPattern(seconds) {
  return new Array(seconds / 1500)
    .fill(null)
    .reduce(prev => [...prev, 0, 1000, 500], [])
}

const ACTIVE = `active`
const BACKGROUND = `background`
const WAIT_TIME = 30000
const PATTERN = buildVibrationPattern(WAIT_TIME)

new Machine(
  {
    id: `courier-state`,
    initial: `initializing`,
    context: {
      appState: ACTIVE,
      currentOrderId: null,
      online: false,
      order: null,
      orders: [],
      time: null
    },
    on: {
      SET_APP_STATE: {
        actions: `setAppState`
      }
    },
    states: {
      initializing: {
        on: {
          '': [
            {
              cond: `isOffline`,
              target: `offline.success`
            },
            {
              cond: `isOnline`,
              target: `online.offJob`
            }
          ]
        }
      },

      offline: {
        initial: `loading`,
        on: {
          ONLINE: `online`
        },
        states: {
          loading: {
            invoke: {
              id: `go-offline`,
              src: `goOffline`,
              onDone: `success`,
              onError: `failure`
            }
          },

          success: {
            entry: `setOffline`
          },

          failure: {
            entry: `setOffline`
          }
        }
      },

      online: {
        initial: `loading`,
        on: {
          OFFLINE: `offline`
        },
        states: {
          loading: {
            invoke: {
              id: `go-online`,
              src: `goOnline`,
              onDone: `offJob`,
              onError: `failure`
            }
          },

          failure: {
            entry: `setOffline`
          },

          offJob: {
            entry: `setOnline`,
            on: {
              OFFER: {
                actions: [`setCurrentOrderId`, `setTime`],
                target: `offer`
              }
            }
          },

          offer: {
            initial: `checkAppState`,
            states: {
              checkAppState: {
                entry: `vibrate`,
                on: {
                  '': [
                    {
                      cond: `isBackground`,
                      target: `background`
                    },
                    {
                      cond: `isActive`,
                      target: `waiting`
                    }
                  ]
                }
              },

              background: {
                on: {
                  ACTIVE: `waiting`
                }
              },

              waiting: {
                on: {
                  ACCEPT_JOB: `accepted`,
                  REJECT_JOB: `rejected`
                },
                after: {
                  ORDER_DELAY: `rejected`
                }
              },

              accepted: {
                entry: `cancelVibration`,
                invoke: {
                  id: `accept-order`,
                  src: `acceptOrder`,
                  onDone: `#courier-state.online.onJob`
                }
              },

              rejected: {
                entry: `cancelVibration`,
                invoke: {
                  id: `reject-order`,
                  src: `rejectOrder`,
                  onDone: `#courier-state.online.offJob`
                }
              }
            }
          },

          onJob: {
            entry: `setOrder`
          }
        }
      }
    }
  },
  {
    actions: {
      vibrate: () => {},
      cancelVibration: () => {},
      setAppState: assign({
        appState: ctx => ctx.appState === ACTIVE ? BACKGROUND : ACTIVE
      }),
      setOffline: assign({
        online: false
      }),
      setOnline: assign({
        online: true
      }),
      setOrder: assign({
        order: {
          id: 1
        }
      }),
      setTime: assign({
        time: Date.now()
      })
    },
    delays: {
      ORDER_DELAY: ctx => {
        if (!ctx.time) {
          return WAIT_TIME
        }

        return Math.floor(ctx.time + WAIT_TIME - Date.now())
      }
    },
    guards: {
      isActive: ctx => ctx.appState === ACTIVE,
      isBackground: ctx => ctx.appState === BACKGROUND,
      isOffline: ctx => !ctx.online,
      isOnline: ctx => ctx.online
    }
  }
)