// Available variables:
  // - Machine
  // - interpret
  // - assign
  // - send
  // - sendParent
  // - spawn
  // - raise
  // - actions
  // - XState (all XState exports)
  
  const fetchMachine = Machine({
    id: 'order-sequencing',

    type: "parallel",
    
    states: {
      calendar: {
        type: "parallel",

        states: {
          mode: {
            initial: 'week',

            states: {
              day: {
                on: {
                  SHOW_WEEK: {
                    target: "week",
                    actions: ["setFilterToWeek", send("LOAD")]
                  },
                  
                  SHOW_TODAY: {
                    actions: ["setFilterToToday", send("LOAD")]
                  },
                  
                  BEFORE: {
                    actions: ["setFilterToDayBefore", send("LOAD")]
                  },
                  
                  AFTER: {
                    actions: ["setFilterToDayAfter", send("LOAD")]
                  }
                }
              },

              week: {
                on: {
                  SHOW_DAY: {
                    target: "day",
                    actions: ["setFilterToBeginningOfWeek", send("LOAD")]
                  },
                  
                  SHOW_TODAY: {
                    actions: ["setFilterToToday", send("LOAD")]
                  },
                  
                  BEFORE: {
                    actions: ["setFilterToWeekBefore", send("LOAD")]
                  },
                  
                  AFTER: {
                    actions: ["setFilterToWeekAfter", send("LOAD")]
                  }
                }
              }
            }
          },
          
          // data for listing production schedule items for currently set filer
          data: {
            initial: "idle",

            states: {
              idle: {
                on: {
                  LOAD: "loading"
                },
                
                after: {
                  10000: "loading"
                }
              },

              loading: {
                onEntry: [send("LOAD")],
                on: {
                  LOAD: {
                    actions: ["loadProductionScheduleItemsForCurrentFilter"]
                  },
                  LOAD_SUCCESS: "success",
                  LOAD_ERROR: "error"
                }
              },

              success: {
                onEntry: ["setListOfProductionScheduleItems"],
                on: {
                  "": "idle"
                }
              },

              error: {
                onEntry: ["showErrorToUser"]
              }
            }
          }
        }
      },
      
      workflow: {
        type: "parallel",

        states: {
          mode: {
            initial: "read",

            states: {
              read: {
                on: {
                  START_EDITING: "write"
                }
              },
    
              write: {
                type: "parallel",
                
                on: {
                  STOP_EDITING: "read"
                },
                
                states: {
                  production_orders: {
                    initial: "empty",
    
                    states: {
                      empty: {
                        on: {
                          SELECTION_UPDATED: "selection"
                        }
                      },
    
                      selection: {
                        on: {
                          SELECTION_UPDATED: [
                            {
                              target: "empty",
                              cond: "emptySelection"
                            }
                          ]
                        }
                      }
                    }
                  },
      
                  production_schedule_item: {
                    initial: "empty",
    
                    states: {
                      empty: {
                        on: {
                          CLICKED_ITEM: {
                            target: "selection"
                          }
                        }
                      },
    
                      selection: {
                        onEntry: ["setItem"],

                        on: {
                          CLICKED_ITEM: [{
                            target: "empty",
                            cond: "isSameItem"
                          }, {
                            target: "selection"
                          }],
                          
                          MOVE_UP: {
                            actions: ["moveUp", send("SAVE")]
                          },
                          
                          MOVE_DOWN: {
                            actions: ["moveDown", send("SAVE")]
                          },
                          
                          REMOVE_FROM_PLANNING: {
                            target: "empty",
                            actions: ["removeFromPlanning", send("SAVE")]
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          },
          
          data: {
            initial: "idle",
    
            states: {
              idle: {
                on: {
                  SAVE: {
                    target: "saving"
                  }
                }
              },

              saving: {
                onEntry: ["save"],
                
                on: {
                  SAVE_SUCCESS: "success",
                  SAVE_ERROR: "error"
                }
              },

              success: {
                onEntry: ["load", send("LOAD")],
                on: {
                  "": "idle"
                }
              },

              error: {}
            }
          }
        }
      }
    }
  });