Machine(
  {
    id: `createContract`,
    initial: `editing`,
    context: {
      students: [],
      grades: [],
      services: [],
    },
    states: {
      editing: {
        on: {
          SELECT_MODALITY: `loading`,
          SUBMIT: `creating`,
          SEARCH_STUDENT: {
            cond: `searchValid`,
            target: `searching`,
          },
        },
      },

      loading: {
        onDone: `editing`,
        type: `parallel`,
        states: {
          grades: {
            initial: `loading`,
            states: {
              loading: {
                invoke: {
                  id: `loadGrades`,
                  src: `loadGrades`,
                  onDone: {
                    actions: `setGrades`,
                    target: `done`,
                  },
                },
              },

              done: {
                type: `final`,
              },
            },
          },

          services: {
            initial: `loading`,
            states: {
              loading: {
                invoke: {
                  id: `loadServices`,
                  src: `loadServices`,
                  onDone: {
                    actions: `setServices`,
                    target: `done`,
                  },
                },
              },

              done: {
                type: `final`,
              },
            },
          },
        },
      },

      searching: {
        invoke: {
          id: `searchStudents`,
          src: `searchStudents`,
          onDone: {
            actions: `setStudents`,
            target: `editing`,
          },
        },
      },

      creating: {
        invoke: {
          id: `createContract`,
          src: `createContract`,
          onDone: `success`,
          onError: {
            actions: `handleGraphQLErrors`,
            target: `editing`,
          },
        },
      },

      success: {
        entry: `createContractSuccess`,
        type: `final`,
      },
    },
  },
  {
    actions: {
      setStudents: assign((ctx, event) => {
        // ctx.students = event.data
      }),
      setGrades: assign((ctx, event) => {
        // ctx.grades = event.data.allGrades
      }),
      setServices: assign((ctx, event) => {
        // ctx.services = event.data.allServices
      }),
    },
    guards: {
      hasErrors: (ctx, event) => false,
      searchValid: (ctx, event) => true,
    },
  }
)