Document API / document merging

[clemens-msupply]

Integrate the document api (#19) to:

• fetch documents (e.g. needed to view full patient details including none standard fields)
• update document (e.g. needed to create patients)
• implement document updates that require auto merge

(document api is currently in PR

Example to add a new document and update it:

  // get the graphql api
  const api = getApi();

  // pick one store
  const stores = (await api.getStores()).stores.nodes;
  const store0 = stores[0];
  console.log(`Store: ${store0.id}, code: ${store0.code}`);

  // insert first version of the document
  const u0 = await api.updateDocument({
    storeId: store0.id,
    input: {
      author: "me",
      type: "testtype",
      data: {
        version: 1,
        txt: "hello",
      },
      name: docName,
      parents: [],
      schemaId: undefined,
      timestamp: new Date().toISOString(),
    },
  });
  console.log(u0);

  // fetch the latest version of the document
  const filter = {
    name: {
      equalTo: docName,
    },
  };
  const d1 = await api.getDocuments({
    storeId: store0.id,
    filter,
  });
  console.log(d1);

  // modify the last version and set parents correctly
  const u1 = await api.updateDocument({
    storeId: store0.id,
    input: {
      author: "me",
      type: "testtype",
      data: {
        version: 2,
        txt: "hello update",
        more: "more",
      },
      name: docName,
      parents: [d1.documents.nodes[0].id],
      schemaId: undefined,
      timestamp: new Date().toISOString(),
    },
  });
  console.log(u1);
  const exhaustiveCheck = (_: never) => {};

  // example error handling
  let docId: string = "";
  switch (u1.updateDocument.__typename) {
    case "DocumentNode":
      docId = u1.updateDocument.id;
      break;
    case "UpdateDocumentError": {
      const error = u1.updateDocument.error;
      switch (error.__typename) {
        case "MergeRequiredError":
          // TODO: merge and resubmit
          throw Error("unhandled");
        default:
        //exhaustiveCheck(error);
      }
      throw Error("unhandled");
    }
    default:
      exhaustiveCheck(u1.updateDocument);
  }

  // do another update
  const u2 = await api.updateDocument({
    storeId: store0.id,
    input: {
      author: "me",
      type: "testtype",
      data: {
        version: 3,
        txt: "hello update 2",
        more: "more...",
      },
      name: docName,
      parents: [docId],
      schemaId: undefined,
      timestamp: new Date().toISOString(),
    },
  });
  console.log(u2);

Merge concurrently edited documents

The API may detect concurrent edits which requires a merge of both versions.
In this case the API returns a MergeRequiredError.
The MergeRequiredError error contains a proposed auto-merged document.
If the FE is happy the auto-merged version can be used to update the document.
This operation will succeeds as long as there wasn't a further concurrent edit.