Every day, prompt users to back up their files if they're so inclined

package.json

@@ -47,6 +47,7 @@
     "govuk-svelte": "github:acteng/govuk-svelte",
     "humanize-string": "^3.0.0",
     "js-cookie": "^3.0.5",
+    "jszip": "^3.10.1",
     "maplibre-gl": "^4.7.1",
     "scheme-sketcher-lib": "github:acteng/scheme-sketcher-lib",
     "svelte": "^4.2.10",

src/lib/common/files.ts

@@ -1,4 +1,5 @@
 import { findSmallestAuthority, type AuthorityBoundaries } from "boundaries";
+import JSZip from "jszip";
 import type { Schema, Schemes } from "types";
 
 // Returns the local storage key for a file
@@ -130,6 +131,37 @@ export function exportFile(authority: string, filename: string, gj: Schemes) {
   );
 }
 
+export function checkThenExportAll() {
+  let today = getDateString();
+  let lastBackup =
+    window.localStorage.getItem("sketches-last-backup-prompt") ?? "";
+  if (today != lastBackup) {
+    if (
+      window.confirm(`Would you like to download a backup copy of your files?`)
+    ) {
+      exportAll();
+    }
+  }
+  window.localStorage.setItem("sketches-last-backup-prompt", getDateString());
+}
+
+// Downloads all sketches as .zip
+async function exportAll() {
+  let name = `scheme_sketch_backup_${getDateString()}`;
+  let zip = new JSZip();
+  let folder = zip.folder(name)!;
+
+  for (let key of getFileKeys()) {
+    folder.file(
+      `${key.replaceAll("/", "-")}.json`,
+      window.localStorage.getItem(key)!,
+    );
+  }
+
+  let bytes = await zip.generateAsync({ type: "arraybuffer" });
+  downloadBinaryFile(bytes, `${name}.zip`);
+}
+
 export function detectSchema(gj: any): Schema {
   // Blindly assume the input is valid, and let the try/catch handle otherwise
   try {
@@ -207,3 +239,37 @@ function stripPrefix(value: string, prefix: string): string {
 function stripSuffix(value: string, suffix: string): string {
   return value.endsWith(suffix) ? value.slice(0, -suffix.length) : value;
 }
+
+function getFileKeys(): string[] {
+  let results: string[] = [];
+  for (let i = 0; i < window.localStorage.length; i++) {
+    let key = window.localStorage.key(i)!;
+    if (key.startsWith("sketch")) {
+      results.push(key);
+    }
+  }
+  return results;
+}
+
+function getDateString(): string {
+  let today = new Date();
+  let day = today.getDate().toString().padStart(2, "0");
+  let month = (today.getMonth() + 1).toString().padStart(2, "0");
+  return `${day}_${month}_${today.getFullYear()}`;
+}
+
+function downloadBinaryFile(bytes: ArrayBuffer, filename: string) {
+  let blob = new Blob([bytes], { type: "application/octet-stream" });
+  let url = URL.createObjectURL(blob);
+
+  let link = document.createElement("a");
+  link.href = url;
+  link.download = filename;
+  link.style.display = "none";
+
+  document.body.appendChild(link);
+  link.click();
+
+  document.body.removeChild(link);
+  URL.revokeObjectURL(url);
+}

src/pages/ChooseArea.svelte

@@ -21,6 +21,7 @@
     Popup,
   } from "lib/common";
   import {
+    checkThenExportAll,
     countFilesPerAuthority,
     importFile,
     importOldFiles,
@@ -63,6 +64,7 @@
     }
 
     filesPerAuthority = countFilesPerAuthority();
+    checkThenExportAll();
   });
 
   function onClick(e: CustomEvent<LayerClickInfo>) {

src/pages/ManageFiles.svelte

@@ -17,6 +17,7 @@
     Header,
   } from "lib/common";
   import {
+    checkThenExportAll,
     downloadGeneratedFile,
     exportFile,
     getEditUrl,
@@ -52,6 +53,8 @@
     ) {
       window.location.href = `choose_area.html?schema=${$schemaStore}&error=Authority name not found: ${authority}`;
     }
+
+    checkThenExportAll();
   });
 
   function renameFile(filename: string) {

src/pages/SketchSchemes.svelte

@@ -13,7 +13,7 @@
     MapLibreMap,
   } from "lib/common";
   import ExternalLink from "lib/common/ExternalLink.svelte";
-  import { getKey } from "lib/common/files";
+  import { checkThenExportAll, getKey } from "lib/common/files";
   import { cfg } from "lib/sketch/config";
   import FileManagement from "lib/sketch/FileManagement.svelte";
   import { map as sketchMapStore } from "scheme-sketcher-lib/config";
@@ -61,6 +61,7 @@
     initAll();
 
     boundaryGeojson = await loadAuthorityBoundary();
+    checkThenExportAll();
   });
 
   async function loadAuthorityBoundary(): Promise<AuthorityBoundaries> {

tests/shared.ts

@@ -6,10 +6,18 @@ export async function resetSketch(
   page: Page,
   schema: string = "v1",
 ): Promise<string> {
+  page.on("dialog", (dialog) => {
+    if (dialog.message() === "What do you want to name your new file?"
+      || dialog.message().includes("Really delete")) {
+      dialog.accept(filename);
+    } else {
+      dialog.dismiss();
+    }
+  });
   await page.goto(`/files.html?authority=LAD_Adur&schema=${schema}`);
 
   let filename = uuidv4();
-  page.on("dialog", (dialog) => dialog.accept(filename));
+
   await page.getByRole("button", { name: "Create new file" }).click();
   await expect(page).toHaveURL(/.*scheme.html\?authority=LAD_Adur/);