Add JSON import and export

README.md

@@ -101,6 +101,17 @@ Features:
 - Delete a slot
 - Automatic draft saving for the current unsaved work
 
+## Import and export
+
+The current build can be backed up or shared as JSON:
+
+- Generate JSON in the text box and copy it.
+- Download the current build as a `.json` file.
+- Import by pasting JSON into the text box.
+- Import by uploading a `.json` file.
+
+Imports accept both the app's wrapped export format and the raw build object. Imported builds are normalized, rendered immediately, and autosaved as the current draft.
+
 ## Running locally
 
 Open `index.html` in a browser.

app.js

@@ -43,6 +43,7 @@ const PROFILES = {
 
 const STORAGE_KEY = "forgeMasterOptimizer.v1";
 const DRAFT_KEY = "forgeMasterOptimizer.draft.v1";
+const EXPORT_VERSION = 1;
 const slots = [
   ...Array.from({ length: 8 }, (_, i) => ({ type: "item", title: `Item ${i + 1}` })),
   { type: "mount", title: "Mount" },
@@ -358,6 +359,100 @@ function setStatus(message, danger = false) {
   node.style.color = danger ? "var(--danger)" : "var(--good)";
 }
 
+function setImportExportStatus(message, danger = false) {
+  const node = $("#importExportStatus");
+  node.textContent = message;
+  node.style.color = danger ? "var(--danger)" : "var(--good)";
+}
+
+function createExportPayload() {
+  return {
+    app: "forge-master-strategy-optimizer",
+    version: EXPORT_VERSION,
+    exportedAt: new Date().toISOString(),
+    build: normalizeState(state),
+  };
+}
+
+function createExportJson() {
+  return JSON.stringify(createExportPayload(), null, 2);
+}
+
+async function generateExportJson() {
+  const json = createExportJson();
+  const textarea = $("#jsonTransfer");
+  textarea.value = json;
+  textarea.focus();
+  textarea.select();
+  try {
+    await navigator.clipboard.writeText(json);
+    setImportExportStatus("Export JSON generated and copied to clipboard.");
+  } catch {
+    setImportExportStatus("Export JSON generated. Copy it from the text box or download it as a file.");
+  }
+}
+
+function downloadExportJson() {
+  const json = createExportJson();
+  $("#jsonTransfer").value = json;
+  const blob = new Blob([json], { type: "application/json" });
+  const url = URL.createObjectURL(blob);
+  const link = document.createElement("a");
+  link.href = url;
+  link.download = `forge-master-build-${new Date().toISOString().slice(0, 10)}.json`;
+  document.body.appendChild(link);
+  link.click();
+  link.remove();
+  URL.revokeObjectURL(url);
+  setImportExportStatus("Downloaded current build as JSON.");
+}
+
+function parseImportedState(jsonText) {
+  if (!jsonText.trim()) throw new Error("Paste JSON first or upload a JSON file.");
+  let parsed;
+  try {
+    parsed = JSON.parse(jsonText);
+  } catch {
+    throw new Error("Invalid JSON. Check that the full export was copied.");
+  }
+  const build = parsed?.build || parsed;
+  if (!build || typeof build !== "object" || !Array.isArray(build.pieces)) {
+    throw new Error("JSON does not look like a Forge Master build export.");
+  }
+  return normalizeState(build);
+}
+
+function importJsonText(jsonText, sourceLabel = "JSON") {
+  try {
+    state = parseImportedState(jsonText);
+    render();
+    setImportExportStatus(`Imported ${sourceLabel}. Draft autosaved.`);
+  } catch (error) {
+    setImportExportStatus(error.message, true);
+  }
+}
+
+function importPastedJson() {
+  importJsonText($("#jsonTransfer").value, "pasted JSON");
+}
+
+function importUploadedJson(event) {
+  const file = event.target.files?.[0];
+  if (!file) return;
+  const reader = new FileReader();
+  reader.addEventListener("load", () => {
+    const text = String(reader.result || "");
+    $("#jsonTransfer").value = text;
+    importJsonText(text, file.name);
+    event.target.value = "";
+  });
+  reader.addEventListener("error", () => {
+    setImportExportStatus("Could not read the selected file.", true);
+    event.target.value = "";
+  });
+  reader.readAsText(file);
+}
+
 function bindEvents() {
   $("#profileSelect").addEventListener("change", (event) => {
     state.profile = event.target.value;
@@ -381,6 +476,10 @@ function bindEvents() {
   $("#saveSlot").addEventListener("click", saveNamedSlot);
   $("#loadSlot").addEventListener("click", loadNamedSlot);
   $("#deleteSlot").addEventListener("click", deleteNamedSlot);
+  $("#copyExport").addEventListener("click", generateExportJson);
+  $("#downloadExport").addEventListener("click", downloadExportJson);
+  $("#importJson").addEventListener("click", importPastedJson);
+  $("#importFile").addEventListener("change", importUploadedJson);
 }
 
 function handleGearInput(event) {

index.html

@@ -47,6 +47,24 @@
         <button id="resetBuild" type="button" class="secondary">Reset current build</button>
       </section>
 
+      <section class="card import-export" aria-labelledby="import-export-heading">
+        <div>
+          <h2 id="import-export-heading">Import / Export</h2>
+          <p>Back up or share the current build as JSON. Paste JSON directly or upload a saved file to import.</p>
+        </div>
+        <div class="io-actions">
+          <button id="copyExport" type="button">Generate / Copy JSON</button>
+          <button id="downloadExport" type="button" class="secondary">Download JSON</button>
+          <label class="file-button secondary">
+            Upload JSON
+            <input id="importFile" type="file" accept="application/json,.json" />
+          </label>
+          <button id="importJson" type="button">Import pasted JSON</button>
+        </div>
+        <textarea id="jsonTransfer" rows="8" spellcheck="false" placeholder="Generated export JSON appears here. You can also paste JSON here and click Import pasted JSON."></textarea>
+        <p id="importExportStatus" class="status" role="status"></p>
+      </section>
+
       <section class="summary-grid" aria-label="Build summary">
         <article class="metric"><span>Total damage base</span><strong id="totalDamage">0</strong></article>
         <article class="metric"><span>Total health base</span><strong id="totalHealth">0</strong></article>

styles.css

@@ -26,11 +26,11 @@ body {
     var(--bg);
 }
 
-button, input, select {
+button, input, select, textarea {
   font: inherit;
 }
 
-button, input, select {
+button, input, select, textarea {
   border: 1px solid var(--border);
   border-radius: 0.75rem;
   color: var(--text);
@@ -48,6 +48,7 @@ button {
 button:hover { filter: brightness(1.1); }
 button.secondary { background: var(--panel-2); }
 button.danger { border-color: rgba(251, 113, 133, 0.5); background: rgba(251, 113, 133, 0.16); }
+textarea { width: 100%; min-height: 9rem; resize: vertical; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
 
 label {
   display: grid;
@@ -104,6 +105,31 @@ h3 { margin-bottom: 0; }
 }
 .controls label { min-width: 220px; }
 
+.import-export {
+  display: grid;
+  gap: 0.9rem;
+  margin-bottom: 1rem;
+}
+.import-export p { color: var(--muted); margin-bottom: 0; }
+.io-actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.75rem;
+}
+.file-button {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  cursor: pointer;
+  border: 1px solid var(--border);
+  border-radius: 0.75rem;
+  color: var(--text);
+  background: var(--panel-2);
+  padding: 0.7rem 0.85rem;
+  font-weight: 700;
+}
+.file-button input { display: none; }
+
 .summary-grid, .results, .gear-grid {
   display: grid;
   gap: 1rem;