feat: Add bulk position management and batch transaction building

frontend/index.html

@@ -865,6 +865,38 @@ <h3>Keyboard Shortcuts</h3>
         <!-- Toast stack -->
         <div id="toast-stack" class="toast-stack"></div>
 
+        <!-- Bulk actions menu bar -->
+        <div id="bulk-actions-bar" class="bulk-actions-bar hidden">
+          <div class="bulk-actions-info">
+            <span id="bulk-selected-count">0</span> positions selected
+          </div>
+          <div class="bulk-actions-buttons">
+            <button id="bulk-close-btn" class="btn btn-danger btn-sm">Close Selected</button>
+            <div class="bulk-adjust-group">
+              <span>Adjust Leverage by:</span>
+              <input type="number" id="bulk-adjust-input" class="input mono" placeholder="10" style="width: 70px; padding: 4px 8px; height: 28px; padding-right: 8px;" />
+              <span>%</span>
+              <button id="bulk-adjust-btn" class="btn btn-primary btn-sm">Adjust</button>
+            </div>
+          </div>
+        </div>
+
+        <!-- Bulk Action Confirmation Modal -->
+        <div id="bulk-confirm-overlay" class="alert-modal-overlay hidden" role="dialog" aria-modal="true">
+          <div class="alert-modal" style="max-width: 480px;">
+            <button id="bulk-confirm-close" class="alert-modal-close">&times;</button>
+            <h3 id="bulk-confirm-title">Confirm Bulk Action</h3>
+            <p class="alert-modal-desc">Review the positions affected by this action:</p>
+            <div id="bulk-confirm-list" class="bulk-confirm-list" style="max-height: 200px; overflow-y: auto; margin-bottom: 18px; border: 1px solid var(--border); border-radius: var(--r-xs); padding: 8px; background: var(--input-bg);">
+              <!-- List of positions with details will be injected here -->
+            </div>
+            <div style="display: flex; gap: 8px;">
+              <button id="bulk-confirm-submit" class="btn btn-primary" style="flex: 1;">Confirm &amp; Submit</button>
+              <button id="bulk-confirm-cancel" class="btn btn-secondary" style="flex: 1;">Cancel</button>
+            </div>
+          </div>
+        </div>
+
       </main>
     </div><!-- .main-wrap -->
   </div>

frontend/src/blend.ts

@@ -1378,6 +1378,104 @@ export async function submitClassicXdr(signedXdr: string): Promise<string> {
   return (result as any).hash;
 }
 
+export async function buildBulkCloseXdr(
+  poolPositions: { pool: PoolDef; positions: AssetPosition[] }[],
+  userAddress: string,
+): Promise<string> {
+  const MAX_AMOUNT = 9_223_372_036_854_775_807n; // i64::MAX
+  const acc = await server.getAccount(userAddress);
+  const txBuilder = new TransactionBuilder(acc, {
+    fee: (BigInt(BASE_FEE) * 10n).toString(),
+    networkPassphrase: _cfg.passphrase,
+  });
+
+  const addrScVal = new Address(userAddress).toScVal();
+
+  for (const { pool, positions } of poolPositions) {
+    const reqItems: xdr.ScVal[] = [];
+    for (const pos of positions) {
+      if (pos.dTokens > 0n) {
+        reqItems.push(buildRequest(pos.asset.id, MAX_AMOUNT, REPAY));
+      }
+      reqItems.push(buildRequest(pos.asset.id, MAX_AMOUNT, WITHDRAW_COLLATERAL));
+    }
+    const requests = buildRequestsVec(reqItems);
+    const poolContract = new Contract(pool.id);
+    txBuilder.addOperation(poolContract.call("submit_with_allowance", addrScVal, addrScVal, addrScVal, requests));
+  }
+
+  const tx = txBuilder.setTimeout(60).build();
+  const sim = await server.simulateTransaction(tx);
+  if (!SorobanRpc.Api.isSimulationSuccess(sim))
+    throw new Error(`Bulk close simulation failed: ${(sim as SorobanRpc.Api.SimulateTransactionErrorResponse).error}`);
+  return SorobanRpc.assembleTransaction(tx, sim).build().toXDR();
+}
+
+export async function buildBulkAdjustXdr(
+  poolAdjustments: { pool: PoolDef; adjustments: { asset: AssetInfo; pos: AssetPosition; targetLev: number }[] }[],
+  userAddress: string,
+): Promise<string> {
+  const acc = await server.getAccount(userAddress);
+  const txBuilder = new TransactionBuilder(acc, {
+    fee: (BigInt(BASE_FEE) * 10n).toString(),
+    networkPassphrase: _cfg.passphrase,
+  });
+
+  const addrScVal = new Address(userAddress).toScVal();
+
+  for (const { pool, adjustments } of poolAdjustments) {
+    const reqItems: xdr.ScVal[] = [];
+
+    for (const { asset, pos, targetLev } of adjustments) {
+      if (pos.equity <= 0) throw new Error(`No equity in ${asset.symbol} position`);
+
+      if (targetLev > pos.leverage) {
+        // Increase leverage
+        const targetCollateral = pos.equity * targetLev;
+        const additionalBorrow = targetCollateral - pos.collateral;
+        if (additionalBorrow <= 0) continue;
+
+        const additionalBorrowStroops = BigInt(Math.round(additionalBorrow * 1e7));
+        const cFactorBn = BigInt(Math.round(asset.cFactor * SCALAR_F));
+
+        let remaining = additionalBorrowStroops;
+        let balance = 0n;
+        while (remaining > 0n) {
+          const canBorrow = balance > 0n ? balance * cFactorBn / SCALAR : remaining;
+          const borrow = canBorrow < remaining ? canBorrow : remaining;
+          if (borrow <= 0n) break;
+          reqItems.push(buildRequest(asset.id, borrow, BORROW));
+          reqItems.push(buildRequest(asset.id, borrow, SUPPLY_COLLATERAL));
+          balance = borrow;
+          remaining -= borrow;
+        }
+      } else if (targetLev < pos.leverage) {
+        // Decrease leverage
+        const targetDebt = pos.equity * (targetLev - 1);
+        const debtReduction = pos.debt - targetDebt;
+        if (debtReduction <= 0) continue;
+
+        const debtReductionStroops = BigInt(Math.round(debtReduction * 1e7));
+        reqItems.push(buildRequest(asset.id, debtReductionStroops, WITHDRAW_COLLATERAL));
+        reqItems.push(buildRequest(asset.id, debtReductionStroops, REPAY));
+      }
+    }
+
+    if (reqItems.length === 0) continue;
+
+    const requests = buildRequestsVec(reqItems);
+    const poolContract = new Contract(pool.id);
+    txBuilder.addOperation(poolContract.call("submit_with_allowance", addrScVal, addrScVal, addrScVal, requests));
+  }
+
+  const tx = txBuilder.setTimeout(60).build();
+  const sim = await server.simulateTransaction(tx);
+  if (!SorobanRpc.Api.isSimulationSuccess(sim))
+    throw new Error(`Bulk adjust simulation failed: ${(sim as SorobanRpc.Api.SimulateTransactionErrorResponse).error}`);
+  return SorobanRpc.assembleTransaction(tx, sim).build().toXDR();
+}
+
+
 // ── Position event timeline (A25) ─────────────────────────────────────────────
 
 export type PositionEventKind = "open" | "rebalance" | "harvest" | "close";