App: show lightning address

Some formatting fixes also sneaked in.

src/App.svelte

@@ -55,6 +55,9 @@
   $: autoMemo = genAutoMemo(payway,
 			    accountComplete && accounts[inputId],
 			    realAmount)
+  let lightningAddress;
+  $: lightningAddress = accountComplete ?
+  genAddress(payway, accounts[inputId], realAmount):""
 
   function lnurlEncode(url) {
     return bech32.encode("LNURL",
@@ -66,6 +69,16 @@
       return ('0' + (byte & 0xFF).toString(16)).slice(-2);
     }).join('')
   }
+  function genAddress(payway,account,amount) {
+    if (!account || !payway)
+      return ""
+    const prefix = amount?
+	  ((amount == Math.floor(amount)? ""+amount:
+	    amount.toFixed(2))+payway.currency.toLowerCase()+"-"):""
+    if (account[0]=='+')
+      account=account.slice(1)
+    return prefix + account + "@" + payway.id + ".lnurl-pay.me"
+  }
 
   function genLNURL(payway,account,amount,memo) {
     let params = new URLSearchParams();
@@ -163,7 +176,6 @@
       <input bind:value={memo} placeholder="{autoMemo}"
 	     class="form-control"/>
     </label>
-
   </SiteCard>
   <SiteCard>
     {#if lnurl}
@@ -184,13 +196,6 @@
       </a>
       <!-- {/key} -->
     </div>
-      
-      <div class="d-flex justify-content-center align-items-stretch"
-	   class:invisible={!lnurl}>
-	<p class="form-text">You might want to save image and share it
-	as you like. All form data are present in lnurl: don't share what you wanted to hide.</p>
-      </div>
-      
     <div class="btn-group flex-wrap mt-auto mb-2"
 	 role="group" class:invisible={!lnurl}>
       <CTC let:id let:action text={lnurl}>
@@ -216,6 +221,24 @@
 	<div slot="tip">get an invoice for wallets with no lnurl-pay</div>
       </Tipped>
     </div>
+
+    {#if lightningAddress}
+      <CTC let:id let:action force text={lightningAddress}}>
+	<div class="input-group mt-3">
+	  <div class="input-group-prepend">
+	    <span class="input-group-text">
+	      <a href="https://lightningaddress.com/">Lightning address:</a>
+	    </span>
+	  </div>
+	  <div class="user-select-all form-control"
+	       style="white-space: nowrap; overflow: hidden; text-overflow: ellipsis"
+	       on:click={action} id={id}>{lightningAddress}
+	  </div>
+	</div>
+      </CTC>
+    {/if}
+
+
   </SiteCard>
 </SiteDeck>