more stuff and some polish on EventSigning.

handlers/EventSigning.jsx

@@ -1,17 +1,71 @@
-import React from 'react'
-import {getEventHash, serializeEvent} from 'nostr-tools'
+import React, {useState, useEffect} from 'react'
+import useBooleanState from 'use-boolean-state'
+import useComputedState from 'use-computed-state'
+import {
+  getPublicKey,
+  getEventHash,
+  serializeEvent,
+  verifySignature,
+  signEvent
+} from 'nostr-tools'
 
 import Item from '../components/item'
 
 export default function EventSigning({value}) {
+  let [privateKey, setPrivateKey] = useState(
+    'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
+  )
+  let [isValidSignature, signatureGood, signatureBad] = useBooleanState(false)
+  let privateKeyIsValid = useComputedState(
+    () => privateKey.match(/[a-f0-9]{64}/),
+    [privateKey]
+  )
+  let publicKey = useComputedState(
+    () => (privateKeyIsValid ? getPublicKey(privateKey) : null),
+    [privateKeyIsValid]
+  )
+  let signature = useComputedState(async () => {
+    evt.pubkey = publicKey
+    return await signEvent(evt, privateKey)
+  }, [value, privateKey])
+
   let evt = JSON.parse(value)
 
+  useEffect(() => {
+    verifySignature(evt)
+      .then(ok => (ok ? signatureGood() : signatureBad()))
+      .catch(signatureBad)
+  }, [value])
+
   return (
     <>
-      <Item label="serialized event">{serializeEvent(evt)}</Item>
-      <Item label="event id" hint="sha256 hash of serialized">
+      <Item
+        label="serialized event"
+        hint="according to nip-01 signature algorithm"
+      >
+        {serializeEvent(evt)}
+      </Item>
+      <Item label="event id" hint="sha256 hash of serialized event">
         {getEventHash(evt)}
       </Item>
+      {evt.sig ? (
+        <Item label="signature valid">{isValidSignature.toString()}</Item>
+      ) : (
+        <>
+          <Item
+            label="private key"
+            hint="paste any private key here (32 bytes hex-encoded)"
+          >
+            <input
+              value={privateKey}
+              onChange={e => setPrivateKey(e.target.value.toLowerCase())}
+            />{' '}
+            {privateKeyIsValid ? 'valid' : 'invalid'}
+          </Item>
+          <Item label="public key">{publicKey}</Item>
+          <Item label="signature">{privateKeyIsValid ? signature : ''}</Item>
+        </>
+      )}
     </>
   )
 }