revamp core api + option to use nostr-wasm instead of noble-curves.

core.ts

@@ -0,0 +1,50 @@
+export interface Nostr {
+  generateSecretKey(): Uint8Array
+  getPublicKey(secretKey: Uint8Array): string
+  finalizeEvent(event: EventTemplate, secretKey: Uint8Array): VerifiedEvent
+  verifyEvent(event: Event): event is VerifiedEvent
+}
+
+/** Designates a verified event signature. */
+export const verifiedSymbol = Symbol('verified')
+
+export interface Event {
+  kind: number
+  tags: string[][]
+  content: string
+  created_at: number
+  pubkey: string
+  id: string
+  sig: string
+  [verifiedSymbol]?: boolean
+}
+
+export type EventTemplate = Pick<Event, 'kind' | 'tags' | 'content' | 'created_at'>
+export type UnsignedEvent = Pick<Event, 'kind' | 'tags' | 'content' | 'created_at' | 'pubkey'>
+
+/** An event whose signature has been verified. */
+export interface VerifiedEvent extends Event {
+  [verifiedSymbol]: true
+}
+
+const isRecord = (obj: unknown): obj is Record<string, unknown> => obj instanceof Object
+
+export function validateEvent<T>(event: T): event is T & UnsignedEvent {
+  if (!isRecord(event)) return false
+  if (typeof event.kind !== 'number') return false
+  if (typeof event.content !== 'string') return false
+  if (typeof event.created_at !== 'number') return false
+  if (typeof event.pubkey !== 'string') return false
+  if (!event.pubkey.match(/^[a-f0-9]{64}$/)) return false
+
+  if (!Array.isArray(event.tags)) return false
+  for (let i = 0; i < event.tags.length; i++) {
+    let tag = event.tags[i]
+    if (!Array.isArray(tag)) return false
+    for (let j = 0; j < tag.length; j++) {
+      if (typeof tag[j] === 'object') return false
+    }
+  }
+
+  return true
+}