import { AddressPointer, BECH32_REGEX, decode, EventPointer, ProfilePointer } from './nip19.ts'

/** Nostr URI regex, eg `nostr:npub1...` */
export const NOSTR_URI_REGEX: RegExp = new RegExp(`nostr:(${BECH32_REGEX.source})`)

/** Test whether the value is a Nostr URI. */
export function test(value: unknown): value is `nostr:${string}` {
  return typeof value === 'string' && new RegExp(`^${NOSTR_URI_REGEX.source}$`).test(value)
}

/** Parsed Nostr URI data. */
export interface NostrURI {
  /** Full URI including the `nostr:` protocol. */
  uri: `nostr:${string}`
  /** The bech32-encoded data (eg `npub1...`). */
  value: string
  /** Decoded bech32 string, according to NIP-19. */
  decoded:
    | {
        type: 'nevent'
        data: EventPointer
      }
    | {
        type: 'nprofile'
        data: ProfilePointer
      }
    | {
        type: 'naddr'
        data: AddressPointer
      }
    | {
        type: 'npub'
        data: string
      }
    | {
        type: 'nsec'
        data: Uint8Array
      }
    | {
        type: 'note'
        data: string
      }
}

/** Parse and decode a Nostr URI. */
export function parse(uri: string): NostrURI {
  const match = uri.match(new RegExp(`^${NOSTR_URI_REGEX.source}$`))
  if (!match) throw new Error(`Invalid Nostr URI: ${uri}`)
  return {
    uri: match[0] as `nostr:${string}`,
    value: match[1],
    decoded: decode(match[1]),
  }
}