add encode command with support for all the nip19 things.

encode.go

@@ -0,0 +1,212 @@
+package main
+
+import (
+	"encoding/hex"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"github.com/nbd-wtf/go-nostr/nip19"
+	"github.com/urfave/cli/v2"
+)
+
+var encode = &cli.Command{
+	Name:  "encode",
+	Usage: "encodes notes and other stuff to nip19 entities",
+	Description: `example usage:
+		nak encode npub <pubkey-hex>
+		nak encode nprofile <pubkey-hex>
+		nak encode nprofile --relay <relay-url> <pubkey-hex>
+		nak encode nevent <event-id>
+		nak encode nevent --author <pubkey-hex> --relay <relay-url> --relay <other-relay> <event-id>
+		nak encode nsec <privkey-hex>`,
+	Before: func(c *cli.Context) error {
+		if c.Args().First() == "naddr" {
+			// validation will be done on the specific handler
+			return nil
+		}
+
+		if c.Args().Len() < 2 {
+			return fmt.Errorf("expected more than 2 arguments.")
+		}
+		target := c.Args().Get(c.Args().Len() - 1)
+		if target == "--help" {
+			return nil
+		}
+
+		return validate32BytesHex(target)
+	},
+	Subcommands: []*cli.Command{
+		{
+			Name:  "npub",
+			Usage: "encode a hex private key into bech32 'npub' format",
+			Action: func(c *cli.Context) error {
+				if npub, err := nip19.EncodePublicKey(c.Args().First()); err == nil {
+					fmt.Println(npub)
+					return nil
+				} else {
+					return err
+				}
+			},
+		},
+		{
+			Name:  "nsec",
+			Usage: "encode a hex private key into bech32 'nsec' format",
+			Action: func(c *cli.Context) error {
+				if npub, err := nip19.EncodePrivateKey(c.Args().First()); err == nil {
+					fmt.Println(npub)
+					return nil
+				} else {
+					return err
+				}
+			},
+		},
+		{
+			Name:  "nprofile",
+			Usage: "generate profile codes with attached relay information",
+			Flags: []cli.Flag{
+				&cli.StringSliceFlag{
+					Name:    "relay",
+					Aliases: []string{"r"},
+					Usage:   "attach relay hints to nprofile code",
+				},
+			},
+			Action: func(c *cli.Context) error {
+				relays := c.StringSlice("relay")
+				if err := validateRelayURLs(relays); err != nil {
+					return err
+				}
+
+				if npub, err := nip19.EncodeProfile(c.Args().First(), relays); err == nil {
+					fmt.Println(npub)
+					return nil
+				} else {
+					return err
+				}
+			},
+		},
+		{
+			Name:  "nevent",
+			Usage: "generate event codes with optionally attached relay information",
+			Flags: []cli.Flag{
+				&cli.StringSliceFlag{
+					Name:    "relay",
+					Aliases: []string{"r"},
+					Usage:   "attach relay hints to nevent code",
+				},
+				&cli.StringFlag{
+					Name:  "author",
+					Usage: "attach an author pubkey as a hint to the nevent code",
+				},
+			},
+			Action: func(c *cli.Context) error {
+				author := c.String("author")
+				if err := validate32BytesHex(author); err != nil {
+					return err
+				}
+
+				relays := c.StringSlice("relay")
+				if err := validateRelayURLs(relays); err != nil {
+					return err
+				}
+
+				if npub, err := nip19.EncodeEvent(c.Args().First(), relays, author); err == nil {
+					fmt.Println(npub)
+					return nil
+				} else {
+					return err
+				}
+			},
+		},
+		{
+			Name:  "naddr",
+			Usage: "generate codes for NIP-33 parameterized replaceable events",
+			Flags: []cli.Flag{
+				&cli.StringFlag{
+					Name:     "identifier",
+					Aliases:  []string{"d"},
+					Usage:    "the \"d\" tag identifier of this replaceable event",
+					Required: true,
+				},
+				&cli.StringFlag{
+					Name:     "pubkey",
+					Usage:    "pubkey of the naddr author",
+					Aliases:  []string{"p"},
+					Required: true,
+				},
+				&cli.Int64Flag{
+					Name:     "kind",
+					Aliases:  []string{"k"},
+					Usage:    "kind of referred replaceable event",
+					Required: true,
+				},
+				&cli.StringSliceFlag{
+					Name:    "relay",
+					Aliases: []string{"r"},
+					Usage:   "attach relay hints to naddr code",
+				},
+			},
+			Action: func(c *cli.Context) error {
+				pubkey := c.String("pubkey")
+				if err := validate32BytesHex(pubkey); err != nil {
+					return err
+				}
+
+				kind := c.Int("kind")
+				if kind < 30000 || kind >= 40000 {
+					return fmt.Errorf("kind must be between 30000 and 39999, as per NIP-16, got %d", kind)
+				}
+
+				d := c.String("identifier")
+				if d == "" {
+					return fmt.Errorf("\"d\" tag identifier can't be empty")
+				}
+
+				relays := c.StringSlice("relay")
+				if err := validateRelayURLs(relays); err != nil {
+					return err
+				}
+
+				if npub, err := nip19.EncodeEntity(pubkey, kind, d, relays); err == nil {
+					fmt.Println(npub)
+					return nil
+				} else {
+					return err
+				}
+			},
+		},
+	},
+}
+
+func validate32BytesHex(target string) error {
+	if _, err := hex.DecodeString(target); err != nil {
+		return fmt.Errorf("target '%s' is not valid hex: %s", target, err)
+	}
+	if len(target) != 64 {
+		return fmt.Errorf("expected '%s' to be 64 characters (32 bytes), got %d", target, len(target))
+	}
+	if strings.ToLower(target) != target {
+		return fmt.Errorf("expected target to be all lowercase hex. try again with '%s'", strings.ToLower(target))
+	}
+
+	return nil
+}
+
+func validateRelayURLs(wsurls []string) error {
+	for _, wsurl := range wsurls {
+		u, err := url.Parse(wsurl)
+		if err != nil {
+			return fmt.Errorf("invalid relay url '%s': %s", wsurl, err)
+		}
+
+		if u.Scheme != "ws" && u.Scheme != "wss" {
+			return fmt.Errorf("relay url must use wss:// or ws:// schemes, got '%s'", wsurl)
+		}
+
+		if u.Host == "" {
+			return fmt.Errorf("relay url '%s' is missing the hostname", wsurl)
+		}
+	}
+
+	return nil
+}

main.go

@@ -15,6 +15,7 @@ func main() {
 			req,
 			event,
 			decode,
+			encode,
 		},
 	}