sq: Derive autocrypt subcommand.

  - This is part of the effort of moving to clap3's derive API and
    profit from the added type safety.

2 files changed, 119 insertions, 91 deletions

diff --git a/sq/src/sq-usage.rs b/sq/src/sq-usage.rs
index e94be2ce..e80dcde5 100644
--- a/sq/src/sq-usage.rs
+++ b/sq/src/sq-usage.rs
@@ -1113,7 +1113,7 @@
 //!     -o, --output <FILE>
 //!             Writes to FILE or stdout if omitted
 //!
-//!         --prefer-encrypt <prefer-encrypt>
+//!         --prefer-encrypt <PREFER-ENCRYPT>
 //!             Sets the prefer-encrypt attribute
 //! 
 //!             [default: nopreference]
diff --git a/sq/src/sq_cli.rs b/sq/src/sq_cli.rs
index 1b328612..2caf4bec 100644
--- a/sq/src/sq_cli.rs
+++ b/sq/src/sq_cli.rs
@@ -1,5 +1,5 @@
 /// Command-line parser for sq.
-use clap::{Arg, ArgGroup, Command, ArgEnum, Args};
+use clap::{Arg, ArgGroup, Command, ArgEnum, Args, Subcommand};
 use clap::{CommandFactory, Parser};
 
 pub fn build() -> Command<'static> {
@@ -1618,95 +1618,7 @@ as being human readable."))
         app
     } else {
         // With Autocrypt support.
-        app.subcommand(
-            Command::new("autocrypt")
-                .display_order(400)
-                .about("Communicates certificates using Autocrypt")
-                .long_about(
-"Communicates certificates using Autocrypt
-
-Autocrypt is a standard for mail user agents to provide convenient
-end-to-end encryption of emails.  This subcommand provides a limited
-way to produce and consume headers that are used by Autocrypt to
-communicate certificates between clients.
-
-See https://autocrypt.org/
-")
-                .subcommand_required(true)
-                .arg_required_else_help(true)
-                .subcommand(
-                    Command::new("decode")
-                        .about("Reads Autocrypt-encoded certificates")
-                        .long_about(
-"Reads Autocrypt-encoded certificates
-
-Given an autocrypt header (or an key-gossip header), this command
-extracts the certificate encoded within it.
-
-The converse operation is \"sq autocrypt encode-sender\".
-")
-                        .after_help(
-"EXAMPLES:
-
-# Extract all certificates from a mail
-$ sq autocrypt decode autocrypt.eml
-")
-                        .arg(Arg::new("input")
-                             .value_name("FILE")
-                             .help("Reads from FILE or stdin if omitted"))
-                        .arg(Arg::new("output")
-                             .short('o').long("output").value_name("FILE")
-                             .help("Writes to FILE or stdout if omitted"))
-                        .arg(Arg::new("binary")
-                             .short('B').long("binary")
-                             .help("Emits binary data"))
-                )
-                .subcommand(
-                    Command::new("encode-sender")
-                        .about("Encodes a certificate into \
-                                an Autocrypt header")
-                        .long_about(
-"Encodes a certificate into an Autocrypt header
-
-A certificate can be encoded and included in a header of an email
-message.  This command encodes the certificate, adds the senders email
-address (which must match the one used in the \"From\" header), and the
-senders \"prefer-encrypt\" state (see the Autocrypt spec for more
-information).
-
-The converse operation is \"sq autocrypt decode\".
-")
-                        .after_help(
-"EXAMPLES:
-
-# Encodes a certificate
-$ sq autocrypt encode-sender juliet.pgp
-
-# Encodes a certificate with an explicit sender address
-$ sq autocrypt encode-sender --email juliet@example.org juliet.pgp
-
-# Encodes a certificate while indicating the willingness to encrypt
-$ sq autocrypt encode-sender --prefer-encrypt mutual juliet.pgp
-")
-                        .arg(Arg::new("input")
-                             .value_name("FILE")
-                             .help("Reads from FILE or stdin if omitted"))
-                        .arg(Arg::new("output")
-                             .short('o').long("output").value_name("FILE")
-                             .help("Writes to FILE or stdout if omitted"))
-                        .arg(Arg::new("address")
-                             .long("email").value_name("ADDRESS")
-                             .help("Sets the address \
-                                    [default: primary userid]"))
-                             .arg(Arg::new("prefer-encrypt")
-                                  .long("prefer-encrypt")
-                                  .possible_values(&["nopreference",
-                                                     "mutual"])
-                                  .default_value("nopreference")
-                                  .help("Sets the prefer-encrypt \
-                                         attribute"))
-                )
-        )
+        app.subcommand(AutocryptCommand::command())
     }
     .subcommand(ArmorCommand::command())
     .subcommand(DearmorCommand::command())
@@ -2023,3 +1935,119 @@ pub struct SignCommand {
     // TODO: Also, no need for the Option
     pub notation: Option<Vec<String>>,
 }
+
+#[derive(Parser, Debug)]
+#[clap(name = "autocrypt", display_order(400))]
+#[clap(
+    about = "Communicates certificates using Autocrypt",
+    long_about =
+"Communicates certificates using Autocrypt
+
+Autocrypt is a standard for mail user agents to provide convenient
+end-to-end encryption of emails.  This subcommand provides a limited
+way to produce and consume headers that are used by Autocrypt to
+communicate certificates between clients.
+
+See https://autocrypt.org/
+",
+    subcommand_required = true,
+    arg_required_else_help = true,
+)]
+pub struct AutocryptCommand {
+    #[clap(subcommand)]
+    subcommand: AutocryptSubCommands,
+}
+
+#[derive(Debug, Subcommand)]
+pub enum AutocryptSubCommands {
+    Decode(AutocyptDecodeCommand),
+
+    EncodeSender(AutocyptEncodeSenderCommand),
+}
+#[derive(Debug, Args)]
+#[clap(
+    about = "Reads Autocrypt-encoded certificates",
+    long_about =
+"Reads Autocrypt-encoded certificates
+
+Given an autocrypt header (or an key-gossip header), this command
+extracts the certificate encoded within it.
+
+The converse operation is \"sq autocrypt encode-sender\".
+",
+    after_help =
+"EXAMPLES:
+
+# Extract all certificates from a mail
+$ sq autocrypt decode autocrypt.eml
+",
+)]
+pub struct AutocyptDecodeCommand {
+    #[clap(flatten)]
+    pub io: IoArgs,
+    #[clap(
+        short = 'B',
+        long,
+        help = "Emits binary data",
+    )]
+    pub binary: bool,
+}
+
+//#[derive(Subcommand)]
+#[derive(Debug, Args)]
+#[clap(
+    name = "encode-sender",
+    about = "Encodes a certificate into an Autocrypt header",
+    long_about =
+"Encodes a certificate into an Autocrypt header
+
+A certificate can be encoded and included in a header of an email
+message.  This command encodes the certificate, adds the senders email
+address (which must match the one used in the \"From\" header), and the
+senders \"prefer-encrypt\" state (see the Autocrypt spec for more
+information).
+
+The converse operation is \"sq autocrypt decode\".
+",
+    after_help =
+"EXAMPLES:
+
+# Encodes a certificate
+$ sq autocrypt encode-sender juliet.pgp
+
+# Encodes a certificate with an explicit sender address
+$ sq autocrypt encode-sender --email juliet@example.org juliet.pgp
+
+# Encodes a certificate while indicating the willingness to encrypt
+$ sq autocrypt encode-sender --prefer-encrypt mutual juliet.pgp
+",
+)]
+pub struct AutocyptEncodeSenderCommand {
+    #[clap(flatten)]
+    pub io: IoArgs,
+    // TODO the help message looks like "primary userid" might be the default
+    // email. clarify
+    #[clap(
+        long = "email",
+        value_name = "ADDRESS",
+        help = "Sets the address [default: primary userid]",
+    )]
+    pub address: Option<String>,
+    #[clap(
+        long = "prefer-encrypt",
+        value_name = "PREFER-ENCRYPT",
+        default_value_t = PreferEncryptArgs::NoPreference,
+        help = "Sets the prefer-encrypt attribute",
+        arg_enum,
+    )]
+    pub prefer_encrypt: PreferEncryptArgs,
+
+}
+
+#[derive(ArgEnum)]
+#[derive(Debug, Clone)]
+pub enum PreferEncryptArgs {
+    #[clap(name = "nopreference")]
+    NoPreference,
+    Mutual
+}