bpaf improvements

* use latest published crate. This is a build fix: it was broken
  when the `exit_code` branch was deleted from the `bpaf` repo, even
  though the commit still exists!
  https://github.com/scottlamb/moonfire-nvr/pull/259

* clean up `db-dir` parsing redundancy, as suggested here:
  https://github.com/pacak/bpaf/discussions/165#discussioncomment-4983158

server/Cargo.lock

@@ -147,7 +147,8 @@ dependencies = [
 [[package]]
 name = "bpaf"
 version = "0.7.9"
-source = "git+https://github.com/pacak/bpaf.git?branch=exit_code#5238a6069abca0d61cf1c000e56bbac946e7ee18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "31f4c9de9c67618395106c81fb9461290a8910af29aa0188daec29001a1181ae"
 dependencies = [
  "bpaf_derive",
  "owo-colors",
@@ -156,7 +157,8 @@ dependencies = [
 [[package]]
 name = "bpaf_derive"
 version = "0.3.4"
-source = "git+https://github.com/pacak/bpaf.git?branch=exit_code#5238a6069abca0d61cf1c000e56bbac946e7ee18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "223f3c9e7034f98c9f315d9945fcc22831b3f03d9f4c42c96a7ab6abd209a195"
 dependencies = [
  "proc-macro2",
  "quote",

server/Cargo.toml

@@ -24,7 +24,7 @@ members = ["base", "db"]
 base = { package = "moonfire-base", path = "base" }
 base64 = "0.13.0"
 blake3 = "1.0.0"
-bpaf = { git = "https://github.com/pacak/bpaf.git", branch = "exit_code", features = ["autocomplete", "bright-color", "derive"]}
+bpaf = { version = "0.7.9", features = ["autocomplete", "bright-color", "derive"]}
 bytes = "1"
 byteorder = "1.0"
 cursive = "0.20.0"

server/src/cmds/check.rs

@@ -13,10 +13,7 @@ use std::path::PathBuf;
 #[derive(Bpaf, Debug)]
 #[bpaf(options)]
 pub struct Args {
-    /// Directory holding the SQLite3 index database.
-    ///
-    /// default: `/var/lib/moonfire-nvr/db`.
-    #[bpaf(argument("PATH"), fallback_with(crate::default_db_dir))]
+    #[bpaf(external(crate::parse_db_dir))]
     db_dir: PathBuf,
 
     /// Compares sample file lengths on disk to the database.

server/src/cmds/config/mod.rs

@@ -23,10 +23,7 @@ mod users;
 #[derive(Bpaf, Debug)]
 #[bpaf(options)]
 pub struct Args {
-    /// Directory holding the SQLite3 index database.
-    ///
-    /// default: `/var/lib/moonfire-nvr/db`.
-    #[bpaf(argument("PATH"), fallback_with(crate::default_db_dir))]
+    #[bpaf(external(crate::parse_db_dir))]
     db_dir: PathBuf,
 }
 

server/src/cmds/init.rs

@@ -11,10 +11,7 @@ use std::path::PathBuf;
 #[derive(Bpaf, Debug)]
 #[bpaf(options)]
 pub struct Args {
-    /// Directory holding the SQLite3 index database.
-    ///
-    /// default: `/var/lib/moonfire-nvr/db`.
-    #[bpaf(argument("PATH"), fallback_with(crate::default_db_dir))]
+    #[bpaf(external(crate::parse_db_dir))]
     db_dir: PathBuf,
 }
 

server/src/cmds/login.rs

@@ -33,10 +33,7 @@ fn parse_flags(flags: String) -> Result<Vec<SessionFlag>, Error> {
 #[derive(Bpaf, Debug, PartialEq, Eq)]
 #[bpaf(options)]
 pub struct Args {
-    /// Directory holding the SQLite3 index database.
-    ///
-    /// default: `/var/lib/moonfire-nvr/db`.
-    #[bpaf(argument("PATH"), fallback_with(crate::default_db_dir))]
+    #[bpaf(external(crate::parse_db_dir))]
     db_dir: PathBuf,
 
     /// Creates a session with the given permissions, as a JSON object.
@@ -173,7 +170,7 @@ mod tests {
         assert_eq!(
             args,
             Args {
-                db_dir: crate::default_db_dir().unwrap(),
+                db_dir: crate::DEFAULT_DB_DIR.into(),
                 domain: None,
                 curl_cookie_jar: None,
                 permissions: Some(crate::json::Permissions {

server/src/cmds/run/config.rs

@@ -12,7 +12,7 @@ use serde::Deserialize;
 use crate::json::Permissions;
 
 fn default_db_dir() -> PathBuf {
-    "/var/lib/moonfire-nvr/db".into()
+    crate::DEFAULT_DB_DIR.into()
 }
 
 fn default_ui_dir() -> PathBuf {

server/src/cmds/sql.rs

@@ -20,10 +20,7 @@ use std::process::Command;
 #[derive(Bpaf, Debug, PartialEq, Eq)]
 #[bpaf(options)]
 pub struct Args {
-    /// Directory holding the SQLite3 index database.
-    ///
-    /// default: `/var/lib/moonfire-nvr/db`.
-    #[bpaf(fallback_with(crate::default_db_dir))]
+    #[bpaf(external(crate::parse_db_dir))]
     db_dir: PathBuf,
 
     /// Opens the database in read-only mode and locks it only for shared access.

server/src/cmds/upgrade/mod.rs

@@ -12,11 +12,7 @@ use failure::Error;
 #[derive(Bpaf, Debug)]
 #[bpaf(options)]
 pub struct Args {
-    /// Directory holding the SQLite3 index database.
-    ///
-    ///
-    /// default: `/var/lib/moonfire-nvr/db`.
-    #[bpaf(argument("PATH"), fallback_with(crate::default_db_dir))]
+    #[bpaf(external(crate::parse_db_dir))]
     db_dir: std::path::PathBuf,
 
     /// When upgrading from schema version 1 to 2, the sample file directory.

server/src/main.rs

@@ -4,7 +4,7 @@
 
 #![cfg_attr(all(feature = "nightly", test), feature(test))]
 
-use bpaf::Bpaf;
+use bpaf::{Bpaf, Parser};
 use log::{debug, error};
 use std::fmt::Write;
 use std::str::FromStr;
@@ -43,6 +43,8 @@ fn subcommand<T: 'static>(
     parser.usage(Box::leak(usage.into_boxed_str())).command(cmd)
 }
 
+const DEFAULT_DB_DIR: &str = "/var/lib/moonfire-nvr/db";
+
 /// Moonfire NVR: security camera network video recorder.
 #[derive(Bpaf, Debug)]
 #[bpaf(options, version)]
@@ -73,9 +75,14 @@ impl Args {
     }
 }
 
-/// Returns the default database dir, for use in argument parsing with `bpaf(fallback_with(...))`.
-fn default_db_dir() -> Result<std::path::PathBuf, std::convert::Infallible> {
-    Ok("/var/lib/moonfire-nvr/db".into())
+fn parse_db_dir() -> impl Parser<std::path::PathBuf> {
+    bpaf::long("db-dir")
+        .help(format!(
+            "Directory holding the SQLite3 index database.\nDefault: `{}`",
+            DEFAULT_DB_DIR
+        ))
+        .argument::<std::path::PathBuf>("PATH")
+        .fallback_with(|| Ok::<_, std::convert::Infallible>(DEFAULT_DB_DIR.into()))
 }
 
 /// Custom panic hook that logs instead of directly writing to stderr.