config_spec: various improvements

- more color, using colored
- better wording of options
- highlight default choices
- various other small fixes

src/config_spec.rs

@@ -37,9 +37,10 @@
 //! };
 //! // open a config file somewhere (we use a dummy to not cause side-effects)
 //! let config = KeyValueStore::new_dummy()?;
-//! assert_eq!( config.get("modname-user").unwrap(), "xyzzy" );
 //! // always:
 //! CONFIG_SPEC.populate_defaults(&config);
+//! // (and then defaults will be set:)
+//! assert_eq!( config.get("modname-user").unwrap(), "xyzzy" );
 //! ```
 //!
 //! ```ignore
@@ -57,11 +58,27 @@ const EMPTY_VALUE: &str = "(empty)";
 /// Text shown in place of a password.
 const HIDDEN_PASSWORD: &str = "*****";
 
-// highlight some of the info
+/// semantic highlighting (in contrast to the pure formatting-based stuff you get from colored)
-const ANSI_GROUP: &str = "\x1b[1;31m";
+#[rustfmt::skip]
-const ANSI_FIELD: &str = "\x1b[1;33m";
+mod style {
-const ANSI_NOTICE: &str = "\x1b[33m";
+    use colored::{ColoredString, Colorize};
-const ANSI_RESET: &str = "\x1b[0m";
+    /// general emphasis
+    pub fn emph      (text: &str) -> ColoredString { text.underline()                 }
+    /// group header
+    pub fn group     (text: &str) -> ColoredString { text.bold()     .cyan()          }
+    /// field name or group-level fields
+    pub fn field     (text: &str) -> ColoredString { text.bold()     .blue()          }
+    /// low priority (generally field-level extra info)
+    pub fn info      (text: &str) -> ColoredString { text            .blue()          }
+    /// default value, or unchanged value
+    pub fn default   (text: &str) -> ColoredString { text            .green()         }
+    /// generator (or description thereof)
+    pub fn generator (text: &str) -> ColoredString { text.bold()     .yellow()        }
+    /// changed value
+    pub fn changed   (text: &str) -> ColoredString { text            .magenta()       }
+    /// informative messages
+    pub fn notice    (text: &str) -> ColoredString { text            .bright_yellow() }
+}
 
 /* ***** config structure definition ***** */
 
@@ -69,7 +86,7 @@ const ANSI_RESET: &str = "\x1b[0m";
 pub enum CfgField<'a> {
     /// Silently writes a default to the DB if absent, never prompts for changes.
     Silent { key: &'a str, default: &'a str },
-    /// Writes a default, asks for changes.
+    /// Writes a default, asks for / allows changes.
     Default { key: &'a str, default: &'a str, description: &'a str },
     /// No default, asks for value, but can stay empty.
     Optional { key: &'a str, description: &'a str },
@@ -110,6 +127,10 @@ impl<'a> CfgField<'a> {
         matches!(self, CfgField::Password { .. })
     }
 
+    fn is_generator(&self) -> bool {
+        matches!(self, CfgField::Generated { .. })
+    }
+
     /// Optional fields are allowed to be (and stay) empty.
     fn is_optional(&self) -> bool {
         matches!(self, CfgField::Optional { .. })
@@ -212,18 +233,21 @@ pub fn interactive_check(spec: &CfgSpec, config: KV) -> Result<(), Box<dyn Error
         // TODO: add distinction between edit all / edit necessary only
         let choices = if !todo.is_empty() {
             println!(
-                "{}The following fields need adjustment: {}{}",
+                "{}",
-                ANSI_NOTICE,
+                style::notice(&format!(
-                todo.join(", "),
+                    "The following fields need adjustment: {}",
-                ANSI_RESET
+                    todo.join(", ")
+                ))
             );
-            &["[E]dit (default)", "[L]ist all", "[S]kip group"]
+            &["[F]ixes only", "[E]dit all", "[L]ist all", "[S]kip group"][..]
         } else {
             println!(
-                "{}This group looks fine. OK to [S]kip, unless you want to adjust values here.{}",
+                "{}",
-                ANSI_NOTICE, ANSI_RESET
+                style::notice(
+                    "This group looks fine. OK to [S]kip, unless you want to adjust values here."
+                )
             );
-            &["[S]kip group (default)", "[E]dit", "[L]ist all"]
+            &["[S]kip group", "[E]dit all", "[L]ist all"][..]
         };
         loop {
             let choice = prompt_action(choices);
@@ -237,6 +261,13 @@ pub fn interactive_check(spec: &CfgSpec, config: KV) -> Result<(), Box<dyn Error
                     }
                     break;
                 },
+                'F' => {
+                    for field in group.fields {
+                        if field.is_action_required(&config, group.name) {
+                            check_field(&config, group.name, field, &mut all_valid)?;
+                        }
+                    }
+                },
                 'S' => {
                     if !todo.is_empty() {
                         all_valid = false;
@@ -244,8 +275,8 @@ pub fn interactive_check(spec: &CfgSpec, config: KV) -> Result<(), Box<dyn Error
                     break;
                 },
                 _ => {
-                    unreachable!();
+                    unreachable!(); // (prompt already checks)
-                }, // (prompt already checks)
+                },
             }
         }
     }
@@ -256,6 +287,7 @@ pub fn interactive_check(spec: &CfgSpec, config: KV) -> Result<(), Box<dyn Error
     }
 }
 
+/// Checks a single field and asks what to do with it.
 fn check_field(
     config: &KV, grpname: &str, field: &CfgField, ok: &mut bool,
 ) -> Result<(), Box<dyn Error>> {
@@ -267,20 +299,23 @@ fn check_field(
     let value = config.get(&key).ok();
     let mut actions: Vec<&'static str> = Vec::new();
     // TODO: adjust order: empty password should offer input first
-    // TODO: RandomId should offer generating as [R]egenerate
     if value.is_some() | field.is_password() | field.is_optional() {
         actions.push("[K]eep as-is");
     }
     if field.default_description().is_some() {
-        actions.push("[R]eset to default");
+        if field.is_generator() {
+            actions.push("[R]e-generate value");
+        } else {
+            actions.push("[R]eset to default");
+        }
     }
     if field.is_password() {
         actions.push("[R]emove");
     }
     actions.push("[I]nput new value");
     if !field.is_password() {
-        actions.push("[L]ong (multiline) input")
+        actions.push("[L]ong (multiline) input");
-    };
+    }
 
     match prompt_action(&actions) {
         'K' => {
@@ -310,7 +345,7 @@ fn check_field(
             config.set(&key, &value)?;
         },
         _ => {
-            return Err("Wat.".into());
+            unreachable!(); // (prompt already checks)
         },
     }
     Ok(())
@@ -319,8 +354,9 @@ fn check_field(
 /* ***** displaying various kinds of info ***** */
 
 fn group_header(name: &str, description: &str) {
-    println!("==============================");
+    println!("{}", style::group(&("=".repeat(name.len() + description.len() + 3))));
-    println!("{}{}{} - {}", ANSI_GROUP, name, ANSI_RESET, description);
+    println!("{} - {}", style::group(name), style::field(description));
+    println!("{}", style::group(&("=".repeat(name.len() + description.len() + 3))));
     println!("");
 }
 
@@ -335,14 +371,20 @@ fn show_field(config: &KV, grpname: &str, field: &CfgField) {
         return;
     }
     let key = field.full_key(grpname);
-    println!("{}{}{} - {}", ANSI_FIELD, &key, ANSI_RESET, field.description());
+    println!("{} - {}", style::field(&key), style::info(&field.description()));
-    println!("  default: {}", field.default_description().unwrap_or(EMPTY_VALUE.to_string()));
+    let default_desc = field.default_description().unwrap_or(EMPTY_VALUE.to_string());
+    println!(
+        "  {} {}",
+        style::info("default:"),
+        (if field.is_generator() { style::generator } else { style::default })(&default_desc)
+    );
     let value = config
         .get(&key)
         .ok()
         .map(|s| if field.is_password() { HIDDEN_PASSWORD.to_string() } else { s })
         .unwrap_or(EMPTY_VALUE.to_string());
-    println!("  current: {}", value);
+    let fmt = if value == default_desc { style::default } else { style::changed };
+    println!("  {} {}", style::info("current:"), fmt(&value));
 }
 
 /* ***** basic validation ***** */
@@ -362,7 +404,16 @@ fn needs_info(config: &KV, group: &CfgGroup) -> Vec<String> {
 /// Ask for a choice between several options.  First option is the default,
 /// format options with the first character in brackets like so: `"[E]xample"`.
 fn prompt_action(choices: &[&str]) -> char {
-    let prompt_message = choices.join(", ");
+    let prompt_message = {
+        let mut formatted_choices = Vec::new();
+        if let Some((first, rest)) = choices.split_first() {
+            formatted_choices.push(format!("{} (default)", style::emph(first)));
+            formatted_choices.extend(rest.iter().map(|&choice| choice.to_string()));
+        } else {
+            panic!("Empty list of choices.");
+        }
+        formatted_choices.join(", ")
+    };
     let default_choice = choices[0].to_uppercase().chars().nth(1).unwrap_or_default();
     loop {
         println!("{}", prompt_message);