Want a Matrix client that uses Vim keybindings (#1)

src/config.rs

@@ -0,0 +1,203 @@
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::BufReader;
+use std::path::{Path, PathBuf};
+use std::process;
+
+use clap::Parser;
+use matrix_sdk::ruma::OwnedUserId;
+use serde::Deserialize;
+use url::Url;
+
+macro_rules! usage {
+    ( $($args: tt)* ) => {
+        println!($($args)*);
+        process::exit(2);
+    }
+}
+
+fn is_profile_char(c: char) -> bool {
+    c.is_ascii_alphanumeric() || c == '.' || c == '-'
+}
+
+fn validate_profile_name(name: &str) -> bool {
+    if name.is_empty() {
+        return false;
+    }
+
+    let mut chars = name.chars();
+
+    if !chars.next().map_or(false, |c| c.is_ascii_alphanumeric()) {
+        return false;
+    }
+
+    name.chars().all(is_profile_char)
+}
+
+fn validate_profile_names(names: &HashMap<String, ProfileConfig>) {
+    for name in names.keys() {
+        if validate_profile_name(name.as_str()) {
+            continue;
+        }
+
+        usage!(
+            "{:?} is not a valid profile name.\n\n\
+            Profile names can only contain the characters \
+            a-z, A-Z, and 0-9. Period (.) and hyphen (-) are allowed after the first character.",
+            name
+        );
+    }
+}
+
+#[derive(Parser)]
+#[clap(version, about, long_about = None)]
+#[clap(propagate_version = true)]
+pub struct Iamb {
+    #[clap(short = 'P', long, value_parser)]
+    pub profile: Option<String>,
+
+    #[clap(short = 'C', long, value_parser)]
+    pub config_directory: Option<PathBuf>,
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum ConfigError {
+    #[error("Error reading configuration file: {0}")]
+    IO(#[from] std::io::Error),
+
+    #[error("Error loading configuration file: {0}")]
+    Invalid(#[from] serde_json::Error),
+}
+
+#[derive(Clone, Deserialize)]
+pub struct ProfileConfig {
+    pub user_id: OwnedUserId,
+    pub url: Url,
+}
+
+#[derive(Clone, Deserialize)]
+pub struct IambConfig {
+    pub profiles: HashMap<String, ProfileConfig>,
+    pub default_profile: Option<String>,
+    pub cache: Option<PathBuf>,
+}
+
+impl IambConfig {
+    pub fn load(config_json: &Path) -> Result<Self, ConfigError> {
+        if !config_json.is_file() {
+            usage!(
+                "Please create a configuration file at {}\n\n\
+                For more information try '--help'",
+                config_json.display(),
+            );
+        }
+
+        let file = File::open(config_json)?;
+        let reader = BufReader::new(file);
+        let config = serde_json::from_reader(reader)?;
+
+        Ok(config)
+    }
+}
+
+#[derive(Clone)]
+pub struct ApplicationSettings {
+    pub matrix_dir: PathBuf,
+    pub cache_dir: PathBuf,
+    pub session_json: PathBuf,
+    pub profile_name: String,
+    pub profile: ProfileConfig,
+}
+
+impl ApplicationSettings {
+    pub fn load(cli: Iamb) -> Result<Self, Box<dyn std::error::Error>> {
+        let mut config_dir = cli.config_directory.or_else(dirs::config_dir).unwrap_or_else(|| {
+            usage!(
+                "No user configuration directory found;\
+                please specify one via -C.\n\n
+                For more information try '--help'"
+            );
+        });
+        config_dir.push("iamb");
+        let mut config_json = config_dir.clone();
+        config_json.push("config.json");
+
+        let IambConfig { mut profiles, default_profile, cache } =
+            IambConfig::load(config_json.as_path())?;
+
+        validate_profile_names(&profiles);
+
+        let (profile_name, profile) = if let Some(profile) = cli.profile.or(default_profile) {
+            profiles.remove_entry(&profile).unwrap_or_else(|| {
+                usage!(
+                    "No configured profile with the name {:?} in {}",
+                    profile,
+                    config_json.display()
+                );
+            })
+        } else if profiles.len() == 1 {
+            profiles.into_iter().next().unwrap()
+        } else {
+            usage!(
+                "No profile specified. \
+                Please use -P or add \"default_profile\" to {}.\n\n\
+                For more information try '--help'",
+                config_json.display()
+            );
+        };
+
+        let mut profile_dir = config_dir.clone();
+        profile_dir.push("profiles");
+        profile_dir.push(profile_name.as_str());
+
+        let mut matrix_dir = profile_dir.clone();
+        matrix_dir.push("matrix");
+
+        let mut session_json = profile_dir;
+        session_json.push("session.json");
+
+        let cache_dir = cache.unwrap_or_else(|| {
+            let mut cache = dirs::cache_dir().expect("no user cache directory");
+            cache.push("iamb");
+            cache
+        });
+
+        let settings = ApplicationSettings {
+            matrix_dir,
+            cache_dir,
+            session_json,
+            profile_name,
+            profile,
+        };
+
+        Ok(settings)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_profile_name_invalid() {
+        assert_eq!(validate_profile_name(""), false);
+        assert_eq!(validate_profile_name(" "), false);
+        assert_eq!(validate_profile_name("a b"), false);
+        assert_eq!(validate_profile_name("foo^bar"), false);
+        assert_eq!(validate_profile_name("FOO/BAR"), false);
+        assert_eq!(validate_profile_name("-b-c"), false);
+        assert_eq!(validate_profile_name("-B-c"), false);
+        assert_eq!(validate_profile_name(".b-c"), false);
+        assert_eq!(validate_profile_name(".B-c"), false);
+    }
+
+    #[test]
+    fn test_profile_name_valid() {
+        assert_eq!(validate_profile_name("foo"), true);
+        assert_eq!(validate_profile_name("FOO"), true);
+        assert_eq!(validate_profile_name("a-b-c"), true);
+        assert_eq!(validate_profile_name("a-B-c"), true);
+        assert_eq!(validate_profile_name("a.b-c"), true);
+        assert_eq!(validate_profile_name("a.B-c"), true);
+    }
+}