roezio: first config draft; missing write

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>

Cargo.toml

@@ -18,6 +18,8 @@ lazy_static = "1"
 enum-set = "0.0"
 clap = { version = "3.2.17", features = ["derive"] }
 directories = "4.0.1"
+configparser = "3.0.1"
+jid = "0.9.4"
 
 [lib]
 crate-type = ["cdylib"]

src/config.rs

@@ -0,0 +1,177 @@
+// Copyright (C) 2018-2099 The crate authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+use crate::error::Error;
+
+use std::cell::LazyCell;
+use std::collections::HashMap;
+use std::fmt;
+use std::path::PathBuf;
+
+use configparser::ini::Ini;
+use jid::Jid;
+
+#[derive(Clone, Debug, Hash, Eq, PartialEq)]
+pub(crate) enum ConfigValue {
+    Bool(bool),
+    UInt(u64),
+    Int(i64),
+    String(String),
+}
+
+impl ConfigValue {
+    pub(crate) fn to_bool<S: Into<String>>(_val: S) -> Result<ConfigValue, Error> {
+        Ok(ConfigValue::Bool(true))
+    }
+
+    pub(crate) fn to_uint<S: Into<String>>(_val: S) -> Result<ConfigValue, Error> {
+        Ok(ConfigValue::UInt(0u64))
+    }
+
+    pub(crate) fn to_int<S: Into<String>>(_val: S) -> Result<ConfigValue, Error> {
+        Ok(ConfigValue::Int(0i64))
+    }
+
+    pub(crate) fn to_string<S: Into<String>>(_val: S) -> Result<ConfigValue, Error> {
+        Ok(ConfigValue::String(String::new()))
+    }
+}
+
+impl fmt::Display for ConfigValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                ConfigValue::Bool(b) => b.to_string(),
+                ConfigValue::UInt(i) => i.to_string(),
+                ConfigValue::Int(i) => i.to_string(),
+                ConfigValue::String(s) => s.to_string(),
+            }
+        )
+    }
+}
+
+const DEFAULT_CONFIG: LazyCell<HashMap<&str, HashMap<&str, ConfigValue>>> =
+    LazyCell::new(|| HashMap::new());
+
+pub(crate) struct Config<'a> {
+    filename: PathBuf,
+    defaults: LazyCell<HashMap<&'a str, HashMap<&'a str, ConfigValue>>>,
+    ini: Ini,
+}
+
+impl Config<'static> {
+    /// Create a new Config object
+    pub(crate) fn new<P: Into<PathBuf>>(filename: P) -> Self {
+        // TODO: read ini file.
+
+        Config {
+            filename: filename.into(),
+            defaults: DEFAULT_CONFIG,
+            ini: Ini::new(),
+        }
+    }
+
+    /// Sets a key/value pair in memory and updates the config file.
+    pub(crate) fn set(
+        &mut self,
+        key: &str,
+        value: ConfigValue,
+        section: Option<Jid>,
+    ) -> Result<(), Error> {
+        let section: String = section
+            .map(|jid| jid.to_string())
+            .unwrap_or(String::from("default"));
+        self.write(key.clone(), value.clone(), section.as_str())?;
+        let _ = self.ini.set(section.as_str(), key, Some(value.to_string()));
+        Ok(())
+    }
+
+    fn write(&self, _key: &str, _value: ConfigValue, _section: &str) -> Result<(), Error> {
+        // TODO: Copy the file and parse it manually. If the key exists, edit it in place during
+        // parsing. If it doesn't, add it at the end of the section. Replace the original file
+        // atomically.
+        Ok(())
+    }
+
+    /// Fetches a value
+    pub(crate) fn get(
+        &self,
+        key: &str,
+        section: Option<Jid>,
+    ) -> Result<Option<ConfigValue>, Error> {
+        let section: String = section
+            .map(|jid| jid.to_string())
+            .unwrap_or(String::from("default"));
+        let value = self.ini.get(&section, key);
+        let default = self
+            .defaults
+            .get(section.as_str())
+            .map(|section| section.get(key));
+
+        Ok(match (default, value) {
+            // Default exists, value exists
+            (Some(Some(def)), Some(val)) => Some(match def {
+                ConfigValue::Bool(_) => ConfigValue::to_bool(val.clone())?,
+                ConfigValue::UInt(_) => ConfigValue::to_uint(val.clone())?,
+                ConfigValue::Int(_) => ConfigValue::to_int(val.clone())?,
+                ConfigValue::String(_) => ConfigValue::to_string(val.clone())?,
+            }),
+            // Default exists, value doesn't
+            (Some(Some(def)), _) => Some(def.clone()),
+            // Default doesn't exist, value does
+            // XXX: How do we know what type to return?
+            (_, Some(val)) => Some(ConfigValue::to_string(val)?),
+            _ => None,
+        })
+    }
+
+    pub(crate) fn getbool(&self, key: &str, section: Option<Jid>) -> Result<Option<bool>, Error> {
+        match self.get(key, section)? {
+            Some(ConfigValue::Bool(v)) => Ok(Some(v)),
+            Some(v) => Err(Error::InvalidConfigValueType(v)),
+            None => Ok(None),
+        }
+    }
+
+    pub(crate) fn getuint(&self, key: &str, section: Option<Jid>) -> Result<Option<u64>, Error> {
+        match self.get(key, section)? {
+            Some(ConfigValue::UInt(v)) => Ok(Some(v)),
+            Some(v) => Err(Error::InvalidConfigValueType(v)),
+            None => Ok(None),
+        }
+    }
+
+    pub(crate) fn getint(&self, key: &str, section: Option<Jid>) -> Result<Option<i64>, Error> {
+        match self.get(key, section)? {
+            Some(ConfigValue::Int(v)) => Ok(Some(v)),
+            Some(v) => Err(Error::InvalidConfigValueType(v)),
+            None => Ok(None),
+        }
+    }
+
+    pub(crate) fn getstring(
+        &self,
+        key: &str,
+        section: Option<Jid>,
+    ) -> Result<Option<String>, Error> {
+        match self.get(key, section)? {
+            Some(ConfigValue::String(v)) => Ok(Some(v)),
+            Some(v) => Err(Error::InvalidConfigValueType(v)),
+            None => Ok(None),
+        }
+    }
+}

src/error.rs

@@ -13,6 +13,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
+use crate::config::ConfigValue;
+
 use std::error::Error as StdError;
 use std::fmt;
 use std::io;
@@ -21,6 +23,7 @@ use std::io;
 pub(crate) enum Error {
     IOError(io::Error),
     UnableToCreateConfigDir,
+    InvalidConfigValueType(ConfigValue),
 }
 
 impl fmt::Display for Error {
@@ -28,6 +31,7 @@ impl fmt::Display for Error {
         match self {
             Error::IOError(e) => write!(f, "io error: {}", e),
             Error::UnableToCreateConfigDir => write!(f, "Unable to create config dir"),
+            Error::InvalidConfigValueType(err) => write!(f, "Invalid ConfigValue type: {}", err),
         }
     }
 }

src/lib.rs

@@ -1,6 +1,7 @@
 #![feature(once_cell)]
 
 mod args;
+mod config;
 mod error;
 mod logger;
 mod theming;