5 files changed, 162 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index 088ba6b..83c440c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 # Generated by Cargo
 # will have compiled files and executables
-/target/
+**/target/**
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
diff --git a/fondant/Cargo.toml b/fondant/Cargo.toml
new file mode 100644
index 0000000..d6886b1
--- /dev/null
+++ b/fondant/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "fondant"
+version = "0.1.0"
+authors = ["Akshay <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+fondant_derive = {version = "0.1.0", path = "../fondant_derive"}
+fondant_deps = {version = "0.1.0", path = "../fondant_deps"}
diff --git a/fondant/src/lib.rs b/fondant/src/lib.rs
new file mode 100644
index 0000000..d5758dc
--- /dev/null
+++ b/fondant/src/lib.rs
@@ -0,0 +1,86 @@
+//! `fondant` is a macro based library to take the boilerplate out of
+//! configuration handling. Most of `fondant` is based off the `confy` crate.
+//!
+//! `fondant` adds a couple of extra features:
+//!
+//!  - support for json, yaml and toml
+//!  - support for custom config paths
+//!  - support for custom config file names
+//!
+//!  ### Sample usage
+//!
+//! ```
+//! // the struct has to derive Serialize, Deserialize and Default
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "config.toml"]
+//! // |
+//! // `-- this attribute sets the file name to "config.toml"
+//! // `-- the file format to "toml"
+//! // `-- the file path to "default" (read the notes below)
+//! struct AppConfig {
+//!     version: u32,
+//!     port: u32,
+//!     username: String,
+//! }
+//!
+//! fn main() {
+//!     // use `load` (associated method) to load the config file
+//!     let mut conf = AppConfig::load().unwrap();
+//!
+//!     // do stuff with conf
+//!     conf.version = 2;
+//!
+//!     // call `store` to save changes
+//!     conf.store().unwrap();
+//! }
+//! ```
+//! **Notes**:  
+//!  - `load` returns `Default::default` if the config file is not present, and stores
+//!  a serialized `Default::default` at the specified path
+//!  - the "default" config path varies by platform:
+//!     * GNU/Linux: `$XDG_CONFIG_HOME/my_cool_crate/config.toml` (follows xdg spec)
+//!     * MacOS: `$HOME/Library/Preferences/my_cool_crate/config.toml`
+//!     * Windows: `{FOLDERID_RoamingAppData}\_project_path_\config`
+//!
+//! ### Customization
+//!
+//! Set your own filename, for ex.: `apprc`
+//!
+//! ```
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "apprc.toml"]
+//! struct AppConfig {
+//!     // -- snip --
+//! }
+//! // effective path: $XDG_CONFIG_HOME/my_cool_crate/apprc.toml
+//! // effective format: toml
+//! ```
+//!
+//! Change file format to `yaml`, by changing the file extension.
+//! Supported extensions are `yaml`, `toml`, `json`:
+//! ```
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "config.yaml"]
+//! struct AppConfig {
+//!     // -- snip --
+//! }
+//! // effective path: $XDG_CONFIG_HOME/my_cool_crate/config.yaml
+//! // effective format: yaml
+//! ```
+//!
+//! Override the default config path, for ex.: the home directory
+//! (it is not recommended to override config path):
+//! ```
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "~/.apprc.json"]
+//! struct AppConfig {
+//!     // -- snip --
+//! }
+//! // effective path: $HOME/.apprc.json
+//! // effective format: json
+//! ```
+
+pub use fondant_deps::fondant_exports;
+pub use fondant_deps::Configure;
+pub use fondant_deps::FondantError;
+pub use fondant_derive::Configure;
diff --git a/fondant_deps/Cargo.toml b/fondant_deps/Cargo.toml
new file mode 100644
index 0000000..2d1a2db
--- /dev/null
+++ b/fondant_deps/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+name = "fondant_deps"
+version = "0.1.0"
+authors = ["Akshay <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+toml = "^0.5"
+serde_yaml = "0.8"
+serde_json = "1.0.48"
+directories = "2.0"
+
+[dependencies.serde]
+version = "1.0.103"
+features = ["derive"]
+
+[dependencies.syn]
+version = "1.0"
+features = ["full"]
diff --git a/fondant_deps/src/lib.rs b/fondant_deps/src/lib.rs
new file mode 100644
index 0000000..6f62ce8
--- /dev/null
+++ b/fondant_deps/src/lib.rs
@@ -0,0 +1,47 @@
+pub mod fondant_exports {
+    pub use directories::{ProjectDirs, UserDirs};
+    pub use serde::{de::DeserializeOwned, Serialize};
+    pub use serde_json;
+    pub use serde_yaml;
+    use std::path::{Path, PathBuf};
+    pub use toml;
+    pub fn expand_tilde<P: AsRef<Path>>(path: P) -> PathBuf {
+        let p = path.as_ref();
+        if p.starts_with("~") {
+            if p == Path::new("~") {
+                return UserDirs::new().unwrap().home_dir().to_path_buf();
+            } else {
+                let mut h = UserDirs::new().unwrap().home_dir().to_path_buf();
+                h.push(p.strip_prefix("~/").unwrap());
+                return h;
+            }
+        }
+        return p.to_path_buf();
+    }
+}
+
+use serde::{de::DeserializeOwned, Serialize};
+#[derive(Debug)]
+/// Errors that `load` and `store` can result in
+pub enum FondantError {
+    /// Occurs when the home dir is not accessible.
+    /// You should probably `panic!` when this is thrown.
+    InvalidHomeDir,
+
+    /// Invalid toml/yaml/json config.
+    ConfigParseError,
+
+    /// Invalid permissions to create config dir.
+    /// Might occur when you set config dir to, say, `/etc/config.toml` and run without superuser.
+    DirCreateErr(std::io::Error),
+    LoadError,
+    FileWriteError,
+    FileReadError,
+    FileOpenError,
+}
+
+/// Derive this trait on a struct to mark it as a 'configuration' struct.
+pub trait Configure: Serialize + DeserializeOwned + Default {
+    fn load() -> Result<Self, FondantError>;
+    fn store(&self) -> Result<(), FondantError>;
+}