config: Add a function to read a config file (WIP)

A new function that will read a TOML config file. Doesn't currently
access the filesystem. This commit is mostly supporting code to allow
that to work.

* Add the 'toml' crate
* `parse_args()`: Take a mutable `Config` and return that config instead
  of creating a new one. The recipe will now be to read the config from
  a file first and then pass that config to this function to be updated.
* Modify `c_parse_args()` to take a `*Config` and mirror the new method
  signature of `parse_args()`

5 files changed, 21 insertions, 6 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 45b5883..17a080b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ objc = "0.2.5"
 serde = "1.0.58"
 serde_derive = "1.0.58"
 stderrlog = "0.4.1"
+toml = "0.4.8"
 xdg = "2.1.0"
 
 [build-dependencies]
diff --git a/dome_key_map.h b/dome_key_map.h
index 2a73d8f..224cc21 100644
--- a/dome_key_map.h
+++ b/dome_key_map.h
@@ -36,7 +36,7 @@ typedef struct {
   size_t length;
 } Trigger;
 
-Config *c_parse_args(const char *const *args, size_t length);
+Config *c_parse_args(const char *const *args, size_t length, Config *config_ptr);
 
 void c_run_key_action(State *state, Trigger trigger, const Trigger *mode);
 
diff --git a/src/cocoa_bridge.rs b/src/cocoa_bridge.rs
index 37654ea..ba7b432 100644
--- a/src/cocoa_bridge.rs
+++ b/src/cocoa_bridge.rs
@@ -302,6 +302,7 @@ fn run_action(map_action: &MapAction) {
 pub extern "C" fn c_parse_args(
     args: *const *const c_char,
     length: size_t,
+    config_ptr: *mut Config
 ) -> *mut Config {
     let args = unsafe {
         assert!(!args.is_null());
@@ -320,9 +321,14 @@ pub extern "C" fn c_parse_args(
             .collect::<Vec<String>>()
     };
 
-    let config = config::parse_args(&args);
+    let config = unsafe {
+        assert!(!config_ptr.is_null());
 
-    Box::into_raw(Box::new(config))
+        &mut *config_ptr
+    };
+    let config = config::parse_args(&args, config);
+
+    config_ptr
 }
 
 #[no_mangle]
diff --git a/src/config.rs b/src/config.rs
index 22f37b6..9962ba0 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,4 +1,5 @@
 use getopts::Options;
+use toml;
 
 type Milliseconds = u16;
 
@@ -11,6 +12,7 @@ struct Args {
 
 #[repr(C)]
 #[derive(Deserialize)]
+#[serde(default)]
 pub struct Config {
     #[serde(skip)]
     args: Args,
@@ -31,7 +33,7 @@ fn print_usage(opts: Options) {
     print!("{}", opts.usage(&brief));
 }
 
-pub fn parse_args(args: &[String]) -> Config {
+pub fn parse_args<'a>(args: &[String], config: &'a mut Config) -> &'a mut Config {
     let mut opts = Options::new();
 
     opts.optflag("d", "daemon", "run the daemon in the current shell");
@@ -43,8 +45,6 @@ pub fn parse_args(args: &[String]) -> Config {
         Err(e) => panic!(e),
     };
 
-    let mut config = Config::default();
-
     if matches.opt_present("h") {
         print_usage(opts);
         return config;
@@ -60,3 +60,10 @@ pub fn parse_args(args: &[String]) -> Config {
 
     config
 }
+
+// TODO: Get config file from .config/dome-key/config.toml
+pub fn read_config_file() -> Config {
+    let config = toml::from_str("").unwrap();
+
+    config
+}
diff --git a/src/lib.rs b/src/lib.rs
index 300cc66..d5af695 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -19,6 +19,7 @@ extern crate objc;
 #[macro_use]
 extern crate serde_derive;
 extern crate stderrlog;
+extern crate toml;
 extern crate xdg;
 
 mod autopilot_internal;