riscii

commit 4e5686762875bf86a41238b951d111a6e052a54b
parent 05c903f535e52bfb5a4c7979eb87ba5e75d54dc2
Author: Ryan Jeffrey <ryan@ryanmj.xyz>
Date:   Wed,  8 Jun 2022 17:39:43 -0700

Configuration paths customization

Diffstat:
M
src/config.rs
 | 
93
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------

1 file changed, 80 insertions(+), 13 deletions(-)
diff --git a/src/config.rs b/src/config.rs
@@ -16,7 +16,10 @@
 // Struct definitions.
 
 use std::env;
+use std::env::JoinPathsError;
+use std::ffi::OsString;
 use std::fmt;
+use std::path::Path;
 
 /// Configuration of the emulator.
 pub struct Config {
@@ -24,22 +27,65 @@ pub struct Config {
     mem: u32,
     /// Number of CPUs the system will have.
     ncpu: u32,
+    /// Path to the configuration directory.
     config_path: String,
+    /// Path to the configuration file.
+    config_file_path: String,
+    /// Path to the system cache directory.
+    cache_path: String,
 }
 
 // Struct impls.
 
 impl Config {
-    pub fn new() -> Config {
-        Config {
+    pub fn new() -> Result<Config, String> {
+        let home_dir = match env::var("HOME") {
+            Ok(v) => format!("{}", v),
+            Err(e) => {
+                eprintln!("$HOME is not set. Defaulting to current directory.");
+                format!(
+                    "{}",
+                    match env::current_dir() {
+                        Ok(r) => os_string_result_to_strings(r.into_os_string().into_string())?,
+                        Err(e) => format!("{}", e),
+                    }
+                )
+            }
+        };
+
+        let config_path = match env::var("XDG_CONFIG_HOME") {
+            Ok(v) => format!("{}", v),
+            Err(e) => format!("{}", home_dir),
+        };
+
+        let cache_dir = ".cache/riscii".to_string();
+        Ok(Config {
             mem: 0,
             ncpu: 0,
-            config_path: format!(""),
-        }
+            config_file_path: concat_paths(
+                &config_path,
+                &".config/riscii/config.toml".to_string(),
+            )?,
+            cache_path: match env::var("XDG_CACHE_HOME") {
+                Ok(v) => concat_paths(&v, &cache_dir)?,
+                Err(v) => concat_paths(&home_dir, &cache_dir)?,
+            },
+            config_path: config_path,
+        })
     }
 
     pub fn init() -> Result<Config, String> {
-        let mut config = Self::new();
+        let mut config = Self::new()?;
+        config.parse_cmd_args()?;
+        config.read_config_file()?;
+        Ok(config)
+    }
+
+    fn read_config_file(&mut self) -> Result<(), String> {
+        Ok(())
+    }
+
+    fn parse_cmd_args(&mut self) -> Result<(), String> {
         let args: Vec<String> = env::args().collect();
 
         let mut skips = 1i32;
@@ -51,21 +97,21 @@ impl Config {
 
             match arg.as_str() {
                 "--mem" => {
-                    config.mem = args_get_next_uint(&args, i, &format!("mem"))?;
+                    self.mem = args_get_next_uint(&args, i, &format!("mem"))?;
                     skips += 1;
                 }
                 "--ncpu" => {
-                    config.ncpu = args_get_next_uint(&args, i, &format!("ncpu"))?;
+                    self.ncpu = args_get_next_uint(&args, i, &format!("ncpu"))?;
                     skips += 1;
                 }
                 "--config" => {
-                    config.config_path = args_get_next_arg(&args, i, &format!("config"))?.clone();
+                    self.config_path = args_get_next_arg(&args, i, &format!("config"))?.clone();
                     skips += 1;
                 }
                 _ => {
                     println!(
                         "Usage: riscii [OPTIONS]
---config    Path to configuration file (default=~/.config/riscii/config.toml)
+--config    Path to configuration file (default=~/.config/riscii/self.toml)
 --mem       Size of memory (in megabytes) (default=512)
 --ncpu      Number of cores to emulate (default=1)
 "
@@ -74,8 +120,7 @@ impl Config {
                 }
             }
         }
-
-        Ok(config)
+        Ok(())
     }
 }
 
@@ -122,8 +167,30 @@ impl fmt::Display for Config {
             f,
             "Number of cpus: {}
 Memory (MB): {}
-Configuration file: {}",
-            self.ncpu, self.mem, self.config_path
+Configuration directory: {}
+Configuration file: {}
+Cache Directory: {}",
+            self.ncpu, self.mem, self.config_path, self.config_file_path, self.cache_path
         )
     }
 }
+
+// Local functions.
+
+fn os_string_result_to_strings(r: Result<String, OsString>) -> Result<String, String> {
+    match r {
+        Err(e) => Err(match e.into_string() {
+            Ok(s) => s,
+            Err(ee) => "Could not coerce OS string into utf8 string".to_string(),
+        }),
+        Ok(rr) => Ok(rr.to_string()),
+    }
+}
+
+fn concat_paths(base: &String, rest: &String) -> Result<String, String> {
+    let p = Path::new(&base).join(&rest);
+    match p.to_str() {
+        None => Err(format!("{} and {} joined is not valid utf8", base, rest)),
+        Some(s) => Ok(s.to_string()),
+    }
+}