add preliminary support for user configurations

3 files changed, 162 insertions, 20 deletions

diff --git a/src/main.rs b/src/main.rs
index 395e683..f990319 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,6 +9,7 @@ extern crate num_traits;
 extern crate reqwest;
 extern crate rusttype;
 extern crate termcolor;
+extern crate toml;
 extern crate xdg;
 #[macro_use]
 extern crate lazy_static;
@@ -33,6 +34,7 @@ mod bt;
 mod cache;
 mod output;
 mod render;
+mod useropts;
 
 use clap::{App, Arg, ArgMatches};
 
@@ -345,6 +347,12 @@ fn run() -> MainResult<()> {
                 .default_value("buildtemplate.png")
                 .takes_value(true),
         )
+        .arg(
+            Arg::with_name("config")
+                .help("Specifies the render option file.")
+                .long("config")
+                .takes_value(true),
+        )
         .get_matches();
 
     let mut api = Api::new(cache::FileCache::new());
@@ -360,7 +368,13 @@ fn run() -> MainResult<()> {
         println!("{}", build.chatlink());
     }
 
-    let mut renderer = render::Renderer::new(&mut api, Default::default());
+    let render_options = if let Some(config_path) = matches.value_of("config") {
+        useropts::load_file(config_path)?
+    } else {
+        Default::default()
+    };
+
+    let mut renderer = render::Renderer::new(&mut api, render_options);
     match renderer.render_buildtemplate(&build) {
         Ok(img) => {
             let filename = matches.value_of("outfile").unwrap();
@@ -368,7 +382,7 @@ fn run() -> MainResult<()> {
             if !matches.is_present("quiet") {
                 println!("Image saved in {}", filename);
             }
-        },
+        }
         Err(RenderError::EmptyBuild) => (),
         Err(err) => {
             eprintln!("Image could not be rendered:");
diff --git a/src/render.rs b/src/render.rs
index cbfd54f..6513cd5 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -7,6 +7,7 @@ use image::{
 use imageproc::{drawing, rect::Rect};
 use num_traits::{Num, NumCast};
 use rusttype::{Font, Scale, SharedBytes};
+use serde::{Deserialize, Serialize};
 use std::{error::Error, fmt};
 
 #[derive(Debug)]
@@ -43,7 +44,7 @@ impl Error for RenderError {
     }
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub enum Alignment {
     Left,
     Center,
@@ -52,23 +53,23 @@ pub enum Alignment {
 
 #[derive(Debug, Clone)]
 pub struct RenderOptions {
-    skill_size: u32,
-    traitline_height: u32,
-    traitline_width: u32,
-    traitline_brightness: i32,
-    traitline_use_gradient: bool,
-    traitline_gradient_size: u32,
-    traitline_x_offset: u32,
-    trait_size: u32,
-    line_color: Rgba<u8>,
-    line_height: u32,
-    font: Font<'static>,
-    text_color: Rgba<u8>,
-    text_size: u32,
-    background_color: Rgba<u8>,
-    render_specialization_names: bool,
-    skill_offset: u32,
-    skill_alignment: Alignment,
+    pub skill_size: u32,
+    pub traitline_height: u32,
+    pub traitline_width: u32,
+    pub traitline_brightness: i32,
+    pub traitline_use_gradient: bool,
+    pub traitline_gradient_size: u32,
+    pub traitline_x_offset: u32,
+    pub trait_size: u32,
+    pub line_color: Rgba<u8>,
+    pub line_height: u32,
+    pub font: Font<'static>,
+    pub text_color: Rgba<u8>,
+    pub text_size: u32,
+    pub background_color: Rgba<u8>,
+    pub render_specialization_names: bool,
+    pub skill_offset: u32,
+    pub skill_alignment: Alignment,
 }
 
 impl Default for RenderOptions {
diff --git a/src/useropts.rs b/src/useropts.rs
new file mode 100644
index 0000000..e6de8de
--- /dev/null
+++ b/src/useropts.rs
@@ -0,0 +1,127 @@
+//! Support for loading user defined rendering options.
+//!
+//! User options are given in a toml file, for example
+//!
+//! ```toml
+//! skill_size = 20
+//! ```
+//!
+//! The file is automatically deserialized by serde, so all fields defined in
+//! [`UserOptions`](struct.UserOptions.html) can be used.
+use image::Rgba;
+use rusttype::Font;
+use serde::{Deserialize, Serialize};
+use std::{error::Error, fmt, fs, io, path::Path};
+
+use super::render::{Alignment, RenderOptions};
+
+/// Error that can occur during loading or converting user options.
+#[derive(Debug)]
+pub enum ConfigError {
+    Io(io::Error),
+    Serialization(toml::de::Error),
+    Font(rusttype::Error),
+}
+
+error_froms! {
+    ConfigError,
+    err: io::Error => ConfigError::Io(err),
+    err: toml::de::Error => ConfigError::Serialization(err),
+    err: rusttype::Error => ConfigError::Font(err),
+}
+
+impl fmt::Display for ConfigError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "ConfigError: ")?;
+        match *self {
+            ConfigError::Io(_) => write!(f, "input/output error"),
+            ConfigError::Serialization(_) => write!(f, "serialization error"),
+            ConfigError::Font(_) => write!(f, "could not load the font"),
+        }
+    }
+}
+
+impl Error for ConfigError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match *self {
+            ConfigError::Io(ref err) => Some(err),
+            ConfigError::Serialization(ref err) => Some(err),
+            ConfigError::Font(ref err) => Some(err),
+        }
+    }
+}
+
+macro_rules! maybe_take_from {
+    (from: $from:expr, to: $to:ident, $($field:ident,)*) => {
+        $(
+            if let Some(data) = $from.$field {
+                $to.$field = data;
+            }
+        )*
+    }
+}
+
+/// A struct for deserializing user defined options.
+///
+/// This is basically a struct containing the same fields, but optional. If a field is given, it
+/// should override the corresponding field in
+/// [`RenderOptions`](../render/struct.RenderOptions.html).
+///
+/// Some fields require some pre-processing, as the proper type cannot be serialized (e.g.
+/// `image::Rgba` for `background_color`).
+#[derive(Debug, Serialize, Deserialize)]
+pub struct UserOptions {
+    pub traitline_x_offset: Option<u32>,
+    pub trait_size: Option<u32>,
+    pub line_color: Option<[u8; 4]>,
+    pub line_height: Option<u32>,
+    pub text_size: Option<u32>,
+    pub background_color: Option<[u8; 4]>,
+    pub font_path: Option<String>,
+    pub render_specialization_names: Option<bool>,
+    pub skill_alignment: Option<Alignment>,
+}
+
+impl UserOptions {
+    /// Converts this `UserOptions` to a proper
+    /// [`RenderOptions`](../render/struct.RenderOptions.html).
+    pub fn convert(self) -> Result<RenderOptions, ConfigError> {
+        let mut result = RenderOptions::default();
+
+        if let Some(data) = self.background_color {
+            result.background_color = Rgba(data);
+        }
+
+        if let Some(data) = self.line_color {
+            result.line_color = Rgba(data);
+        }
+
+        if let Some(path) = self.font_path {
+            let data = fs::read(path)?;
+            let font = Font::from_bytes(data)?;
+            result.font = font;
+        }
+
+        maybe_take_from! {
+            from: self, to: result,
+            traitline_x_offset,
+            trait_size,
+            line_height,
+            text_size,
+            render_specialization_names,
+            skill_alignment,
+        }
+
+        Ok(result)
+    }
+}
+
+/// Load user given options from the given file path.
+///
+/// This is basically a convenience function around reading the data, deserializing it from toml
+/// and returning [`UserOptions::convert`](struct.UserOptions.html#method.convert).
+pub fn load_file<P: AsRef<Path>>(path: P) -> Result<RenderOptions, ConfigError> {
+    let data = fs::read(path)?;
+    let opts = toml::from_slice::<UserOptions>(&data)?;
+    opts.convert()
+}