Added preset file saving and tests

src/save_preset.rs

@@ -0,0 +1,149 @@
+use crate::{
+    DirectionPolicy, EFFECTS, EffectInfo, Effects, Preset,
+    save_preset::{LoadPresetError::InvalidOrCorruptedFile, SavePresetError::InvalidPreset},
+};
+use std::{
+    collections::VecDeque,
+    fs::File,
+    io::{Read, Write},
+    vec,
+};
+
+#[derive(Debug)]
+pub enum SavePresetError {
+    InvalidPreset,
+}
+
+#[derive(Debug)]
+pub enum LoadPresetError {
+    InvalidOrCorruptedFile,
+    OpenFileError(std::io::Error),
+}
+
+const MAGIC_NUMBER_1: u8 = 0b10100100;
+const MAGIC_NUMBER_2: u8 = 0b00010000;
+const VERSION: u8 = 1;
+
+impl Preset {
+    pub fn save_to_file(&self, _file: &mut File) -> Result<(), SavePresetError> {
+        if !self.is_valid() {
+            return Err(SavePresetError::InvalidPreset);
+        }
+        _file.write_all(&self._encode_to_buffer()).expect("");
+        Ok(())
+    }
+
+    pub(crate) fn _encode_to_buffer(&self) -> Vec<u8> {
+        let effect_info: EffectInfo = EFFECTS[usize::from(self.effect.to_u8() - 1)].clone();
+        let mut buffer: Vec<u8> = vec![MAGIC_NUMBER_1, MAGIC_NUMBER_2, VERSION];
+
+        buffer
+            .push(self.effect.to_u8() + (u8::from(self.full_color) * 128) + (self.direction * 32)); //Effect id, full_color, and direction in a single byte
+
+        if !self.full_color && effect_info.can_set_color {
+            buffer.extend(&self.color.to_array());
+        }
+
+        if effect_info.can_set_speed {
+            buffer.push(self.speed);
+        }
+
+        buffer.push(self.brightness);
+
+        if effect_info.requires_keymap {
+            for key_color in self.keymap.expect("keymap is Option::None").iter() {
+                buffer.extend(key_color);
+            }
+        }
+
+        buffer
+    }
+
+    pub fn load_from_file(_file: &mut File) -> Result<Self, LoadPresetError> {
+        let mut buffer: Vec<u8> = vec![];
+        match _file.read_to_end(&mut buffer) {
+            Ok(_) => {
+                let mut buffer: VecDeque<u8> = buffer.into();
+
+                Self::_decode_from_buffer(&mut buffer)
+            }
+            Err(err) => return Err(LoadPresetError::OpenFileError(err)),
+        }
+    }
+
+    pub(crate) fn _decode_from_buffer(buffer: &mut VecDeque<u8>) -> Result<Self, LoadPresetError> {
+        let mut save: Preset = Default::default();
+
+        if buffer.pop_front() != Some(MAGIC_NUMBER_1) || buffer.pop_front() != Some(MAGIC_NUMBER_2)
+        {
+            return Err(LoadPresetError::InvalidOrCorruptedFile);
+        }
+
+        if buffer.pop_front().expect("") != VERSION {
+            return Err(LoadPresetError::InvalidOrCorruptedFile);
+            //todo!("TOO BAD, Invalid VERSION")
+        }
+
+        if buffer[0] & 128 != 0 {
+            buffer[0] -= 128;
+            save.full_color = true;
+        }
+
+        let direction: u8 = (buffer[0] >> 5) & 0b11;
+        buffer[0] -= direction * 32;
+
+        save.effect = Effects::from_u8(
+            buffer
+                .pop_front()
+                .ok_or(LoadPresetError::InvalidOrCorruptedFile)?,
+        )
+        .ok_or(LoadPresetError::InvalidOrCorruptedFile)?;
+        let effect_info: EffectInfo = EFFECTS[usize::from(save.effect.to_u8() - 1)].clone();
+
+        if !save.full_color && effect_info.can_set_color {
+            save.color.red = buffer
+                .pop_front()
+                .ok_or(LoadPresetError::InvalidOrCorruptedFile)?;
+            save.color.green = buffer
+                .pop_front()
+                .ok_or(LoadPresetError::InvalidOrCorruptedFile)?;
+            save.color.blue = buffer
+                .pop_front()
+                .ok_or(LoadPresetError::InvalidOrCorruptedFile)?;
+        }
+
+        if effect_info.can_set_direction != DirectionPolicy::None {
+            save.direction = direction;
+        }
+
+        if effect_info.can_set_speed {
+            save.speed = buffer
+                .pop_front()
+                .ok_or(LoadPresetError::InvalidOrCorruptedFile)?;
+        }
+
+        save.brightness = buffer
+            .pop_front()
+            .ok_or(LoadPresetError::InvalidOrCorruptedFile)?;
+
+        if effect_info.requires_keymap {
+            let mut keymap_buffer: [[u8; 3]; 144] = [[0; 3]; 144];
+            #[allow(clippy::needless_range_loop)]
+            for i in 0..keymap_buffer.len() {
+                keymap_buffer[i] = [
+                    buffer
+                        .pop_front()
+                        .ok_or(LoadPresetError::InvalidOrCorruptedFile)?,
+                    buffer
+                        .pop_front()
+                        .ok_or(LoadPresetError::InvalidOrCorruptedFile)?,
+                    buffer
+                        .pop_front()
+                        .ok_or(LoadPresetError::InvalidOrCorruptedFile)?,
+                ];
+            }
+            save.keymap = Some(keymap_buffer);
+        }
+        Ok(save)
+    }
+}