base_d/core/
config.rs

1use serde::Deserialize;
2use std::collections::HashMap;
3
4/// Encoding strategy for converting binary data to text.
5///
6/// Different modes offer different tradeoffs between efficiency, compatibility,
7/// and features.
8#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
9#[serde(rename_all = "snake_case")]
10pub enum EncodingMode {
11    /// Mathematical base conversion treating data as a large number.
12    /// Works with any dictionary size. Output length varies with input.
13    BaseConversion,
14    /// Fixed-size bit chunking per RFC 4648.
15    /// Requires power-of-two dictionary size. Supports padding.
16    Chunked,
17    /// Direct 1:1 byte-to-character mapping using Unicode codepoint ranges.
18    /// Zero encoding overhead. Always 256 characters.
19    ByteRange,
20}
21
22impl Default for EncodingMode {
23    fn default() -> Self {
24        EncodingMode::BaseConversion
25    }
26}
27
28/// Configuration for a single dictionary loaded from TOML.
29#[derive(Debug, Deserialize, Clone)]
30pub struct DictionaryConfig {
31    /// The characters comprising the dictionary
32    #[serde(default)]
33    pub chars: String,
34    /// The encoding mode to use
35    #[serde(default)]
36    pub mode: EncodingMode,
37    /// Optional padding character (e.g., "=" for base64)
38    #[serde(default)]
39    pub padding: Option<String>,
40    /// Starting Unicode codepoint for ByteRange mode
41    #[serde(default)]
42    pub start_codepoint: Option<u32>,
43}
44
45/// Collection of dictionary configurations loaded from TOML files.
46#[derive(Debug, Deserialize)]
47pub struct DictionariesConfig {
48    /// Map of dictionary names to their configurations
49    pub dictionaries: HashMap<String, DictionaryConfig>,
50    /// Compression algorithm configurations
51    #[serde(default)]
52    pub compression: HashMap<String, CompressionConfig>,
53    /// Global settings
54    #[serde(default)]
55    pub settings: Settings,
56}
57
58/// Configuration for a compression algorithm.
59#[derive(Debug, Deserialize, Clone)]
60pub struct CompressionConfig {
61    /// Default compression level
62    pub default_level: u32,
63}
64
65/// Global settings for base-d.
66#[derive(Debug, Deserialize, Clone, Default)]
67pub struct Settings {
68    /// Default dictionary to use when compressing without explicit encoding
69    #[serde(default = "default_dictionary")]
70    pub default_dictionary: String,
71}
72
73fn default_dictionary() -> String {
74    "base64".to_string()
75}
76
77impl DictionariesConfig {
78    /// Parses dictionary configurations from TOML content.
79    pub fn from_toml(content: &str) -> Result<Self, toml::de::Error> {
80        toml::from_str(content)
81    }
82    
83    /// Loads the built-in dictionary configurations.
84    ///
85    /// Returns the default alphabets bundled with the library.
86    pub fn load_default() -> Result<Self, Box<dyn std::error::Error>> {
87        let content = include_str!("../../dictionaries.toml");
88        Ok(Self::from_toml(content)?)
89    }
90    
91    /// Loads configuration from a custom file path.
92    pub fn load_from_file(path: &std::path::Path) -> Result<Self, Box<dyn std::error::Error>> {
93        let content = std::fs::read_to_string(path)?;
94        Ok(Self::from_toml(&content)?)
95    }
96    
97    /// Loads configuration with user overrides from standard locations.
98    ///
99    /// Searches in priority order:
100    /// 1. Built-in dictionaries (from library)
101    /// 2. `~/.config/base-d/dictionaries.toml` (user overrides)
102    /// 3. `./dictionaries.toml` (project-local overrides)
103    ///
104    /// Later configurations override earlier ones for matching dictionary names.
105    pub fn load_with_overrides() -> Result<Self, Box<dyn std::error::Error>> {
106        let mut config = Self::load_default()?;
107        
108        // Try to load user config from ~/.config/base-d/dictionaries.toml
109        if let Some(config_dir) = dirs::config_dir() {
110            let user_config_path = config_dir.join("base-d").join("dictionaries.toml");
111            if user_config_path.exists() {
112                match Self::load_from_file(&user_config_path) {
113                    Ok(user_config) => {
114                        config.merge(user_config);
115                    }
116                    Err(e) => {
117                        eprintln!("Warning: Failed to load user config from {:?}: {}", user_config_path, e);
118                    }
119                }
120            }
121        }
122        
123        // Try to load local config from ./dictionaries.toml
124        let local_config_path = std::path::Path::new("dictionaries.toml");
125        if local_config_path.exists() {
126            match Self::load_from_file(local_config_path) {
127                Ok(local_config) => {
128                    config.merge(local_config);
129                }
130                Err(e) => {
131                    eprintln!("Warning: Failed to load local config from {:?}: {}", local_config_path, e);
132                }
133            }
134        }
135        
136        Ok(config)
137    }
138    
139    /// Merges another configuration into this one.
140    ///
141    /// Alphabets from `other` override alphabets with the same name in `self`.
142    pub fn merge(&mut self, other: DictionariesConfig) {
143        for (name, dictionary) in other.dictionaries {
144            self.dictionaries.insert(name, dictionary);
145        }
146    }
147    
148    /// Retrieves an dictionary configuration by name.
149    pub fn get_dictionary(&self, name: &str) -> Option<&DictionaryConfig> {
150        self.dictionaries.get(name)
151    }
152}
153
154#[cfg(test)]
155mod tests {
156    use super::*;
157    
158    #[test]
159    fn test_load_default_config() {
160        let config = DictionariesConfig::load_default().unwrap();
161        assert!(config.dictionaries.contains_key("cards"));
162    }
163    
164    #[test]
165    fn test_cards_alphabet_length() {
166        let config = DictionariesConfig::load_default().unwrap();
167        let cards = config.get_dictionary("cards").unwrap();
168        assert_eq!(cards.chars.chars().count(), 52);
169    }
170    
171    #[test]
172    fn test_base64_chunked_mode() {
173        let config = DictionariesConfig::load_default().unwrap();
174        let base64 = config.get_dictionary("base64").unwrap();
175        assert_eq!(base64.mode, EncodingMode::Chunked);
176        assert_eq!(base64.padding, Some("=".to_string()));
177    }
178    
179    #[test]
180    fn test_base64_math_mode() {
181        let config = DictionariesConfig::load_default().unwrap();
182        let base64_math = config.get_dictionary("base64_math").unwrap();
183        assert_eq!(base64_math.mode, EncodingMode::BaseConversion);
184    }
185    
186    #[test]
187    fn test_merge_configs() {
188        let mut config1 = DictionariesConfig {
189            dictionaries: HashMap::new(),
190            compression: HashMap::new(),
191            settings: Settings::default(),
192        };
193        config1.dictionaries.insert("test1".to_string(), DictionaryConfig {
194            chars: "ABC".to_string(),
195            mode: EncodingMode::BaseConversion,
196            padding: None,
197            start_codepoint: None,
198        });
199        
200        let mut config2 = DictionariesConfig {
201            dictionaries: HashMap::new(),
202            compression: HashMap::new(),
203            settings: Settings::default(),
204        };
205        config2.dictionaries.insert("test2".to_string(), DictionaryConfig {
206            chars: "XYZ".to_string(),
207            mode: EncodingMode::BaseConversion,
208            padding: None,
209            start_codepoint: None,
210        });
211        config2.dictionaries.insert("test1".to_string(), DictionaryConfig {
212            chars: "DEF".to_string(),
213            mode: EncodingMode::BaseConversion,
214            padding: None,
215            start_codepoint: None,
216        });
217        
218        config1.merge(config2);
219        
220        assert_eq!(config1.dictionaries.len(), 2);
221        assert_eq!(config1.get_dictionary("test1").unwrap().chars, "DEF");
222        assert_eq!(config1.get_dictionary("test2").unwrap().chars, "XYZ");
223    }
224    
225    #[test]
226    fn test_load_from_toml_string() {
227        let toml_content = r#"
228[dictionaries.custom]
229chars = "0123456789"
230mode = "base_conversion"
231"#;
232        let config = DictionariesConfig::from_toml(toml_content).unwrap();
233        assert!(config.dictionaries.contains_key("custom"));
234        assert_eq!(config.get_dictionary("custom").unwrap().chars, "0123456789");
235    }
236}
237
base_d/core/config.rs

base_d/core/
config.rs
