1 files changed, 134 insertions, 0 deletions
diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..4e81bbe
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,134 @@
+//! Optional configuration in `~/.config/drae/config.toml`.
+//!
+//! Everything has a sensible default: the file is only needed to change
+//! something. Command-line flags always win over it. The keys are in Spanish
+//! because the users are Spanish speakers.
+//!
+//! ```toml
+//! fuente = "auto"        # auto | dle | rae-api
+//! timeout = 15
+//! # cache = "~/.cache/drae/entries.db"
+//! # diccionario = "/usr/share/hunspell/es_AR.dic"
+//! ```
+
+use std::path::{Path, PathBuf};
+
+use anyhow::{Context, Result};
+use serde::Deserialize;
+
+use crate::cache::Cache;
+
+#[derive(Debug, Clone, Default, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct ConfigFile {
+    /// Where to read from: `auto` (rae-api with fallback), `dle` or `rae-api`.
+    #[serde(rename = "fuente")]
+    pub source: Option<String>,
+    /// Seconds to wait for each request.
+    pub timeout: Option<u64>,
+    /// Cache database.
+    pub cache: Option<String>,
+    /// Hunspell `.dic` used for suggestions.
+    #[serde(rename = "diccionario")]
+    pub dictionary: Option<String>,
+    /// Fixed output width; defaults to the terminal width.
+    #[serde(rename = "ancho")]
+    pub width: Option<usize>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Config {
+    pub source: String,
+    pub timeout: u64,
+    pub cache: PathBuf,
+    pub dictionary: Option<PathBuf>,
+    pub width: Option<usize>,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            source: "auto".into(),
+            timeout: 15,
+            cache: Cache::default_path(),
+            dictionary: None,
+            width: None,
+        }
+    }
+}
+
+pub fn default_path() -> PathBuf {
+    let base = std::env::var_os("XDG_CONFIG_HOME")
+        .map(PathBuf::from)
+        .or_else(|| std::env::var_os("HOME").map(|h| PathBuf::from(h).join(".config")))
+        .unwrap_or_else(|| PathBuf::from(".config"));
+    base.join("drae").join("config.toml")
+}
+
+/// Loads the file if it exists. A missing file is not an error.
+pub fn load(explicit: Option<&Path>) -> Result<Config> {
+    let path = explicit.map(PathBuf::from).unwrap_or_else(default_path);
+    let mut cfg = Config::default();
+    let Ok(raw) = std::fs::read_to_string(&path) else {
+        return Ok(cfg);
+    };
+    let file: ConfigFile = toml::from_str(&raw)
+        .with_context(|| format!("no se pudo leer la configuración {}", path.display()))?;
+
+    if let Some(s) = file.source {
+        cfg.source = s;
+    }
+    if let Some(t) = file.timeout {
+        cfg.timeout = t;
+    }
+    if let Some(c) = file.cache {
+        cfg.cache = expand_tilde(&c);
+    }
+    if let Some(d) = file.dictionary {
+        cfg.dictionary = Some(expand_tilde(&d));
+    }
+    cfg.width = file.width.or(cfg.width);
+    Ok(cfg)
+}
+
+fn expand_tilde(s: &str) -> PathBuf {
+    match s.strip_prefix("~/") {
+        Some(rest) => match std::env::var_os("HOME") {
+            Some(home) => PathBuf::from(home).join(rest),
+            None => PathBuf::from(s),
+        },
+        None => PathBuf::from(s),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn missing_file_yields_defaults() {
+        let cfg = load(Some(Path::new("/does/not/exist/config.toml"))).unwrap();
+        assert_eq!(cfg.source, "auto");
+        assert_eq!(cfg.timeout, 15);
+    }
+
+    #[test]
+    fn parses_a_config_file() {
+        let dir = std::env::temp_dir().join(format!("drae-cfg-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let p = dir.join("config.toml");
+        std::fs::write(&p, "fuente = \"dle\"\ntimeout = 30\nancho = 72\n").unwrap();
+        let cfg = load(Some(&p)).unwrap();
+        assert_eq!(cfg.source, "dle");
+        assert_eq!(cfg.timeout, 30);
+        assert_eq!(cfg.width, Some(72));
+        std::fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn expands_a_leading_tilde() {
+        std::env::set_var("HOME", "/home/test");
+        assert_eq!(expand_tilde("~/x/y.db"), PathBuf::from("/home/test/x/y.db"));
+        assert_eq!(expand_tilde("/abs/x.db"), PathBuf::from("/abs/x.db"));
+    }
+}