Add daemon weatherd

- Add daemon `weatherd` to fetch and cache weather data
- Update API libraries to serialize to json
- Add "cache_file" parameter to "general" config
- Cargo `fmt` and `clippy`

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 resolver = "3"
 members = [
-    "owm_api25", "owm_widg_config",
+    "owm_api25", "owm_widg_config", "weatherd",
     "widget",
 ]

owm_api25/src/forecast.rs

@@ -1,6 +1,6 @@
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct ForecastWeather {
     pub id: u32,
     pub main: String,
@@ -8,14 +8,14 @@ pub struct ForecastWeather {
     pub icon: String,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct ForecastMain {
     pub temp: f32,
     pub pressure: f32,
     pub humidity: u8,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct ForecastEntry {
     pub dt: u64,
     pub main: ForecastMain,
@@ -23,7 +23,7 @@ pub struct ForecastEntry {
     pub dt_txt: String,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct ForecastResponse {
     pub cod: String,
     pub cnt: u32,

owm_api25/src/lib.rs

@@ -1,3 +1,3 @@
 pub mod forecast;
-pub mod weather;
 pub mod query;
+pub mod weather;

owm_api25/src/query.rs

@@ -22,7 +22,7 @@ impl fmt::Display for Units {
     }
 }
 
-/// Query parameters for OpenWeatherMap Free API v2.5 endpoints
+/// Query parameters for `OpenWeatherMap` Free API v2.5 endpoints
 #[derive(Debug)]
 pub struct QueryParams {
     pub api_key: String,

owm_api25/src/weather.rs

@@ -1,27 +1,27 @@
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct Weather {
     pub main: String,
     pub icon: String,
     pub description: String,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct Main {
     pub temp: f32,
     pub pressure: u32,
     pub humidity: u8,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct Sys {
     pub country: String,
     pub sunrise: u64,
     pub sunset: u64,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct WeatherResponse {
     pub name: String,
     pub sys: Sys,

owm_widg_config/src/config.rs

@@ -1,6 +1,6 @@
-use serde::Deserialize;
-use crate::general::General;
 use crate::free25::Free25Query;
+use crate::general::General;
+use serde::Deserialize;
 
 #[derive(Debug, Deserialize)]
 pub struct Config {

owm_widg_config/src/free25.rs

@@ -1,5 +1,5 @@
-use serde::Deserialize;
 use owm_api25::query::{QueryParams, Units};
+use serde::Deserialize;
 
 #[derive(Debug, Deserialize)]
 pub struct Free25Query {

owm_widg_config/src/general.rs

@@ -3,4 +3,5 @@ use serde::Deserialize;
 #[derive(Debug, Deserialize)]
 pub struct General {
     pub api_version: String,        // "free_2.5", "onecall_3.0", etc.
+    pub cache_file: Option<String>, // Default: "~/.cache/candydesktop/owm_widget.json"
 }

owm_widg_config/src/lib.rs

@@ -1,3 +1,3 @@
-pub mod general;
-pub mod free25;
 pub mod config;
+pub mod free25;
+pub mod general;

weatherd/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "weatherd"
+version = "0.0.1"
+edition = "2024"
+
+[dependencies]
+reqwest = {version = "0.12.23", features = ["blocking", "json"] }
+toml = "0.9.7"
+dirs = "6.0.0"
+serde = { version = "1.0.225", features = ["derive"] }
+serde_json = "1.0.145"
+owm_api25 = { path = "../owm_api25" }
+owm_widg_config = { path = "../owm_widg_config" }

weatherd/src/main.rs

@@ -0,0 +1,71 @@
+use owm_api25::weather::WeatherResponse;
+use owm_widg_config::config::Config;
+use reqwest::blocking;
+use std::error::Error;
+use std::{fs, path::PathBuf, thread, time::Duration};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    println!("weatherd: starting daemon...");
+
+    loop {
+        if let Err(e) = fetch_and_cache() {
+            eprintln!("weatherd error: {e}");
+        }
+
+        // sleep 15 minutes between updates (customize later)
+        thread::sleep(Duration::from_secs(900));
+    }
+}
+
+fn fetch_and_cache() -> Result<(), Box<dyn Error>> {
+    // load config
+    let path = dirs::config_dir()
+        .ok_or("No config dir found")?
+        .join("candywidgets/openweathermap.toml");
+
+    let toml_str = fs::read_to_string(&path)
+        .map_err(|_| format!("Failed to read config: {}", path.display()))?;
+
+    // Deserialize whole config
+    let cfg: Config = toml::from_str(&toml_str)?;
+
+    match cfg.general.api_version.as_str() {
+        "free_2.5" => {
+            let query = owm_api25::query::QueryParams::from(cfg.query_params);
+
+            let url = query.weather_url()?;
+            let resp = blocking::get(&url)?.json::<WeatherResponse>()?;
+            let json_str = serde_json::to_string_pretty(&resp)?;
+
+            // resolve cache path
+            let cache_path = expand_tilde(
+                cfg.general
+                    .cache_file
+                    .unwrap_or_else(|| "~/.cache/candydesktop/owm_widget.json".into()),
+            );
+
+            if let Some(parent) = cache_path.parent() {
+                fs::create_dir_all(parent)?;
+            }
+
+            fs::write(&cache_path, json_str)?;
+            println!("weatherd: updated {}", cache_path.display());
+        }
+        other => {
+            eprintln!("Unsupported api_version: {other}");
+        }
+    }
+
+    Ok(())
+}
+
+/// Expand `~` to `$HOME`
+fn expand_tilde(path: String) -> PathBuf {
+    if let Some(stripped) = path.strip_prefix("~/")
+        && let Some(home) = dirs::home_dir()
+    {
+        return home.join(stripped);
+    }
+
+    PathBuf::from(path)
+}