First commit

src/main.rs

@@ -0,0 +1,140 @@
+use std::str;
+use std::fmt;
+use curl::easy::{Easy, List};
+use serde_json::Value;
+use clap::Parser;
+
+//
+// Enums
+//
+#[derive(Debug,PartialEq,Eq,Copy,Clone)]
+enum TemperatureUnits {
+    Metric,
+    Imperial,
+}
+
+impl fmt::Display for TemperatureUnits {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+       match self {
+           TemperatureUnits::Metric => write!(f, "Metric"),
+           TemperatureUnits::Imperial => write!(f, "Imperial"),
+       }
+    }
+}
+
+// Commandline parsing
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+struct CommandlineArgs {
+    /// Name of the weather station
+    #[arg(short, long, default_value = "khio")]
+    station: String,
+
+    /// Use Metric units. Imperial units otherwise
+    #[arg(short, long)]
+    metric: bool,
+}
+
+
+//
+// Application options
+//
+#[derive(Debug,Clone)]
+struct AppOptions {
+    units: TemperatureUnits,
+    station: String,
+}
+
+//
+// Application (BarWeather)
+//
+struct BarWeather {
+    // acts    :BarWeatherActions
+    opts :AppOptions,
+}
+
+impl BarWeather {
+    fn run(self) {
+        self.check_options();
+        self.get_weather();
+    }
+
+    fn get_weather(self) {
+        // Print a web page onto stdout
+        let mut easy = Easy::new();
+        let app = self;
+        let url_string_1 :String = "https://api.weather.gov/stations/".to_owned();
+        let url_string_2 :&str = app.opts.station.as_str();
+        let url_string_3 :String = "/observations?limit=1".to_owned();
+        let url_string = url_string_1 + url_string_2 + &url_string_3;
+        easy.url(url_string.as_str()).unwrap();
+
+        let mut list = List::new();
+        list.append("User-Agent: Bar Weather (mahesh@heshapps.com)").unwrap();
+        easy.http_headers(list).unwrap();
+
+        easy.write_function(move |data| {
+            // To debug returned JSON
+            // use std::io::{stdout, Write};
+            // stdout().write_all(data).unwrap();
+
+            let v: Value = serde_json::from_str(str::from_utf8(data).unwrap()).unwrap();
+            let temperature_value :f32 = app.get_current_temperature(v);
+            let temperature_unit :String = app.get_temperature_unit();
+
+            println!("{}{}", temperature_value, temperature_unit);
+            println!("{:.2}{}", temperature_value, temperature_unit);
+
+            Ok(data.len())
+
+        }
+        ).unwrap();
+        easy.perform().unwrap();
+    }
+
+    fn check_options(&self) -> bool {
+        let mut all_good = true;
+
+        if ! ((self.opts.units == TemperatureUnits::Metric)
+            || (self.opts.units == TemperatureUnits::Imperial)) {
+            all_good &= false;
+        }
+
+        return all_good;
+    }
+
+    fn get_current_temperature(&self, v: Value) -> f32 {
+        let deg_c :f32 = v["features"][0]["properties"]["temperature"]["value"]
+                            .to_string().parse().unwrap();
+
+        return if self.opts.units == TemperatureUnits::Metric { deg_c }
+                                                         else { (deg_c * 9.0 / 5.0) + 32.0};
+    }
+
+    fn get_temperature_unit(&self) -> String{
+        return if self.opts.units == TemperatureUnits::Metric { "°C".to_string() }
+                                                         else { "°F".to_string() };
+    }
+}
+
+//
+// Entry point
+//
+fn main() {
+    let cmd_args = CommandlineArgs::parse();
+    let app = BarWeather {
+        //acts: BarWeatherActions {
+            opts: AppOptions {
+                // units: TemperatureUnits::Imperial,
+                // units: TemperatureUnits::Metric,
+                units: if cmd_args.metric { TemperatureUnits::Metric }
+                                     else { TemperatureUnits::Imperial },
+                station: cmd_args.station,
+            },
+        //},
+    };
+
+    app.run();
+}
+// References:
+// https://reintech.io/blog/working-with-json-in-rust

src/main.rs.backup

@@ -0,0 +1,134 @@
+use std::str;
+use std::fmt;
+use curl::easy::{Easy, List};
+use serde_json::Value;
+
+//
+// Enums
+//
+#[derive(Debug,PartialEq,Eq,Copy,Clone)]
+enum TemperatureUnits {
+    Metric,
+    Imperial,
+}
+
+impl fmt::Display for TemperatureUnits {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+       match self {
+           TemperatureUnits::Metric => write!(f, "Metric"),
+           TemperatureUnits::Imperial => write!(f, "Imperial"),
+       }
+    }
+}
+
+// Commandline parsing
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+struct CommandlineArgs {
+    /// Name of the weather station
+    #[arg(short, long, default_value = "khio")]
+    station: String,
+}
+
+
+//
+// Application options
+//
+#[derive(Debug,Copy,Clone)]
+struct AppOptions {
+    units: TemperatureUnits,
+    station: String,
+}
+
+//
+// Application (BarWeather) actions
+struct BarWeatherActions {
+    opts :AppOptions,
+}
+
+impl BarWeatherActions {
+    fn check_options(&self) -> bool {
+        let mut all_good = true;
+
+        if ! ((self.opts.units == TemperatureUnits::Metric)
+            || (self.opts.units == TemperatureUnits::Imperial)) {
+            all_good &= false;
+        }
+
+        return all_good;
+    }
+
+    fn get_current_temperature(&self, v: Value) -> f32 {
+        let deg_c :f32 = v["features"][0]["properties"]["temperature"]["value"]
+                            .to_string().parse().unwrap();
+
+        return if self.opts.units == TemperatureUnits::Metric { deg_c }
+                                                         else { (deg_c * 9.0 / 5.0) + 32.0};
+    }
+
+    fn get_temperature_unit(&self) -> String{
+        return if self.opts.units == TemperatureUnits::Metric { "°C".to_string() }
+                                                         else { "°F".to_string() };
+    }
+}
+
+//
+// Application (BarWeather)
+//
+struct BarWeather {
+    acts    :BarWeatherActions
+}
+
+impl BarWeather {
+    fn run(self) {
+        self.acts.check_options();
+        self.get_weather();
+    }
+
+    fn get_weather(self) {
+        // Print a web page onto stdout
+        let mut easy = Easy::new();
+        let app = self;
+        easy.url("https://api.weather.gov/stations/" +  + "/observations?limit=1").unwrap();
+
+        let mut list = List::new();
+        list.append("User-Agent: Bar Weather (mahesh@heshapps.com)").unwrap();
+        easy.http_headers(list).unwrap();
+
+        easy.write_function(move |data| {
+            // To debug returned JSON
+            // use std::io::{stdout, Write};
+            // stdout().write_all(data).unwrap();
+
+            let v: Value = serde_json::from_str(str::from_utf8(data).unwrap()).unwrap();
+            let temperature_value :f32 = app.acts.get_current_temperature(v);
+            let temperature_unit :String = app.acts.get_temperature_unit();
+
+            println!("{}{}", temperature_value, temperature_unit);
+            println!("{:.2}{}", temperature_value, temperature_unit);
+
+            Ok(data.len())
+
+        }
+        ).unwrap();
+        easy.perform().unwrap();
+    }
+}
+
+//
+// Entry point
+//
+fn main() {
+    let app = BarWeather {
+        acts: BarWeatherActions {
+            opts: AppOptions {
+                units: TemperatureUnits::Imperial,
+                // units: TemperatureUnits::Metric,
+            },
+        },
+    };
+
+    app.run();
+}
+// References:
+// https://reintech.io/blog/working-with-json-in-rust