implemented khal JSON output

src/main.rs

@@ -1,23 +1,81 @@
-use structopt::StructOpt;
 use chrono::{Local, NaiveTime};
 use std::process;
 use std::process::Command;
+use structopt::StructOpt;
 
 #[derive(Debug, StructOpt)]
-#[structopt( author, about)]
+#[structopt(author, about)]
 struct Cli {
-    #[structopt(short, long, help="output khal events")]
+    #[structopt(short, long, help = "output khal events")]
     khal: bool,
-    #[structopt(short, long, help="output todos")]
+
+    #[structopt(short, long, help = "output todos")]
     todo: bool,
+
+    #[structopt(
+        short = "w",
+        default_value = "60",
+        help = "threshold for warning status in minutes"
+    )]
+    threshold_warn: i64,
+
+    #[structopt(
+        short = "c",
+        default_value = "15",
+        help = "threshold for critical status in minutes"
+    )]
+    threshold_crit: i64,
+
+    #[structopt(
+        short,
+        long,
+        default_value = "calendar",
+        help = "the icon used (only names valid in i3status-rust)"
+    )]
+    icon: String,
+}
+
+#[derive(Debug)]
+enum Status {
+    Idle,
+    Warn,
+    Crit,
+}
+
+fn get_status(events: Vec<String>, w: i64, c: i64) -> Result<Status, String> {
+    let now = Local::now().time();
+    let mut event_remaining: i64 = 24 * 60;
+    let mut state = Status::Idle;
+
+    for e in events.iter() {
+        let e_start = match NaiveTime::parse_from_str(e, "%H:%M") {
+            Ok(s) => s,
+            Err(f) => {
+                let message = format!("error parsing time value: {}", f);
+                return Err(message);
+            }
+        };
+        let diff = e_start - now;
+        if (diff.num_minutes() < event_remaining) && (diff.num_minutes() >= 0) {
+            event_remaining = diff.num_minutes()
+        }
+
+        if event_remaining >= 0 {
+            if event_remaining <= w {
+                state = Status::Warn;
+            }
+            if event_remaining <= c {
+                state = Status::Crit;
+            }
+        }
+    }
+    Ok(state)
 }
 
 fn main() {
     let args = Cli::from_args();
 
-    if ( !args.khal && !args.todo ) || 
+    if (!args.khal && !args.todo) || (args.khal && args.todo) {
-        ( args.khal && args.todo ) 
-    {
         eprintln!("Please provide either khal or todo flag.");
         Cli::clap().print_help();
         println!();
@@ -39,10 +97,52 @@ fn main() {
             .arg("23:59")
             .output();
 
-        println!("khal output");
+        let stdout = match cmd {
+            Ok(o) => o.stdout,
+            Err(e) => {
+                eprintln!("Error running khal: {}", e);
+                process::exit(1);
+            }
+        };
+
+        let output = match String::from_utf8(stdout) {
+            Ok(o) => o,
+            Err(e) => {
+                eprintln!("Converting output failed: {}", e);
+                process::exit(1);
+            }
+        };
+
+        let mut out_iter = output.lines();
+
+        let dayline = match out_iter.nth(0) {
+            Some(d) => d,
+            None => {
+                eprintln!("Output seems empty. Exiting");
+                process::exit(1);
+            }
+        };
+
+        let mut events: Vec<String> = Vec::new();
+        if dayline.trim() == "Today" {
+            for e in out_iter {
+                events.push(e.to_string());
+            }
+        }
+        let count = events.len();
+        let state = match get_status(events, args.threshold_warn, args.threshold_crit) {
+            Ok(s) => s,
+            Err(e) => {
+                eprintln!("{}", e);
+                process::exit(1);
+            }
+        };
+
+        println!(
+            "{{ \"icon\": \"{}\", \"state\": \"{:?}\", \"text\": \"{}\" }}",
+            args.icon, state, count
+        );
     } else if args.todo {
         println!("todo output");
     }
-
-
 }