7 changed files with 240 additions and 237 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -2,15 +2,6 @@
 # It is not intended for manual editing.
 version = 3

-[[package]]
-name = "aho-corasick"
-version = "1.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "android-tzdata"
 version = "0.1.1"
@ -81,6 +72,17 @@ version = "1.0.72"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3b13c32d80ecc7ab747b80c3784bce54ee8a7a0cc4fbda9bf4cda2cf6fe90854"

+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi 0.1.19",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@ -206,6 +208,15 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"

+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.3.2"
@ -241,7 +252,7 @@ version = "0.4.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb0889898416213fab133e1d33a0e5858a48177452750691bde3666d0fdbaf8b"
 dependencies = [
- "hermit-abi",
+ "hermit-abi 0.3.2",
 "rustix",
 "windows-sys",
 ]
@ -273,12 +284,6 @@ version = "0.4.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b06a4cde4c0f271a446782e3eff8de789548ce57dbc8eca9292c27f4a42004b4"

-[[package]]
-name = "memchr"
-version = "2.7.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
-
 [[package]]
 name = "num-traits"
 version = "0.2.15"
@ -312,35 +317,6 @@ dependencies = [
 "proc-macro2",
 ]

-[[package]]
-name = "regex"
-version = "1.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-automata",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-automata"
-version = "0.4.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "368758f23274712b504848e9d5a6f010445cc8b87a7cdb4d7cbee666c1288da3"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-syntax"
-version = "0.8.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
-
 [[package]]
 name = "rustix"
 version = "0.38.3"
@ -384,12 +360,12 @@ dependencies = [

 [[package]]
 name = "time-track"
-version = "2.1.4"
+version = "1.1.0"
 dependencies = [
 "anyhow",
+ "atty",
 "chrono",
 "clap",
- "regex",
 ]

 [[package]]
--- a/Cargo.toml
+++ b/Cargo.toml
@ -1,12 +1,12 @@
 [package]
 name = "time-track"
-version = "2.1.4"
+version = "1.1.0"
 edition = "2021"

 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
 anyhow = "1.0.72"
+atty = "0.2.14"
 chrono = "0.4.26"
 clap = { version = "4.3.11", features = ["derive"] }
-regex = "1.11.1"
--- a/README.md
+++ b/README.md
@ -1,22 +0,0 @@
-# time-track
-
-A simple CLI tool for tracking how much time you have left to work. I find myself stressing about whether I'm hitting 8 real hours, so this little tool helps me avoid wasting
-time calculating when my work day will end.
-
-Simply enter times, one per line and send an EOF character when you're done. The first lines opens a span of work and the next line closes it so that you can build up working
-time be clocking in and out. Finally, you can send additional arguments to the program to configure how long you intend to work (the default is 8 hours).
-
-```
-❯ time-track
-Working for 8 hours
-Input times one per line. Send an EOF character to finish inputting...
-8:30
-9:30
-11:15
-12:30
-13:16
-18:20
-19:30
-20:11 # Send an EOF
-Exactly done
-```
--- a/src/args.rs
+++ b/src/args.rs
@ -1,19 +0,0 @@
-use clap::Parser;
-
-/// A simple program to track time spans and calculate remaining hours to work
-#[derive(Parser, Debug)]
-#[command(author, version, about, long_about = None)]
-pub struct Args {
-    /// How many hours you intend to work (sums with `minutes`)
-    /// Usually defaults to 8 hours, but if discount is set then it defaults to 0
-    #[arg(long)]
-    pub hours: Option<i64>,
-
-    /// How many minutes you intend to work (sums with `hours`)
-    #[arg(long, default_value_t = 0)]
-    pub minutes: i64,
-
-    /// If true, the the hours and minutes fields are treated as subtracting from 8 hours
-    #[arg(long, default_value_t = false)]
-    pub discount: bool,
-}
--- a/src/main.rs
+++ b/src/main.rs
@ -1,65 +1,186 @@
-use std::io::{self, BufRead};
-use chrono::{DateTime, Local};
+use std::io::{stdin, BufRead};

+use chrono::{NaiveTime, Duration, Local, NaiveDateTime};
 use clap::Parser;
+use atty::Stream;
 use anyhow::{anyhow, Result};
-mod args;
-mod time;

-use args::Args;
+mod modes;
+use modes::Modes;

-fn main() -> Result<()> {
-    let args = Args::parse();
-    let stdin = io::stdin();
-    let hours = args.hours.unwrap_or(
-        if args.discount {
-            0
-        } else {
-            8
+/// A simple program to track time spans
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Args {
+    /// Specify how the program should behave
+    #[clap(value_enum, default_value_t = Modes::default())]
+    mode: Modes,
+
+    #[arg(long, default_value_t = 8)]
+    hours: i64,
 }
-    );

-    let target_minutes = if args.discount {
-        (8 * 60) - ((hours * 60) + args.minutes)
+fn epoch() -> NaiveTime {
+    NaiveTime::from_hms_opt(0, 0, 0).expect("0, 0, 0 to be valid arguments to from_hms_opt")
+}
+
+/// Given an arbitrary string, attempt to parse it as a naive time in the format HH:mm
+fn parse_time(time_str: &str) -> Result<NaiveDateTime> {
+    let time = NaiveTime::parse_from_str(time_str, "%H:%M")?;
+    let naive_date = NaiveDateTime::from_timestamp_millis(
+        time.signed_duration_since(epoch()).num_milliseconds(),
+    ).ok_or(anyhow!("Should be able to make a datetime"))?;
+    Ok(naive_date)
+}
+
+fn adjust_last(first: &NaiveTime, second: NaiveTime) -> NaiveTime {
+    // The following logic attempts to handle wrapping from AM -> PM and also from PM ->
+    // AM but cannot handle multiple days in a single span
+    if (second < *first) && first.signed_duration_since(epoch()).num_hours() < 12 {
+        // Assuming wrapped to PM
+        // first = 8:00
+        // second: 1:00
+        second + Duration::hours(12)
+    } else if second < *first {
+        // Wrapped to a new day because first was after noon.
+        // first = 14:40
+        // second = 1:30
+        second + Duration::hours(24)
    } else {
-         hours * 60 + args.minutes
+        second
+    }
+}
+
+/// The default way of calculating time. Time values are given one per line and subsequent pairs of
+/// lines are considered time spans. If an odd number of spans is given, then the final time value
+/// is ignored.
+fn all_at_once(is_terminal: bool) -> Result<Vec<Duration>> {
+    if is_terminal {
+        println!("Enter simple times one per line. Send an EOF character to sum all time spans");
+    }
+
+    let mut durations = vec![];
+    let mut seen: Option<String> = None;
+    for line in stdin().lock().lines() {
+        let cleaned = line?.trim().to_string();
+        if let Some(previous) = &seen {
+            let first = parse_time(previous)?;
+            let second = adjust_last(&first.time(), parse_time(&cleaned)?.time());
+
+            durations.push(second - first.time());
+            seen = None;
+        } else {
+            seen = Some(cleaned.to_string());
+        }
+    }
+    if let Some(unpaired) = seen {
+        let now = Local::now().naive_local().time();
+        let last = adjust_last(&now, parse_time(&unpaired)?.time());
+        println!("Ended with an open span from {unpaired}... assuming now: {}", now.format("%H:%M"));
+        durations.push(now - last);
+    }
+    return Ok(durations);
+}
+
+/// A "live" time tracker. Each time the user presses enter a new span is started or an existing
+/// span is closed. The user may end the tracking at any time by sending an EOF command.
+fn live_spans() -> Result<Vec<Duration>> {
+    println!("Tracking Spans Live. Press ENTER to start a span\n");
+    let mut durations = vec![];
+    let mut seen: Option<NaiveTime> = None;
+    for _line in stdin().lock().lines() {
+        let mut now = Local::now().naive_local().time();
+        if let Some(previous) = &seen {
+            now = adjust_last(previous, now);
+            let prev_time = previous.format("%H:%M");
+            let now_time = now.format("%H:%M");
+            println!("Closing span from {prev_time} - {now_time}");
+            println!("Status: Away");
+            durations.push(now - *previous);
+            seen = None;
+        } else {
+            let now_time = now.format("%H:%M");
+            println!("Starting span at {now_time}");
+            println!("Status: Working");
+            seen = Some(now);
+        }
+    }
+    if let Some(unpaired) = seen {
+        println!("Closing unpaired span now");
+        let mut now = Local::now().naive_local().time();
+        now = adjust_last(&unpaired, now);
+        durations.push(now - unpaired);
+    }
+    return Ok(durations);
+}
+
+fn to_hrs_minutes(total_minutes: i64) -> (i64, i64) {
+    let minutes = total_minutes % 60;
+    let hours = total_minutes / 60;
+    (hours, minutes)
+}
+
+fn show_time(hours: i64, minutes: i64) -> String {
+    let pluralized_hours = match hours {
+        1 => "1 hour".to_string(),
+        _ => format!("{hours} hours"),
    };
-    let (hrs, mins) = time::to_hrs_minutes(target_minutes);
-    println!("Working for {}", time::show_time(hrs, mins));
-    println!("Input times one per line. Send an EOF character to finish inputting...");
-    let mut lines: Vec<String> = vec![];
-    for line in stdin.lock().lines() {
-        lines.push(line.expect("Issues when reading from stdin"));
+    let pluralized_minutes = match minutes {
+        1 => "1 minute".to_string(),
+        _ => format!("{minutes} minutes"),
+    };
+
+    if hours == 0 {
+        return pluralized_minutes.to_string();
    }

-    // This is immeidately going to be turned back into a DateTime, which the doc says is fine
-    #[allow(deprecated)]
-    let midnight = Local::now().date().and_hms_opt(0, 0, 0).ok_or(anyhow!("Expected midnight to exist"))?;
-    let times = time::from_stream(&midnight, lines.iter())?;
+    if minutes == 0 {
+        return pluralized_hours.to_string();
+    }

-    let mut total_minutes: i64 = 0;
-    let mut first: Option<DateTime<Local>> = None;
-    let mut last: Option<DateTime<Local>> = None;
-    for time in times {
-        match first {
-            None => {
-                first = Some(time);
+    return format!("{pluralized_hours} and {pluralized_minutes}");
+}
+
+fn get_charaterized_time_remaining(total_minutes: i64, target_minutes: i64) -> String {
+    if total_minutes == target_minutes {
+        return "Exactly done".to_string();
+    }
+
+    if total_minutes > target_minutes {
+        let diff = total_minutes - target_minutes;
+        let (hours, minutes) = to_hrs_minutes(diff);
+        return format!("You have overworked {}", show_time(hours, minutes))
+    } else {
+        let diff = target_minutes - total_minutes;
+        let (hours, minutes) = to_hrs_minutes(diff);
+        let end_at = (Local::now() + Duration::minutes(diff)).time();
+        let end_str = end_at.format("%-I:%M %p");
+        return format!("You have {} remaining (end at {} starting now)", show_time(hours, minutes), end_str)
+    }
+}
+
+fn main() {
+    let args = Args::parse();
+    let is_terminal = atty::is(Stream::Stdin);
+
+    if !is_terminal && !args.mode.supports_piped_input() {
+        panic!("Cannot run {0} mode on piped input", args.mode);
+    }
+
+    let maybe_durations = match args.mode {
+        Modes::TimeTable => all_at_once(is_terminal),
+        Modes::Live => live_spans(),
+    };
+
+    match maybe_durations {
+        Ok(durations) => {
+            let total_minutes: i64  = durations.iter().map(|d| { d.num_minutes() }).sum();
+            let (hours, minutes) = to_hrs_minutes(total_minutes);
+
+            println!("-----------------");
+            println!("You have been working for {}", show_time(hours, minutes));
+            println!("{}", get_charaterized_time_remaining(total_minutes, args.hours * 60))
        },
-            Some(prev) => {
-                total_minutes += (time - prev).num_minutes();
-                first = None;
-                last = Some(time);
+        Err(err) => eprintln!("{}\nExiting...", err),
    }
 }
-    }
-
-    if let Some(remaining) = first {
-        let now = Local::now();
-        let now_str = now.format("%-I:%M %p");
-        println!("Ended with unclosed span... assuming ending now: {}", now_str);
-        total_minutes += (now - remaining).num_minutes();
-    }
-
-    println!("{}", time::get_charaterized_time_remaining(total_minutes, target_minutes, last.unwrap_or_else(|| Local::now())));
-    Ok(())
-}
--- a/src/modes.rs
+++ b/src/modes.rs
@ -0,0 +1,36 @@
+use clap::ValueEnum;
+
+#[derive(ValueEnum, Debug, Copy, Clone, Eq, PartialEq)]
+pub enum Modes {
+    /// Perform calculations by treating stdin as a stream of time pairs separated by newlines
+    TimeTable,
+    /// Perform live tracking of the user's time until an EOF character is received.
+    Live,
+}
+
+impl Modes {
+    /// Determine whether or not the variant supports piped input vs being used as a CLI tool
+    /// directly by a human
+    pub fn supports_piped_input(&self) -> bool {
+        match self {
+            Modes::TimeTable => true,
+            Modes::Live => false,
+        }
+    }
+}
+
+
+impl Default for Modes {
+    fn default() -> Self {
+        Self::TimeTable
+    }
+}
+
+impl std::fmt::Display for Modes {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.to_possible_value()
+            .expect("no values are skipped")
+            .get_name()
+            .fmt(f)
+    }
+}
--- a/src/time.rs
+++ b/src/time.rs
@ -1,89 +0,0 @@
-use chrono::{Duration, Local, DateTime};
-use anyhow::{Result, anyhow};
-use std::iter::Iterator;
-use regex::Regex;
-
-fn parse_datetime(reference_date: &DateTime<Local>, s: &str) -> Result<DateTime<Local>> {
-    let re = Regex::new(r"^\s*([12]?\d):([012345]\d)\s*$")?;
-    let (_, [hrs, mins]) = re.captures(s).ok_or(anyhow!(format!("Failed to parse \"{s}\" as a time")))?.extract();
-    let mins: u32 = mins.parse()?;
-    let mut hrs: u32 = hrs.parse()?;
-    let mut date = *reference_date;
-
-    if hrs > 23 {
-        let num_days = hrs / 24;
-        date = *reference_date + Duration::days(num_days.into());
-        hrs = hrs % 24;
-    }
-    #[allow(deprecated)]
-    Ok(date.date().and_hms_opt(hrs, mins, 0).ok_or(anyhow!(format!("{}:{:0>2} not a real time", hrs, mins)))?)
-}
-
-pub fn from_stream<'a>(reference_date: &DateTime<Local>, stream: impl Iterator<Item = &'a String>) -> Result<Vec<DateTime<Local>>> {
-    let mut durations: Vec<DateTime<Local>> = vec![];
-    for val in stream {
-        durations.push(parse_datetime(reference_date, val)?);
-    }
-    return Ok(durations);
-}
-
-pub fn show_time(hours: i64, minutes: i64) -> String {
-    let pluralized_hours = match hours {
-        1 => "1 hour".to_string(),
-        _ => format!("{hours} hours"),
-    };
-    let pluralized_minutes = match minutes {
-        1 => "1 minute".to_string(),
-        _ => format!("{minutes} minutes"),
-    };
-
-    if hours == 0 {
-        return pluralized_minutes.to_string();
-    }
-
-    if minutes == 0 {
-        return pluralized_hours.to_string();
-    }
-
-    return format!("{pluralized_hours} and {pluralized_minutes}");
-}
-
-pub fn to_hrs_minutes(total_minutes: i64) -> (i64, i64) {
-    let minutes = total_minutes % 60;
-    let hours = total_minutes / 60;
-    (hours, minutes)
-}
-
-pub fn get_charaterized_time_remaining(
-    total_minutes: i64,
-    target_minutes: i64,
-    ended_at: DateTime<Local>,
-) -> String {
-    if total_minutes == target_minutes {
-        return "Exactly done".to_string();
-    }
-
-    if total_minutes > target_minutes {
-        let diff = total_minutes - target_minutes;
-        let (hours, minutes) = to_hrs_minutes(diff);
-        return format!("You have overworked {}", show_time(hours, minutes))
-    } else {
-        let diff = target_minutes - total_minutes;
-        let (hours, minutes) = to_hrs_minutes(diff);
-        let now = Local::now();
-        return if ended_at > now {
-            let end_at = (ended_at + Duration::minutes(diff)).time();
-            let end_str = end_at.format("%-I:%M %p");
-            format!(
-                "You have {} remaining (end at {} starting from {})",
-                show_time(hours, minutes),
-                end_str,
-                ended_at.format("%-I:%M %p"),
-            )
-        } else {
-            let end_at = (now + Duration::minutes(diff)).time();
-            let end_str = end_at.format("%-I:%M %p");
-            format!("You have {} remaining (end at {} starting now)", show_time(hours, minutes), end_str)
-        }
-    }
-}