#[macro_use]
extern crate log;
#[macro_use]
extern crate lazy_static;

use regex::Regex;
use std::fs::{File, OpenOptions};
use std::io::{BufReader, Write};
use std::io;
use std::str::FromStr;
use std::convert::TryFrom;
use std::io::BufRead;
use std::ops::{Add, Mul, MulAssign, AddAssign, SubAssign, Sub};
use std::fmt::{self, Display};
use serde::export::fmt::Debug;

const LOG_LEVELS: [&str; 5] = ["error", "warn", "info", "debug", "trace"];
const SPAMMY_LIBS: [&str; 5] = ["tokio_reactor", "hyper", "reqwest", "mio", "want"];

fn main() {
    let argv =
        clap::App::new("srtune")
            .version(env!("CARGO_PKG_VERSION"))
            .about("Modify a .srt file to match a video. Input and output can be a file or stream, \
            so you pipe multiple invocations to create more complex operations. However, a single \
            invocation should suffice in most cases.\n\
            Times can be specified in any format: \
            seconds (400, 14.52), hours:minutes:seconds (14:00, 15:51.12, 1:30:00). Decimal point \
            can be period or comma; Times copied directly from the .srt file will also work.\n\
            When a command allows both time and index as a value, index must be prefixed with '@'.\
            The tool should be used iteratively, adjusting the invocation until the generated \
            subtitle file meets expectations. As such, times and indices accepted by its parameters \
            are, by default, the ones seen in the output file. Prefix a time or index with '^' \
            to use the original value from the input instead (i.e. original index 14 is '^@14')
            ")
            .arg(clap::Arg::with_name("input")
                     .value_name("INFILE")
                     .help("Input file, leave out for stdin"),
            )
            .arg(clap::Arg::with_name("output")
                     .short("o")
                     .long("output")
                     .value_name("OUTFILE")
                     .help("Output file, defaults to stdout"),
            )
            .arg(clap::Arg::with_name("from")
                     .short("f")
                     .long("from-time")
                     .value_name("TIME")
                     .help("Time of the first affected entry, or its index. Defaults to 0/^@0."),
            )
            .arg(clap::Arg::with_name("move")
                     .short("m")
                     .long("move")
                     .value_name("TIME")
                     .help("Move subtitles in time. Use seconds, M:S or H:M:S, decimals and minus \
                     are supported. Starts at the point specified by '--from'"),
            )
            .arg(clap::Arg::with_name("automove")
                     .short("M")
                     .long("automove")
                     .value_name("SUBTIME=VIDEOTIME")
                     .multiple(true)
                     .help("Move subtitles following a given time or index to match video times. \
                     This automatically sets '--from' if not given explicitly."),
            )
            .arg(clap::Arg::with_name("scale")
                     .short("s")
                     .long("scale")
                     .value_name("RATIO")
                     .help("Scale subtitle times and durations to compensate for bitrate \
                     differences. 1 means identity, 1.1 makes all times 10% longer. Scaling is \
                     relative to the first emitted subtitle with positive time (after shifting). \
                     Has no effect if '--autoscale' is used."),
            )
            .arg(clap::Arg::with_name("autoscale")
                     .short("S")
                     .long("autoscale")
                     .value_name("SUBTIME=VIDEOTIME")
                     .help("Calculate scaling based on a perceived difference. The scaling is \
                     related to the first emitted subtitle, so ensure it is aligned properly \
                     with '--move'."),
            )
            .arg(clap::Arg::with_name("durscale")
                     .short("d")
                     .long("durscale")
                     .value_name("RATIO")
                     .help("Scale durations, can be combined with '--scale' or '--autoscale'. The \
                     given value will always be multiplied by the absolute time scale. 1 means \
                     identity, 1.1 makes all times 10% longer."),
            )
            .arg(clap::Arg::with_name("renumber")
                     .short("r")
                     .long("renumber")
                     .help("Change all numbers to be sequential starting with 1"),
            )
            .arg(clap::Arg::with_name("v").short("v").multiple(true).help(
                "Sets the level of verbosity (adds to the default - info)",
            ))
            .get_matches();

    let mut log_level = "info".to_owned();

    if argv.is_present("v") {
        // bump verbosity if -v's are present
        let pos = LOG_LEVELS
            .iter()
            .position(|x| x == &log_level)
            .unwrap();

        log_level = match LOG_LEVELS
            .iter()
            .nth(pos + argv.occurrences_of("v") as usize)
            {
                Some(new_level) => new_level.to_string(),
                None => "trace".to_owned(),
            };
    }

    //println!("LEVEL={}", log_level);

    // init logging
    let env = env_logger::Env::default().default_filter_or(log_level);
    let mut builder = env_logger::Builder::from_env(env);
    let lib_level = log::LevelFilter::Info;
    for lib in &SPAMMY_LIBS {
        builder.filter_module(lib, lib_level);
    }
    builder.init();

    let from = match argv.value_of("from") {
        Some(mut s) => {
            if s.starts_with('^') {
                s = &s[1..];
                if s.starts_with('@') {
                    let index = &s[1..].parse().expect("Bad --from format");
                    FromTag::ByIndexOrig(*index)
                } else {
                    // this is always the orig time
                    FromTag::ByTime(SubDuration::try_from(s).expect("Bad --from format").as_instant())
                }
            } else {
                if s.starts_with('@') {
                    let index = &s[1..].parse().expect("Bad --from format");
                    FromTag::ByIndex(*index)
                } else{
                    FromTag::ByTime(SubDuration::try_from(s).expect("Bad --from format").as_instant())
                }
            }
        }
        None => FromTag::ByIndex(0)
    };

    let shift = match argv.value_of("move") {
        Some(s) => {
            SubDuration::try_from(s).expect("Bad --move format")
        }
        None => SubDuration(0f32)
    };

    let scale = match argv.value_of("scale") {
        Some(s) => {
            s.parse().expect("Bad --scale format")
        }
        None => 1f32
    };

    let durscale = match argv.value_of("durscale") {
        Some(s) => {
            s.parse().expect("Bad --durscale format")
        }
        None => 1f32
    }; // always also shrink durations

    let autoscale = match argv.value_of("autoscale") {
        Some(s) => {
            let halves : Vec<&str> = s.split("=").collect();
            if halves.len() != 2 {
                panic!("Bad --autoscale format, should be SUBTIME=VIDEOTIME")
            }
            let (first, second) = (halves[0], halves[1]);
            if first.starts_with('^') {
                panic!("'--autoscale' always uses original times");
            }
            let subtime = SubDuration::try_from(first).expect("Bad --autoscale format").as_instant();
            let vidtime = SubDuration::try_from(second).expect("Bad --autoscale format").as_instant();

            Some((subtime, vidtime))
        }
        None => None
    };

    let mut automove = Vec::<AutoMoveTag>::new();
    match argv.values_of("automove") {
        Some(ss) => {
            for s in ss {
                let halves: Vec<&str> = s.split("=").collect();
                if halves.len() != 2 {
                    panic!("Bad --automove format, should be SUBTIME=VIDEOTIME")
                }
                let (mut first, second) = (halves[0], halves[1]);
                let vidtime = SubDuration::try_from(second).expect("Bad --automove format").as_instant();

                if first.starts_with('^') {
                    first = &first[1..];
                    if s.starts_with('@') {
                        let index = &first[1..].parse().expect("Bad --automove format");
                        automove.push(AutoMoveTag::ByIndexOrig(*index, vidtime));
                    } else {
                        let subtime = SubDuration::try_from(first).expect("Bad --automove format").as_instant();
                        automove.push(AutoMoveTag::ByTimeOrig(subtime, vidtime));
                    }
                } else {
                    if s.starts_with('@') {
                        let index = &first[1..].parse().expect("Bad --automove format");
                        automove.push(AutoMoveTag::ByIndex(*index, vidtime));
                    } else{
                        let subtime = SubDuration::try_from(first).expect("Bad --automove format").as_instant();
                        automove.push(AutoMoveTag::ByTime(subtime, vidtime));
                    }
                }
            }
        }
        None => (/* no automoves */)
    }

    let inf = argv.value_of("input");
    let outf = argv.value_of("output");
    let stdin = io::stdin();
    let stdout = io::stdout();

    let mut lines_iterator: Box<dyn Iterator<Item=Result<String, io::Error>>> = match inf {
        None => {
            Box::new(stdin.lock().lines())
        }
        Some(f) => {
            let file = File::open(f).expect(&format!("Could not open file: {:?}", f));
            Box::new(BufReader::new(file).lines())
        }
    };

    let mut outfile: Box<dyn Write> = match outf {
        None => {
            Box::new(stdout.lock())
        }
        Some(f) => {
            let file = OpenOptions::new()
                .create(true)
                .truncate(true)
                .write(true)
                .open(f)
                .expect(&format!("Could not open file: {:?}", f));
            Box::new(file)
        }
    };

    let renumber = argv.is_present("renumber");

    transform_subtitles(&mut lines_iterator, &mut outfile, TransformOpts {
        renumber,
        autoscale,
        durscale,
        scale,
        shift,
        from,
        automove,
    });
}

#[derive(Debug)]
struct TransformOpts {
    renumber: bool,
    autoscale: Option<(SubInstant, SubInstant)>,
    durscale: f32,
    scale: f32,
    shift: SubDuration,
    automove: Vec<AutoMoveTag>,
    from: FromTag,
}

#[derive(Debug)]
enum AutoMoveTag {
    ByTime(SubInstant, SubInstant),
    ByTimeOrig(SubInstant, SubInstant),
    ByIndex(u32, SubInstant),
    ByIndexOrig(u32, SubInstant),
    ByIndexRelative(u32, SubDuration),
}

#[derive(Debug)]
enum FromTag {
    ByTime(SubInstant),
    ByIndex(u32),
    ByIndexOrig(u32)
}

#[derive(Debug,Default,Clone,Copy)]
struct IterState {
    start_time : Option<SubInstant>,
    renumber_i : u32,
}

fn transform_subtitles<'a>(lines : &mut Box<dyn Iterator<Item=Result<String, io::Error>> + 'a>,
                       outfile : &mut Box<dyn Write + 'a>,
                       mut opts : TransformOpts) {
    debug!("Opts: {:#?}", opts);

    let mut istate = IterState::default();

    let mut linebuf = vec![];
    while let Some(Ok(x)) = lines.next() {
        let mut x = x.trim();
        if x.starts_with('\u{feff}') {
            debug!("Stripping BOM mark");
            x = &x[3..];
        }
        let x = x.trim();
        if x.is_empty() {
            continue;
        }

        let istate_backup = istate;

        // 236
        // 00:18:01,755 --> 00:18:03,774
        // （掃除機の音）
        // う～ん…。
        match u32::from_str(x) {
            Ok(num_orig) => {
                // println!("Entry {}", num);
                let datesrow = lines.next().unwrap().unwrap();
                if datesrow.contains(" --> ") {
                    let mut halves = datesrow.split(" --> ");
                    let (first, second) = (halves.next().unwrap(), halves.next().unwrap());
                    let sub_start = SubInstant::try_from(first).unwrap();
                    let sub_end = SubInstant::try_from(second).unwrap();

                    linebuf.clear();
                    while let Some(Ok(x)) = lines.next() {
                        if x.is_empty() {
                            break; // space between the entries
                        }
                        linebuf.push(x);
                    }

                    let num_new = if opts.renumber {
                        istate.renumber_i += 1;
                        istate.renumber_i
                    } else {
                        num_orig
                    };

                    // advance numbering only for the really emitted entries


                    let mut subtitle = Subtitle {
                        num : num_new,
                        start: sub_start,
                        dur: sub_end - sub_start,
                        text: linebuf.join("\n"),
                    };

                    if match opts.from {
                        FromTag::ByTime(ins) => ins <= sub_start,
                        FromTag::ByIndex(idx) => idx <= num_new,
                        FromTag::ByIndexOrig(idx) => idx <= num_orig,
                    } {
                        if istate.start_time.is_none() {
                            debug!("Scaling anchored at {} (#{}), editing starts", sub_start, num_orig);
                            debug!("Shifting by: {}", opts.shift);

                            istate.start_time = Some(sub_start);

                            if let Some((mut subt, mut vidt)) = opts.autoscale {
                                debug!("Autoscale: VT {} -> ST {}", vidt, subt);
                                subt -= sub_start;
                                vidt -= sub_start + opts.shift;
                                if subt.0 <= 0f32 {
                                    panic!("Error in autoscale, start time is negative or zero.");
                                }
                                if vidt.0 <= 0f32 {
                                    panic!("Error in autoscale, end time is negative or zero.");
                                }
                                debug!("  relative to #{}, after \"move\": VT {} -> ST {}", num_orig, vidt, subt);
                                opts.scale = vidt.0 / subt.0;
                                debug!("Resolved scale as {}", opts.scale);
                            }

                            opts.durscale *= opts.scale;
                            debug!("Duration scaling is {}", opts.durscale);
                        }

                        if opts.scale != 1f32 {
                            subtitle.start = subtitle.start.scale(istate.start_time.unwrap(), opts.scale);
                        }

                        subtitle.dur *= opts.durscale;
                        subtitle.start += opts.shift;

                        for amove in opts.automove.iter_mut() {
                            match amove {
                                AutoMoveTag::ByIndex(idx, ref vidt) => {
                                    if num_new >= *idx {
                                        debug!("Move by new index starts, reached {}", idx);
                                        let vidt = *vidt;
                                        let dif = vidt - subtitle.start;
                                        subtitle.start = vidt;
                                        std::mem::replace(amove, AutoMoveTag::ByIndexRelative(num_new, dif));
                                    } else if *vidt < subtitle.start && *idx > num_new {
//                                        istate = istate_backup;
                                        warn!("Skip overlapped #{} (by index)", num_orig);
                                        continue;
                                    }
                                }
                                AutoMoveTag::ByIndexOrig(idx, ref vidt) => {
                                    if num_orig >= *idx {
                                        debug!("Move by orig index starts, reached {}", idx);
                                        let vidt = *vidt;
                                        let dif = vidt - subtitle.start;
                                        subtitle.start = vidt;
                                        std::mem::replace(amove, AutoMoveTag::ByIndexRelative(num_new, dif));
                                    } else if *vidt < sub_start && *idx > num_orig {
//                                        istate = istate_backup;
                                        warn!("Skip overlapped #{} (by orig index)", num_orig);
                                        continue;
                                    }
                                }
                                AutoMoveTag::ByTime(ref subt, ref vidt) => {
                                    if subtitle.start >= *vidt {
                                        // TODO verify
                                        subtitle.start += *vidt - *subt;
                                    } else if *vidt < subtitle.start && *subt > subtitle.start {
//                                        istate = istate_backup;
                                        warn!("Skip overlapped #{} (by time)", num_orig);
                                        continue;
                                    }
                                }
                                AutoMoveTag::ByTimeOrig(ref subt, ref vidt) => {
                                    if sub_start >= *subt {
                                        // TODO verify
                                        subtitle.start += *vidt - *subt;
                                    } else if *vidt < subtitle.start && *subt > sub_start {
//                                        istate = istate_backup;
                                        warn!("Skip overlapped #{} (by orig time)", num_orig);
                                        continue;
                                    }
                                },
                                // this is used internally
                                AutoMoveTag::ByIndexRelative(ref idx, ref dif) => {
                                    if num_new >= *idx {
                                        subtitle.start += *dif;
                                    }
                                },
                            }
                        }
                    }

                    if subtitle.start.0 < 0f32 {
                        warn!("Discarding negative time entry #{} @ {:.3}s", subtitle.num, subtitle.start.0);
                        istate = istate_backup;
                        continue;
                    }

                    outfile.write(subtitle.to_string().as_bytes()).expect("failed to write");
                }
            }
            Err(e) => {
                error!("couldnt parse >{}<: {}", x, e);
                for b in x.as_bytes() {
                    error!("{:#02x} - {}", b, b);
                }
                error!("\n");
            }
        }
    }

    outfile.flush().unwrap();
}

#[derive(Copy, Clone, PartialEq, PartialOrd)]
struct SubInstant(f32);

impl Debug for SubInstant {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        write!(f, "Time({})", self)
    }
}

#[derive(Copy, Clone, PartialEq, PartialOrd)]
struct SubDuration(f32);

impl Debug for SubDuration {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        write!(f, "Duration({})", self)
    }
}

impl Display for SubDuration {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        write!(f, "{}", SubInstant(self.0))
    }
}

impl Add<SubDuration> for SubInstant {
    type Output = SubInstant;

    fn add(self, rhs: SubDuration) -> Self::Output {
        SubInstant(self.0 + rhs.0)
    }
}

impl Sub<SubDuration> for SubInstant {
    type Output = SubInstant;

    fn sub(self, rhs: SubDuration) -> Self::Output {
        SubInstant(self.0 - rhs.0)
    }
}

impl Sub<SubInstant> for SubInstant {
    type Output = SubDuration;

    fn sub(self, rhs: SubInstant) -> Self::Output {
        SubDuration(self.0 - rhs.0)
    }
}

impl Mul<f32> for SubDuration {
    type Output = SubDuration;

    fn mul(self, rhs: f32) -> Self::Output {
        SubDuration(self.0 * rhs)
    }
}

impl MulAssign<f32> for SubDuration {
    fn mul_assign(&mut self, rhs: f32) {
        self.0 *= rhs;
    }
}

impl AddAssign<f32> for SubDuration {
    fn add_assign(&mut self, rhs: f32) {
        self.0 += rhs;
    }
}

impl SubInstant {
    /// Scale by a factor with a custom start time
    pub fn scale(&self, start: SubInstant, factor: f32) -> SubInstant {
        SubInstant(start.0 + (self.0 - start.0) * factor)
    }
}

impl AddAssign<f32> for SubInstant {
    fn add_assign(&mut self, rhs: f32) {
        self.0 += rhs;
    }
}

impl AddAssign<SubInstant> for SubInstant {
    fn add_assign(&mut self, rhs: SubInstant) {
        self.0 += rhs.0;
    }
}

impl SubAssign<SubInstant> for SubInstant {
    fn sub_assign(&mut self, rhs: SubInstant) {
        self.0 -= rhs.0;
    }
}

impl SubAssign<SubDuration> for SubInstant {
    fn sub_assign(&mut self, rhs: SubDuration) {
        self.0 -= rhs.0;
    }
}

impl AddAssign<SubDuration> for SubInstant {
    fn add_assign(&mut self, rhs: SubDuration) {
        self.0 += rhs.0;
    }
}

impl Display for SubInstant {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        // TODO optimize this
        let sign = self.0.signum();
        let mut secs = self.0.abs();
        let hours = (secs / 3600f32).floor();
        secs -= hours * 3600f32;
        let minutes = (secs / 60f32).floor();
        secs -= minutes * 60f32;
        let msecs = ((secs % 1f32) * 1000f32).round();
        write!(f, "{}{:02}:{:02}:{:02},{:03}",
               if sign.is_sign_negative() { "-" } else { "" },
               hours, minutes, secs.floor(), msecs)
    }
}

#[derive(Clone, Debug)]
struct Subtitle {
    num: u32,
    start: SubInstant,
    dur: SubDuration,
    text: String,
}

impl Display for Subtitle {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        write!(f, "{}\n{} --> {}\n{}\n\n",
               self.num,
               self.start, self.start + self.dur,
               self.text
        )
    }
}


impl TryFrom<&str> for SubInstant {
    type Error = failure::Error;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        lazy_static! {
            static ref DATE_RE: Regex = Regex::new(r"^(-)?(?P<h>\d+):(?P<m>\d+):(?P<s>\d+(:?[,.]\d+)?)$").unwrap();
        }

        match DATE_RE.captures(value) {
            Some(caps) => {
                let minus = if caps.get(1).is_some() { -1f32 } else { 1f32 };

                let h = &caps["h"];
                let m = &caps["m"];
                let s = caps["s"].replace(",", ".");

                Ok(SubInstant(minus * (f32::from_str(h).unwrap() * 3600f32 +
                    f32::from_str(m).unwrap() * 60f32 +
                    f32::from_str(&s).unwrap())))
            }
            None => Err(failure::format_err!("Error parsing time: {}", value))
        }
    }
}

impl SubDuration {
    pub fn as_instant(&self) -> SubInstant {
        SubInstant(self.0)
    }
}

impl TryFrom<&str> for SubDuration {
    type Error = failure::Error;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        lazy_static! {
            static ref TIME_RE: Regex = Regex::new(r"^(?U)(?P<n>-)?(?:(?P<h>\d+):)?(?:(?P<m>\d+):)?(?P<s>\d+(?:[.,]\d+)?)$").unwrap();
        }

        match TIME_RE.captures(value) {
            Some(caps) => {
                let minus = if caps.name("n").is_some() { -1f32 } else { 1f32 };
                let h = caps.name("h").map_or(0f32, |m| f32::from_str(m.as_str()).unwrap());
                let m = caps.name("m").map_or(0f32, |m| f32::from_str(m.as_str()).unwrap());
                let s = caps.name("s").map_or(0f32, |m| f32::from_str(&m.as_str().replace(",", ".")).unwrap());

                Ok(SubDuration(minus * (h * 3600f32 +
                    m * 60f32 +
                    s)))
            }
            None => {
                Err(failure::format_err!("Error parsing time: {}", value))
            }
        }
    }
}

#[test]
fn test_parse_duration() {
    // this is used for user input on the command line
    let bad = SubDuration(-1f32);
    assert_eq!(SubDuration(45678f32), SubDuration::try_from("45678").unwrap_or(bad), "integer secs");
    assert_eq!(SubDuration(1.23f32), SubDuration::try_from("1.23").unwrap_or(bad), "float secs with period");
    assert_eq!(SubDuration(-1.23f32), SubDuration::try_from("-1.23").unwrap_or(bad), "MINUS float secs with period");
    assert_eq!(SubDuration(1.23f32), SubDuration::try_from("1,23").unwrap_or(bad), "float secs with comma");
    assert_eq!(SubDuration(121.15f32), SubDuration::try_from("2:1.15").unwrap_or(bad), "m:s.frac");
    assert_eq!(SubDuration(121.15f32), SubDuration::try_from("2:01.15").unwrap_or(bad), "m:0s.frac");
    assert_eq!(SubDuration(121.15f32), SubDuration::try_from("02:01.15").unwrap_or(bad), "0m:0s.frac");
    assert_eq!(SubDuration(121.15f32), SubDuration::try_from("02:01,15").unwrap_or(bad), "0m:0s,frac");

    assert_eq!(SubDuration(3721.15f32), SubDuration::try_from("1:02:01,15").unwrap_or(bad), "h:0m:0s,frac");
    assert_eq!(SubDuration(3721.15f32), SubDuration::try_from("1:02:01,15").unwrap_or(bad), "h:0m:0s.frac");
    assert_eq!(SubDuration(3721.15f32), SubDuration::try_from("01:02:01,15").unwrap_or(bad), "0h:0m:0s,frac");
    assert_eq!(SubDuration(-3721.15f32), SubDuration::try_from("-01:02:01,15").unwrap_or(bad), "-0h:0m:0s,frac");
}

#[test]
fn test_parse_instant() {
    let bad = SubInstant(-1f32);
    assert_eq!(SubInstant(1081.755f32), SubInstant::try_from("00:18:01,755").unwrap_or(bad));
    assert_eq!(SubInstant(1081.755f32), SubInstant::try_from("00:18:01.755").unwrap_or(bad));
    assert_eq!(SubInstant(1081.7f32), SubInstant::try_from("00:18:01.7").unwrap_or(bad));
    assert_eq!(SubInstant(1081.7f32), SubInstant::try_from("0:18:1.7").unwrap_or(bad));
    assert_eq!(SubInstant(0f32), SubInstant::try_from("00:00:00,000").unwrap_or(bad));
    assert_eq!(SubInstant(-3600f32), SubInstant::try_from("-01:00:00,000").unwrap_or(bad));
}

#[test]
fn test_stringify_instant() {
    assert_eq!("00:18:01,755", SubInstant::try_from("00:18:01,755").unwrap().to_string());
    assert_eq!("-00:18:01,755", SubInstant::try_from("-00:18:01,755").unwrap().to_string());
    assert_eq!("-00:18:01,700", SubInstant::try_from("-00:18:01.7").unwrap().to_string());
    assert_eq!("00:00:00,000", SubInstant::try_from("00:00:00,000").unwrap().to_string());
    assert_eq!("-00:00:00,000", SubInstant::try_from("-00:00:00,000").unwrap().to_string());
}