igc 0.2.2

use std::fmt;

use crate::records::extension::Extendable;
use crate::util::{ParseError, Time};

/// An extension data record.
///
/// Contains only a timestamp by default, but can be extended with a J record.
#[derive(Debug, PartialEq, Eq)]
pub struct KRecord<'a> {
    pub time: Time,
    extension_string: &'a str,
}

impl<'a> KRecord<'a> {
    pub fn parse(line: &'a str) -> Result<Self, ParseError> {
        assert_eq!(line.as_bytes()[0], b'K');

        if line.len() <= 7 {
            return Err(ParseError::SyntaxError);
        }
        if !line.is_ascii() {
            return Err(ParseError::NonASCIICharacters);
        }

        let time = line[1..7].parse()?;
        let extension_string = &line[7..];

        Ok(Self {
            time,
            extension_string,
        })
    }
}

impl<'a> Extendable for KRecord<'a> {
    const BASE_LENGTH: usize = 7;

    fn extension_string(&self) -> &str {
        self.extension_string
    }
}

impl<'a> fmt::Display for KRecord<'a> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "K{}{}", self.time, self.extension_string)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::records::extension::Extension;

    #[test]
    fn krecord_parse() {
        let sample_string = "K095214FooTheBar";
        let parsed = KRecord::parse(sample_string).unwrap();
        let expected = KRecord {
            time: Time::from_hms(9, 52, 14),
            extension_string: "FooTheBar",
        };

        assert_eq!(parsed, expected);
    }

    #[test]
    fn parse_with_invalid_char_boundary() {
        assert!(KRecord::parse("Kኲበ᧞").is_err());
    }

    #[test]
    fn krecord_format() {
        let expected_string = "K095214FooTheBar";
        let record = KRecord {
            time: Time::from_hms(9, 52, 14),
            extension_string: "FooTheBar",
        };

        assert_eq!(format!("{}", record), expected_string);
    }

    #[test]
    fn krecord_extensions() {
        let record = KRecord {
            time: Time::from_hms(9, 52, 14),
            extension_string: "FooTheBar",
        };
        let ext1 = Extension {
            start_byte: 8,
            end_byte: 10,
            mnemonic: "One",
        };
        let ext2 = Extension {
            start_byte: 11,
            end_byte: 13,
            mnemonic: "Two",
        };
        let ext3 = Extension {
            start_byte: 14,
            end_byte: 16,
            mnemonic: "Th3",
        };

        assert_eq!(record.get_extension(&ext1).unwrap(), "Foo");
        assert_eq!(record.get_extension(&ext2).unwrap(), "The");
        assert_eq!(record.get_extension(&ext3).unwrap(), "Bar");
    }

    proptest! {
        #[test]
        #[allow(unused_must_use)]
        fn parse_doesnt_crash(s in "K\\PC*") {
            KRecord::parse(&s);
        }
    }
}