use super::{parse_data_structure, parse_delimiter, parse_string_parameter};
use crate::Event;
use crate::FilterPhase;
use crate::SubSystem;
use crate::TimeVal;
use nom::branch::alt;
use nom::bytes::streaming::tag;
use nom::character::streaming::digit1;
use nom::combinator::map_res;
use nom::IResult;

pub struct ReportEntry {
    pub version: String,
    pub timestamp: TimeVal,
    pub subsystem: SubSystem,
    pub event: Event,
    pub session_id: String,
}

pub struct FilterEntry {
    pub version: String,
    pub timestamp: TimeVal,
    pub subsystem: SubSystem,
    pub phase: FilterPhase,
    pub session_id: String,
    pub token: String,
}

pub(crate) enum EntryOption {
    Report(ReportEntry),
    Filter(FilterEntry),
}

pub(crate) fn parse_entry(input: &[u8]) -> IResult<&[u8], EntryOption> {
    let (input, entry) = alt((parse_report_entry_meta, parse_filter_entry_meta))(input)?;
    Ok((input, entry))
}

fn parse_report_entry_meta(input: &[u8]) -> IResult<&[u8], EntryOption> {
    let (input, _) = tag("report")(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, entry) = parse_report_entry(input)?;
    Ok((input, EntryOption::Report(entry)))
}

fn parse_filter_entry_meta(input: &[u8]) -> IResult<&[u8], EntryOption> {
    let (input, _) = tag("filter")(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, entry) = parse_filter_entry(input)?;
    Ok((input, EntryOption::Filter(entry)))
}

fn parse_report_entry(input: &[u8]) -> IResult<&[u8], ReportEntry> {
    let (input, version) = parse_string_parameter(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, timestamp) = parse_timestamp(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, subsystem) = parse_data_structure::<SubSystem>(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, event) = parse_data_structure::<Event>(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, session_id) = parse_string_parameter(input)?;
    let entry = ReportEntry {
        version,
        timestamp,
        subsystem,
        event,
        session_id,
    };
    Ok((input, entry))
}

fn parse_filter_entry(input: &[u8]) -> IResult<&[u8], FilterEntry> {
    let (input, version) = parse_string_parameter(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, timestamp) = parse_timestamp(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, subsystem) = parse_data_structure::<SubSystem>(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, phase) = parse_data_structure::<FilterPhase>(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, session_id) = parse_string_parameter(input)?;
    let (input, _) = parse_delimiter(input)?;
    let (input, token) = parse_string_parameter(input)?;
    let entry = FilterEntry {
        version,
        timestamp,
        subsystem,
        phase,
        session_id,
        token,
    };
    Ok((input, entry))
}

fn parse_timestamp(input: &[u8]) -> IResult<&[u8], TimeVal> {
    let (input, sec) = map_res(digit1, |s| String::from_utf8_lossy(s).parse::<i64>())(input)?;
    let (input, _) = tag(".")(input)?;
    let (input, usec) = map_res(digit1, |s| {
        format!("{:0<6}", String::from_utf8_lossy(s)).parse::<i64>()
    })(input)?;
    let timestamp = TimeVal { sec, usec };
    Ok((input, timestamp))
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_report_link_connect() {
        let input = b"report|0.5|1576146008.06099|smtp-in|link-connect|7641df9771b4ed00|mail.openbsd.org|pass|199.185.178.25:33174|45.77.67.80:25";
        let res = parse_entry(input);
        assert!(res.is_ok());
        let (_, res) = res.unwrap();
        let res = match res {
            EntryOption::Report(r) => r,
            _ => {
                assert!(false);
                return;
            }
        };
        assert_eq!(res.version, String::from("0.5"));
        assert_eq!(
            res.timestamp,
            TimeVal {
                sec: 1576146008,
                usec: 60990
            }
        );
        assert_eq!(res.subsystem, SubSystem::SmtpIn);
        assert_eq!(res.event, Event::LinkConnect);
        assert_eq!(res.session_id, String::from("7641df9771b4ed00"));
    }
}