use serde::de;
use std::collections::HashMap;
mod error;
use error::{Error, MpdResult};
mod structs;
pub use structs::{Position, Track};

/// some unprintable character to separate repeated keys
const SEPARATOR: char = '\x02';

pub fn deserialize_response<'a, I: Iterator<Item = &'a str>, T: de::DeserializeOwned>(input: I) -> MpdResult<T> {
  let mut map: HashMap<String, String> = HashMap::new();
  for line in input {
    if line.starts_with("OK") {
      break;
    } else if let Some(message) = line.strip_prefix("ACK") {
      return Err(Error::from_str(message.trim()));
    }

    let mut fields = line.splitn(2, ": ");
    match (fields.next(), fields.next()) {
      (Some(k), Some(v)) => {
        if let Some(existing) = map.get_mut(k) {
          existing.push(SEPARATOR);
          existing.push_str(v);
        } else {
          map.insert(k.to_string(), v.to_string());
        }
      }
      _ => panic!("invalid response line: {:?}", line),
    }
  }
  // Eventually, I’d like to use my own deserializer instead of envy
  Ok(envy::from_iter(map).unwrap())
}

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

  #[test]
  fn track_de_test() {
    let input_str = "file: American Pie.flac
Last-Modified: 2019-12-16T21:38:54Z
Album: American Pie
Artist: Don McLean
Date: 1979
Genre: Rock
Title: American Pie
Track: 1
Time: 512
duration: 512.380
Pos: 1367
Id: 1368
OK";
    let t: Track = deserialize_response(input_str.lines()).unwrap();
    assert_eq!(
      t,
      Track {
        file: "American Pie.flac".to_string(),
        last_modified: Some(DateTime::parse_from_rfc3339("2019-12-16T21:38:54Z").unwrap()),
        album: Some("American Pie".to_string()),
        artist: Some("Don McLean".to_string()),
        date: Some(1979),
        genre: Some("Rock".to_string()),
        title: Some("American Pie".to_string()),
        track: Some(Position {
          item_position: 1,
          total_items:   None,
        }),
        duration: std::time::Duration::from_secs_f64(512.380),
        pos: 1367,
        id: 1368,
        ..Track::default()
      }
    );
  }

  #[test]
  fn repeated_field_test() {
    let input_str = r#"file: 06 Symphonie No. 41 en ut majeur, K. 551 _Jupiter_ I. Allegro Vivace.flac
Last-Modified: 2018-11-11T09:01:54Z
Album: Symphonies n°40 & n°41
AlbumArtist: Wolfgang Amadeus Mozart; Royal Philharmonic Orchestra, Jane Glover
AlbumArtistSort: Mozart, Wolfgang Amadeus; Royal Philharmonic Orchestra, Glover, Jane
Artist: Wolfgang Amadeus Mozart
ArtistSort: Mozart, Wolfgang Amadeus
Composer: Wolfgang Amadeus Mozart
Date: 2005
Disc: 1
Disc: 1
MUSICBRAINZ_ALBUMARTISTID: b972f589-fb0e-474e-b64a-803b0364fa75
MUSICBRAINZ_ALBUMID: 688d9252-f897-4ab6-879d-5cb83bb71087
MUSICBRAINZ_ARTISTID: b972f589-fb0e-474e-b64a-803b0364fa75
MUSICBRAINZ_RELEASETRACKID: 54a2632f-fa98-3713-bd75-d7effc03d0b1
MUSICBRAINZ_TRACKID: 2dd10dd8-e8de-4479-a092-9a04c2760fd6
OriginalDate: 1993
Title: Symphonie No. 41 en ut majeur, K. 551 "Jupiter": I. Allegro Vivace
Track: 6
Track: 6
Time: 683
Performer: Royal Philharmonic Orchestra
duration: 682.840
Performer: Jane Glover
Pos: 3439
Id: 3440
OK"#;
    let t: Track = deserialize_response(input_str.lines()).unwrap();
    assert_eq!(
      t,
      Track {
        file: "06 Symphonie No. 41 en ut majeur, K. 551 _Jupiter_ I. Allegro Vivace.flac".to_string(),
        last_modified: Some(DateTime::parse_from_rfc3339("2018-11-11T09:01:54Z").unwrap()),
        album: Some("Symphonies n°40 & n°41".to_string()),
        artist: Some("Wolfgang Amadeus Mozart".to_string()),
        artist_sort: Some("Mozart, Wolfgang Amadeus".to_string()),
        album_artist: Some("Wolfgang Amadeus Mozart; Royal Philharmonic Orchestra, Jane Glover".to_string()),
        album_artist_sort: Some("Mozart, Wolfgang Amadeus; Royal Philharmonic Orchestra, Glover, Jane".to_string()),
        composer: Some("Wolfgang Amadeus Mozart".to_string()),
        date: Some(2005),
        original_date: Some(1993),
        title: Some("Symphonie No. 41 en ut majeur, K. 551 \"Jupiter\": I. Allegro Vivace".to_string()),
        disc: Some(Position {
          item_position: 1,
          total_items:   Some(1),
        }),
        track: Some(Position {
          item_position: 6,
          total_items:   Some(6),
        }),
        duration: std::time::Duration::from_secs_f64(682.840),
        pos: 3439,
        id: 3440,
        performers: vec!["Royal Philharmonic Orchestra".to_string(), "Jane Glover".to_string()],
        musicbrainz_albumartistid: Some("b972f589-fb0e-474e-b64a-803b0364fa75".to_string()),
        musicbrainz_albumid: Some("688d9252-f897-4ab6-879d-5cb83bb71087".to_string()),
        musicbrainz_artistid: Some("b972f589-fb0e-474e-b64a-803b0364fa75".to_string()),
        musicbrainz_releasetrackid: Some("54a2632f-fa98-3713-bd75-d7effc03d0b1".to_string()),
        musicbrainz_trackid: Some("2dd10dd8-e8de-4479-a092-9a04c2760fd6".to_string()),
        ..Track::default()
      }
    );
  }
}