use crate::*;
use tek_core::midly::Smf;
use std::path::PathBuf;

pub trait HasPhrases {
    fn phrases (&self) -> &Vec<Arc<RwLock<Phrase>>>;
    fn phrases_mut (&mut self) -> &mut Vec<Arc<RwLock<Phrase>>>;
}

#[derive(Clone, Debug, PartialEq)]
pub enum PhrasePoolCommand {
    Add(usize, Phrase),
    Delete(usize),
    Swap(usize, usize),
    Import(usize, PathBuf),
    Export(usize, PathBuf),
    SetName(usize, String),
    SetLength(usize, usize),
    SetColor(usize, ItemColor),
}

impl<T: HasPhrases> Command<T> for PhrasePoolCommand {
    fn execute (self, model: &mut T) -> Perhaps<Self> {
        use PhrasePoolCommand::*;
        Ok(match self {
            Add(mut index, phrase) => {
                let phrase  = Arc::new(RwLock::new(phrase));
                let phrases = model.phrases_mut();
                if index >= phrases.len() {
                    index = phrases.len();
                    phrases.push(phrase)
                } else {
                    phrases.insert(index, phrase);
                }
                Some(Self::Delete(index))
            },
            Delete(index) => {
                let phrase = model.phrases_mut().remove(index).read().unwrap().clone();
                Some(Self::Add(index, phrase))
            },
            Swap(index, other) => {
                model.phrases_mut().swap(index, other);
                Some(Self::Swap(index, other))
            },
            Import(index, path) => {
                let bytes = std::fs::read(&path)?;
                let smf = Smf::parse(bytes.as_slice())?;
                let mut t = 0u32;
                let mut events = vec![];
                for track in smf.tracks.iter() {
                    for event in track.iter() {
                        t += event.delta.as_int();
                        if let TrackEventKind::Midi { channel, message } = event.kind {
                            events.push((t, channel.as_int(), message));
                        }
                    }
                }
                let mut phrase = Phrase::new("imported", true, t as usize + 1, None, None);
                for event in events.iter() {
                    phrase.notes[event.0 as usize].push(event.2);
                }
                Self::Add(index, phrase).execute(model)?
            },
            Export(_index, _path) => {
                todo!("export phrase to midi file");
            },
            SetName(index, name) => {
                let mut phrase = model.phrases()[index].write().unwrap();
                let old_name = phrase.name.clone();
                phrase.name = name;
                Some(Self::SetName(index, old_name))
            },
            SetLength(index, length) => {
                let mut phrase = model.phrases()[index].write().unwrap();
                let old_len = phrase.length;
                phrase.length = length;
                Some(Self::SetLength(index, old_len))
            },
            SetColor(index, color) => {
                let mut color = ItemColorTriplet::from(color);
                std::mem::swap(&mut color, &mut model.phrases()[index].write().unwrap().color);
                Some(Self::SetColor(index, color.base))
            },
        })
    }
}

/// A MIDI sequence.
#[derive(Debug, Clone)]
pub struct Phrase {
    pub uuid:        uuid::Uuid,
    /// Name of phrase
    pub name:        String,
    /// Temporal resolution in pulses per quarter note
    pub ppq:         usize,
    /// Length of phrase in pulses
    pub length:      usize,
    /// Notes in phrase
    pub notes:       PhraseData,
    /// Whether to loop the phrase or play it once
    pub loop_on:     bool,
    /// Start of loop
    pub loop_start:  usize,
    /// Length of loop
    pub loop_length: usize,
    /// All notes are displayed with minimum length
    pub percussive:  bool,
    /// Identifying color of phrase
    pub color:       ItemColorTriplet,
}

/// MIDI message structural
pub type PhraseData = Vec<Vec<MidiMessage>>;

impl Phrase {
    pub fn new (
        name:    impl AsRef<str>,
        loop_on: bool,
        length:  usize,
        notes:   Option<PhraseData>,
        color:   Option<ItemColorTriplet>,
    ) -> Self {
        Self {
            uuid:        uuid::Uuid::new_v4(),
            name:        name.as_ref().to_string(),
            ppq:         PPQ,
            length,
            notes:       notes.unwrap_or(vec![Vec::with_capacity(16);length]),
            loop_on,
            loop_start:  0,
            loop_length: length,
            percussive:  true,
            color:       color.unwrap_or_else(ItemColorTriplet::random)
        }
    }
    pub fn duplicate (&self) -> Self {
        let mut clone = self.clone();
        clone.uuid = uuid::Uuid::new_v4();
        clone
    }
    pub fn toggle_loop (&mut self) { self.loop_on = !self.loop_on; }
    pub fn record_event (&mut self, pulse: usize, message: MidiMessage) {
        if pulse >= self.length { panic!("extend phrase first") }
        self.notes[pulse].push(message);
    }
    /// Check if a range `start..end` contains MIDI Note On `k`
    pub fn contains_note_on (&self, k: u7, start: usize, end: usize) -> bool {
        //panic!("{:?} {start} {end}", &self);
        for events in self.notes[start.max(0)..end.min(self.notes.len())].iter() {
            for event in events.iter() {
                if let MidiMessage::NoteOn {key,..} = event { if *key == k { return true } }
            }
        }
        return false
    }
}

impl Default for Phrase {
    fn default () -> Self {
        Self::new("(empty)", false, 0, None, Some(ItemColor::from(Color::Rgb(0, 0, 0)).into()))
    }
}

impl PartialEq for Phrase {
    fn eq (&self, other: &Self) -> bool {
        self.uuid == other.uuid
    }
}

impl Eq for Phrase {}