use crate::*;

pub struct PhrasesTui {
    /// Collection of phrases
    pub phrases: Vec<Arc<RwLock<Phrase>>>,
    /// Selected phrase
    pub phrase:  usize,
    /// Scroll offset
    pub scroll:  usize,
    /// Mode switch
    pub mode:    Option<PhrasesMode>,
    /// Whether this widget is focused
    pub focused: bool,
    /// Whether this widget is entered
    pub entered: bool,
}

/// Modes for phrase pool
pub enum PhrasesMode {
    /// Renaming a pattern
    Rename(usize, String),
    /// Editing the length of a pattern
    Length(usize, usize, PhraseLengthFocus),
}

impl PhrasesTui {
    pub fn new (phrases: Vec<Arc<RwLock<Phrase>>>) -> Self {
        Self {
            scroll:  0,
            phrase:  0,
            mode:    None,
            focused: false,
            entered: false,
            phrases,
        }
    }
    pub fn len (&self) -> usize {
        self.phrases.len()
    }
    pub fn phrase (&self) -> &Arc<RwLock<Phrase>> {
        &self.phrases[self.phrase]
    }
    pub fn index_before (&self, index: usize) -> usize {
        index.overflowing_sub(1).0.min(self.len() - 1)
    }
    pub fn index_after (&self, index: usize) -> usize {
        (index + 1) % self.len()
    }
    pub fn index_of (&self, phrase: &Phrase) -> Option<usize> {
        for i in 0..self.phrases.len() {
            if *self.phrases[i].read().unwrap() == *phrase { return Some(i) }
        }
        return None
    }
    fn new_phrase (name: Option<&str>, color: Option<ItemColorTriplet>) -> Arc<RwLock<Phrase>> {
        Arc::new(RwLock::new(Phrase::new(
            String::from(name.unwrap_or("(new)")), true, 4 * PPQ, None, color
        )))
    }
    pub fn delete_selected (&mut self) {
        if self.phrase > 0 {
            self.phrases.remove(self.phrase);
            self.phrase = self.phrase.min(self.phrases.len().saturating_sub(1));
        }
    }
    pub fn append_new (&mut self, name: Option<&str>, color: Option<ItemColorTriplet>) {
        self.phrases.push(Self::new_phrase(name, color));
        self.phrase = self.phrases.len() - 1;
    }
    pub fn insert_new (&mut self, name: Option<&str>, color: Option<ItemColorTriplet>) {
        self.phrases.insert(self.phrase + 1, Self::new_phrase(name, color));
        self.phrase += 1;
    }
    pub fn insert_dup (&mut self) {
        let mut phrase = self.phrases[self.phrase].read().unwrap().duplicate();
        phrase.color = ItemColorTriplet::random_near(phrase.color, 0.25);
        self.phrases.insert(self.phrase + 1, Arc::new(RwLock::new(phrase)));
        self.phrase += 1;
    }
    pub fn move_up (&mut self) {
        if self.phrase > 1 {
            self.phrases.swap(self.phrase - 1, self.phrase);
            self.phrase -= 1;
        }
    }
    pub fn move_down (&mut self) {
        if self.phrase < self.phrases.len().saturating_sub(1) {
            self.phrases.swap(self.phrase + 1, self.phrase);
            self.phrase += 1;
        }
    }
}

/// Displays and edits phrase length.
pub struct PhraseLength {
    /// Pulses per beat (quaver)
    pub ppq:    usize,
    /// Beats per bar
    pub bpb:    usize,
    /// Length of phrase in pulses
    pub pulses: usize,
    /// Selected subdivision
    pub focus:  Option<PhraseLengthFocus>,
}

impl PhraseLength {
    pub fn new (pulses: usize, focus: Option<PhraseLengthFocus>) -> Self {
        Self { _engine: Default::default(), ppq: PPQ, bpb: 4, pulses, focus }
    }
    pub fn bars  (&self) -> usize {
        self.pulses / (self.bpb * self.ppq)
    }
    pub fn beats (&self) -> usize {
        (self.pulses % (self.bpb * self.ppq)) / self.ppq
    }
    pub fn ticks (&self) -> usize {
        self.pulses % self.ppq
    }
    pub fn bars_string  (&self) -> String {
        format!("{}", self.bars())
    }
    pub fn beats_string (&self) -> String {
        format!("{}", self.beats())
    }
    pub fn ticks_string (&self) -> String {
        format!("{:>02}", self.ticks())
    }
}

impl Content for PhraseLength {
    type Engine = Tui;
    fn content (&self) -> impl Widget<Engine = Tui> {
        Layers::new(move|add|{
            match self.focus {
                None => add(&row!(
                    " ", self.bars_string(),
                    ".", self.beats_string(),
                    ".", self.ticks_string(),
                    " "
                )),
                Some(PhraseLengthFocus::Bar) => add(&row!(
                    "[", self.bars_string(),
                    "]", self.beats_string(),
                    ".", self.ticks_string(),
                    " "
                )),
                Some(PhraseLengthFocus::Beat) => add(&row!(
                    " ", self.bars_string(),
                    "[", self.beats_string(),
                    "]", self.ticks_string(),
                    " "
                )),
                Some(PhraseLengthFocus::Tick) => add(&row!(
                    " ", self.bars_string(),
                    ".", self.beats_string(),
                    "[", self.ticks_string(),
                    "]"
                )),
            }
        })
    }
}

/// Focused field of `PhraseLength`
#[derive(Copy, Clone)]
pub enum PhraseLengthFocus {
    /// Editing the number of bars
    Bar,
    /// Editing the number of beats
    Beat,
    /// Editing the number of ticks
    Tick,
}

impl PhraseLengthFocus {
    pub fn next (&mut self) {
        *self = match self {
            Self::Bar  => Self::Beat,
            Self::Beat => Self::Tick,
            Self::Tick => Self::Bar,
        }
    }
    pub fn prev (&mut self) {
        *self = match self {
            Self::Bar  => Self::Tick,
            Self::Beat => Self::Bar,
            Self::Tick => Self::Beat,
        }
    }
}