use midir::MidiOutputConnection;

pub use crate::protocols::query::*;

use super::Button;
use crate::OutputDevice;

/// A color from the Mk2 color palette. See the "Launchpad MK2 Programmers Reference Manual"
/// to see the palette, or [see here](http://launchpaddr.com/mk2palette/).
///
/// Everywhere where a PaletteColor is expected as a funcion argument, you can also directly pass
/// in the palette index and call `.into()` on it. Example:
/// ```no_run
/// # use launchy::mk2::{PaletteColor};
/// # let output: launchy::mk2::Output = unimplemented!();
/// // This:
/// output.light_all(PaletteColor::new(92));
/// // can also be written as:
/// output.light_all(92.into());
/// # Ok::<(), launchy::MidiError>(())
/// ```
#[derive(Debug, Copy, Clone, Hash, Eq, PartialEq)]
pub struct PaletteColor {
    pub(crate) id: u8,
}

impl PaletteColor {
    pub fn is_valid(&self) -> bool {
        self.id <= 127
    }

    pub fn new(id: u8) -> Self {
        let self_ = Self { id };
        assert!(self_.is_valid());
        self_
    }

    pub fn id(&self) -> u8 {
        self.id
    }
    pub fn set_id(&mut self, id: u8) {
        self.id = id
    }
}

impl From<u8> for PaletteColor {
    fn from(id: u8) -> Self {
        Self::new(id)
    }
}

#[derive(Debug, Copy, Clone, Hash, Eq, PartialEq)]
/// An RGB color. Each component may only go up to 63
pub struct RgbColor {
    r: u8,
    g: u8,
    b: u8,
}

impl RgbColor {
    /// Create a new RgbColor from the individual component values
    pub fn new(r: u8, g: u8, b: u8) -> Self {
        let self_ = Self { r, g, b };
        assert!(self_.is_valid());
        self_
    }

    /// Check whether the rgb color is valid - each component may only go up to 63.
    pub fn is_valid(&self) -> bool {
        self.r <= 63 && self.g <= 63 && self.b <= 63
    }

    pub fn red(&self) -> u8 {
        self.r
    }
    pub fn green(&self) -> u8 {
        self.g
    }
    pub fn blue(&self) -> u8 {
        self.b
    }
    pub fn set_red(&mut self, r: u8) {
        assert!(r <= 63);
        self.r = r
    }
    pub fn set_green(&mut self, g: u8) {
        assert!(g <= 63);
        self.g = g
    }
    pub fn set_blue(&mut self, b: u8) {
        assert!(b <= 63);
        self.b = b
    }
}

impl PaletteColor {
    // These are some commonly used colors as palette colors. I don't have Rgb colors as constants
    // because in the case of rgb colors you can just make your required colors yourself

    // Basic colors, the top row
    pub const BLACK: PaletteColor = Self { id: 0 };
    pub const DARK_GRAY: PaletteColor = Self { id: 1 };
    pub const LIGHT_GRAY: PaletteColor = Self { id: 2 };
    pub const WHITE: PaletteColor = Self { id: 3 };

    // Third column from the right
    pub const RED: PaletteColor = Self { id: 5 };
    pub const YELLOW: PaletteColor = Self { id: 13 };
    pub const GREEN: PaletteColor = Self { id: 21 };
    pub const SLIGHTLY_LIGHT_GREEN: PaletteColor = Self { id: 29 };
    pub const LIGHT_BLUE: PaletteColor = Self { id: 37 };
    pub const BLUE: PaletteColor = Self { id: 45 };
    pub const MAGENTA: PaletteColor = Self { id: 53 };
    pub const BROWN: PaletteColor = Self { id: 61 };

    // This is not belonging to any of the columns/rows but included anyway cuz cyan is important
    pub const CYAN: PaletteColor = Self { id: 90 };
}

/// The Mk2 can light a button in different ways
#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
pub enum LightMode {
    /// This is the standard mode. A straight consistent light
    Plain,
    /// A flashing motion On->Off->On->Off->...
    Flash,
    /// A smooth pulse
    Pulse,
}

/// Volume faders light from the bottom up, and pan faders light from the centre out.
#[derive(Copy, Clone, Hash, Eq, PartialEq)]
pub enum FaderType {
    Volume,
    Pan,
}

/// Specifies information about a fader
pub struct Fader {
    index: u8,
    color: PaletteColor,
    initial_value: u8,
}

impl Fader {
    pub fn new(index: u8, color: PaletteColor, initial_value: u8) -> Self {
        assert!(initial_value <= 127);
        // future reader, don't attempt to raise this limit to 8, it breaks the Mk2 until you
        // reconnect :p
        assert!(index <= 7);

        Self {
            index,
            color,
            initial_value,
        }
    }

    pub fn index(&self) -> u8 {
        self.index
    }
    pub fn color(&self) -> PaletteColor {
        self.color
    }
    pub fn initial_value(&self) -> u8 {
        self.initial_value
    }
}

#[allow(dead_code)] // to prevent "variant is never constructed" warning
enum Layout {
    Session,
    User1, // drum rack
    User2,
    Reserved, // reserved for Ableton Live, shouldn't be used here
    Volume,
    Pan,
}

/// This is the handler object for the Launchpad Mk2's fader mode, in which you can utilize the
/// built-in fader functionality. You can specify for each fader its position, its color, and its
/// default value.
///
/// For further documentation and examples, see [`Output::enter_fader_mode`].
pub struct FaderMode {
    output: Output,
    fader_type: FaderType,
}

impl FaderMode {
    fn new(mut output: Output, fader_type: FaderType) -> Result<Self, crate::MidiError> {
        output.change_layout(match fader_type {
            FaderType::Volume => Layout::Volume,
            FaderType::Pan => Layout::Pan,
        })?;
        Ok(Self { output, fader_type })
    }

    /// Exit fader mode by transforming this FaderMode object back into a Output object.
    #[must_use = "You must use the returned object, or the MIDI connection will be dropped"]
    pub fn exit(mut self) -> Result<Output, crate::MidiError> {
        self.output.change_layout(Layout::Session)?;
        Ok(self.output)
    }

    /// Place faders on the screen. The faders' properties are specified using the `&[Fader]` slice.
    pub fn designate_faders(&mut self, faders: &[Fader]) -> Result<(), crate::MidiError> {
        assert!(faders.len() <= 8);

        let fader_type = match self.fader_type {
            FaderType::Volume => 0,
            FaderType::Pan => 1,
        };

        let mut bytes = Vec::with_capacity(8 + 4 * faders.len());
        bytes.extend(&[240, 0, 32, 41, 2, 24, 43]);
        for fader in faders {
            bytes.extend(&[
                fader.index,
                fader_type,
                fader.color.id(),
                fader.initial_value,
            ]);
        }
        bytes.push(247);

        self.output.send(&bytes)
    }

    /// Moves a fader, specified by `index`, to a specific `value`
    pub fn set_fader(&mut self, index: u8, value: u8) -> Result<(), crate::MidiError> {
        assert!(index <= 7);
        assert!(value <= 127);

        self.output.send(&[176, 21 + index, value])
    }
}

/// The object handling any messages _to_ the launchpad. To get started, initialize with
/// [(`Output::guess`)[OutputDevice::guess]] and then send messages to your liking. The connection
/// to the launchpad will get closed when this object goes out of scope.
///
/// For example:
/// ```no_run
/// # use launchy::OutputDevice as _;
/// # use launchy::mk2::{PaletteColor, Button, Output};
/// let mut output = Output::guess()?;
///
/// output.light_all(PaletteColor::BLACK); // clear screen
///
/// // make a red cross in the center
/// output.light_row(4, PaletteColor::RED);
/// output.light_row(5, PaletteColor::RED);
/// output.light_column(4, PaletteColor::RED);
/// output.light_column(5, PaletteColor::RED);
///
/// // light top left button magenta
/// output.light(Button::GridButton { x: 0, y: 0 }, PaletteColor::MAGENTA);
/// # Ok::<(), launchy::MidiError>(())
/// ```
///
/// # Representing color
/// The Launchpad Mk2 has two different ways to represent color. You can either use one of the 128
/// built-in palette colors, or you can create a custom color with custom rgb components.
/// Why would you choose the palette colors when you can just create your required colors yourself?
/// Well some operations on the Mk2 only support palette colors. Besides, sending palette color midi
/// messages is simply faster. Therefore you should aim to use the palette colors when possible.
pub struct Output {
    connection: MidiOutputConnection,
}

impl crate::OutputDevice for Output {
    const MIDI_CONNECTION_NAME: &'static str = "Launchy Mk2 output";
    const MIDI_DEVICE_KEYWORD: &'static str = "Launchpad MK2";

    fn from_connection(connection: MidiOutputConnection) -> Result<Self, crate::MidiError> {
        let mut self_ = Self { connection };
        self_.change_layout(Layout::Session)?;
        Ok(self_)
    }

    fn send(&mut self, bytes: &[u8]) -> Result<(), crate::MidiError> {
        self.connection.send(bytes)?;
        Ok(())
    }
}

impl Output {
    /// This is a function testing various parts of this API by executing various commands in order
    /// to find issues either in this library or in your device
    pub fn test_api(&mut self) -> Result<(), crate::MidiError> {
        self.light_all(PaletteColor::DARK_GRAY)?;
        std::thread::sleep(std::time::Duration::from_millis(250));
        self.light_all(PaletteColor::BLACK)?;

        // Test single led lighting, only plain
        self.light(Button::ControlButton { index: 0 }, PaletteColor { id: 5 })?;
        self.light_rgb(
            Button::ControlButton { index: 1 },
            RgbColor { r: 63, g: 0, b: 63 },
        )?;
        self.light(Button::GridButton { x: 0, y: 0 }, PaletteColor { id: 5 })?;
        self.light_rgb(
            Button::GridButton { x: 1, y: 0 },
            RgbColor { r: 63, g: 0, b: 63 },
        )?;

        // Test multiple lights
        self.light_multiple(&[
            (Button::GridButton { x: 0, y: 1 }, PaletteColor { id: 18 }),
            (Button::GridButton { x: 0, y: 2 }, PaletteColor { id: 18 }),
        ])?;
        self.light_multiple_rgb(&[
            (
                Button::GridButton { x: 0, y: 3 },
                RgbColor {
                    r: 63,
                    g: 63,
                    b: 63,
                },
            ),
            (
                Button::GridButton { x: 0, y: 4 },
                RgbColor {
                    r: 63,
                    g: 40,
                    b: 63,
                },
            ),
        ])?;

        // Test pulse and flash
        self.flash(Button::GridButton { x: 1, y: 1 }, PaletteColor { id: 5 })?;
        self.pulse(Button::GridButton { x: 1, y: 2 }, PaletteColor { id: 9 })?;
        self.flash_multiple(&[
            (Button::GridButton { x: 2, y: 1 }, PaletteColor { id: 5 }),
            (Button::GridButton { x: 2, y: 2 }, PaletteColor { id: 9 }),
        ])?;
        self.pulse_multiple(&[
            (Button::GridButton { x: 3, y: 1 }, PaletteColor { id: 5 }),
            (Button::GridButton { x: 3, y: 2 }, PaletteColor { id: 9 }),
        ])?;
        // same but for control row
        self.flash(Button::ControlButton { index: 2 }, PaletteColor { id: 5 })?;
        self.pulse(Button::ControlButton { index: 3 }, PaletteColor { id: 9 })?;
        self.flash_multiple(&[
            (Button::ControlButton { index: 4 }, PaletteColor { id: 5 }),
            (Button::ControlButton { index: 5 }, PaletteColor { id: 9 }),
        ])?;
        self.pulse_multiple(&[
            (Button::ControlButton { index: 6 }, PaletteColor { id: 5 }),
            (Button::ControlButton { index: 7 }, PaletteColor { id: 9 }),
        ])?;

        // Test row, only grid
        self.light_rows(&[(7, PaletteColor { id: 16 }), (8, PaletteColor { id: 18 })])?;

        // loop {
        //     // default is 120 BPM
        //     let bpm: f32 = 240.0; // 60-240
        //     let interval_ms = (2500.0 / bpm).ceil() as u64;

        //     self.send_clock_tick()?;
        //     std::thread::sleep(std::time::Duration::from_millis(interval_ms));
        // }

        // std::thread::sleep(std::time::Duration::from_millis(1000));
        // // Test control button row
        // self.light_row(0, PaletteColor { id: 5 })?;

        Ok(())
    }

    /// Set a `button` to a certain `color` with a certain `light_mode`.
    ///
    /// For example to start a yellow pulse on the leftmost control button:
    /// ```no_run
    /// # use launchy::mk2::{PaletteColor, Button, LightMode};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// let button = Button::ControlButton { index: 0 };
    /// let color = PaletteColor::YELLOW;
    /// let light_mode = LightMode::Pulse;
    /// output.set_button(button, color, light_mode)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn set_button(
        &mut self,
        button: Button,
        color: PaletteColor,
        light_mode: LightMode,
    ) -> Result<(), crate::MidiError> {
        assert!(color.id <= 127);

        let type_byte = match button {
            Button::GridButton { .. } => 0x90,
            Button::ControlButton { .. } => 0xB0,
        } + match light_mode {
            LightMode::Plain => 0,
            LightMode::Flash => 1,
            LightMode::Pulse => 2,
        };

        self.send(&[type_byte, Self::encode_button(button), color.id])
    }

    /// Like `set_button()`, but for multiple buttons. This method lights multiple buttons with
    /// varying color. The light mode can't be varied between buttons.
    ///
    /// For example to start a yellow flash on the leftmost control button and a red flash on the
    /// button to the right:
    /// ```no_run
    /// # use launchy::mk2::{PaletteColor, Button, LightMode};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.set_buttons(&[
    ///     (Button::ControlButton { index: 0 }, PaletteColor::YELLOW),
    ///     (Button::ControlButton { index: 1 }, PaletteColor::RED),
    /// ], LightMode::Flash)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn set_buttons(
        &mut self,
        buttons: impl IntoIterator<Item = impl std::borrow::Borrow<(Button, PaletteColor)>>,
        light_mode: LightMode,
    ) -> Result<(), crate::MidiError> {
        let msg_type_byte = match light_mode {
            LightMode::Plain => 10,
            LightMode::Flash => 35,
            LightMode::Pulse => 40,
        };

        // I have NO IDEA why this is needed?!?! It's not in the official documentation, but
        // experimentation revealed that each packet needs to be prefixed with a dummy null byte
        // in order to work ONLY FOR FLASH AND PULSE THOUGH! why? xD
        let add_null_byte = match light_mode {
            LightMode::Plain => false,
            LightMode::Flash | LightMode::Pulse => true,
        };

        self.send_multiple(
            msg_type_byte,
            add_null_byte,
            80,
            buttons.into_iter().map(|pair| {
                let &(button, color) = pair.borrow();
                (Self::encode_button(button), color)
            }),
        )
    }

    /// Light multiple buttons with varying color. This method support RGB.
    ///
    /// For example to light the top left button green and the top right button red:
    /// ```no_run
    /// # use launchy::mk2::{Button, RgbColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_multiple_rgb(&[
    ///     (Button::GridButton { x: 0, y: 0 }, RgbColor::new(0, 0, 63)),
    ///     (Button::GridButton { x: 7, y: 0 }, RgbColor::new(63, 0, 0)),
    /// ])?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_multiple_rgb<I, T>(&mut self, buttons: I) -> Result<(), crate::MidiError>
    where
        I: IntoIterator<Item = T>,
        T: std::borrow::Borrow<(Button, RgbColor)>,
        I::IntoIter: ExactSizeIterator,
    {
        let buttons = buttons.into_iter();

        assert!(buttons.size_hint().0 <= 80);

        let mut bytes = Vec::with_capacity(8 + 12 * buttons.len());

        bytes.extend(&[240, 0, 32, 41, 2, 24, 11]);
        for pair in buttons {
            let &(button, color) = pair.borrow();
            assert!(color.is_valid());
            bytes.extend(&[Self::encode_button(button), color.r, color.g, color.b]);
        }
        bytes.push(247);

        self.send(&bytes)
    }

    /// Light multiple columns with varying colors. This method does not light up the control
    /// buttons
    ///
    /// For example to light the first column yellow and the second column blue:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_columns(&[
    ///     (0, PaletteColor::YELLOW),
    ///     (1, PaletteColor::BLUE),
    /// ])?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_columns(
        &mut self,
        buttons: impl IntoIterator<Item = impl std::borrow::Borrow<(u8, PaletteColor)>>,
    ) -> Result<(), crate::MidiError> {
        self.send_multiple(12, false, 9, buttons)
    }

    /// Light multiple row with varying colors. This method _does_ light up the side buttons.
    ///
    /// Note: the row are counted starting at the control row! For example to light the control row
    /// magenta and the first grid row green:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_rows(&[
    ///     (0, PaletteColor::MAGENTA),
    ///     (1, PaletteColor::GREEN),
    /// ])?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_rows(
        &mut self,
        buttons: impl IntoIterator<Item = impl std::borrow::Borrow<(u8, PaletteColor)>>,
    ) -> Result<(), crate::MidiError> {
        self.send_multiple(
            13,
            false,
            9,
            buttons.into_iter().map(|pair| {
                let &(row, color) = pair.borrow();
                (8 - row, color)
            }),
        )
    }

    /// Light all buttons, including control and side buttons.
    ///
    /// For example to clear the screen:
    /// ```no_run
    /// # use launchy::mk2::PaletteColor;
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_all(PaletteColor::BLACK)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_all(&mut self, color: PaletteColor) -> Result<(), crate::MidiError> {
        self.send(&[240, 0, 32, 41, 2, 24, 14, color.id, 247])
    }

    /// By default, Launchpad MK2 will flash and pulse at 120 BPM. This can be altered by sending
    /// these clock ticks by calling `send_clock_tick()`. These ticks should be sent at a rate of 24
    /// per beat.
    ///
    /// To set a tempo of 100 BPM, 2400 clock ticks should be sent each minute, or with a time
    /// interval of 25ms.
    ///
    /// Launchpad MK2 supports tempos between 40 and 240 BPM, faster clock ticks are apparently
    /// ignored.
    ///
    /// For example to send clock ticks at 200 BPM:
    /// ```no_run
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// let beats_per_minute = 200;
    /// let clock_ticks_per_second = beats_per_minute * 60 * 24;
    /// let clock_tick_interval = std::time::Duration::from_millis(1000 / clock_ticks_per_second);
    /// loop {
    ///     output.send_clock_tick()?;
    ///     std::thread::sleep(clock_tick_interval);
    /// }
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn send_clock_tick(&mut self) -> Result<(), crate::MidiError> {
        self.send(&[248, 0, 0])
    }

    /// Requests the Launchpad Mk2 to send a so-called device inquiry. The device inquiry contains
    /// information about the device ID and the firmware revision number.
    ///
    /// In order to be able to receive the Launchpad Mk2's response to this request,
    /// you must have a Launchpad Mk2 input object set up.
    pub fn request_device_inquiry(&mut self, query: DeviceIdQuery) -> Result<(), crate::MidiError> {
        request_device_inquiry(self, query)
    }

    /// Requests the Launchpad Mk2 to send a so-called version inquiry. The version inquiry contains
    /// information about the current bootloader and firmware versions, as well as the size of the
    /// bootloader in KB.
    ///
    /// In order to be able to receive the Launchpad Mk2's response to this request,
    /// you must have a Launchpad Mk2 input object set up.
    pub fn request_version_inquiry(&mut self) -> Result<(), crate::MidiError> {
        request_version_inquiry(self)
    }

    /// Starts a text scroll across the screen. The screen is temporarily cleared. You can specify
    /// the color of the text and whether the text should loop indefinitely.
    ///
    /// In addition to the standard ASCII characters, Launchpad MK2 recognises plain values 1 – 7 as
    /// speed commands (where 1 is the slowest and 7 is fastest). This allows the scrolling speed to
    /// be manipulated mid-text. The default speed is 4.
    ///
    /// When the text ends, Launchpad MK2 restores the LEDs to their previous settings. As the text
    /// either ends or loops, a message will be sent to the Input.
    ///
    /// For example to scroll the text "Hello, world!" in blue; "Hello" scrolling slow and "world"
    /// fast:
    /// ```no_run
    /// # use launchy::mk2::PaletteColor;
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.scroll_text(b"\x01Hello, \x07world!", PaletteColor::BLUE, false)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn scroll_text(
        &mut self,
        text: &[u8],
        color: PaletteColor,
        should_loop: bool,
    ) -> Result<(), crate::MidiError> {
        let bytes = &[
            &[240, 0, 32, 41, 2, 24, 20, color.id(), should_loop as u8],
            text,
            &[247],
        ]
        .concat();

        self.send(bytes)
    }

    /// Transforms this Output object to go into "fader mode". In fader mode, you have
    /// the ability to utilize the Mk2's built-in fader functionality.
    ///
    /// Launchpad MK2 has two virtual fader modes, one with volume style faders and one with pan
    /// style (the two styles cannot be mixed).
    ///
    /// The fader will light up according to its current value with volume faders lighting from the
    /// bottom up, and pan faders lighting from the centre out.
    ///
    /// When a button is pressed to change the level of a fader, Launchpad MK2 will move the fader
    /// to that position and send interim values to smooth the transition. For each interim value, a
    /// message is sent to Input.
    ///
    /// See [FaderMode](struct.FaderMode.html) for documentation on FaderMode's methods.
    ///
    /// For example to place three pan faders:
    /// - A green one on the left, turned all the way down
    /// - Another green one next to the first fader, turned all the way up
    /// - A white one on the right, centered
    /// ```no_run
    /// # use launchy::mk2::{PaletteColor, Fader, FaderType};
    /// # let mut output: launchy::mk2::Output = unimplemented!();
    /// let mut fader_setup = output.enter_fader_mode(FaderType::Volume)?;
    ///
    /// fader_setup.designate_faders(&[
    ///     Fader::new(0, PaletteColor::GREEN, 0),
    ///     Fader::new(1, PaletteColor::GREEN, 127),
    ///     Fader::new(7, PaletteColor::WHITE, 63),
    /// ])?;
    ///
    /// let mut output = fader_setup.exit()?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    #[must_use = "If you don't use the returned object, the MIDI connection will be dropped immediately"]
    pub fn enter_fader_mode(self, fader_type: FaderType) -> Result<FaderMode, crate::MidiError> {
        FaderMode::new(self, fader_type)
    }

    /// Force the Launchpad MK2 into bootloader mode
    pub fn enter_bootloader(&mut self) -> Result<(), crate::MidiError> {
        self.send(&[240, 0, 32, 41, 0, 113, 0, 105, 247])
    }

    fn change_layout(&mut self, layout: Layout) -> Result<(), crate::MidiError> {
        let layout = match layout {
            Layout::Session => 0,
            Layout::User1 => 1,
            Layout::User2 => 2,
            Layout::Reserved => 3,
            Layout::Volume => 4,
            Layout::Pan => 5,
        };
        self.send(&[240, 0, 32, 41, 2, 24, 34, layout, 247])
    }

    // param `insert_null_bytes`: whether every packet should be preceeded by a null byte
    fn send_multiple(
        &mut self,
        msg_type_byte: u8,
        insert_null_bytes: bool,
        max_packets: usize,
        pair_iterator: impl IntoIterator<Item = impl std::borrow::Borrow<(u8, PaletteColor)>>,
    ) -> Result<(), crate::MidiError> {
        let pair_iterator = pair_iterator.into_iter();

        let capacity = 8 + 12 * (pair_iterator.size_hint().0 + insert_null_bytes as usize);
        let mut bytes = Vec::with_capacity(capacity);

        bytes.extend(&[240, 0, 32, 41, 2, 24, msg_type_byte]);
        for (i, pair) in pair_iterator.enumerate() {
            if i >= max_packets {
                panic!(
                    "Only {} or less elements are supported per message!",
                    max_packets
                );
            }

            let &(button_specifier, color) = pair.borrow();
            if insert_null_bytes {
                bytes.push(0)
            }
            bytes.extend(&[button_specifier, color.id]);
        }
        bytes.push(247);

        self.send(&bytes)
    }

    fn encode_button(button: Button) -> u8 {
        match button {
            Button::GridButton { x, y } => {
                assert!(x <= 8);
                assert!(y <= 7);

                10 * (8 - y) + x + 1
            }
            Button::ControlButton { index } => {
                assert!(index <= 7);

                index + 104
            }
        }
    }

    // --------------------------------------------------------------------------------------------
    // Below this point are shorthand function
    // --------------------------------------------------------------------------------------------

    /// Light a button with a color from the Mk2 palette. Identical to
    /// `set_button(<button>, <color>, LightMode::Plain)`.
    ///
    /// For example to light the "Volume" side button cyan:
    ///
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light(Button::VOLUME, PaletteColor::CYAN)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light(&mut self, button: Button, color: PaletteColor) -> Result<(), crate::MidiError> {
        self.set_button(button, color, LightMode::Plain)
    }

    /// Starts a flashing motion between the previously shown color on this button and palette color
    /// `color`, with a duty cycle of 50% and a bpm of 120. The bpm can be controlled using
    /// `send_clock_tick()`.
    ///
    /// Identical to `set_button(<button>, <color>, LightMode::FLASH)`.
    ///
    /// For example to start a red flash on the "Session" button at the top:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.flash(Button::UP, PaletteColor::RED)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn flash(&mut self, button: Button, color: PaletteColor) -> Result<(), crate::MidiError> {
        self.set_button(button, color, LightMode::Flash)
    }

    /// Start a pulse; a rhythmic increase and decreases in brightness. The speed can be controlled
    /// using `send_clock_tick()`. Identical to `set_button(<button>, <color>, LightMode::PULSE)`.
    ///
    /// For example to start a magenta pulse on the top right grid button:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.pulse(Button::GridButton { x: 7, y: 0 }, PaletteColor::MAGENTA)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn pulse(&mut self, button: Button, color: PaletteColor) -> Result<(), crate::MidiError> {
        self.set_button(button, color, LightMode::Pulse)
    }

    /// Light a single column, specified by `column` (0-8).
    ///
    /// For example to light the entire side button column white:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_column(8, PaletteColor::WHITE)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_column(
        &mut self,
        column: u8,
        color: PaletteColor,
    ) -> Result<(), crate::MidiError> {
        self.light_columns(&[(column, color)])
    }

    /// Light a single row, specified by `row` (0-8). Note: the row counting begins at the control
    /// row! So e.g. when you want to light the first grid row, pass `1` not `0`.
    ///
    /// For example to light the first grid row green:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_row(1, PaletteColor::GREEN)?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_row(&mut self, row: u8, color: PaletteColor) -> Result<(), crate::MidiError> {
        self.light_rows(&[(row, color)])
    }

    /// Light a single button with an RGB color.
    ///
    /// For example to light the bottom right button cyan:
    /// ```no_run
    /// # use launchy::mk2::{Button, RgbColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_rgb(Button::GridButton { x: 7, y: 7 }, RgbColor::new(0, 63, 63))?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_rgb(&mut self, button: Button, color: RgbColor) -> Result<(), crate::MidiError> {
        self.light_multiple_rgb(&[(button, color)])
    }

    /// Light multiple buttons with varying colors. Identical to
    /// `set_buttons(<pairs>, LightMode::Plain)`
    ///
    /// For example to light both User 1 and User 2 buttons orange:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.light_multiple(&[
    ///     (Button::USER_1, PaletteColor::new(9)),
    ///     (Button::USER_2, PaletteColor::new(9)),
    /// ])?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn light_multiple(
        &mut self,
        buttons: impl IntoIterator<Item = impl std::borrow::Borrow<(Button, PaletteColor)>>,
    ) -> Result<(), crate::MidiError> {
        self.set_buttons(buttons, LightMode::Plain)
    }

    /// Start flashing multiple buttons with varying colors. Identical to
    /// `set_buttons(<pairs>, LightMode::Flash)`
    ///
    /// For example to flash both User 1 and User 2 buttons orange:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.flash_multiple(&[
    ///     (Button::USER_1, PaletteColor::new(9)),
    ///     (Button::USER_2, PaletteColor::new(9)),
    /// ])?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn flash_multiple(
        &mut self,
        buttons: impl IntoIterator<Item = impl std::borrow::Borrow<(Button, PaletteColor)>>,
    ) -> Result<(), crate::MidiError> {
        self.set_buttons(buttons, LightMode::Flash)
    }

    /// Start pulsing multiple buttons with varying colors. Identical to
    /// `set_buttons(<pairs>, LightMode::Pulse)`
    ///
    /// For example to pulse both User 1 and User 2 buttons orange:
    /// ```no_run
    /// # use launchy::mk2::{Button, PaletteColor};
    /// # let output: launchy::mk2::Output = unimplemented!();
    /// output.pulse_multiple(&[
    ///     (Button::USER_1, PaletteColor::new(9)),
    ///     (Button::USER_2, PaletteColor::new(9)),
    /// ])?;
    /// # Ok::<(), launchy::MidiError>(())
    /// ```
    pub fn pulse_multiple(
        &mut self,
        buttons: impl IntoIterator<Item = impl std::borrow::Borrow<(Button, PaletteColor)>>,
    ) -> Result<(), crate::MidiError> {
        self.set_buttons(buttons, LightMode::Pulse)
    }

    /// Clears the entire field of buttons. Equivalent to `output.light_all(PaletteColor::BLACK)`.
    pub fn clear(&mut self) -> Result<(), crate::MidiError> {
        self.light_all(PaletteColor::BLACK)
    }
}