// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
// This file is a part of HexoDSP. Released under GPL-3.0-or-later.
// See README.md and COPYING for details.

use crate::dsp::helpers::Trigger;
use crate::dsp::{DspNode, LedPhaseVals, NodeContext, NodeId, ProcBuf, SAtom};
use crate::nodes::{NodeAudioContext, NodeExecContext};

#[macro_export]
macro_rules! fa_mux9_in_cnt {
    ($formatter: expr, $v: expr, $denorm_v: expr) => {{
        let s = match ($v.round() as usize) {
            0 => "1",
            1 => "2",
            2 => "3",
            3 => "4",
            4 => "5",
            5 => "6",
            6 => "7",
            7 => "8",
            8 => "9",
            _ => "?",
        };
        write!($formatter, "{}", s)
    }};
}

/// A 9 channel signal multiplexer
#[derive(Debug, Clone)]
pub struct Mux9 {
    trig_rst: Trigger,
    trig_up: Trigger,
    trig_down: Trigger,
    idx: u8,
}

impl Mux9 {
    pub fn new(_nid: &NodeId) -> Self {
        Self {
            trig_rst: Trigger::new(),
            trig_up: Trigger::new(),
            trig_down: Trigger::new(),
            idx: 0,
        }
    }
    pub const slct: &'static str =
        "Mux9 slct\nSelects the input that is routed to the output 'sig'.\
        But only if this input is actually connected. If there is no \
        connection, the 't_rst', 't_up' and 't_down' inputs are used to \
        control the current routing. The maximum routed input is determined \
        by the 'in_cnt' setting.\nRange: (0..1)";
    pub const t_rst: &'static str =
        "Mux9 t_rst\nResets the internal routing to the first input 'in_1'.\
        Keep in mind: This input is only used if 'slct' is not connected.\
        \nRange: (-1..1)\n";
    pub const t_up: &'static str =
        "Mux9 t_up\nIncreases the internal routing to the next input port.\
        If the last input (depending on the 'in_cnt' setting) was selected\
        if will wrap around to 'in_1'.\
        Keep in mind: This input is only used if 'slct' is not connected.\
        \nRange: (-1..1)\n";
    pub const t_down: &'static str =
        "Mux9 t_down\nDecreases the internal routing to the previous input \
        port (eg. 'in_3' => 'in_2'). If 'in_1' as selected, then it will \
        wrap around to the highest possible input port (depending on the \
        'in_cnt' setting).\
        Keep in mind: This input is only used if 'slct' is not connected.\
        \nRange: (-1..1)\n";
    pub const in_1: &'static str = "Mux9 in_1\nInput port 1.\nRange: (-1..1)\n";
    pub const in_2: &'static str = "Mux9 in_2\nInput port 2.\nRange: (-1..1)\n";
    pub const in_3: &'static str = "Mux9 in_3\nInput port 3.\nRange: (-1..1)\n";
    pub const in_4: &'static str = "Mux9 in_4\nInput port 4.\nRange: (-1..1)\n";
    pub const in_5: &'static str = "Mux9 in_5\nInput port 5.\nRange: (-1..1)\n";
    pub const in_6: &'static str = "Mux9 in_6\nInput port 6.\nRange: (-1..1)\n";
    pub const in_7: &'static str = "Mux9 in_7\nInput port 7.\nRange: (-1..1)\n";
    pub const in_8: &'static str = "Mux9 in_8\nInput port 8.\nRange: (-1..1)\n";
    pub const in_9: &'static str = "Mux9 in_9\nInput port 9.\nRange: (-1..1)\n";
    pub const in_cnt: &'static str =
        "Mux9 in_cnt\nThe number of inputs that are routed to the output. \
        This will limit the number of maximally used inputs.\n";
    pub const sig: &'static str =
        "Mux9 sig\nThe currently selected input port will be presented on \
        this output port.\nRange: (-1..1)\n";
    pub const DESC: &'static str = r#"9 Ch. Multiplexer

An up to 9 channel multiplexer aka switch or junction. You can route one of the 9 (or fewer) inputs to the output. The opposite of this node is the 'Demux9', which demultiplexes or routes the one input signal to one of the 9 outputs.
"#;
    pub const HELP: &'static str = r#"Mux9 - 9 Channel Multiplexer/Switch

This is an up to 9 channel multiplexer, also known as switch or junction.
You can route one of the 9 (or fewer) inputs to the one output.
Selection of the input is done either via a control signal to the
'slct' input (range 0..1) (exclusive) or via the 't_rst', 't_up' or
't_down' triggers.

If the 'slct' input is not connected, the trigger inputs are active.
If you still prefer a knob for manually selecting the input, consider using
some constant signal source like an 'Amp' node with an unconnected input.

The 'in_cnt' parameter allows selecting the number of routed input channels.

The opposite of this node is the 'Demux9', which demultiplexes or routes
the one input signal to one of the 9 outputs.

Tip:
    An interesting use case for this node is to use it as (up to) 9 step
    control signal sequencer. Leave the 'in_1' to 'in_9' ports unconnected
    and dial in the desired value via the parameter knobs. This can lead to
    interesting results. Even more interesting it can become if you stack
    multiple 'Demux9' in series and connect just some of the input ports
    for slightly changing sequences. Attach a slew limiter node (eg. 'LSlew'
    or 'ESlew') if less harsh transitions between the input routings is
    desired.
"#;
}

impl DspNode for Mux9 {
    fn outputs() -> usize {
        1
    }

    fn set_sample_rate(&mut self, _srate: f32) {}
    fn reset(&mut self) {}

    #[inline]
    fn process<T: NodeAudioContext>(
        &mut self,
        ctx: &mut T,
        _ectx: &mut NodeExecContext,
        nctx: &NodeContext,
        atoms: &[SAtom],
        inputs: &[ProcBuf],
        outputs: &mut [ProcBuf],
        ctx_vals: LedPhaseVals,
    ) {
        use crate::dsp::{at, denorm, inp, out};

        let in_1 = inp::Mux9::in_1(inputs);
        let in_2 = inp::Mux9::in_2(inputs);
        let in_3 = inp::Mux9::in_3(inputs);
        let in_4 = inp::Mux9::in_4(inputs);
        let in_5 = inp::Mux9::in_5(inputs);
        let in_6 = inp::Mux9::in_6(inputs);
        let in_7 = inp::Mux9::in_7(inputs);
        let in_8 = inp::Mux9::in_8(inputs);
        let in_9 = inp::Mux9::in_9(inputs);
        let slct = inp::Mux9::slct(inputs);
        let t_rst = inp::Mux9::t_rst(inputs);
        let t_up = inp::Mux9::t_up(inputs);
        let t_down = inp::Mux9::t_down(inputs);
        let out = out::Mux9::sig(outputs);

        let max: u8 = at::Mux9::in_cnt(atoms).i() as u8 + 1;
        self.idx = self.idx % max;

        if nctx.in_connected & 0x1 == 0x1 {
            for frame in 0..ctx.nframes() {
                self.idx = (max as f32 * denorm::Mux9::slct(slct, frame)).floor() as u8 % max;

                out.write(
                    frame,
                    match self.idx {
                        0 => denorm::Mux9::in_1(in_1, frame),
                        1 => denorm::Mux9::in_2(in_2, frame),
                        2 => denorm::Mux9::in_3(in_3, frame),
                        3 => denorm::Mux9::in_4(in_4, frame),
                        4 => denorm::Mux9::in_5(in_5, frame),
                        5 => denorm::Mux9::in_6(in_6, frame),
                        6 => denorm::Mux9::in_7(in_7, frame),
                        7 => denorm::Mux9::in_8(in_8, frame),
                        _ => denorm::Mux9::in_9(in_9, frame),
                    },
                );
            }
        } else {
            for frame in 0..ctx.nframes() {
                if self.trig_rst.check_trigger(denorm::Mux9::t_rst(t_rst, frame)) {
                    self.idx = 0;
                }

                if self.trig_up.check_trigger(denorm::Mux9::t_up(t_up, frame)) {
                    self.idx = (self.idx + 1) % max;
                }

                if self.trig_down.check_trigger(denorm::Mux9::t_down(t_down, frame)) {
                    self.idx = (self.idx + max - 1) % max;
                }

                out.write(
                    frame,
                    match self.idx {
                        0 => denorm::Mux9::in_1(in_1, frame),
                        1 => denorm::Mux9::in_2(in_2, frame),
                        2 => denorm::Mux9::in_3(in_3, frame),
                        3 => denorm::Mux9::in_4(in_4, frame),
                        4 => denorm::Mux9::in_5(in_5, frame),
                        5 => denorm::Mux9::in_6(in_6, frame),
                        6 => denorm::Mux9::in_7(in_7, frame),
                        7 => denorm::Mux9::in_8(in_8, frame),
                        _ => denorm::Mux9::in_9(in_9, frame),
                    },
                );
            }
        }

        ctx_vals[0].set(out.read(ctx.nframes() - 1));
    }
}
