use cortex_m::prelude::{_embedded_hal_blocking_i2c_Write, _embedded_hal_blocking_i2c_WriteRead};

use crate::CodecPins;
use crate::hal::prelude::*;
use crate::traits::Dac;

const AK4490_I2C_ADDRESS: u8 = 0x10;

#[repr(u8)]
#[allow(dead_code)]
enum RegisterAddress {
    Control1 = 0x00,
    Control2 = 0x01,
    Control3 = 0x02,
    LeftAtt = 0x03,
    RightAtt = 0x04,
    Control4 = 0x05,
    Control5 = 0x06,
    Control6 = 0x07,
    Control7 = 0x08,
    Control8 = 0x09,
}

pub struct Ak4490Dac<T> {
    i2c: T,
    pins: CodecPins, // this dependency is unfortunate, but non trivial to generalize
}

impl<T> Ak4490Dac<T>
where
    T: _embedded_hal_blocking_i2c_WriteRead + _embedded_hal_blocking_i2c_Write,
{
    #[inline]
    fn write_reg(&mut self, reg: RegisterAddress, val: u8) {
        self.i2c.write(AK4490_I2C_ADDRESS, &[reg as u8, val]).ok();
    }
    fn dfs_for_rate(&self, rate: u32) -> u8 {
        match rate {
            r if r < 54000 => 0,
            r if r < 108000 => 1,
            r if r < 216000 => 2,
            r if r <= 384000 => 4,
            _ => 5,
        }
    }
}

impl<T> Dac<T> for Ak4490Dac<T>
where
    T: _embedded_hal_blocking_i2c_WriteRead + _embedded_hal_blocking_i2c_Write,
{
    fn new(i2c: T, pins: CodecPins) -> Self {
        Self { i2c, pins }
    }
    fn init(&mut self) {
        // bring out of reset
        self.pins.reset.set_high();
        self.write_reg(RegisterAddress::Control1, (1 << 7) | 0x0e | (1 << 0)); // ACKS | I2S-32 | RSTN
        let dfs = 0; // start in 48k mode, change_rate will be called after init
        self.write_reg(RegisterAddress::Control2, 0x22 | ((dfs & 0x3) << 3));
        self.write_reg(RegisterAddress::Control4, (dfs & 0x4) >> 1);
    }
    fn change_rate(&mut self, new_rate: u32) {
        let dfs = self.dfs_for_rate(new_rate);
        self.write_reg(RegisterAddress::Control2, 0x22 | ((dfs & 0x3) << 3));
        self.write_reg(RegisterAddress::Control4, (dfs & 0x4) >> 1);
    }
    fn set_volume(&mut self, left: u8, right: u8) {
        self.write_reg(RegisterAddress::LeftAtt, left);
        self.write_reg(RegisterAddress::RightAtt, right);
    }
}