#![no_std]

use embedded_hal::i2c::SevenBitAddress;

pub const I2C_ADDR: SevenBitAddress = 0b0_0110100;

pub struct TCA8418<I2C> {
    i2c: I2C,
}

#[derive(Clone, Copy)]
pub struct MatrixConfig {
    rows: u8,
    columns: u16,
}

impl MatrixConfig {
    /// A new config where the matrix has no rows or columns and all of the pins are
    /// allocated for GPIO.
    pub const fn new_empty() -> Self {
        MatrixConfig {
            rows: 0,
            columns: 0,
        }
    }

    /// Add a row to the keyboard matrix, meaning its pin will not be available for GPIO.
    ///
    /// `row_number` must be in the range `0..=7`
    pub const fn with_row(self, row_number: u8) -> Self {
        if row_number >= 8 {
            panic!("row_number out of bounds");
        }
        MatrixConfig {
            rows: self.rows | (1 << row_number),
            columns: self.columns,
        }
    }

    /// Add a column to the keyboard matrix, meaning its pin will not be available for GPIO.
    ///
    /// `column_number` must be in the range `0..=9`
    pub const fn with_column(self, column_number: u8) -> Self {
        if column_number >= 10 {
            panic!("column_number out of bounds");
        }
        MatrixConfig {
            rows: self.rows,
            columns: self.columns | (1 << column_number),
        }
    }
}