library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

-- Definition of the audio_codec entity
entity audio_codec is
port (
    -- Interface signals for the WM8731 audio codec
    AUD_BCLK: out std_logic;        -- Bit clock signal
    AUD_XCK: out std_logic;         -- Master clock signal
    AUD_ADCLRCK: out std_logic;     -- ADC clock signal (receiving side)
    AUD_ADCDAT: in std_logic;       -- ADC received data
    AUD_DACLRCK: out std_logic;     -- DAC clock signal
    AUD_DACDAT: out std_logic;      -- DAC data output

    -- Interface signals for FPGA
    clock_50: in std_logic;         -- 50 MHz clock signal from the FPGA
    key: in std_logic_vector(3 downto 0); -- Input buttons
    ledr: out std_logic_vector(9 downto 0); -- Output LEDs
    sw: in std_logic_vector(9 downto 0);    -- Input switches
    FPGA_I2C_SCLK: out std_logic;  -- I2C clock signal
    FPGA_I2C_SDAT: inout std_logic -- I2C data signal
);
end audio_codec;

architecture main of audio_codec is

-- Internal signals
signal bitprsc: integer range 0 to 4 := 0; -- Bit processing counter
signal aud_mono: std_logic_vector(31 downto 0) := (others => '0'); -- Mono audio data
signal read_addr: integer range 0 to 240254 := 0; -- ROM read address
signal ROM_ADDR: std_logic_vector(17 downto 0); -- ROM address
signal ROM_OUT: std_logic_vector(15 downto 0); -- Data read from ROM
signal clock_12pll: std_logic; -- 12 MHz clock signal generated by the PLL
signal WM_i2c_busy: std_logic; -- I2C busy status
signal WM_i2c_done: std_logic; -- I2C transaction completion signal
signal WM_i2c_send_flag: std_logic; -- I2C send flag
signal WM_i2c_data: std_logic_vector(15 downto 0); -- Data to be sent via I2C
signal DA_CLR: std_logic := '0'; -- DAC control clock

-- PLL component for clock generation
component pll is
port (
    clk_clk: in std_logic;          -- Input clock
    clock_12_clk: out std_logic;   -- Output 12 MHz clock
    reset_reset_n: in std_logic;   -- Reset signal (active low)
    ...
);
end component pll;

-- Audio generation component
component aud_gen is
port (
    aud_clock_12: in std_logic;            -- 12 MHz clock
    aud_bk: out std_logic;                 -- Bit clock (BCLK)
    aud_dalr: out std_logic;               -- DAC LRCLK
    aud_dadat: out std_logic;              -- DAC data output
    aud_data_in: in std_logic_vector(31 downto 0) -- Input audio data
);
end component aud_gen;

-- I2C communication component
component i2c is
port (
    i2c_busy: out std_logic;               -- I2C busy status
    i2c_scl: out std_logic;                -- I2C clock signal
    i2c_send_flag: in std_logic;           -- I2C send flag
    i2c_sda: inout std_logic;              -- I2C data signal
    i2c_addr: in std_logic_vector(7 downto 0); -- I2C address
    i2c_done: out std_logic;               -- I2C transaction completion signal
    i2c_data: in std_logic_vector(15 downto 0); -- I2C data
    i2c_clock_50: in std_logic             -- 50 MHz clock
);
end component i2c;

-- Main logic block
begin
    -- Connect the PLL to generate a 12 MHz clock from the 50 MHz input
    u0: pll port map (
        clk_clk => clock_50,
        reset_reset_n => '1',
        clock_12_clk => clock_12pll,
        ...
    );

    -- Connect the audio generation module
    sound: aud_gen port map (
        aud_clock_12 => clock_12pll,
        aud_bk => AUD_BCLK,
        aud_dalr => DA_CLR,
        aud_dadat => AUD_DACDAT,
        aud_data_in => aud_mono
    );

    -- Connect the I2C communication module to interface with the WM8731 codec
    WM8731: i2c port map (
        i2c_busy => WM_i2c_busy,
        i2c_scl => FPGA_I2C_SCLK,
        i2c_send_flag => WM_i2c_send_flag,
        i2c_sda => FPGA_I2C_SDAT,
        i2c_addr => "00110100", -- WM8731 address
        i2c_done => WM_i2c_done,
        i2c_data => WM_i2c_data,
        i2c_clock_50 => clock_50
    );

    -- Audio and I2C control logic
    -- (Manage ROM read addresses, process audio signals, configure I2C, etc.)
    ...
end main;