circuits_sim

defmodule CircuitsSim.Device.ADS7138 do
  @moduledoc """
  MCP23008 8-bit I/O Expander

  Small, 8-Channel, 12-Bit ADC with I2C interface, GPIOs, and CRC. Supports
  addresses 0x10 to 0x17

  See the [datasheet](https://www.ti.com/lit/ds/symlink/ads7138.pdf) for details.
  Many features aren't implemented.
  """
  alias CircuitsSim.I2C.I2CDevice
  alias CircuitsSim.I2C.I2CServer
  alias CircuitsSim.Tools

  defstruct registers: %{}, current: 0
  @type t() :: %__MODULE__{registers: map(), current: non_neg_integer()}

  @spec child_spec(keyword()) :: Supervisor.child_spec()
  def child_spec(args) do
    device = __MODULE__.new()
    I2CServer.child_spec_helper(device, args)
  end

  @spec new() :: %__MODULE__{current: 0, registers: %{}}
  def new() do
    %__MODULE__{}
  end

  defimpl I2CDevice do
    @single_register_read 0b00010000
    @single_register_write 0b00001000
    @continuous_register_read 0b00110000
    @continuous_register_write 0b00101000

    @impl I2CDevice
    def read(state, count) do
      # This isn't really supported since ADS7138 always requires a command to set a register
      # for reading, but we'll include it here just in case.
      last = state.current + count
      result = for reg <- state.current..last, into: <<>>, do: read_register(state, reg)
      {{:ok, result}, %{state | current: last}}
    end

    @impl I2CDevice
    def write(state, <<@single_register_write, register, value::binary>>) do
      put_in(state.registers[register], value)
    end

    def write(state, <<@continuous_register_write, register, values::binary>>) do
      current =
        for <<val <- values>>, reduce: register do
          reg ->
            write_register(state, reg, val)
            reg + 1
        end

      %{state | current: current - 1}
    end

    def write(state, <<>>) do
      state
    end

    @impl I2CDevice
    def write_read(state, <<@single_register_read, register>>, 1) do
      {{:ok, read_register(state, register)}, %{state | current: register}}
    end

    def write_read(state, <<@continuous_register_read, register>>, count) do
      last = state.current + count
      result = for reg <- state.current..last, into: <<>>, do: read_register(state, reg)
      {{:ok, result}, %{state | current: register}}
    end

    @impl I2CDevice
    def render(state) do
      for {reg, data} <- state.registers do
        [
          "  ",
          Tools.hex_byte(reg),
          ": ",
          for(<<b::1 <- data>>, do: to_string(b)),
          " (",
          reg_name(reg),
          ")\n"
        ]
      end
    end

    @impl I2CDevice
    def handle_message(state, _message) do
      {:not_implemented, state}
    end

    defp read_register(state, register) do
      state.registers[register] || <<0>>
    end

    # Section 8.5.2.4 - "Writing data to addresses that do not exist
    # in the register map of the device have no effect."
    defp write_register(state, register, val) when register < 0xEB do
      put_in(state.registers[register], val)
    end

    defp write_register(state, _reg, _val), do: state

    defp reg_name(0x0), do: "SYSTEM_STATUS"
    defp reg_name(0x1), do: "GENERAL_CFG"
    defp reg_name(0x2), do: "DATA_CFG"
    defp reg_name(0x3), do: "OSR_CFG"
    defp reg_name(0x4), do: "OPMODE_CFG"
    defp reg_name(0x5), do: "PIN_CFG"
    defp reg_name(0x7), do: "GPIO_CFG"
    defp reg_name(0x9), do: "GPO_DRIVE_CFG"
    defp reg_name(0xB), do: "GPO_VALUE"
    defp reg_name(0xD), do: "GPI_VALUE"
    defp reg_name(0x10), do: "SEQUENCE_CFG"
    defp reg_name(0x11), do: "CHANNEL_SEL"
    defp reg_name(0x12), do: "AUTO_SEQ_CH_SEL"
    defp reg_name(0x14), do: "ALERT_CH_SEL"
    defp reg_name(0x16), do: "ALERT_MAP"
    defp reg_name(0x17), do: "ALERT_PIN_CFG"
    defp reg_name(0x18), do: "EVENT_FLAG"
    defp reg_name(0x1A), do: "EVENT_HIGH_FLAG"
    defp reg_name(0x1C), do: "EVENT_LOW_FLAG"
    defp reg_name(0x1E), do: "EVENT_RGN"
    defp reg_name(0x20), do: "HYSTERESIS_CH0"
    defp reg_name(0x21), do: "HIGH_TH_CH0"
    defp reg_name(0x22), do: "EVENT_COUNT_CH0"
    defp reg_name(0x23), do: "LOW_TH_CH0"
    defp reg_name(0x24), do: "HYSTERESIS_CH1"
    defp reg_name(0x25), do: "HIGH_TH_CH1"
    defp reg_name(0x26), do: "EVENT_COUNT_CH1"
    defp reg_name(0x27), do: "LOW_TH_CH1"
    defp reg_name(0x28), do: "HYSTERESIS_CH2"
    defp reg_name(0x29), do: "HIGH_TH_CH2"
    defp reg_name(0x2A), do: "EVENT_COUNT_CH2"
    defp reg_name(0x2B), do: "LOW_TH_CH2"
    defp reg_name(0x2C), do: "HYSTERESIS_CH3"
    defp reg_name(0x2D), do: "HIGH_TH_CH3"
    defp reg_name(0x2E), do: "EVENT_COUNT_CH3"
    defp reg_name(0x2F), do: "LOW_TH_CH3"
    defp reg_name(0x30), do: "HYSTERESIS_CH4"
    defp reg_name(0x31), do: "HIGH_TH_CH4"
    defp reg_name(0x32), do: "EVENT_COUNT_CH4"
    defp reg_name(0x33), do: "LOW_TH_CH4"
    defp reg_name(0x34), do: "HYSTERESIS_CH5"
    defp reg_name(0x35), do: "HIGH_TH_CH5"
    defp reg_name(0x36), do: "EVENT_COUNT_CH5"
    defp reg_name(0x37), do: "LOW_TH_CH5"
    defp reg_name(0x38), do: "HYSTERESIS_CH6"
    defp reg_name(0x39), do: "HIGH_TH_CH6"
    defp reg_name(0x3A), do: "EVENT_COUNT_CH6"
    defp reg_name(0x3B), do: "LOW_TH_CH6"
    defp reg_name(0x3C), do: "HYSTERESIS_CH7"
    defp reg_name(0x3D), do: "HIGH_TH_CH7"
    defp reg_name(0x3E), do: "EVENT_COUNT_CH7"
    defp reg_name(0x3F), do: "LOW_TH_CH7"
    defp reg_name(0x60), do: "MAX_CH0_LSB"
    defp reg_name(0x61), do: "MAX_CH0_MSB"
    defp reg_name(0x62), do: "MAX_CH1_LSB"
    defp reg_name(0x63), do: "MAX_CH1_MSB"
    defp reg_name(0x64), do: "MAX_CH2_LSB"
    defp reg_name(0x65), do: "MAX_CH2_MSB"
    defp reg_name(0x66), do: "MAX_CH3_LSB"
    defp reg_name(0x67), do: "MAX_CH3_MSB"
    defp reg_name(0x68), do: "MAX_CH4_LSB"
    defp reg_name(0x69), do: "MAX_CH4_MSB"
    defp reg_name(0x6A), do: "MAX_CH5_LSB"
    defp reg_name(0x6B), do: "MAX_CH5_MSB"
    defp reg_name(0x6C), do: "MAX_CH6_LSB"
    defp reg_name(0x6D), do: "MAX_CH6_MSB"
    defp reg_name(0x6E), do: "MAX_CH7_LSB"
    defp reg_name(0x6F), do: "MAX_CH7_MSB"
    defp reg_name(0x80), do: "MIN_CH0_LSB"
    defp reg_name(0x81), do: "MIN_CH0_MSB"
    defp reg_name(0x82), do: "MIN_CH1_LSB"
    defp reg_name(0x83), do: "MIN_CH1_MSB"
    defp reg_name(0x84), do: "MIN_CH2_LSB"
    defp reg_name(0x85), do: "MIN_CH2_MSB"
    defp reg_name(0x86), do: "MIN_CH3_LSB"
    defp reg_name(0x87), do: "MIN_CH3_MSB"
    defp reg_name(0x88), do: "MIN_CH4_LSB"
    defp reg_name(0x89), do: "MIN_CH4_MSB"
    defp reg_name(0x8A), do: "MIN_CH5_LSB"
    defp reg_name(0x8B), do: "MIN_CH5_MSB"
    defp reg_name(0x8C), do: "MIN_CH6_LSB"
    defp reg_name(0x8D), do: "MIN_CH6_MSB"
    defp reg_name(0x8E), do: "MIN_CH7_LSB"
    defp reg_name(0x8F), do: "MIN_CH7_MSB"
    defp reg_name(0xA0), do: "RECENT_CH0_LSB"
    defp reg_name(0xA1), do: "RECENT_CH0_MSB"
    defp reg_name(0xA2), do: "RECENT_CH1_LSB"
    defp reg_name(0xA3), do: "RECENT_CH1_MSB"
    defp reg_name(0xA4), do: "RECENT_CH2_LSB"
    defp reg_name(0xA5), do: "RECENT_CH2_MSB"
    defp reg_name(0xA6), do: "RECENT_CH3_LSB"
    defp reg_name(0xA7), do: "RECENT_CH3_MSB"
    defp reg_name(0xA8), do: "RECENT_CH4_LSB"
    defp reg_name(0xA9), do: "RECENT_CH4_MSB"
    defp reg_name(0xAA), do: "RECENT_CH5_LSB"
    defp reg_name(0xAB), do: "RECENT_CH5_MSB"
    defp reg_name(0xAC), do: "RECENT_CH6_LSB"
    defp reg_name(0xAD), do: "RECENT_CH6_MSB"
    defp reg_name(0xAE), do: "RECENT_CH7_LSB"
    defp reg_name(0xAF), do: "RECENT_CH7_MSB"
    defp reg_name(0xC3), do: "GPO0_TRIG_EVENT_SEL"
    defp reg_name(0xC5), do: "GPO1_TRIG_EVENT_SEL"
    defp reg_name(0xC7), do: "GPO2_TRIG_EVENT_SEL"
    defp reg_name(0xC9), do: "GPO3_TRIG_EVENT_SEL"
    defp reg_name(0xCB), do: "GPO4_TRIG_EVENT_SEL"
    defp reg_name(0xCD), do: "GPO5_TRIG_EVENT_SEL"
    defp reg_name(0xCF), do: "GPO6_TRIG_EVENT_SEL"
    defp reg_name(0xD1), do: "GPO7_TRIG_EVENT_SEL"
    defp reg_name(0xE9), do: "GPO_TRIGGER_CFG"
    defp reg_name(0xEB), do: "GPO_VALUE_TRIG"
  end
end