#ifndef EXPANDER_H
#define EXPANDER_H

#include "blk_box_drivers/i2c.h"
#include <freertos/FreeRTOS.h>
#include <freertos/semphr.h>

#define EXPANDER_I2C_ADDR (0x7E)
#define EXPANDER_I2C_SPEED (400000)
// the actual transaction takes ~0.3ms, but for some reason a timout of ~10 or lower causes issues.
#define EXPANDER_TIMEOUT_MS (100)

#define EXPANDER_WHOAMI_VALUE (0x85)

// queue sizes
#define EXPANDER_EVENT_QUEUE_SIZE 4
#define EXPANDER_KEYPAD_QUEUE_SIZE 16

void init_expander();

/// The four buttons on the bottom half.
enum class Button: uint8_t {
    B1 = 0,
    B2 = 1,
    B3 = 2,
    B4 = 3,
    GREEN = 0,
    YELLOW = 1,
    RED = 2,
    BLUE = 3,
};

/// The four switches on the bottom half.
enum class Switch: uint8_t {
    S1 = 0,
    S2 = 1,
    S3 = 2,
    S4 = 3,
};

enum class TouchedReleased: uint8_t {
    Released = 0,
    Touched = 1,
};

/// One of the keys on the keypad.
enum class KeypadKey: uint8_t {
    K0 = 0,
    K1 = 1,
    K2 = 2,
    K3 = 3,
    K4 = 4,
    K5 = 5,
    K6 = 6,
    K7 = 7,
    K8 = 8,
    K9 = 9,
    A = 10,
    B = 11,
    C = 12,
    D = 13,
    STAR = 14,
    POUND = 15,
};

struct SwitchFlip {
private:
    // [bit2: pressed] [bit1-0: switch] 
    uint8_t data;

public:
    // Constructor
    SwitchFlip(Switch sw, bool pressed)
        : data((static_cast<uint8_t>(sw) & 0b11) |
               ((pressed ? 1 : 0) << 2)) {}

    // Default constructor
    SwitchFlip() : data(0) {}

    // Getters
    Switch get_switch() const {
        return static_cast<Switch>(data & 0b11);
    }

    bool is_pressed() const {
        return (data >> 2) & 1;
    }

    // Setters
    void set_switch(Switch sw) {
        data = (data & ~0b11) | (static_cast<uint8_t>(sw) & 0b11);
    }

    void set_pressed(bool pressed) {
        data = (data & ~(1 << 2)) | ((pressed ? 1 : 0) << 2);
    }
};
static_assert(sizeof(SwitchFlip) == 1);

struct SwitchTouch {
private:
    // [bit2: touched] [bit1-0: switch] 
    uint8_t data;

public:
    // Constructor
    SwitchTouch(Switch sw, bool touched)
        : data((static_cast<uint8_t>(sw) & 0b11) |
               ((touched ? 1 : 0) << 2)) {}

    // Default constructor
    SwitchTouch() : data(0) {}

    // Getters
    Switch get_switch() const {
        return static_cast<Switch>(data & 0b11);
    }

    bool is_touched() const {
        return (data >> 2) & 1;
    }

    // Setters
    void set_switch(Switch sw) {
        data = (data & ~0b11) | (static_cast<uint8_t>(sw) & 0b11);
    }

    void set_touched(bool touched) {
        data = (data & ~(1 << 2)) | ((touched ? 1 : 0) << 2);
    }
};
static_assert(sizeof(SwitchTouch) == 1);

struct ButtonOrSwitch {
private:
    // [bit2: is_switch] [bit1-0: number]
    uint8_t data;

public:
    // Constructor
    ButtonOrSwitch(uint8_t number, bool is_switch)
        : data((number & 0b11) |
               ((is_switch ? 1 : 0) << 2)) {}

    ButtonOrSwitch() : data(0) {}

    // Getters
    uint8_t number() const {
        return data & 0b11;
    }

    bool is_switch() const {
        return (data >> 2) & 1;
    }

    // Setters
    void set_number(uint8_t number) {
        data = (data & ~0b11) | (number & 0b11);
    }

    void set_is_switch(bool is_switch) {
        data = (data & ~(1 << 2)) | ((is_switch ? 1 : 0) << 2);
    }
};
static_assert(sizeof(ButtonOrSwitch) == 1);


/// @brief The state of the bottom half of the box.
struct ExpanderState {
    /// The touch state of the switches in the lower 4 bits.
    /// The touch pad state in bit 4.
    uint8_t touch_state;
    /// The current state of the buttons in the lower 4 bits.
    uint8_t button_state;
    /// The current state of the switches. Up switches are stored
    /// in the lower 4 bits, switches that are down are stored in
    /// the upper 4 bits. If switches are in the middle, the
    /// corresponding bit will be `0` in the upper and lower 4.
    uint8_t switch_state;
    /// The state of the keypad.
    uint16_t keypad_state;
    /// The sensitivity of the `hal` value to auto update.
    uint16_t hal_sense;
    /// The sensitivity of the `close_hal` value to auto update.
    uint16_t close_hal_sense;
    /// A non-exact hal value reading.
    /// This only gets updated when it changes by `hal_sense`
    uint16_t hal;
    /// A non-exact hal value reading.
    /// This only gets updated when it changes by `close_hal_sense`
    uint16_t close_hal;
    /// The RFID card that was presented last.
    uint32_t rfid_state;

    ExpanderState() : touch_state(0), button_state(0), switch_state(0), keypad_state(0), hal_sense(0), close_hal_sense(0), hal(0), close_hal(0), rfid_state(0) {}
};

/// The global data for the expander peripheral.
class ExpanderPeripheral {
    // TODO: change these to private
    public: 
    SemaphoreHandle_t state_mutex;
    ExpanderState state;

    // channels
    QueueHandle_t button_press_events;
    QueueHandle_t button_release_events;
    QueueHandle_t switch_flip_events;
    QueueHandle_t switch_touch_events;
    QueueHandle_t touch_events;
    QueueHandle_t keypad_press_events;
    QueueHandle_t keypad_release_events;

    
};

#endif // EXPANDER_H