#include "ui.h"

#include "stm32h7a3xx.h"
#include "stm32h7xx_hal.h"
#include "stm32h7xx_hal_gpio.h"
#include "tx_api.h"

#include "hx8357d.h"
#include "main.h"
#include <stdint.h>

void ui_thread_entry(ULONG _) {
  GPIO_TypeDef *button_ports[NUM_BUTTONS] = {BTN1_GPIO_Port, BTN2_GPIO_Port,
                                             BTN3_GPIO_Port, BTN4_GPIO_Port,
                                             BTN5_GPIO_Port, BTN6_GPIO_Port};
  uint16_t button_pins[NUM_BUTTONS] = {BTN1_Pin, BTN2_Pin, BTN3_Pin,
                                       BTN4_Pin, BTN5_Pin, BTN6_Pin};
  GPIO_PinState button_states[NUM_BUTTONS] = {GPIO_PIN_RESET};
  uint32_t button_change_times[NUM_BUTTONS] = {HAL_GetTick()};

  while (1) {
    for (int i = 0; i < NUM_BUTTONS; i++) {
      GPIO_PinState state = HAL_GPIO_ReadPin(button_ports[i], button_pins[i]);
      if (state != button_states[i]) {
        uint32_t now = HAL_GetTick();
        if (state == GPIO_PIN_RESET && now - button_change_times[i]) {
          // Button release event!
          ButtonMessage msg = {.kind = UMK_BTN_RELEASED, .number = i};
          tx_queue_send(&gui_button_queue, &msg, TX_NO_WAIT);
        }
        button_change_times[i] = now;
        button_states[i] = state;
      }
    }
    // Release so other threads can get scheduled
    tx_thread_sleep(1);
  }
}

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
  // This gets called when an edge on one of the encoder pins is detected.
  static uint32_t last_change[NUM_ENCS * 2] = {0};
  static GPIO_PinState last_state[NUM_ENCS * 2] = {GPIO_PIN_RESET};

  if (GPIO_Pin == ENC2B_Pin) {
    // ENC2A and ENC2B share an interrupt line, so the HAL calls this callback
    // once with each pin. Since we already handled the interrupt once for
    // ENC2A, we can just ignore it now.
  }

  uint32_t now = HAL_GetTick();

  uint16_t pin_a, pin_b;
  int idx_a, idx_b;
  ButtonMessage msg;
  if (GPIO_Pin == ENC1A_Pin || GPIO_Pin == ENC1B_Pin) {
    pin_a = ENC1A_Pin;
    pin_b = ENC1B_Pin;
    idx_a = 0;
    idx_b = 1;
    msg.number = 0;
  } else {
    pin_a = ENC2A_Pin;
    pin_b = ENC2B_Pin;
    idx_a = 2;
    idx_b = 3;
    msg.number = 1;
  }

  // All encoder pins are on port E
  GPIO_PinState state_a = HAL_GPIO_ReadPin(GPIOE, pin_a);
  GPIO_PinState state_b = HAL_GPIO_ReadPin(GPIOE, pin_b);
  int a_changed = state_a != last_state[idx_a];
  int b_changed = state_b != last_state[idx_b];
  last_state[idx_a] = state_a;
  last_state[idx_b] = state_b;

  if (state_a == GPIO_PIN_RESET && state_b == GPIO_PIN_RESET) {
    // Second falling edge, direction depends on which pin changed last
    if (a_changed && b_changed) {
      // This shouldn't happen. Ignore this event.
      last_change[idx_a] = now;
      last_change[idx_b] = now;
      return;
    } else if (a_changed) {
      last_change[idx_a] = now;
      msg.kind = UMK_ENC_CCW;
    } else if (b_changed) {
      last_change[idx_b] = now;
      msg.kind = UMK_ENC_CW;
    } else {
      // This shouldn't happen. Ignore this event.
      return;
    }
    tx_queue_send(&gui_button_queue, &msg, TX_NO_WAIT);
  }
}