#include "UIThread.h"
#include "SharedState.h"
#include <Wire.h>

// --- Local State ---
static int g_last_clk_state;

// --- Forward Declarations ---
static void readEncoder();
static void updateDisplay();

void setupUI() {
  // --- Initialize I2C and Display ---
  Wire.setSDA(OLED_SDA_PIN);
  Wire.setSCL(OLED_SCL_PIN);
  Wire.begin();

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  display.setTextSize(1);
  display.println("NoiceSynth Booting...");
  display.display();
  delay(1000);

  // --- Initialize Controls ---
  pinMode(ENCODER_CLK_PIN, INPUT_PULLUP);
  pinMode(ENCODER_DT_PIN, INPUT_PULLUP);
  pinMode(ENCODER_SW_PIN, INPUT_PULLUP);
  g_last_clk_state = digitalRead(ENCODER_CLK_PIN);
}

void loopUI() {
  // Read the volume potentiometer (Pico ADC is 12-bit, 0-4095)
  // We use a bit of filtering by averaging with the old value to reduce noise.
  float new_volume = analogRead(VOL_POT_PIN) / 4095.0f;
  g_volume = (g_volume * 0.95) + (new_volume * 0.05);

  // Read the rotary encoder
  readEncoder();

  // Update the display periodically
  static uint32_t last_display_update = 0;
  if (millis() - last_display_update > 100) { // Update 10 times/sec
    last_display_update = millis();
    updateDisplay();
  }
}

static void updateDisplay() {
  display.clearDisplay();
  display.setCursor(0, 0);

  display.println(F("    NoiceSynth"));
  display.println(F("--------------------"));

  if (g_note_on) {
    display.print(F("Note Freq: "));
    display.print(g_note_frequency, 2);
    display.println(F(" Hz"));
  } else {
    display.println(F("Note: Off"));
  }

  display.print(F("Volume: "));
  display.print(static_cast<int>(g_volume * 100));
  display.println(F("%"));

  display.print(F("Encoder: "));
  display.println(g_encoder_value);

  display.display();
}

static void readEncoder() {
  int new_clk_state = digitalRead(ENCODER_CLK_PIN);
  // Check for a change on the CLK pin (a "tick" of the encoder)
  if (new_clk_state != g_last_clk_state && new_clk_state == LOW) {
    // Read the DT pin to determine direction
    if (digitalRead(ENCODER_DT_PIN) == LOW) {
      g_encoder_value++; // Clockwise
    } else {
      g_encoder_value--; // Counter-clockwise
    }
  }
  g_last_clk_state = new_clk_state;
}