/*
 * ============================================================
 *  3.5" TFT LCD Shield Test — ESP32 Heltec WiFi
 *  Driver: ILI9486 / ILI9481 (common on 3.5" MCUFRIEND shield)
 *  Libraries needed:
 *    - Adafruit_GFX        (Library Manager)
 *    - MCUFRIEND_kbv       (Library Manager)
 * ============================================================
 *
 *  WIRING (8-bit parallel — shield pins → ESP32 GPIO):
TFT Shield	    Heltec V3
LCD_RST         GPIO48
LCD_CS	        GPIO47
LCD_RS (DC)	    GPIO21
LCD_WR	        GPIO20
LCD_RD	        GPIO19
LCD_D0	        GPIO1
LCD_D1	        GPIO2
LCD_D2	        GPIO3
LCD_D3	        GPIO4
LCD_D4	        GPIO5
LCD_D5	        GPIO6
LCD_D6	        GPIO7
LCD_D7	        GPIO8
GND	            GND
3V3	            3.3V
 *
 *  NOTE: If you're using the shield on a dedicated adapter/PCB
 *  for Heltec, adjust GPIO numbers to match your adapter.
 *  Shield backlight (BL/LED) → 3.3V or GPIO with PWM.
 * ============================================================
 */

#include <Adafruit_GFX.h>
#include <MCUFRIEND_kbv.h>

MCUFRIEND_kbv tft;

// ── Color shortcuts ──────────────────────────────────────────
#define BLACK   0x0000
#define WHITE   0xFFFF
#define RED     0xF800
#define GREEN   0x07E0
#define BLUE    0x001F
#define YELLOW  0xFFE0
#define CYAN    0x07FF
#define MAGENTA 0xF81F
#define ORANGE  0xFD20

// ── Test helpers ──────────────────────────────────────────────
void fillColorTest();
void drawGridTest();
void textTest();
void drawShapesTest();
void touchReadTest();

// ─────────────────────────────────────────────────────────────
void setup() {
  Serial.begin(115200);
  Serial.println("\n=== TFT LCD Shield Test — ESP32 Heltec ===");

  // Auto-detect driver ID
  uint16_t ID = tft.readID();
  Serial.print("Driver ID: 0x");
  Serial.println(ID, HEX);

  if (ID == 0xD3D3) {
    ID = 0x9486;   // Most 3.5" shields use ILI9486
    Serial.println("Forcing ILI9486 (write-only display)");
  }

  tft.begin(ID);
  tft.setRotation(1);  // Landscape: 0=Portrait, 1=Landscape, 2=Portrait flip, 3=Landscape flip

  Serial.print("Screen size: ");
  Serial.print(tft.width());
  Serial.print(" x ");
  Serial.println(tft.height());
}

// ─────────────────────────────────────────────────────────────
void loop() {
  // ── TEST 1: Full-screen color fills ──
  fillColorTest();
  delay(500);

  // ── TEST 2: Grid lines ──
  drawGridTest();
  delay(1500);

  // ── TEST 3: Text rendering ──
  textTest();
  delay(2000);

  // ── TEST 4: Geometric shapes ──
  drawShapesTest();
  delay(2000);

  // ── TEST 5: Gradient bar ──
  gradientTest();
  delay(2000);

  // ── TEST 6: TrailNav splash ──
  trailNavSplash();
  delay(3000);
}

// ─────────────────────────────────────────────────────────────
//  TEST 1 — Color fills
// ─────────────────────────────────────────────────────────────
void fillColorTest() {
  uint16_t colors[] = { RED, GREEN, BLUE, YELLOW, CYAN, MAGENTA, WHITE, BLACK };
  const char* names[] = { "RED","GREEN","BLUE","YELLOW","CYAN","MAGENTA","WHITE","BLACK" };
  for (uint8_t i = 0; i < 8; i++) {
    tft.fillScreen(colors[i]);
    tft.setCursor(10, tft.height() / 2 - 8);
    tft.setTextColor(colors[i] == WHITE ? BLACK : WHITE);
    tft.setTextSize(3);
    tft.print(names[i]);
    Serial.print("Color: "); Serial.println(names[i]);
    delay(400);
  }
}

// ─────────────────────────────────────────────────────────────
//  TEST 2 — Grid
// ─────────────────────────────────────────────────────────────
void drawGridTest() {
  tft.fillScreen(BLACK);
  int w = tft.width(), h = tft.height();

  // Vertical lines every 40px
  for (int x = 0; x <= w; x += 40)
    tft.drawFastVLine(x, 0, h, GREEN);

  // Horizontal lines every 40px
  for (int y = 0; y <= h; y += 40)
    tft.drawFastHLine(0, y, w, GREEN);

  // Centre cross
  tft.drawFastVLine(w / 2, 0, h, RED);
  tft.drawFastHLine(0, h / 2, w, RED);

  tft.setTextColor(WHITE);
  tft.setTextSize(2);
  tft.setCursor(4, 4);
  tft.print("GRID TEST");
  Serial.println("Grid drawn");
}

// ─────────────────────────────────────────────────────────────
//  TEST 3 — Text
// ─────────────────────────────────────────────────────────────
void textTest() {
  tft.fillScreen(BLACK);

  tft.setTextColor(WHITE);
  tft.setTextSize(1); tft.setCursor(0, 0);   tft.println("Size 1 — Hello World!");
  tft.setTextSize(2); tft.setCursor(0, 16);  tft.println("Size 2 — Hello!");
  tft.setTextSize(3); tft.setCursor(0, 40);  tft.println("Size 3");
  tft.setTextSize(4); tft.setCursor(0, 72);  tft.println("Size 4");

  tft.setTextSize(2);
  tft.setTextColor(RED);    tft.setCursor(0, 120); tft.println("RED text");
  tft.setTextColor(GREEN);  tft.setCursor(0, 145); tft.println("GREEN text");
  tft.setTextColor(BLUE);   tft.setCursor(0, 170); tft.println("BLUE text");
  tft.setTextColor(YELLOW); tft.setCursor(0, 195); tft.println("YELLOW text");

  Serial.println("Text test complete");
}

// ─────────────────────────────────────────────────────────────
//  TEST 4 — Shapes
// ─────────────────────────────────────────────────────────────
void drawShapesTest() {
  tft.fillScreen(BLACK);
  int cx = tft.width() / 2, cy = tft.height() / 2;

  // Filled + outlined circles
  tft.fillCircle(cx - 100, cy, 50, BLUE);
  tft.drawCircle(cx - 100, cy, 50, WHITE);

  // Filled + outlined rectangle
  tft.fillRect(cx - 30, cy - 50, 80, 100, GREEN);
  tft.drawRect(cx - 30, cy - 50, 80, 100, WHITE);

  // Triangle
  tft.fillTriangle(cx + 80, cy - 50, cx + 150, cy + 50, cx + 10, cy + 50, RED);
  tft.drawTriangle(cx + 80, cy - 50, cx + 150, cy + 50, cx + 10, cy + 50, WHITE);

  // Rounded rect
  tft.fillRoundRect(10, 10, 120, 60, 12, MAGENTA);
  tft.drawRoundRect(10, 10, 120, 60, 12, WHITE);

  tft.setTextColor(WHITE); tft.setTextSize(2);
  tft.setCursor(10, tft.height() - 30);
  tft.print("SHAPES TEST");
  Serial.println("Shapes drawn");
}

// ─────────────────────────────────────────────────────────────
//  TEST 5 — Gradient bar
// ─────────────────────────────────────────────────────────────
void gradientTest() {
  tft.fillScreen(BLACK);
  int w = tft.width(), h = tft.height();
  int barH = 40;

  tft.setTextColor(WHITE); tft.setTextSize(2);
  tft.setCursor(10, 10); tft.print("GRADIENT TEST");

  // Red gradient bar
  for (int x = 0; x < w; x++) {
    uint16_t r = map(x, 0, w, 0, 31);
    tft.drawFastVLine(x, 60, barH, tft.color565(r * 8, 0, 0));
  }

  // Green gradient bar
  for (int x = 0; x < w; x++) {
    uint16_t g = map(x, 0, w, 0, 63);
    tft.drawFastVLine(x, 110, barH, tft.color565(0, g * 4, 0));
  }

  // Blue gradient bar
  for (int x = 0; x < w; x++) {
    uint16_t b = map(x, 0, w, 0, 31);
    tft.drawFastVLine(x, 160, barH, tft.color565(0, 0, b * 8));
  }

  // Full RGB sweep
  for (int x = 0; x < w; x++) {
    uint16_t hue = map(x, 0, w, 0, 359);
    // Simple HSV→RGB (S=1, V=1)
    uint8_t hi = hue / 60;
    float f = (hue / 60.0) - hi;
    uint8_t q = 255 * (1 - f);
    uint8_t t8 = 255 * f;
    uint8_t r, g, b;
    switch(hi % 6) {
      case 0: r=255; g=t8;  b=0;   break;
      case 1: r=q;   g=255; b=0;   break;
      case 2: r=0;   g=255; b=t8;  break;
      case 3: r=0;   g=q;   b=255; break;
      case 4: r=t8;  g=0;   b=255; break;
      default:r=255; g=0;   b=q;   break;
    }
    tft.drawFastVLine(x, 220, barH, tft.color565(r, g, b));
  }
  Serial.println("Gradient test complete");
}

// ─────────────────────────────────────────────────────────────
//  TEST 6 — TrailNav project splash screen
// ─────────────────────────────────────────────────────────────
void trailNavSplash() {
  tft.fillScreen(BLACK);
  int w = tft.width(), h = tft.height();

  // Header bar
  tft.fillRect(0, 0, w, 50, 0x0460);   // Dark teal

  // Title
  tft.setTextColor(WHITE); tft.setTextSize(3);
  tft.setCursor(20, 12);
  tft.print("TrailNav");

  // Compass icon (simple lines)
  int ox = w - 60, oy = 25;
  tft.drawCircle(ox, oy, 20, CYAN);
  tft.fillTriangle(ox, oy - 18, ox - 6, oy + 8, ox + 6, oy + 8, RED);   // N arrow (red)
  tft.fillTriangle(ox, oy + 18, ox - 6, oy - 8, ox + 6, oy - 8, WHITE); // S arrow (white)

  // Status info
  tft.setTextSize(2);
  tft.setTextColor(GREEN);
  tft.setCursor(10, 70);  tft.print("GPS:  Searching...");
  tft.setTextColor(YELLOW);
  tft.setCursor(10, 98);  tft.print("ALT:  --- m");
  tft.setTextColor(CYAN);
  tft.setCursor(10, 126); tft.print("SPD:  0.0 km/h");
  tft.setTextColor(WHITE);
  tft.setCursor(10, 154); tft.print("HDG:  ---°");

  // Divider
  tft.drawFastHLine(0, 180, w, 0x0460);

  // Footer
  tft.setTextColor(0x8410); // Dark grey
  tft.setTextSize(1);
  tft.setCursor(10, h - 20);
  tft.print("ESP32 Heltec WiFi  |  TFT 3.5\"  |  OK");

  // Screen OK badge
  tft.fillRoundRect(w - 80, h - 35, 70, 25, 6, GREEN);
  tft.setTextColor(BLACK); tft.setTextSize(2);
  tft.setCursor(w - 75, h - 31);
  tft.print("OK");

  Serial.println("TrailNav splash rendered — screen PASS");
}