/*
 * Server Status Dashboard - "ALIVE" (LCD + Captive Portal)
 * ESP32-S3 Super Mini + GC9A01 1.28" Round LCD + Status LEDs
 *
 * Features:
 * - Web-based configuration (no hardcoded credentials)
 * - WiFi network scanning
 * - Configurable servers (up to 5), check interval, display settings
 * - Settings persist in flash memory
 *
 * Config Mode Triggers:
 * - First boot (no saved WiFi)
 * - Hold BOOT button during power-on
 *
 * Hardware:
 * - GC9A01 240x240 Round LCD (SPI): SCK=12, MOSI=11, CS=8, DC=9, RST=10, BL=7
 * - Status LEDs: Blue=GPIO 5, Red=GPIO 10
 */

#include <WiFi.h>
#include <ESP32Ping.h>
#include <Arduino_GFX_Library.h>
#include <WebServer.h>
#include <DNSServer.h>
#include <Preferences.h>

// ============== PIN DEFINITIONS ==============
// GC9A01 Display (SPI)
#define TFT_SCK   12
#define TFT_MOSI  11
#define TFT_CS    8
#define TFT_DC    9
#define TFT_RST   10
#define TFT_BL    7

// Status LEDs
#define LED_BLUE  5
#define LED_RED   10
#define BOOT_BTN  0    // GPIO0 is BOOT button

// ============== DISPLAY SETTINGS ==============
#define SCREEN_WIDTH  240
#define SCREEN_HEIGHT 240
#define CX (SCREEN_WIDTH / 2)
#define CY (SCREEN_HEIGHT / 2)

// Colors (RGB565)
#define COLOR_BG       0x0821  // Dark blue-black
#define COLOR_TEXT     0xB5B6  // Light gray
#define COLOR_CYAN     0x07FF  // Neon Cyan
#define COLOR_MAGENTA  0xF81F  // Neon Magenta
#define COLOR_YELLOW   0xFFE0  // Neon Yellow
#define COLOR_GREEN    0x07E0  // Neon Green
#define COLOR_RED      0xF800  // Red

// ============== CONFIGURATION STRUCTURE ==============
struct Config {
  char ssid[33];
  char password[65];
  char servers[5][64];
  char serverNames[5][16];
  int numServers;
  unsigned long checkInterval;
  uint8_t brightness;
};

Config config;
Preferences prefs;

// Display setup using Arduino_GFX
Arduino_DataBus *bus = new Arduino_ESP32SPI(TFT_DC, TFT_CS, TFT_SCK, TFT_MOSI, GFX_NOT_DEFINED, HSPI);
Arduino_GFX *gfx = new Arduino_GC9A01(bus, TFT_RST, 0, true);

WebServer server(80);
DNSServer dnsServer;

// ============== STATE VARIABLES ==============
bool configMode = false;
bool serverStatus[5];
bool allServersUp = true;
unsigned long lastCheck = 0;
unsigned long lastBlink = 0;
unsigned long lastFlashUpdate = 0;
bool redLedState = false;
bool flashState = true;

// ============== DEFAULT CONFIGURATION ==============
void setDefaults() {
  memset(&config, 0, sizeof(config));
  config.numServers = 3;
  config.checkInterval = 30000;
  config.brightness = 255;
  strcpy(config.servers[0], "8.8.8.8");
  strcpy(config.serverNames[0], "Google");
  strcpy(config.servers[1], "1.1.1.1");
  strcpy(config.serverNames[1], "Cloudflare");
  strcpy(config.servers[2], "192.168.1.1");
  strcpy(config.serverNames[2], "Router");
}

// ============== LOAD/SAVE CONFIG ==============
void loadConfig() {
  prefs.begin("alivelcd", true);

  if (!prefs.isKey("ssid")) {
    prefs.end();
    setDefaults();
    return;
  }

  strcpy(config.ssid, prefs.getString("ssid", "").c_str());
  strcpy(config.password, prefs.getString("pass", "").c_str());
  config.numServers = prefs.getInt("numSrv", 3);
  config.checkInterval = prefs.getULong("interval", 30000);
  config.brightness = prefs.getUChar("bright", 255);

  for (int i = 0; i < 5; i++) {
    String srvKey = "srv" + String(i);
    String nameKey = "name" + String(i);
    strcpy(config.servers[i], prefs.getString(srvKey.c_str(), "").c_str());
    strcpy(config.serverNames[i], prefs.getString(nameKey.c_str(), "").c_str());
  }

  prefs.end();
}

void saveConfig() {
  prefs.begin("alivelcd", false);
  prefs.putString("ssid", config.ssid);
  prefs.putString("pass", config.password);
  prefs.putInt("numSrv", config.numServers);
  prefs.putULong("interval", config.checkInterval);
  prefs.putUChar("bright", config.brightness);

  for (int i = 0; i < 5; i++) {
    String srvKey = "srv" + String(i);
    String nameKey = "name" + String(i);
    prefs.putString(srvKey.c_str(), config.servers[i]);
    prefs.putString(nameKey.c_str(), config.serverNames[i]);
  }

  prefs.end();
}

// ============== DRAW HELPERS ==============
void drawGlowRing(int cx, int cy, int r, uint16_t color) {
  gfx->drawCircle(cx, cy, r, color);
  gfx->drawCircle(cx, cy, r - 1, color);
}

void drawCenteredText(const char* text, int y, uint16_t color, uint8_t size) {
  gfx->setTextSize(size);
  gfx->setTextColor(color);
  int16_t x1, y1;
  uint16_t w, h;
  gfx->getTextBounds(text, 0, 0, &x1, &y1, &w, &h);
  gfx->setCursor(CX - w/2, y);
  gfx->print(text);
}

// ============== CONFIG PAGE HTML ==============
const char* configPage = R"rawhtml(
<!DOCTYPE html>
<html>
<head>
  <meta name="viewport" content="width=device-width,initial-scale=1">
  <title>ALIVE LCD Setup</title>
  <style>
    *{box-sizing:border-box;margin:0;padding:0}
    body{font-family:'Courier New',monospace;background:#0a0a1a;color:#b0b0b0;padding:20px}
    h1{color:#ff00ff;text-align:center;margin-bottom:20px;text-shadow:0 0 10px #ff00ff}
    .card{background:#12121f;border:1px solid #333;border-radius:8px;padding:15px;margin-bottom:15px}
    .card h2{color:#00ffff;font-size:0.9rem;margin-bottom:10px;letter-spacing:2px}
    label{display:block;color:#888;font-size:0.75rem;margin-bottom:3px}
    input,select{width:100%;padding:8px;background:#1a1a2e;border:1px solid #00ffff;color:#fff;border-radius:4px;margin-bottom:10px;font-family:inherit}
    input:focus{outline:none;box-shadow:0 0 5px #00ffff}
    .row{display:flex;gap:10px}
    .row>*{flex:1}
    button{width:100%;padding:12px;background:#ff00ff;border:none;color:#000;font-weight:bold;cursor:pointer;border-radius:4px;font-family:inherit;letter-spacing:2px;margin-top:10px}
    button:hover{box-shadow:0 0 15px #ff00ff}
    .scan-btn{background:transparent;border:1px solid #00ffff;color:#00ffff;padding:8px;margin-bottom:10px}
    .scan-btn:hover{background:#00ffff;color:#000}
    #networks{max-height:150px;overflow-y:auto;border:1px solid #333;border-radius:4px;margin-bottom:10px}
    .net{padding:8px;cursor:pointer;border-bottom:1px solid #222}
    .net:hover{background:#1a1a2e}
    .net .rssi{float:right;color:#666}
  </style>
</head>
<body>
  <h1>[ALIVE LCD SETUP]</h1>
  <form action="/save" method="POST">
    <div class="card">
      <h2>WiFi NETWORK</h2>
      <button type="button" class="scan-btn" onclick="scanNetworks()">SCAN NETWORKS</button>
      <div id="networks"></div>
      <label>SSID</label>
      <input type="text" name="ssid" id="ssid" maxlength="32" required>
      <label>PASSWORD</label>
      <input type="password" name="pass" maxlength="64">
    </div>

    <div class="card">
      <h2>SERVERS TO MONITOR</h2>
      <div class="row">
        <div><label>Server 1 IP/Host</label><input type="text" name="srv0" maxlength="63"></div>
        <div><label>Name</label><input type="text" name="name0" maxlength="15"></div>
      </div>
      <div class="row">
        <div><label>Server 2 IP/Host</label><input type="text" name="srv1" maxlength="63"></div>
        <div><label>Name</label><input type="text" name="name1" maxlength="15"></div>
      </div>
      <div class="row">
        <div><label>Server 3 IP/Host</label><input type="text" name="srv2" maxlength="63"></div>
        <div><label>Name</label><input type="text" name="name2" maxlength="15"></div>
      </div>
      <div class="row">
        <div><label>Server 4 IP/Host</label><input type="text" name="srv3" maxlength="63"></div>
        <div><label>Name</label><input type="text" name="name3" maxlength="15"></div>
      </div>
      <div class="row">
        <div><label>Server 5 IP/Host</label><input type="text" name="srv4" maxlength="63"></div>
        <div><label>Name</label><input type="text" name="name4" maxlength="15"></div>
      </div>
    </div>

    <div class="card">
      <h2>DISPLAY SETTINGS</h2>
      <div class="row">
        <div>
          <label>Check Interval (sec)</label>
          <input type="number" name="interval" value="30" min="10" max="300">
        </div>
        <div>
          <label>Brightness (0-255)</label>
          <input type="number" name="bright" value="255" min="0" max="255">
        </div>
      </div>
    </div>

    <button type="submit">SAVE & REBOOT</button>
  </form>

  <script>
    function scanNetworks() {
      var box = document.getElementById('networks');
      box.innerHTML = '<div style="color:#00ff00">Scanning...</div>';
      var xhr = new XMLHttpRequest();
      xhr.open('GET', '/scan', true);
      xhr.onreadystatechange = function() {
        if (xhr.readyState === 4) {
          if (xhr.status === 200) {
            try {
              var nets = JSON.parse(xhr.responseText);
              if (!nets || nets.length === 0) {
                box.innerHTML = '<div style="color:#888">No networks found</div>';
                return;
              }
              var html = '';
              for (var i = 0; i < nets.length; i++) {
                var n = nets[i];
                html += '<div class="net" onclick="document.getElementById(\'ssid\').value=\'' + n.ssid.replace(/'/g, '') + '\'">' + n.ssid + '<span class="rssi">' + n.rssi + ' dBm</span></div>';
              }
              box.innerHTML = html;
            } catch (e) {
              box.innerHTML = '<div style="color:#f00">Parse error: ' + e.message + '</div>';
            }
          } else {
            box.innerHTML = '<div style="color:#f00">HTTP error: ' + xhr.status + '</div>';
          }
        }
      };
      xhr.onerror = function() {
        box.innerHTML = '<div style="color:#f00">Network error</div>';
      };
      xhr.send();
    }
  </script>
</body>
</html>
)rawhtml";

// ============== WEB SERVER HANDLERS ==============
void handleRoot() {
  server.send(200, "text/html", configPage);
}

String escapeJson(String s) {
  s.replace("\\", "\\\\");
  s.replace("\"", "\\\"");
  return s;
}

void handleScan() {
  Serial.println("Scanning WiFi networks...");
  int n = WiFi.scanNetworks();
  Serial.printf("Found %d networks\n", n);

  if (n < 0) {
    server.send(500, "application/json", "[]");
    return;
  }

  String json = "[";
  for (int i = 0; i < n; i++) {
    if (i > 0) json += ",";
    json += "{\"ssid\":\"" + escapeJson(WiFi.SSID(i)) + "\",\"rssi\":" + WiFi.RSSI(i) + "}";
  }
  json += "]";
  server.send(200, "application/json", json);
  WiFi.scanDelete();
}

void handleSave() {
  strcpy(config.ssid, server.arg("ssid").c_str());
  strcpy(config.password, server.arg("pass").c_str());

  config.numServers = 0;
  for (int i = 0; i < 5; i++) {
    String srv = server.arg("srv" + String(i));
    String name = server.arg("name" + String(i));
    if (srv.length() > 0) {
      strcpy(config.servers[i], srv.c_str());
      strcpy(config.serverNames[i], name.length() > 0 ? name.c_str() : srv.c_str());
      config.numServers++;
    }
  }

  config.checkInterval = server.arg("interval").toInt() * 1000;
  config.brightness = server.arg("bright").toInt();

  if (config.numServers == 0) config.numServers = 1;
  if (config.checkInterval < 10000) config.checkInterval = 30000;

  saveConfig();

  server.send(200, "text/html", "<h1 style='color:#0f0;text-align:center;font-family:monospace'>SAVED! Rebooting...</h1>");
  delay(1000);
  ESP.restart();
}

// ============== CONFIG MODE DISPLAY ==============
void drawConfigScreen() {
  gfx->fillScreen(COLOR_BG);
  drawGlowRing(CX, CY, 115, COLOR_MAGENTA);

  // Header
  drawCenteredText("CONFIG", 30, COLOR_MAGENTA, 2);
  drawCenteredText("MODE", 55, COLOR_MAGENTA, 2);

  // Instructions
  gfx->setTextSize(1);
  gfx->setTextColor(COLOR_TEXT);
  drawCenteredText("Connect WiFi to:", 100, COLOR_TEXT, 1);
  drawCenteredText("ALIVE-LCD-Setup", 125, COLOR_CYAN, 1);

  drawCenteredText("Then open:", 160, COLOR_TEXT, 1);
  drawCenteredText("192.168.4.1", 185, COLOR_YELLOW, 1);
}

// ============== START CONFIG MODE ==============
void startConfigMode() {
  configMode = true;
  Serial.println("Starting Config Mode...");

  drawConfigScreen();

  // Start AP
  WiFi.mode(WIFI_AP);
  WiFi.softAP("ALIVE-LCD-Setup");

  // Start DNS (captive portal)
  dnsServer.start(53, "*", WiFi.softAPIP());

  // Start web server
  server.on("/", handleRoot);
  server.on("/scan", handleScan);
  server.on("/save", HTTP_POST, handleSave);
  server.onNotFound(handleRoot);  // Redirect all to config
  server.begin();

  Serial.println("AP IP: 192.168.4.1");
}

// ============== CONNECT WiFi ==============
bool connectWiFi() {
  if (strlen(config.ssid) == 0) return false;

  gfx->fillScreen(COLOR_BG);
  drawGlowRing(CX, CY, 115, COLOR_YELLOW);
  drawCenteredText("WIFI", CY - 40, COLOR_YELLOW, 2);
  drawCenteredText("Connecting...", CY - 10, COLOR_TEXT, 1);
  drawCenteredText(config.ssid, CY + 10, COLOR_CYAN, 1);

  // Progress bar
  int barX = 40, barY = CY + 35, barW = 160, barH = 12;
  gfx->drawRect(barX, barY, barW, barH, COLOR_CYAN);

  WiFi.mode(WIFI_STA);
  WiFi.begin(config.ssid, config.password);

  int attempts = 0;
  while (WiFi.status() != WL_CONNECTED && attempts < 30) {
    delay(500);
    attempts++;
    int progress = (attempts * 100) / 30;
    int fillW = (barW - 4) * progress / 100;
    gfx->fillRect(barX + 2, barY + 2, fillW, barH - 4, COLOR_CYAN);
  }

  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("WiFi connected: " + WiFi.localIP().toString());

    gfx->fillScreen(COLOR_BG);
    drawGlowRing(CX, CY, 115, COLOR_CYAN);
    drawCenteredText("CONNECTED", CY - 20, COLOR_CYAN, 2);
    drawCenteredText(WiFi.localIP().toString().c_str(), CY + 15, COLOR_GREEN, 1);
    delay(1000);
    return true;
  }

  Serial.println("WiFi connection failed!");
  return false;
}

// ============== STARTUP SCREEN ==============
void drawStartupScreen() {
  gfx->fillScreen(COLOR_BG);
  drawGlowRing(CX, CY, 115, COLOR_CYAN);
  drawCenteredText("ALIVE", 35, COLOR_CYAN, 3);
  drawCenteredText("SERVER MONITOR", 195, COLOR_TEXT, 1);

  // Triangle animation
  int triR = 45;
  for (int frame = 0; frame < 20; frame++) {
    float angle = frame * 0.3;
    for (int p = 0; p < 3; p++) {
      float a1 = angle + (p * 2.094);
      float a2 = angle + ((p + 1) * 2.094);
      int x1 = CX + cos(a1) * triR;
      int y1 = CY + sin(a1) * triR;
      int x2 = CX + cos(a2) * triR;
      int y2 = CY + sin(a2) * triR;
      gfx->drawLine(x1, y1, x2, y2, COLOR_CYAN);
    }
    delay(40);
    for (int p = 0; p < 3; p++) {
      float a1 = angle + (p * 2.094);
      float a2 = angle + ((p + 1) * 2.094);
      int x1 = CX + cos(a1) * triR;
      int y1 = CY + sin(a1) * triR;
      int x2 = CX + cos(a2) * triR;
      int y2 = CY + sin(a2) * triR;
      gfx->drawLine(x1, y1, x2, y2, COLOR_BG);
    }
  }
}

// ============== SETUP ==============
void setup() {
  Serial.begin(115200);
  delay(100);
  Serial.println("\n=== ALIVE LCD - Captive Portal Version ===");

  // Init LEDs
  pinMode(LED_BLUE, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(BOOT_BTN, INPUT_PULLUP);
  digitalWrite(LED_BLUE, HIGH);  // Blue on during boot

  // Init backlight
  pinMode(TFT_BL, OUTPUT);
  digitalWrite(TFT_BL, HIGH);

  // Init display
  gfx->begin();
  gfx->setRotation(0);
  gfx->fillScreen(COLOR_BG);

  // Load saved config
  loadConfig();

  // Apply brightness
  analogWrite(TFT_BL, config.brightness);

  // Check if BOOT button held (force config mode)
  bool forceConfig = (digitalRead(BOOT_BTN) == LOW);
  delay(100);  // Debounce
  forceConfig = forceConfig && (digitalRead(BOOT_BTN) == LOW);

  // Enter config if no WiFi saved OR button held
  if (forceConfig || strlen(config.ssid) == 0) {
    startConfigMode();
    return;
  }

  // Show startup animation
  drawStartupScreen();

  // Try to connect to saved WiFi
  if (!connectWiFi()) {
    startConfigMode();
    return;
  }

  // Initial server check
  checkAllServers();
  updateDisplay();
  lastCheck = millis();
  lastFlashUpdate = millis();
}

// ============== CHECK ALL SERVERS ==============
void checkAllServers() {
  Serial.println("\n--- Checking servers ---");
  allServersUp = true;

  for (int i = 0; i < config.numServers; i++) {
    Serial.print("Pinging ");
    Serial.print(config.servers[i]);
    Serial.print("... ");

    bool success = Ping.ping(config.servers[i], 2);
    serverStatus[i] = success;

    if (success) {
      Serial.println("OK");
    } else {
      Serial.println("FAILED");
      allServersUp = false;
    }
  }
}

// ============== UPDATE DISPLAY ==============
void updateDisplay() {
  gfx->fillScreen(COLOR_BG);

  // Draw outer status ring
  uint16_t ringColor = allServersUp ? COLOR_CYAN : COLOR_MAGENTA;
  drawGlowRing(CX, CY, 115, ringColor);

  // Draw header
  drawCenteredText("ALIVE", 28, COLOR_CYAN, 2);

  // Draw server status list
  int startY = 50;
  int lineHeight = 26;
  int maxVisible = min(config.numServers, 6);

  gfx->setTextSize(1);

  for (int i = 0; i < maxVisible; i++) {
    int yPos = startY + (i * lineHeight);

    // Status indicator circle
    if (serverStatus[i]) {
      gfx->fillCircle(45, yPos + 6, 6, COLOR_CYAN);
    } else {
      gfx->fillCircle(45, yPos + 6, 6, COLOR_MAGENTA);
      gfx->drawLine(42, yPos + 3, 48, yPos + 9, COLOR_BG);
      gfx->drawLine(48, yPos + 3, 42, yPos + 9, COLOR_BG);
    }

    // Server name
    gfx->setTextColor(COLOR_TEXT);
    gfx->setCursor(58, yPos + 3);
    String name = String(config.serverNames[i]);
    if (name.length() > 12) {
      name = name.substring(0, 11) + ".";
    }
    gfx->print(name);

    // Status text
    gfx->setCursor(170, yPos + 3);
    if (serverStatus[i]) {
      gfx->setTextColor(COLOR_GREEN);
      gfx->print("OK");
    } else {
      gfx->setTextColor(COLOR_RED);
      gfx->print("DOWN");
    }
  }
}

// ============== FLASH DOWN TEXT ==============
void flashDownText(bool showText) {
  int startY = 50;
  int lineHeight = 26;
  int maxVisible = min(config.numServers, 6);

  gfx->setTextSize(1);

  for (int i = 0; i < maxVisible; i++) {
    if (!serverStatus[i]) {
      int yPos = startY + (i * lineHeight);
      gfx->fillRect(170, yPos + 1, 30, 10, COLOR_BG);
      if (showText) {
        gfx->setTextColor(COLOR_RED);
        gfx->setCursor(170, yPos + 3);
        gfx->print("DOWN");
      }
    }
  }
}

// ============== UPDATE LEDs ==============
void updateLEDs() {
  digitalWrite(LED_BLUE, HIGH);  // Blue always on

  if (allServersUp) {
    digitalWrite(LED_RED, LOW);
    redLedState = false;
  } else {
    if (millis() - lastBlink >= 500) {
      redLedState = !redLedState;
      digitalWrite(LED_RED, redLedState ? HIGH : LOW);
      lastBlink = millis();
    }
  }
}

// ============== MAIN LOOP ==============
void loop() {
  if (configMode) {
    dnsServer.processNextRequest();
    server.handleClient();
    return;
  }

  // Maintain WiFi connection
  if (WiFi.status() != WL_CONNECTED) {
    if (!connectWiFi()) {
      startConfigMode();
      return;
    }
  }

  // Periodic server check
  if (millis() - lastCheck >= config.checkInterval) {
    checkAllServers();
    updateDisplay();
    lastCheck = millis();
    lastFlashUpdate = millis();
    flashState = true;
  }

  // Flash DOWN text
  if (!allServersUp && millis() - lastFlashUpdate >= 300) {
    flashState = !flashState;
    flashDownText(flashState);
    lastFlashUpdate = millis();
  }

  // Update LEDs
  updateLEDs();

  delay(50);
}