/**
 * @file main.cpp
 * @brief Marine Navigation Display — application entry point.
 *
 * Boot sequence
 * ─────────────
 * 1. Initialise Serial, NeoPixel LED, LittleFS config.
 * 2. Check for AP-mode button combo held at boot.
 *    If combo detected (or first boot): start WiFi AP + web server.
 * 3. Otherwise start BLE scanning for the Marine Gateway.
 * 4. main loop:
 *    a. Poll touch buttons.
 *    b. Handle page navigation events.
 *    c. Check BLE status → update LED.
 *    d. Render display (partial refresh where possible).
 *    e. Run WiFi server tasks.
 *
 * WiFi AP ↔ BLE co-existence
 * ──────────────────────────
 * The ESP32-S3 radio is shared. We run in one of two mutually exclusive modes:
 *   MODE_BLE  — BLE client active, WiFi off.
 *   MODE_WIFI — WiFi AP active, BLE off (configuration / OTA mode).
 *
 * The user switches modes via the NEXT+PREV button combo (hold 3 s).
 */

#include <Arduino.h>
#include "Config.h"
#include "ConfigManager.h"
#include "BleManager.h"
#include "DisplayManager.h"
#include "WifiManager.h"
#include "TouchManager.h"
#include "StatusLed.h"

// =============================================================================
// Application state
// =============================================================================

enum class AppMode { BLE, WIFI_AP };
static AppMode  _mode         = AppMode::BLE;
static bool     _otaInProgress = false;

// Cached WiFi status for LED
static AppState::WifiStatus _wifiStatus = AppState::WifiStatus::OFF;

// =============================================================================
// Forward declarations
// =============================================================================
static void enterBleMode();
static void enterApMode();
static void handleTouchEvents();
static void updateDisplay();

// =============================================================================
// setup()
// =============================================================================

void setup() {
    Serial.begin(115200);
    delay(200);
    Serial.println("\n╔═══════════════════════════════╗");
    Serial.println("║  Marine Navigation Display    ║");
    Serial.printf( "║  v%-28s║\n", APP_VERSION);
    Serial.println("╚═══════════════════════════════╝");

    // ── Status LED ────────────────────────────────────────────────────────────
    statusLed.begin();
    statusLed.setColor(0xFFFFFF, 20);  // brief white flash on boot

    // ── Persistent config ─────────────────────────────────────────────────────
    if (!configManager.begin()) {
        Serial.println("[MAIN] FATAL: Config init failed");
        // Continue with defaults — non-fatal
    }

    // ── Display ───────────────────────────────────────────────────────────────
    displayManager.begin();  // Shows splash screen

    // ── Touch ─────────────────────────────────────────────────────────────────
    touchManager.begin();

    // ── Detect boot-time AP combo (hold NEXT+PREV while powering on) ──────────
    // Sample touch pads for 500 ms at boot
    uint32_t comboStart = millis();
    bool comboDetected  = false;
    while (millis() - comboStart < 500) {
        if (touchRead(Pins::TOUCH_NEXT)   < Touch::THRESHOLD &&
            touchRead(Pins::TOUCH_PREV)   < Touch::THRESHOLD) {
            comboDetected = true;
            break;
        }
        delay(10);
    }

    if (comboDetected) {
        Serial.println("[MAIN] Boot combo detected → entering AP mode");
        enterApMode();
    } else {
        enterBleMode();
    }
}

// =============================================================================
// loop()
// =============================================================================

void loop() {
    // ── Touch input ───────────────────────────────────────────────────────────
    touchManager.update();
    handleTouchEvents();

    // ── Status LED ────────────────────────────────────────────────────────────
    statusLed.update(bleManager.status(), _wifiStatus, _otaInProgress);

    // ── BLE mode tasks ────────────────────────────────────────────────────────
    if (_mode == AppMode::BLE) {
        bleManager.update();

        // Show BLE status banner when not connected
        static AppState::BleStatus prevBleStatus = AppState::BleStatus::IDLE;
        AppState::BleStatus curStatus = bleManager.status();
        if (curStatus != prevBleStatus) {
            prevBleStatus = curStatus;
            if (curStatus != AppState::BleStatus::CONNECTED) {
                displayManager.showBleStatus(curStatus);
            }
        }
    }

    // ── WiFi mode tasks ───────────────────────────────────────────────────────
    if (_mode == AppMode::WIFI_AP) {
        wifiManager.update();
    }

    // ── Display render ────────────────────────────────────────────────────────
    if (_mode == AppMode::BLE && !_otaInProgress) {
        updateDisplay();
    }

    // Small yield to let background tasks run
    delay(20);
}

// =============================================================================
// Mode transitions
// =============================================================================

static void enterBleMode() {
    Serial.println("[MAIN] Entering BLE mode");
    _mode       = AppMode::BLE;
    _wifiStatus = AppState::WifiStatus::OFF;

    if (wifiManager.isActive()) wifiManager.stop();

    bleManager.begin();
    displayManager.forceFullRefresh();
}

static void enterApMode() {
    Serial.println("[MAIN] Entering WiFi AP mode");
    _mode       = AppMode::WIFI_AP;
    _wifiStatus = AppState::WifiStatus::AP_ACTIVE;

    // BLE and WiFi share the radio; stop BLE first (NimBLE deinit is implicit
    // when WiFi takes over, but we force a clean state)
    // Note: NimBLEDevice::deinit(true) could be called here if needed.

    const AppConfig& cfg = configManager.config();
    wifiManager.begin(cfg.apSSID, cfg.apPassword);
    displayManager.showApScreen(cfg.apSSID, WifiManager::AP_IP);
}

// =============================================================================
// Touch event dispatcher
// =============================================================================

static void handleTouchEvents() {
    // AP combo (NEXT + PREV held 3 s)
    if (touchManager.apCombo()) {
        if (_mode == AppMode::BLE) {
            enterApMode();
        } else {
            enterBleMode();
        }
        return;
    }

    if (_mode == AppMode::BLE) {
        if (touchManager.nextPressed()) {
            configManager.nextPage();
            displayManager.forceFullRefresh();
            Serial.printf("[MAIN] Page → %u\n", configManager.activePage());
        }
        if (touchManager.prevPressed()) {
            configManager.prevPage();
            displayManager.forceFullRefresh();
            Serial.printf("[MAIN] Page ← %u\n", configManager.activePage());
        }
        if (touchManager.actionPressed()) {
            // Force a full e-ink refresh (clears ghosting)
            displayManager.forceFullRefresh();
            Serial.println("[MAIN] Manual full refresh");
        }
    }
}

// =============================================================================
// Display update
// =============================================================================

static void updateDisplay() {
    BoatState state;
    bleManager.getBoatState(state);

    const AppConfig&  cfg  = configManager.config();
    const PageConfig& page = cfg.pages[cfg.activePage];

    displayManager.render(state, page);
}