#include <Arduino.h>
#include <functional>
#include <map>
#include <vector>
#include <Adafruit_NeoPixel.h>

#include "Globals.h"
#include "NodeContext.h"
#include "NetworkManager.h"
#include "ClusterManager.h"
#include "ApiServer.h"
#include "TaskManager.h"

#ifndef NEOPIXEL_PIN
#define NEOPIXEL_PIN 2
#endif

#ifndef NEOPIXEL_COUNT
#define NEOPIXEL_COUNT 16
#endif

#ifndef NEOPIXEL_TYPE
#define NEOPIXEL_TYPE (NEO_GRB + NEO_KHZ800)
#endif

// Wheel helper: map 0-255 to RGB rainbow
static uint32_t colorWheel(Adafruit_NeoPixel &strip, uint8_t pos) {
  pos = 255 - pos;
  if (pos < 85) {
    return strip.Color(255 - pos * 3, 0, pos * 3);
  }
  if (pos < 170) {
    pos -= 85;
    return strip.Color(0, pos * 3, 255 - pos * 3);
  }
  pos -= 170;
  return strip.Color(pos * 3, 255 - pos * 3, 0);
}

class NeoPixelService {
public:
  enum class Pattern {
    Off,
    ColorWipe,
    Rainbow,
    RainbowCycle,
    TheaterChase,
    TheaterChaseRainbow
  };

  NeoPixelService(NodeContext &ctx, TaskManager &taskMgr,
                  uint16_t numPixels,
                  uint8_t pin,
                  neoPixelType type)
      : ctx(ctx), taskManager(taskMgr),
        strip(numPixels, pin, type),
        currentPattern(Pattern::Off),
        updateIntervalMs(20),
        lastUpdateMs(0),
        wipeIndex(0),
        wipeColor(strip.Color(255, 0, 0)),
        rainbowJ(0),
        cycleJ(0),
        chaseJ(0),
        chaseQ(0),
        chasePhaseOn(true),
        chaseColor(strip.Color(127, 127, 127)),
        brightness(50) {
    strip.begin();
    strip.setBrightness(brightness);
    strip.show();

    registerPatterns();
    registerTasks();
  }

  void registerApi(ApiServer &api) {
    api.addEndpoint("/api/neopixel/status", HTTP_GET, [this](AsyncWebServerRequest *request) {
      JsonDocument doc;
      doc["pin"] = NEOPIXEL_PIN;
      doc["count"] = strip.numPixels();
      doc["interval_ms"] = updateIntervalMs;
      doc["brightness"] = brightness;
      doc["pattern"] = currentPatternName();
      String json;
      serializeJson(doc, json);
      request->send(200, "application/json", json);
    });

    api.addEndpoint("/api/neopixel/patterns", HTTP_GET, [this](AsyncWebServerRequest *request) {
      JsonDocument doc;
      JsonArray arr = doc.to<JsonArray>();
      for (auto &kv : patternUpdaters) arr.add(kv.first);
      String json;
      serializeJson(doc, json);
      request->send(200, "application/json", json);
    });

    api.addEndpoint("/api/neopixel", HTTP_POST,
      [this](AsyncWebServerRequest *request) {
        String pattern = request->hasParam("pattern", true) ? request->getParam("pattern", true)->value() : "";
        if (pattern.length()) {
          setPatternByName(pattern);
        }

        if (request->hasParam("interval_ms", true)) {
          updateIntervalMs = request->getParam("interval_ms", true)->value().toInt();
          if (updateIntervalMs < 1) updateIntervalMs = 1;
          taskManager.setTaskInterval("neopixel_update", updateIntervalMs);
        }

        if (request->hasParam("brightness", true)) {
          int b = request->getParam("brightness", true)->value().toInt();
          if (b < 0) b = 0; if (b > 255) b = 255;
          setBrightness((uint8_t)b);
        }

        // Optional RGB for color_wipe and theater_chase
        if (request->hasParam("r", true) || request->hasParam("g", true) || request->hasParam("b", true)) {
          int r = request->hasParam("r", true) ? request->getParam("r", true)->value().toInt() : 0;
          int g = request->hasParam("g", true) ? request->getParam("g", true)->value().toInt() : 0;
          int b = request->hasParam("b", true) ? request->getParam("b", true)->value().toInt() : 0;
          wipeColor = strip.Color(r, g, b);
          chaseColor = strip.Color(r / 2, g / 2, b / 2); // dimmer for chase
        }

        JsonDocument resp;
        resp["ok"] = true;
        resp["pattern"] = currentPatternName();
        resp["interval_ms"] = updateIntervalMs;
        resp["brightness"] = brightness;
        String json;
        serializeJson(resp, json);
        request->send(200, "application/json", json);
      },
      std::vector<ApiServer::ParamSpec>{
        ApiServer::ParamSpec{ String("pattern"), false, String("body"), String("string"), patternNamesVector() },
        ApiServer::ParamSpec{ String("interval_ms"), false, String("body"), String("number"), {} },
        ApiServer::ParamSpec{ String("brightness"), false, String("body"), String("number"), {} },
        ApiServer::ParamSpec{ String("r"), false, String("body"), String("number"), {} },
        ApiServer::ParamSpec{ String("g"), false, String("body"), String("number"), {} },
        ApiServer::ParamSpec{ String("b"), false, String("body"), String("number"), {} },
      }
    );
  }

  void setPatternByName(const String &name) {
    auto it = patternUpdaters.find(name);
    if (it != patternUpdaters.end()) {
      // Map name to enum for status and reset state
      currentPattern = nameToPattern(name);
      resetStateForPattern(currentPattern);
    }
  }

  void setBrightness(uint8_t b) {
    brightness = b;
    strip.setBrightness(brightness);
    strip.show();
  }

private:
  void registerTasks() {
    taskManager.registerTask("neopixel_update", updateIntervalMs, [this]() { update(); });
    taskManager.registerTask("neopixel_status_print", 10000, [this]() {
      Serial.printf("[NeoPixel] pattern=%s interval=%lu ms brightness=%u\n",
                    currentPatternName().c_str(), updateIntervalMs, brightness);
    });
  }

  void registerPatterns() {
    patternUpdaters["off"] = [this]() { updateOff(); };
    patternUpdaters["color_wipe"] = [this]() { updateColorWipe(); };
    patternUpdaters["rainbow"] = [this]() { updateRainbow(); };
    patternUpdaters["rainbow_cycle"] = [this]() { updateRainbowCycle(); };
    patternUpdaters["theater_chase"] = [this]() { updateTheaterChase(); };
    patternUpdaters["theater_chase_rainbow"] = [this]() { updateTheaterChaseRainbow(); };
  }

  std::vector<String> patternNamesVector() const {
    std::vector<String> v;
    v.reserve(patternUpdaters.size());
    for (const auto &kv : patternUpdaters) v.push_back(kv.first);
    return v;
  }

  String currentPatternName() const {
    switch (currentPattern) {
      case Pattern::Off: return String("off");
      case Pattern::ColorWipe: return String("color_wipe");
      case Pattern::Rainbow: return String("rainbow");
      case Pattern::RainbowCycle: return String("rainbow_cycle");
      case Pattern::TheaterChase: return String("theater_chase");
      case Pattern::TheaterChaseRainbow: return String("theater_chase_rainbow");
    }
    return String("off");
  }

  Pattern nameToPattern(const String &name) const {
    if (name.equalsIgnoreCase("color_wipe")) return Pattern::ColorWipe;
    if (name.equalsIgnoreCase("rainbow")) return Pattern::Rainbow;
    if (name.equalsIgnoreCase("rainbow_cycle")) return Pattern::RainbowCycle;
    if (name.equalsIgnoreCase("theater_chase")) return Pattern::TheaterChase;
    if (name.equalsIgnoreCase("theater_chase_rainbow")) return Pattern::TheaterChaseRainbow;
    return Pattern::Off;
  }

  void resetStateForPattern(Pattern p) {
    // Clear strip by default when changing pattern
    strip.clear();
    strip.show();

    // Reset indexes/state variables
    wipeIndex = 0;
    rainbowJ = 0;
    cycleJ = 0;
    chaseJ = 0;
    chaseQ = 0;
    chasePhaseOn = true;
    lastUpdateMs = 0; // force immediate update on next tick

    currentPattern = p;
  }

  void update() {
    unsigned long now = millis();
    if (now - lastUpdateMs < updateIntervalMs) return;
    lastUpdateMs = now;

    const String name = currentPatternName();
    auto it = patternUpdaters.find(name);
    if (it != patternUpdaters.end()) {
      it->second();
    } else {
      updateOff();
    }
  }

  // Pattern updaters (non-blocking; advance a small step each call)
  void updateOff() {
    // Ensure off state
    strip.clear();
    strip.show();
  }

  void updateColorWipe() {
    if (wipeIndex < strip.numPixels()) {
      strip.setPixelColor(wipeIndex, wipeColor);
      ++wipeIndex;
      strip.show();
    } else {
      // Restart
      strip.clear();
      wipeIndex = 0;
    }
  }

  void updateRainbow() {
    for (uint16_t i = 0; i < strip.numPixels(); i++) {
      strip.setPixelColor(i, colorWheel(strip, (i + rainbowJ) & 255));
    }
    strip.show();
    rainbowJ = (rainbowJ + 1) & 0xFF; // 0..255
  }

  void updateRainbowCycle() {
    for (uint16_t i = 0; i < strip.numPixels(); i++) {
      uint8_t pos = ((i * 256 / strip.numPixels()) + cycleJ) & 0xFF;
      strip.setPixelColor(i, colorWheel(strip, pos));
    }
    strip.show();
    cycleJ = (cycleJ + 1) & 0xFF;
  }

  void updateTheaterChase() {
    // Phase toggles on/off for the current q offset
    if (chasePhaseOn) {
      for (uint16_t i = 0; i < strip.numPixels(); i += 3) {
        uint16_t idx = i + chaseQ;
        if (idx < strip.numPixels()) strip.setPixelColor(idx, chaseColor);
      }
      strip.show();
      chasePhaseOn = false;
    } else {
      for (uint16_t i = 0; i < strip.numPixels(); i += 3) {
        uint16_t idx = i + chaseQ;
        if (idx < strip.numPixels()) strip.setPixelColor(idx, 0);
      }
      strip.show();
      chasePhaseOn = true;
      chaseQ = (chaseQ + 1) % 3; // move the crawl
      chaseJ = (chaseJ + 1) % 10; // cycle count kept for status if needed
    }
  }

  void updateTheaterChaseRainbow() {
    if (chasePhaseOn) {
      for (uint16_t i = 0; i < strip.numPixels(); i += 3) {
        uint16_t idx = i + chaseQ;
        if (idx < strip.numPixels()) strip.setPixelColor(idx, colorWheel(strip, (idx + chaseJ) % 255));
      }
      strip.show();
      chasePhaseOn = false;
    } else {
      for (uint16_t i = 0; i < strip.numPixels(); i += 3) {
        uint16_t idx = i + chaseQ;
        if (idx < strip.numPixels()) strip.setPixelColor(idx, 0);
      }
      strip.show();
      chasePhaseOn = true;
      chaseQ = (chaseQ + 1) % 3;
      chaseJ = (chaseJ + 1) & 0xFF;
    }
  }

private:
  NodeContext &ctx;
  TaskManager &taskManager;
  Adafruit_NeoPixel strip;

  std::map<String, std::function<void()>> patternUpdaters;

  Pattern currentPattern;
  unsigned long updateIntervalMs;
  unsigned long lastUpdateMs;

  // State for patterns
  uint16_t wipeIndex;
  uint32_t wipeColor;

  uint8_t rainbowJ;
  uint8_t cycleJ;

  int chaseJ;
  int chaseQ;
  bool chasePhaseOn;
  uint32_t chaseColor;

  uint8_t brightness;
};

NodeContext ctx({
  {"app", "neopixel"},
  {"device", "light"},
  {"pixels", String(NEOPIXEL_COUNT)},
  {"pin", String(NEOPIXEL_PIN)}
});
NetworkManager network(ctx);
TaskManager taskManager(ctx);
ClusterManager cluster(ctx, taskManager);
ApiServer apiServer(ctx, taskManager, ctx.config.api_server_port);
NeoPixelService neoService(ctx, taskManager, NEOPIXEL_COUNT, NEOPIXEL_PIN, NEOPIXEL_TYPE);

void setup() {
  Serial.begin(115200);

  network.setupWiFi();

  taskManager.initialize();

  apiServer.begin();
  neoService.registerApi(apiServer);

  taskManager.printTaskStatus();
}

void loop() {
  taskManager.execute();
  yield();
}