/********************************************************************************
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Nis Wechselberg
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ********************************************************************************/

/********************************************************************************
 * ESP8266-RGB-WiFiServer
 * Sets the color of an RGB LED Ribbon through an HTTP Server
 ********************************************************************************/
#include <EEPROM.h>
#include <ESP8266WiFi.h>
#include "ESP8266-RGB-WiFiServer.h"

// Pin configuration
const short redPin = 12;
const short greenPin = 13;
const short bluePin = 14;

// EEPROM Adress config
const unsigned char modeAddress = 0;
const unsigned char redAddress = 1;
const unsigned char greenAddress = 2;
const unsigned char blueAddress = 3;

// Color values
unsigned char modeValue;
unsigned char redValue;
unsigned char greenValue;
unsigned char blueValue;
unsigned char decColor;

// Scale factors
const float globalScale = 3.0;
const float redScale = 1.0;
const float greenScale = 1.0;
const float blueScale = 0.7;
float breathScale = 0.999;
float breathAdjustment = -0.001;


// HTTP configuration
const unsigned char port = 80;
WiFiServer server(port);


void setup() {
  // Set wifi mode to client
  WiFi.mode(WIFI_STA);
  
  // Initialize Serial connection
  Serial.begin(115200);
  delay(10);

  // Prepare color pins
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  
  // Connect to WiFi network
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  
  // Start the server
  server.begin();
  Serial.print("Server started at IP address ");
  // Print the IP address
  Serial.println(WiFi.localIP());

  // Read stored mode and previous color values from EEPROM
  EEPROM.begin(16);
  readFromEEPROM();
  
  // Test the LED color channels
  setLight(0,0,0);
  delay(500);
  setLight(100,0,0);
  delay(500);
  setLight(0,100,0);
  delay(500);
  setLight(0,0,100);
  delay(500);
  setLight(100,100,100);
  delay(500);
  updateLight();
}

void loop() {
  // Check if a client has connected
  WiFiClient client = server.available();
  if (client) {
    // Wait until the client sends some data
    Serial.println("Client connected");
    while(!client.available()){
      delay(1);
    }
    
    // Read the first line of the request
    String req = client.readStringUntil('\r');
    Serial.println(req);
    client.flush();

    // Check if new value should be set or values should be read
    if (req.indexOf("/set/") != -1) {
      // Request of the form "/set/mode/red/green/blue/"
      // Delimiters for values
      int indexMode, indexRed, indexGreen, indexBlue, endIndexBlue;
      indexMode = req.indexOf("/set/") + 5;
      indexRed = req.indexOf("/",indexMode + 1);
      indexGreen = req.indexOf("/",indexRed + 1);
      indexBlue = req.indexOf("/",indexGreen + 1);
      endIndexBlue = req.indexOf("/",indexBlue + 1);
      // Check if all values were filled in the request
      if (indexMode == -1 || indexRed == -1 || indexGreen == -1 
            || indexBlue == -1 || endIndexBlue == -1) {
        // Invalid request, abort
        Serial.println("Invalid request");
        client.stop();
      } else {
        // Parse values in request
        int mode  = req.substring(indexMode, indexRed).toInt();
        int red   = req.substring(indexRed + 1, indexGreen).toInt();
        int green = req.substring(indexGreen + 1, indexBlue).toInt();
        int blue  = req.substring(indexBlue + 1, endIndexBlue).toInt();
  
        // Sanitize values
        if (mode < 0) { mode = 0; }
        if (red < 0) { red = 0; }
        if (green < 0) { green = 0; }
        if (blue < 0) { blue = 0; }
        if (mode > 3) { mode = 3; }
        if (red > 255) { red = 255; }
        if (green > 255) { green = 255; }
        if (blue > 255) { blue = 255; }

        // Update values
        modeValue = mode;


        breathScale = 0.999;
        breathAdjustment = -0.001;
        decColor = 0;

        if (modeValue % 2  == 0) {
          redValue = red;
          greenValue = green;
          blueValue = blue;
        }
        if (modeValue % 2 != 0) {
          redValue = 255;
          greenValue = 0;
          blueValue = 0;
        }

        persistToEEPROM();
      }
    } else if (req.indexOf("/get/") != -1) {
      
    } else {
      Serial.println("invalid request");
      client.stop();
    }

    client.flush();

    // Prepare the response
    String response = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n";
    response += modeValue;
    response += "\n";
    response += redValue;
    response += "\n";
    response += greenValue;
    response += "\n";
    response += blueValue;
    response += "\n";
  
    // Send the response to the client
    client.print(response);
    delay(1);
    client.flush();
    Serial.println("Disconnecting client");
    // The client will actually be disconnected 
    // when the function returns and 'client' object is detroyed
  }
  
  updateLight();
  
}

void updateLight() {
  if (modeValue % 2 == 1) {
    // Color cylce mode
    unsigned short rgbColor[3];
    rgbColor[0] = redValue;
    rgbColor[1] = greenValue;
    rgbColor[2] = blueValue;
    
    unsigned short incColor = (decColor + 1) % 3;
    
    rgbColor[decColor] -= 1;
    rgbColor[incColor] += 1;

    redValue = rgbColor[0];
    greenValue = rgbColor[1];
    blueValue = rgbColor[2];

    if (rgbColor[incColor] == 255) {
      decColor = incColor;
    }    
  }

  if (modeValue > 1) {
    // Breath mode
    breathScale += breathAdjustment;
  
    if (breathScale <= 0.001 || breathScale >= 0.999) {
      breathAdjustment = 0 - breathAdjustment;
    }
    
  }
  
  setLight(redValue, greenValue, blueValue);
  delay(30);
}

/* Helper function to set the colors of the led strip */
void setLight(unsigned char red, unsigned char green, unsigned char blue) {
  analogWrite(redPin, red * globalScale * breathScale * redScale);
  analogWrite(greenPin, green * globalScale * breathScale * greenScale);
  analogWrite(bluePin, blue * globalScale * breathScale * blueScale);
}

void readFromEEPROM() {
  unsigned char newMode = EEPROM.read(modeAddress);
  if (newMode > 3) {
    // Uninitialized cells return 255, so reset that
    modeValue = 0;
  } else {
    modeValue = newMode;
  }
  redValue = EEPROM.read(redAddress);
  greenValue = EEPROM.read(greenAddress);
  blueValue = EEPROM.read(blueAddress);
}

void persistToEEPROM() {
  EEPROM.write(modeAddress, modeValue);
  EEPROM.write(redAddress, redValue);
  EEPROM.write(greenAddress, greenValue);
  EEPROM.write(blueAddress, blueValue);
  EEPROM.commit();
}