#include "mbed.h"
#include "stdlib.h"

Serial pc(USBTX, USBRX);
Serial esp(p28, p27); // tx, rx

DigitalOut reset(p26);
DigitalOut led1(LED1);
DigitalOut led4(LED4);

AnalogIn moisture(p20);

InterruptIn espData(p8);

Timer timer;
Ticker tweeter;
Ticker myclock;
 
int  count,ended,timeout;
char buf[2024];

// Buffer to hold info coming FROM the ESP.
char espBuf[2024];
int espBufCount = 0;

// Buffer used to store Lua commands sent to the ESP.
char snd[1024];

int seconds = 0;

int tweetPeriod = 60;
char twitterHandleBuf[64];
char twitterHandle[16] = "\0"; // Used to check if a twitter handle has been supplied or not.

int gotTwitterHandle = 0; // Used to check enter the block that handles the Interrupt.
 
char ssid[32] = "...";     // enter WiFi router ssid inside the quotes
char pwd [32] = "..."; // enter WiFi router password inside the quotes

// This is how many volts my moisture sensor
// outputs when it is submerged in water.
float maxValue = 1.88f;
 
void SendCMD(), getreply(), ESPconfig(), ESPsetbaudrate(), sendTweet(), getTime(char* time), setUpServer(), getDataFromEsp();

// dev meaning the mbed
void dev_recv()
{
    led1 = !led1;
    while(esp.readable()) {
        pc.putc(esp.getc());
    }
}
 
void pc_recv()
{
    led4 = !led4;
    while(pc.readable()) {
        esp.putc(pc.getc());
    }
}        

void increment_time() {
   seconds++;
}
 
int main()
{
    reset=0; //hardware reset for 8266
    pc.baud(9600);  // set what you want here depending on your terminal program speed
    set_time(0);
    pc.printf("\f\n\r-------------ESP8266 Hardware Reset-------------\n\r");
    wait(0.5);
    reset=1;
    timeout=2;
    getreply();
 
    esp.baud(9600);   // change this to the new ESP8266 baudrate if it is changed at any time.
 
    //ESPsetbaudrate();   //******************  include this routine to set a different ESP8266 baudrate  ******************
 
    //ESPconfig();        //******************  include Config to set the ESP8266 configuration  ***********************
    
    pc.printf("\n---------- Get IP's ----------\r\n");
    strcpy(snd, "print(wifi.sta.getip())\r\n");
    SendCMD();
    timeout=3;
    getreply();
    pc.printf(buf);
    
    setUpServer();
 
    // Using a ticker to send tweets repeatedly.
    tweeter.attach(&sendTweet, tweetPeriod);
    
    // Increments clock (seconds since last reset).
    myclock.attach(&increment_time, 1);
 
    pc.attach(&pc_recv, Serial::RxIrq);
    esp.attach(&dev_recv, Serial::RxIrq);
    espData.rise(&getDataFromEsp);
    
    while(1) {
        sleep();
        
        if (gotTwitterHandle) {
            gotTwitterHandle = 0;
            strcpy(twitterHandleBuf, buf);
            
            int i, j = 0;
            // Extracting twitter handle and tweet frequency.
            // 22 is the index of the start of the twitter handle in the buffer.
            // 15 is the max number of characters in a twitter handle
            // 1 is for the ';' used to delimit the twitter handle and the tweet frequency. 
            for (i = 22; i < 22+15+1+1; i++) {
                if (twitterHandleBuf[i] != ';') {
                    twitterHandle[j] = twitterHandleBuf[i];
                } else {
                    twitterHandle[j] = '\0';
                    break;
                }
                j++;
            }
            // Converting the ASCII char to an integer -- numbers have ASCII codes
            // that are 48 larger than the number represented by the code.
            int tweetFrequency = twitterHandleBuf[i+1] - 48;
            pc.printf("%s\r\n", twitterHandle);
            pc.printf("%d\r\n", tweetFrequency);
            
            // Maps the tweetFrequency integer to an actual number of seconds.
            switch(tweetFrequency) {
                case 1: // Tweet every minute
                    tweetPeriod = 60;
                    break;
                case 2: // Tweet every 5 minutes
                    tweetPeriod = 60*5;
                    break;
                case 3: // Tweet every 15 minutes
                    tweetPeriod = 60*15;
                    break;
                case 4: // Tweet every 30 minutes
                    tweetPeriod = 60*30;
                    break;
                default:
                    tweetPeriod = 60;
            }
        }
    }
 
}
 
// Sets new ESP8266 baurate, change the esp.baud(xxxxx) to match your new setting once this has been executed
void ESPsetbaudrate()
{
    strcpy(snd, "AT+CIOBAUD=115200\r\n");   // change the numeric value to the required baudrate
    SendCMD();
}

void getDataFromEsp() {
    strcpy(snd, "print(twitterHandle)\r\n");
    SendCMD();
    timeout=3;
    getreply();
    gotTwitterHandle = 1;
}

void setUpServer() {
    
    // Setting up GPIO pin which should be connected to a DigitalIn on the Mbed.
    // When high, it means the ESP is busy.
    strcpy(snd, "pin = 1\r\n");
    SendCMD();
    wait(1);
    
    strcpy(snd, "gpio.mode(pin, gpio.OUTPUT)\r\n");
    SendCMD();
    wait(1);
    
    strcpy(snd, "srv = net.createServer(net.TCP)\r\n");
    SendCMD();
    wait(1);
    
    strcpy(snd, "srv:listen(80, function(conn1)\r\n");
    SendCMD();
    wait(1);
    
    strcpy(snd, "conn1:on(\"receive\",function(conn1, payload)\r\n");
    SendCMD();
    wait(1);
        
        // If the server receives a GET request, return the web page.
        strcpy(snd, "if string.find(payload, \"GET\") ~= nil then\r\n");
        SendCMD();
        wait(1);
        
            strcpy(snd, "conn1:send(\"<!DOCTYPE html>\")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<html>\")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<form method='POST' autocomplete='off'>\")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<b>Send tweets to: @</b> <input name='twitterHandle' value=''><br>\")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<b>Send tweet every:</b>  <input type='radio' name='freq' value='1' checked='checked'> Minute \")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<input type='radio' name='freq' value='2'> 5 Minutes \")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<input type='radio' name='freq' value='3'> 15 Minutes \")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<input type='radio' name='freq' value='4'> 30 Minutes \")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"<input type='submit' value='Save settings'>\")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"</form>\")\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "conn1:send(\"</html>\")\r\n");
            SendCMD();
            wait(1);
        
        strcpy(snd, "end\r\n");
        SendCMD();
        wait(1);
        
        strcpy(snd, "if string.find(payload, \"POST\") ~= nil then\r\n");
        SendCMD();
        wait(1);
            
            strcpy(snd, "tweetFreq = \"-1\"\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "twitterHandle = \"\"\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "contentLengthIndex = string.find(payload, \"Content\")\r\n");
            SendCMD();
            wait(1);
            
            // Adds 16 to the index of the start of 'Content-Length: '. This gives the index of content length's value.
            strcpy(snd, "contentLengthIndex = contentLengthIndex + 16\r\n");
            SendCMD();
            wait(1);
            
            // Assumes that content length is > 10 and < 100 (fine for this since twitter handles are <= 15 characters long.)
            strcpy(snd, "contentLength = payload:sub(contentLengthIndex, contentLengthIndex + 2)\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "twitterHandleLength = contentLength - 22\r\n");
            SendCMD();
            wait(1);
        
            strcpy(snd, "if string.find(payload, \"freq=1\") ~= nil then tweetFreq = \"1\" end\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "if string.find(payload, \"freq=2\") ~= nil then tweetFreq = \"2\" end\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "if string.find(payload, \"freq=3\") ~= nil then tweetFreq = \"3\" end\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "if string.find(payload, \"freq=4\") ~= nil then tweetFreq = \"4\" end\r\n");
            SendCMD();
            wait(1);
            
            strcpy(snd, "index = string.find(payload, \"twitterHandle=\")\r\n");
            SendCMD();
            wait(1);         
            
            strcpy(snd, "if index ~= nil then\r\n");
            SendCMD();
            wait(1);
            
                strcpy(snd, "index = index + 14\r\n");
                SendCMD();
                wait(1);
                
                strcpy(snd, "for i = 0, twitterHandleLength do\r\n");
                SendCMD();
                wait(1);
                
                    strcpy(snd, "twitterHandle = twitterHandle .. payload:sub(index,index)\r\n");
                    SendCMD();
                    wait(1);
                    
                    strcpy(snd, "index = index + 1\r\n");
                    SendCMD();
                    wait(1);
                
                strcpy(snd, "end\r\n");
                SendCMD();
                wait(1);
                
                strcpy(snd, "twitterHandle = twitterHandle .. \";\" .. tweetFreq\r\n");
                SendCMD();
                wait(1);
            
            strcpy(snd, "end\r\n");
            SendCMD();
            wait(1); 
            
            // ESP pin is high => trigger InterruptIn on mbed to get the twitterHandle
            strcpy(snd, "gpio.write(pin, gpio.HIGH)\r\n");
            SendCMD();
            wait(1);
            
            // Wait half a second
            strcpy(snd, "tmr.delay(500000)\r\n");
            SendCMD();
            wait(1);
            
            // Set the gpio back to low.
            strcpy(snd, "gpio.write(pin, gpio.LOW)\r\n");
            SendCMD();
            wait(1);
                       
            strcpy(snd, "conn1:send(\"Settings saved!\")\r\n");
            SendCMD();
            wait(1);
        
        strcpy(snd, "end\r\n");
        SendCMD();
        wait(1);
    
    strcpy(snd, "end)\r\n");
    SendCMD();
    wait(1);
    
    strcpy(snd, "conn1:on(\"sent\", function(conn1) conn1:close() end)\r\n");
    SendCMD();
    wait(1);
    
    strcpy(snd, "end)\r\n");
    SendCMD();
    wait(1);
    pc.printf("\r\nDONE");
    
}

void sendTweet() {
        
        pc.printf("%s\r\n", twitterHandle);
        pc.printf("%d\r\n", tweetPeriod);
        
        char message[256];
        float value = moisture * maxValue;
        
        char mainMessage[256];
        sprintf(mainMessage, "Soil moisture reading is %f. Seconds since last reset: %d .", value, seconds);
        
        if (twitterHandle[0] != '\0') {
            // This means there is a twitter handle set.
            // Tweet the message at that user.
            sprintf(message, "@%s %s", twitterHandle, mainMessage);
        } else {      
            // Tweeting at no one.
            strcpy(message, mainMessage);
            pc.printf("%s\r\n", message);
        }
        
        pc.printf("\n---------- Sending tweet ----------\r\n");
        
        strcpy(snd, "conn = net.createConnection(net.TCP, 0)\r\n");
        SendCMD();
        wait(1);
        
        strcpy(snd, "conn:on(\"connection\", function(conn, payload)\r\n");
        SendCMD();
        wait(1);
        
        /* APIKEY : Here, in the part of the url that says api_key=... replace ... with your API key. */
        sprintf(snd, "conn:send(\"POST /apps/thingtweet/1/statuses/update?api_key=...&status=%s HTTP/1.1\\r\\nHost: api.thingspeak.com\\r\\n\\r\\n\")\r\n", message);
        SendCMD();
        wait(1);
        
        strcpy(snd, "end)\r\n");
        SendCMD();
        wait(1);
        
        strcpy(snd, "conn:on(\"sent\", function(conn) conn:close() end)\r\n");
        SendCMD();
        wait(1);
        
        strcpy(snd, "conn:connect(80,\"api.thingspeak.com\")\r\n");
        SendCMD();
        wait(1);
}
 
void SendCMD()
{
    esp.printf("%s", snd);
}
 
void getreply()
{
    memset(buf, '\0', sizeof(buf));
    timer.start();
    ended=0;
    count=0;
    while(!ended) {
        if(esp.readable()) {
            buf[count] = esp.getc();
            count++;
        }
        if(timer.read() > timeout) {
            ended = 1;
            timer.stop();
            timer.reset();
        }
    }
}

//  +++++++++++++++++++++++++++++++++ This is for ESP8266 config only, run this once to set up the ESP8266 +++++++++++++++
void ESPconfig()
{

    wait(5);
    pc.printf("\f---------- Starting ESP Config ----------\r\n\n");
    strcpy(snd,".\r\n.\r\n");
    SendCMD();
    wait(1);
    pc.printf("---------- Reset & get Firmware ----------\r\n");
    strcpy(snd,"node.restart()\r\n");
    SendCMD();
    timeout=5;
    getreply();
    pc.printf(buf);
 
    wait(2);
 
    pc.printf("\n---------- Get Version ----------\r\n");
    strcpy(snd,"print(node.info())\r\n");
    SendCMD();
    timeout=4;
    getreply();
    pc.printf(buf);
 
    wait(3);
 
    // set CWMODE to 1=Station,2=AP,3=BOTH, default mode 1 (Station)
    pc.printf("\n---------- Setting Mode ----------\r\n");
    strcpy(snd, "wifi.setmode(wifi.STATION)\r\n");
    SendCMD();
    timeout=4;
    getreply();
    pc.printf(buf);
 
    wait(2);
 
    pc.printf("\n---------- Listing Access Points ----------\r\n");
    strcpy(snd, "function listap(t)\r\n");
        SendCMD();
        wait(1);
        strcpy(snd, "for k,v in pairs(t) do\r\n");
        SendCMD();
        wait(1);
        strcpy(snd, "print(k..\" : \"..v)\r\n");
        SendCMD();
        wait(1);
        strcpy(snd, "end\r\n");
        SendCMD();
        wait(1);
        strcpy(snd, "end\r\n");
        SendCMD();
        wait(1);
        strcpy(snd, "wifi.sta.getap(listap)\r\n");
        SendCMD();
        wait(1);
        timeout=15;
        getreply();
        pc.printf(buf);
 
    wait(2);
 
    pc.printf("\n---------- Connecting to AP ----------\r\n");
    pc.printf("ssid = %s   pwd = %s\r\n",ssid,pwd);
    strcpy(snd, "wifi.sta.config(\"");
    strcat(snd, ssid);
    strcat(snd, "\",\"");
    strcat(snd, pwd);
    strcat(snd, "\")\r\n");
    SendCMD();
    timeout=10;
    getreply();
    pc.printf(buf);
 
    wait(5);
 
    pc.printf("\n---------- Get IP's ----------\r\n");
    strcpy(snd, "print(wifi.sta.getip())\r\n");
    SendCMD();
    timeout=3;
    getreply();
    pc.printf(buf);
 
    wait(1);
 
    pc.printf("\n---------- Get Connection Status ----------\r\n");
    strcpy(snd, "print(wifi.sta.status())\r\n");
    SendCMD();
    timeout=5;
    getreply();
    pc.printf(buf);
 
    pc.printf("\n\n\n  If you get a valid (non zero) IP, ESP8266 has been set up.\r\n");
    pc.printf("  Run this if you want to reconfig the ESP8266 at any time.\r\n");
    pc.printf("  It saves the SSID and password settings internally\r\n");
    wait(10);
}