Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Text.RegularExpressions;
using System.IO;
using VaccineSlotter;
using System.Media;

using System.Net.Mail;

namespace VaccineSlotter
{
    //======================================================================================
    class Program
    {
        static private string LoginStatus = "";

        //======================================================================================

        private static string GetCookie()
        {
            string uri = string.Empty;
            string cookie = string.Empty;

            HttpWebResponse response = POST(uri);
            if (response == null)
            {
                LoginStatus = "Not connected";
                return "";
            }

            WebHeaderCollection headers = response.Headers;

            if ((response.StatusCode == HttpStatusCode.Found) ||
                    (response.StatusCode == HttpStatusCode.Redirect) ||
                    (response.StatusCode == HttpStatusCode.Moved) ||
                    (response.StatusCode == HttpStatusCode.MovedPermanently))
            {
                if (headers["Set-Cookie"] != null)
                {
                    string cookies = headers["Set-Cookie"];
                    String[] fields = Regex.Split(cookies, ";\\s*");
                    cookie = fields[0];

                }
            }
            return cookie;
        }

        //======================================================================================

        public static HttpWebResponse POST(string url)
        {
            try
            {

                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
                request.Method = "POST";
                request.KeepAlive = true;
                request.AllowAutoRedirect = false;
                request.Accept = "*/*";
                request.ContentType = "application/x-www-form-urlencoded";
                request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5";
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                return response;
            }
            catch
            {
                return (HttpWebResponse)null;
            }
        }

        //======================================================================================

        public static HttpWebResponse GET(string url)
        {
            //https://www.codeproject.com/Questions/621289/get-http-request-header-values-in-to-csharp
            try
            {
                ServicePointManager.Expect100Continue = true;
                ServicePointManager.DefaultConnectionLimit = 9999;
                ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072 | SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls; 

                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);

                request.Method = "GET";
                request.KeepAlive = true;
                request.AllowAutoRedirect = false;
                request.Accept = "*/*";
                request.ContentType = "application/x-www-form-urlencoded";
                request.UserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36";
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                return response;
            }
            catch
            {
                return (HttpWebResponse)null;
            }
        }

        //======================================================================================

        public static HttpWebResponse POST(string postData, string url, string referer, string cookie)
        {
            try
            {
                byte[] byteArray = Encoding.UTF8.GetBytes(postData);
                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
                request.Method = "POST";
                request.KeepAlive = true;
                request.AllowAutoRedirect = false;
                request.Accept = "*/*";
                request.ContentType = "application/x-www-form-urlencoded";
                if (!string.IsNullOrEmpty(cookie))
                    request.Headers.Add(HttpRequestHeader.Cookie, cookie);
                if (!string.IsNullOrEmpty(referer))
                    request.Referer = referer;
                request.ContentLength = byteArray.Length;
                request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5";
                //   request.Proxy = null;
                Stream dataStream = request.GetRequestStream();
                dataStream.Write(byteArray, 0, byteArray.Length);
                dataStream.Close();
                try
                {
                    return (HttpWebResponse)request.GetResponse();
                }
                catch
                {
                    return (HttpWebResponse)null;
                }
            }
            catch
            {
                return (HttpWebResponse)null;
            }
        }

        //======================================================================================

        static string  DisplayCenterData(ref CenterData data)
        {
            string result = "\n";
            string endLineCharInMail = " <br />";

            result += "------------------------------------------------------" + endLineCharInMail;
            Console.WriteLine("==============================================\n");

            result += endLineCharInMail + "Name: \t" + data.Name;
            Console.WriteLine("\nName: \t" + data.Name);

            result += endLineCharInMail + "PinCode: \t" + data.PinCode +"\n";
            Console.WriteLine("\nPinCode \t" + data.PinCode);

            List<SessonData> pSessionData = data.SessonsDataArray;

            for (int sCount = 0; pSessionData != null && sCount < pSessionData.Count; ++sCount)
            {
                SessonData pObj = pSessionData[sCount];
                int minAgeInData = pObj.Min_age_limit;
                int slotAvailable = pObj.Available_Capacity;

                result += endLineCharInMail + "Min Age Limit \t" + minAgeInData.ToString() + endLineCharInMail;
                Console.WriteLine("\nMin Age Limit: \t" + minAgeInData.ToString());

                result += "Slot Available: \t" + slotAvailable.ToString() + endLineCharInMail;
                Console.WriteLine("\nSlot Available: \t" + slotAvailable.ToString());

            }
            result += "===========================================" + "\n";
            Console.WriteLine("===========================================\n");

            return result;
        }

        //=======================================================================

        static HttpStatusCode ReadDataByDistrictName(int minAge, int distCode, ref string emailId, ref string mailBody)
        {
            try
            {
                DateTime date = DateTime.Now;
                // converting to string format
                string date_str = date.ToString("dd-MM-yyyy");

                string URL = "https://cdn-api.co-vin.in/api/v2/appointment/sessions/public/calendarByDistrict?district_id=" + distCode.ToString() +
                    "&date=" + date_str;

                HttpWebResponse response = Program.GET(URL);

                if (response == null)
                    return HttpStatusCode.BadRequest;

                HttpStatusCode statusCode = response.StatusCode;
                if (statusCode == HttpStatusCode.OK)
                {
                    //var responseVal = new StreamReader(stream: response.GetResponseStream()).ReadToEnd();
                    ResponseHandler pResponseHandler = new ResponseHandler();
                    string converted = pResponseHandler.ConvertResponseStreamToString(response);

                    List<CenterData> centerData = null;
                    ParseStringByDist.GetCentersData(converted, out centerData);

                    List<CenterData> shortedData = new List<CenterData>();

                    for (int count = 0; count < centerData.Count; ++count)
                    {
                        CenterData pData = centerData[count];
                        List<SessonData> pSessionData = pData.SessonsDataArray;

                        for (int sCount = 0; pSessionData != null && sCount < pSessionData.Count; ++sCount)
                        {
                            SessonData pSessonDataInArray = pSessionData[sCount];
                            int minAgeInData = pSessonDataInArray.Min_age_limit;
                            int slotAvailable = pSessonDataInArray.Available_Capacity;

                            if (minAgeInData == minAge)
                            {
                                if (slotAvailable > 0)
                                {
                                    shortedData.Add(pData);
                                }
                            }
                        }
                    }// Data 

                    if (shortedData.Count > 0)
                    {
                        string mailBodyToSend = "";
                        for (int count = 0; count < shortedData.Count; ++count)
                        {
                            Console.Beep();
                            Console.Beep();

                            CenterData pData = shortedData[count];
                            string result = DisplayCenterData(ref pData);
                            mailBodyToSend += result;

                        }// Vaild data

                        // Send mail if found different info
                        if (string.Equals(mailBodyToSend, mailBody) == false)
                        {
                            mailBody = mailBodyToSend;
                            Email(ref mailBody, ref emailId);
                        }

                    }// checker

                }
                return statusCode;
            }
            catch
            {
                return HttpStatusCode.BadRequest;
            }
        }


        //======================================================================================

        public static void Email(ref string htmlString, ref string emailIdOfReceiver)
        {
            try
            {
                MailMessage message = new MailMessage();
                SmtpClient smtp = new SmtpClient();
                message.From = new MailAddress("akshaypadghan567@gmail.com");
                message.To.Add(new MailAddress(emailIdOfReceiver));
                message.Subject = "Vaccine slot available in your area";
                message.IsBodyHtml = true; //to make message body as html  
                message.Body = htmlString;
                smtp.Port = 587;
                smtp.Host = "smtp.gmail.com"; //for gmail host  
                smtp.EnableSsl = true;
                smtp.UseDefaultCredentials = false;
                smtp.Credentials = new NetworkCredential("akshaypadghan567@gmail.com", "PASSWORD");
                smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
                smtp.Send(message);
            }
            catch (Exception)            
            {
            
            }
        }

        //======================================================================================

        static void ReadDownloadedFile(string filename, ref List<DriveTextData> distData)
        {
            try
            {
                // Read Text file data
                StreamReader sr = new StreamReader(filename);
                string readedLine = sr.ReadLine();
                string emailData = "Email:";
                string districtData = "DistrictCode:";
                string minAgeData = "MinAge:";
                string startData = "<";
                string endData = ">";

                DriveTextData tempData = null;

                while (readedLine != null)
                {
                    int indexEmail = readedLine.IndexOf(emailData);
                    int indexStart = readedLine.IndexOf(startData);
                    int indexEnd = readedLine.IndexOf(endData);
                    int indexMinEdge = readedLine.IndexOf(minAgeData);
                    int indexDistCode = readedLine.IndexOf(districtData);
                    if (indexStart >= 0)
                    {
                        string startString = readedLine.Substring(indexStart + startData.Length);
                        startString = startString.Trim();

                        if (startString.Length == 0)
                            tempData = new DriveTextData();
                    }

                    if (indexEnd >= 0)
                    {
                        string endString = readedLine.Substring(indexEnd + endData.Length);
                        endString = endString.Trim();

                        if (endString.Length == 0)
                        {
                            distData.Add(tempData);
                            tempData = null;
                        }
                    }

                    if (indexEmail >= 0)
                    {
                        string emailId = readedLine.Substring(indexEmail + emailData.Length);
                        emailId = emailId.Trim();
                        tempData.EmailID = emailId;
                    }
                    else if (indexMinEdge >= 0)
                    {
                        string age = readedLine.Substring(indexMinEdge + minAgeData.Length);
                        age = age.Trim();
                        bool tempBool = age.Contains(".");
                        if (tempBool == false)
                            tempData.MinAge = int.Parse(age);
                    }
                    else if (indexDistCode >= 0)
                    {
                        string dist = readedLine.Substring(indexDistCode + districtData.Length);
                        dist = dist.Trim();

                        bool tempBool = dist.Contains(".");
                        if (tempBool == false)
                            tempData.DistCode = int.Parse(dist);
                    }

                    //Read the next line
                    readedLine = sr.ReadLine();
                }
                //close the file
                sr.Close();
            }
            catch
            {

            }
        }

        //======================================================================================

        static void DownloadFileAndReadData(ref List<DriveTextData> driveData)
        {
            // Download drive file
            string path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "text.txt");
            string tempPath = System.IO.Path.GetTempPath();
            path = tempPath + "DownloadedFile.txt";
            FileDownloader fileDownloader = new FileDownloader();
            fileDownloader.DownloadFile("https://drive.google.com/uc?id=1DOTrAk4QtlTVsUg9CE2iQo8Xvao7GVDL&export=download", path);

            ReadDownloadedFile(path, ref driveData);
        }

        //======================================================================================
        
        static void FindVaccineByDriveLink()
        {
            // Download and read drive file
            List<DriveTextData> driveData = new List<DriveTextData>();
            DownloadFileAndReadData(ref driveData);

            DateTime messageTime = DateTime.Now;
            HttpStatusCode statusCode = HttpStatusCode.NotImplemented;
           
            DateTime startTime = DateTime.Now;
            DateTime endTime = DateTime.Now;
            TimeSpan ts = endTime - startTime;
            int sec = 3;

            // Make mail body same as email we got
            List<string> mailBodySendOnEmail = new List<string>();
            for (int countD = 0; countD < driveData.Count; ++countD)
                mailBodySendOnEmail.Add("");

            Console.WriteLine("\n------------------Vaccine-Spotter is Running--------------------------\n");

            while (true)
            {
                if (sec >= 3) // 3 Sec
                {
                    for (int countD = 0; countD < driveData.Count; ++countD )
                    {
                        DriveTextData pDriveData = driveData[countD];
                        string mailSended = mailBodySendOnEmail[countD];
                        string emailId = pDriveData.EmailID;

                        statusCode = ReadDataByDistrictName(pDriveData.MinAge, pDriveData.DistCode,
                            ref emailId, ref mailSended);

                        mailBodySendOnEmail[countD] = mailSended;
                        if (statusCode != HttpStatusCode.OK)
                            break;
                    }// User Loop                    

                    if (statusCode != HttpStatusCode.OK)
                    {
                        continue; // Sometime network is week so avoid it for now. and try again immediately
                    }

                    startTime = DateTime.Now;
                    endTime = DateTime.Now;
                }

                endTime = DateTime.Now;
                ts = endTime - startTime;
                sec = ts.Seconds;

                TimeSpan tempTS = endTime - messageTime;
                if (tempTS.Minutes == 5) // 5 Min-- Download data And update users
                {
                    Console.WriteLine("\n------------------Vaccine-Spotter is Running--------------------------\n");

                    mailBodySendOnEmail.Clear();
                    driveData.Clear();

                    // Download and read data
                    DownloadFileAndReadData(ref driveData);

                    // Make mail body same as email we got
                    for (int countD = 0; countD < driveData.Count; ++countD)
                        mailBodySendOnEmail.Add("");

                    messageTime = DateTime.Now;
                }
            } // While Loop
        }

        //======================================================================================

        static void FindVaccineByUserPreferance()
        {
            Console.WriteLine("Enter min age to set an alert");
            string ageString = Console.ReadLine();
            if (ageString == null || ageString.Length == 0)
            {
                Console.WriteLine("!!!      Invalid Input Age. Run Software Again   !!!!\n");
                Console.ReadLine();
                return;
            }

            int age = Convert.ToInt32(ageString);

            Console.WriteLine("Give me your email ID to alert");
            string emailID = Console.ReadLine();

            Console.WriteLine("\nGive me your District code, ex 367 for Buldhana, 376 for Satara");
            string distCodeString = Console.ReadLine();
            if (distCodeString == null || distCodeString.Length == 0)
            {
                Console.WriteLine("!!!      Invalid Input District Code. Run Software Again   !!!!\n");
                Console.ReadLine();
                return;
            }
            int distCode = Convert.ToInt32(distCodeString);

            Console.WriteLine("\n------------------Vaccine-Spotter is Running--------------------------\n");

            DateTime startTime = DateTime.Now;
            DateTime endTime = DateTime.Now;
            TimeSpan ts = endTime - startTime;
            int sec = 3;

            DateTime messageTime = DateTime.Now;
            HttpStatusCode statusCode = HttpStatusCode.NotImplemented;
            string mailBodySendOnEmail = "";

            while (true)
            {
                if (sec >= 3) // 3 Sec
                {
                    startTime = DateTime.Now;
                    endTime = DateTime.Now;
                    statusCode = ReadDataByDistrictName(age, distCode, ref emailID, ref mailBodySendOnEmail);

                    if (statusCode != HttpStatusCode.OK)
                        break;
                }

                endTime = DateTime.Now;
                ts = endTime - startTime;
                sec = ts.Seconds;

                TimeSpan tempTS = endTime - messageTime;
                if (tempTS.Minutes == 3) // 3 Min
                {
                    Console.WriteLine("\n -----------------Vaccine-Spotter is Running to check Available Slot. -------------\n");
                    messageTime = DateTime.Now;
                }
            } // While Loop

            if (statusCode != HttpStatusCode.OK)
            {
                Console.WriteLine(statusCode.ToString());
                string tempResponseString = Console.ReadLine();
            }
        }

        //======================================================================================

        static void Main(string[] args)
        {

            Console.WriteLine("     Welcome!! \n    I can alert you when slot is available. \n\n");
            Console.WriteLine("     Option 1. Search vaccine Manually \n");
            Console.WriteLine("     Option 2. Search vaccine Using Drive Link \n");
            int opetion = int.Parse(Console.ReadLine());
            Console.WriteLine("\n");
            if (opetion == 1)
            {
                FindVaccineByUserPreferance();
            }
            else if (opetion == 2)
            {
                FindVaccineByDriveLink();
            }

            
        }

        //======================================================================================

    }
}