// See https://aka.ms/new-console-template for more information
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Tesses.WebServer;
using LiteDB;
using System.Security.Cryptography;
using System.Text;
using System.Web;
using MimeKit;
using MailKit.Net.Smtp;

bool serve =true;

string path = "data";

string GetIP(ServerContext ctx)
{
    if(ctx.RequestHeaders.TryGetFirst("X-Real-IP",out var ip))
    {
        return ip;
    }
    return ctx.Client.Address.ToString();
}
long HashIP(ServerContext ctx)
{
    
    return BitConverter.ToInt64(SHA512.HashData(Encoding.UTF8.GetBytes(GetIP(ctx))),0);
}

if(args.Length > 0)
{
    if(args[0] == "serve")
    {
        serve = true;

    }
    else if(args[0] == "send")
    {
        serve = false;
    }
    else 
    {
        Console.WriteLine("Command help");
        Console.WriteLine("serve: serve this app using data folder in working directory");
        Console.WriteLine("send: send emails using data folder in working directory");
        Console.WriteLine("serve <path>: serve this app using path to data folder");
        Console.WriteLine("send <path>: send emails using path to data folder");
        return;
    }
    if(args.Length>1)
    {
        path=args[1];
    }
}
else
{
    Console.WriteLine("Command help");
    Console.WriteLine("serve: serve this app using data folder in working directory");
    Console.WriteLine("send: send emails using data folder in working directory");
    Console.WriteLine("serve <path>: serve this app using path to data folder");
    Console.WriteLine("send <path>: send emails using path to data folder");
    return;
}
Directory.CreateDirectory(path);
EmailBoxConfiguration configuration = EmailBoxConfiguration.OpenConfiguration(Path.Combine(path,"config.json"));
LiteDatabase db = new LiteDatabase(Path.Combine(path,"emailbox.db"));

if(serve)
{
    
    RouteServer routeServer=new RouteServer();
    routeServer.CorsHeader=false;
    routeServer.Add("/",async(ctx)=>{
        var ips = db.GetCollection<IPS>("ips");
        long id=HashIP(ctx);
        if(ips.FindById(id) ==null)
        {
            ips.Insert(id,new IPS());
        }
        long count=ips.LongCount();
        var emails = db.GetCollection<Emails>("emails");
        await ctx.SendTextAsync(File.ReadAllText(Path.Combine(path,"index.html")).Replace("%Name%",configuration.Name).Replace("%Viewers%",count.ToString()).Replace("%Mailing%",emails.LongCount().ToString()).Replace("%Loads%",Views.Increment(db).ToString()));
    });
    routeServer.Add("/bootstrap.min.js",async(ctx)=>{
        await ctx.SendFileAsync(Path.Combine(path,"bootstrap.min.js"));
    });
    routeServer.Add("/bootstrap.min.css",async(ctx)=>{
        await ctx.SendFileAsync(Path.Combine(path,"bootstrap.min.css"));
    });
    routeServer.Add("/addtomailinglist",async(ctx)=>{
        ctx.ParseBody();
        if(ctx.QueryParams.TryGetFirst("email",out var email))
        {
            var emails = db.GetCollection<Emails>("emails");
            var emailAcnt= emails.FindOne(e=>e.Email == email);
            if(emailAcnt == null)
            {
                emailAcnt=new Emails();

                emailAcnt.Email = email;
                var rnd=Convert.ToBase64String(RandomNumberGenerator.GetBytes(32));
                emailAcnt.UnsubscribeCode = rnd;
                emails.Insert(emailAcnt);
            }
            await SendUnsubscribeEmailAsync(emailAcnt);
        }
        await ctx.SendRedirectAsync($"{configuration.Website.TrimEnd('/')}/");
    },"POST");
    routeServer.Add("/unsubscribe",async(ctx)=>{
        Emails? emailAcnt=null;
        var emails = db.GetCollection<Emails>("emails");
        if(ctx.QueryParams.TryGetFirst("email",out var email) && ctx.QueryParams.TryGetFirst("token",out var token))
        {
            
            emailAcnt = emails.FindOne(e=>e.Email == email);
            if(emailAcnt != null && emailAcnt.UnsubscribeCode != token)
            {
                emailAcnt = null;
            }
        }
        if(emailAcnt != null)
        {
            emails.Delete(emailAcnt.Id);
            await ctx.SendFileAsync(Path.Combine(path,"unsubscribe_success.html"));
        
        }
        else await ctx.SendFileAsync(Path.Combine(path,"unsubscribe_failed.html"));
    });
    routeServer.StartServer(configuration.Port);
}
else
{
     var emails = db.GetCollection<Emails>("emails");
    foreach(var item in emails.FindAll())
    {
        await SendActualEmailAsync(item);
    }
}
async Task SendEmailAsync(Emails emailAcnt,string subject,string body)
{
    if(InternetAddress.TryParse(emailAcnt.Email,out var to) && InternetAddress.TryParse(configuration.Email.Email,out var from))
            using(var smtp=new SmtpClient())
            {
                await smtp.ConnectAsync(configuration.Email.Host,configuration.Email.Port,configuration.Email.Encryption);
                await smtp.AuthenticateAsync(configuration.Email.User,configuration.Email.Pass);
                MimeMessage message=new MimeMessage();
                message.From.Add(from);
                message.To.Add(to);
                message.Body = new TextPart(MimeKit.Text.TextFormat.Html){Text=body};
                message.Subject = subject;
                await smtp.SendAsync(message);
            }
}
async Task SendActualEmailAsync(Emails emailAcnt)
{
    await SendEmailAsync(emailAcnt,configuration.ActualEmailSubject,File.ReadAllText(Path.Combine(path,"email.html")).Replace("%Website%",HttpUtility.HtmlAttributeEncode($"{configuration.Website.TrimEnd('/')}/")).Replace("%Name%",HttpUtility.HtmlEncode(configuration.Name).Replace("%Email%",HttpUtility.HtmlEncode(configuration.Email))));
}
async Task SendUnsubscribeEmailAsync(Emails emailAcnt)
{
    string unsubscribeUrl = $"{configuration.Website.TrimEnd('/')}/unsubscribe?email={HttpUtility.UrlEncode(emailAcnt.Email)}&token={HttpUtility.UrlEncode(emailAcnt.UnsubscribeCode)}";
    await SendEmailAsync(emailAcnt,$"Heres your unsubscribe email for {configuration.Name}",File.ReadAllText(Path.Combine(path,"unsubscribe_email.html")).Replace("%Website%",HttpUtility.HtmlAttributeEncode($"{configuration.Website.TrimEnd('/')}/")).Replace("%Name%",HttpUtility.HtmlEncode(configuration.Name)).Replace("%Unsubscribe%",HttpUtility.HtmlAttributeEncode(unsubscribeUrl)));
}

public class EmailBoxConfiguration 
{
    string _aeS="";
    public string ActualEmailSubject 
    {
        get{
            if(string.IsNullOrWhiteSpace(_aeS))
            {
                return $"Email from {Name}";
            }
            return _aeS;
        }
        set{
            _aeS = value;
        }
    }
    public string Website {get;set;}="/";
    public int Port {get;set;}=51777;
    public string Name {get;set;}="";
    public EmailBoxEmailConfiguration Email {get;set;}=new EmailBoxEmailConfiguration();

    internal static EmailBoxConfiguration OpenConfiguration(string v)
    {
        if(File.Exists(v))
        {
            var p = JsonConvert.DeserializeObject<EmailBoxConfiguration>(File.ReadAllText(v));
            if(p!=null) return p;
        }
        return new EmailBoxConfiguration();
    }
}


public class EmailBoxEmailConfiguration
    {
        public string Host {get;set;}="";
        public string Email {get;set;}="";
        public string User {get;set;}="";
        public string Pass {get;set;}="";

        public int Port {get;set;}=587;
        [JsonConverter(typeof(StringEnumConverter))]
        public MailKit.Security.SecureSocketOptions Encryption {get;set;}= MailKit.Security.SecureSocketOptions.StartTls;

        
    }

    public class IPS
    {
        public long Id {get;set;}
    }

    public class Emails 
    {
        public long Id {get;set;}

        public string Email {get;set;}="";

        public string UnsubscribeCode {get;set;}="";
    }

    public class Views 
    {   
        public long Id {get;set;}=1;
        public long PageViews {get;set;}=1;

        public static long Increment(ILiteDatabase db)
        {
            lock(db){
            var views=db.GetCollection<Views>("views");
            var item = views.FindById(1);
            if(item==null)
            {
                item=new Views();
                views.Insert(item);
            }
            else
            {
                item.PageViews++;
                views.Update(item);
            }
        
            return item.PageViews;
            }
        }
    }