using MySqlConnector;
using System.Security.Cryptography;
using System.Text;

var SK_DB = "db-cred";
var SK_LOGGED = "logged-in";

var builder = WebApplication.CreateBuilder(new WebApplicationOptions
{
    Args = args,
    WebRootPath = "frontend/dist"
});

builder.Services.AddDistributedMemoryCache();

builder.Services.AddSession(options =>
{
    options.Cookie.HttpOnly = true;
    options.Cookie.IsEssential = true;
});

var app = builder.Build();

var connection = new MySqlConnection();
app.UseStaticFiles();
app.UseRouting();
app.UseSession();

app.MapPost("/login", (LoginForm lgf, HttpResponse response, HttpContext context) =>
{
    var pass = hashPassword(lgf.password!);
    connection = new MySqlConnection(context.Session.GetString(SK_DB));
    connection.Open();
    var command = new MySqlCommand(null, connection);

    if (lgf.mode == "login")
    {
        command.CommandText = "SELECT * FROM user WHERE login = @login AND password = @password;";

        command.Parameters.AddWithValue("@login", lgf.login);
        command.Parameters.AddWithValue("@password", pass);

        var reader = command.ExecuteReader();
        while (reader.Read())
        {
            context.Session.SetString(SK_LOGGED, "true");
            connection.Close();
            return "ok";
        }
    }
    else
    {
        Console.WriteLine("registering");

        command.CommandText = "INSERT INTO user (email, login, password) VALUES (@email, @login, @password)";

        command.Parameters.AddWithValue("@login", lgf.login);
        command.Parameters.AddWithValue("@password", pass);
        command.Parameters.AddWithValue("@email", lgf.email);

        command.ExecuteNonQuery();
        connection.Close();
        return "ok";
    }
    connection.Close();
    return "error";
});
app.MapPost("/check-db", async (DbForm dbf, HttpResponse response, HttpContext context) =>
{
    try
    {
        var connstr = $"server={dbf.server};port={dbf.port};user={dbf.user};password={dbf.password};database={dbf.database}";
        var conn = new MySqlConnection(connstr);
        Console.WriteLine(connstr);
        await conn.OpenAsync();
        connection = conn;
        await conn.CloseAsync();
        context.Session.SetString(SK_DB, connstr);
        return "ok";
    }
    catch (Exception _)
    {
        return "error";
    }
});
app.MapMethods("/check-db", new[] { "OPTIONS" }, (HttpResponse response) =>
{
    response.Headers.AccessControlAllowOrigin = "*";
    response.Headers.AccessControlAllowHeaders = "*";
    return "ok";
});
app.MapGet("/", (HttpContext context) =>
{
    context.Response.SendFileAsync("./frontend/dist/index.html");
});
app.MapPost("/book", (Book book, HttpContext context) =>
{
    if (!checkRequest(context)) return "error";
    connection.Open();
    var command = new MySqlCommand(null, connection);
    if (book.id == null)
    {
        command.CommandText = "INSERT INTO book (author, title, year, publisher, isbn, format, pages, description) VALUES (@author, @title, @year, @publisher, @isbn, @format, @pages, @description)";
    }
    else
    {
        command.CommandText = "UPDATE book SET author = @author, title = @title, year = @year, publisher = @publisher, isbn = @isbn, format = @format, pages = @pages, description = @description WHERE id = @id";
        command.Parameters.AddWithValue("@id", book.id);
    }
    command.Parameters.AddWithValue("@author", book.author);
    command.Parameters.AddWithValue("@title", book.title);
    command.Parameters.AddWithValue("@year", MySqlDbType.Int32).Value = book.year;
    command.Parameters.AddWithValue("@publisher", book.publisher);
    command.Parameters.AddWithValue("@isbn", book.isbn);
    command.Parameters.AddWithValue("@format", book.format);
    command.Parameters.AddWithValue("@pages", book.pages);
    command.Parameters.AddWithValue("@description", book.description);
    command.ExecuteNonQuery();
    connection.Close();
    return "ok";
});
app.MapGet("/books", (HttpContext context) =>
{
    if (!checkRequest(context)) return Results.Ok("error");

    connection.Open();
    var command = new MySqlCommand("SELECT * FROM book;", connection);
    var reader = command.ExecuteReader();

    List<Dictionary<string, string>> books = new List<Dictionary<string, string>>();

    while (reader.Read())
    {
        Dictionary<string, string> book = new Dictionary<string, string>();

        book.Add("id", reader.GetValue(0).ToString() ?? "");
        book.Add("author", reader.GetValue(1).ToString() ?? "");
        book.Add("title", reader.GetValue(2).ToString() ?? "");
        book.Add("year", reader.GetValue(3).ToString() ?? "");
        book.Add("publisher", reader.GetValue(4).ToString() ?? "");
        book.Add("isbn", reader.GetValue(5).ToString() ?? "");
        book.Add("format", reader.GetValue(6).ToString() ?? "");
        book.Add("pages", reader.GetValue(7).ToString() ?? "");
        book.Add("description", reader.GetValue(8).ToString() ?? "");

        books.Add(book);
    }

    connection.Close();
    return Results.Json(books);
});

// Remove book
app.MapDelete("/book", (HttpContext context) =>
{
    if (!checkRequest(context)) return Results.Unauthorized();

    connection.Open();
    var command = new MySqlCommand(null, connection);

    command.CommandText = "DELETE FROM book WHERE id = @id;";
    command.Parameters.AddWithValue("@id", MySqlDbType.Int32).Value = Int32.Parse(context.Request.Query["bid"]);
    command.ExecuteNonQuery();

    connection.Close();
    return Results.Ok("ok");
});

app.Run("http://localhost:8000");

String hashPassword(string pass)
{
    var sha256 = SHA256.Create();
    return BitConverter.ToString(sha256.ComputeHash(Encoding.UTF8.GetBytes(pass!)));
}

Boolean checkRequest(HttpContext context)
{
    return context.Session.GetString(SK_LOGGED) == "true";
}

class DbForm
{
    public string? server { get; set; }
    public int port { get; set; }
    public string? database { get; set; }
    public string? user { get; set; }
    public string? password { get; set; }
}
class LoginForm
{
    public string? email { get; set; }
    public string? login { get; set; }
    public string? password { get; set; }
    public string? mode { get; set; }
}
class Book
{
    public int? id { get; set; }
    public string? author { get; set; }
    public string? title { get; set; }
    public int? year { get; set; }
    public string? publisher { get; set; }
    public string? isbn { get; set; }
    public string? format { get; set; }
    public int? pages { get; set; }
    public string? description { get; set; }
}