using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MySql.Data;
using MySql.Data.MySqlClient;
using System.Data;
using System.Text.RegularExpressions;
using System.Threading;

namespace azala.info_Scraper {
    public class Program {
        private readonly MySqlConnection connection;

        public Program() {
            connection = new MySqlConnection($"Server={"localhost"};Database={"cardsagainsthumanity"};Uid={"dbuser"};Pwd={"DSKJjojofsa9%=(!=i2100"};");
            connection.StateChange += Connection_StateChange;
            errorstream = new StreamWriter("errors.txt", true);
        }

        private void Connection_StateChange(object sender, StateChangeEventArgs e) {
            Console.WriteLine("MySQL connection is now {0}!", e.CurrentState);
        }

        public async Task OpenConnection() {
            Console.WriteLine("Connecting to MySQL Server...");
            await connection.OpenAsync();
        }
        ~Program() {
            connection.Close();
        }

        public static async Task Main() {
            var program = new Program();
            var openTask = program.OpenConnection();
            Console.WriteLine("Give a directory:");
            var path = XConsole.ReadDirectory();
            try {
                await openTask;
                program.Run(path);
#pragma warning disable CA1031 // Do not catch general exception types
            } catch (Exception e) {
                Console.WriteLine("Uncaught ERROR: {0}", e);
            }
#pragma warning restore CA1031 // Do not catch general exception types
            Console.WriteLine("Program end...");
            Console.ReadLine();
        }

        private static readonly string[] searchPatterns = { "*.que", "*.ans" };
        private readonly StreamWriter errorstream;
        private string processeddirectory;

        private void Run(string path) {
            processeddirectory = Path.Combine(path, "processed");
            if (connection.State != ConnectionState.Open)
                throw new Exception("Connection not opened!");
            Console.WriteLine("Creating tables...");
            try {
                CreateTables();
            } catch (MySqlException e) {
                Console.WriteLine("ERROR: Creating tables: {0}", e.Message);
                throw;
            }
            Console.WriteLine("Tables created!");
            while (true) {
                foreach (var file in XDirectory.GetFiles(path, searchPatterns, SearchOption.TopDirectoryOnly)) {
                    try {
                        ProcessFile(file);
                        Console.WriteLine();
                    } catch (MySqlException e) {
                        Console.WriteLine("MySQL ERROR: Processing file failed: {0}", e.Message);
                    } catch (ArgumentException e) {
                        Console.WriteLine("Argument exception: {0}", e.Message);
                    }
                }
                Console.WriteLine("Waiting 1s..");
                Thread.Sleep(1000);
            }
        }

        private void CreateTables() {
            CreateCardsTable();
        }

        private void CreateCardsTable() {
            var command = connection.CreateCommand();
            command.CommandText = "CREATE TABLE IF NOT EXISTS cards(id INTEGER NOT NULL PRIMARY KEY,deck_id INTEGER NOT NULL,card_text VARCHAR(2048) NOT NULL,num_blanks INTEGER NOT NULL,o INTEGER NOT NULL);";
            if (command.ExecuteNonQuery() == 1)
                Console.WriteLine("Table created!");
            else
                Console.WriteLine("Table not changed!");
        }

        private void ProcessFile(string file) {
            var filename = Path.GetFileName(file);
            Console.WriteLine("Processing file '{0}'", filename);
            var file_id = Path.GetFileNameWithoutExtension(filename);

            if (!Directory.Exists(processeddirectory))
                Directory.CreateDirectory(processeddirectory);

            Console.WriteLine("Id is {0}", file_id);

            if (int.TryParse(file_id, out var deck_id)) {
                var contents = File.ReadAllText(file);
                var cardlist = JsonConvert.DeserializeObject<List<Card>>(contents);
                var insertedIds = new HashSet<long>();

                foreach (var card in cardlist) {
                    if (insertedIds.Contains(card.ID)) {
                        Console.WriteLine("Card with id '{0}' already inserted! Skipping...", card.ID);
                        continue;
                    }
                    card.DeckID = deck_id;
                    AddCard(card);
                    insertedIds.Add(card.ID);
                }
                Console.WriteLine("Sucessfully inserted {0}/{1} new cards!", insertedIds.Count, cardlist.Count);
                File.Move(file, Path.Combine(processeddirectory, filename));
            } else {
                throw new ArgumentException($"File '{filename}' with non-integer ID!");
            }
        }

        private void AddCard(Card card) {
            using var command = connection.CreateCommand();
            command.CommandText = "INSERT IGNORE INTO cards(id,deck_id,card_text,num_blanks,o) VALUES (@id,@deckid,@text,@blanks,@order);";
            command.Parameters.AddWithValue("@deckid", card.DeckID);
            command.Parameters.AddWithValue("@id", card.ID);
            command.Parameters.AddWithValue("@text", card.Text);
            command.Parameters.AddWithValue("@blanks", card.Blanks);
            command.Parameters.AddWithValue("@order", card.Order);
            var result = command.ExecuteNonQuery();
            if (result != 1) {
                Console.WriteLine("ERROR: {0} lines affected!", result);
                errorstream.WriteLine("[{0}] Insertion: {1} rows affected!\n{2}", DateTime.Now.ToString(), result, JsonConvert.SerializeObject(card));
            }
        }
    }

    internal class XConsole {
        internal static string ReadDirectory() {
            while (true) {
                var input = Console.ReadLine();
                if (Directory.Exists(input))
                    return input;
                Console.WriteLine("Directory doesn't exist!");
            }
        }
    }
    public static class XDirectory {   // Regex version
        public static IEnumerable<string> GetFiles(string path,
                            string searchPatternExpression = "",
                            SearchOption searchOption = SearchOption.TopDirectoryOnly) {
            var reSearchPattern = new Regex(searchPatternExpression, RegexOptions.IgnoreCase);
            return Directory.EnumerateFiles(path, "*", searchOption)
                            .Where(file =>
                                     reSearchPattern.IsMatch(Path.GetExtension(file)));
        }

        // Takes same patterns, and executes in parallel
        public static IEnumerable<string> GetFiles(string path,
                            string[] searchPatterns,
                            SearchOption searchOption = SearchOption.TopDirectoryOnly) {
            return searchPatterns.AsParallel()
                   .SelectMany(searchPattern =>
                          Directory.EnumerateFiles(path, searchPattern, searchOption));
        }
    }
}