using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace CarManagerV3
{
    /// <summary>
    /// Handles safe reading and writing of car data to files.
    /// </summary>
    internal class SafeManager
    {
        /// <summary>
        /// The path of the txt file that contains recently opened file paths.
        /// </summary>
        private static readonly string recentPathsFile = "recent_paths.txt";

        /// <summary>
        /// Initializes a file at a specified path if it does not already exist.
        /// </summary>
        /// <param name="path">The path.</param>
        public static void InitializeFile(string path)
        {
            if (!File.Exists(@path))
            {
                using (StreamWriter writer = new StreamWriter(@path))
                {
                    // Create the file, empty
                    writer.WriteLine();
                }
            }
        }

        /// <summary>
        /// Reads cars from a specified file path.
        /// </summary>
        /// <param name="path">The path.</param>
        /// <returns>
        /// A <see cref="List{Car}"/> containing the cars read from the file.
        /// </returns>
        public static List<Car> ReadCars(string path)
        {
            List<Car> cars = new List<Car>();
            using (StreamReader reader = new StreamReader(@path))
            {
                string line;
                while ((line = reader.ReadLine()) != null)
                {
                    // Process the line
                    if (line == "") continue;
                    cars.Add(Car.FromCsvString(line));
                }
            }
            return cars;
        }

        /// <summary>
        /// Saves the cars to a specified file path.
        /// </summary>
        /// <param name="path">The path.</param>
        /// <param name="cars">A <see cref="List{Car}"/> containing all cars to save.</param>
        public static void SaveCars(string path, List<Car> cars)
        {
            using (StreamWriter writer = new StreamWriter(@path))
            {
                foreach (Car car in cars)
                {
                    writer.WriteLine(car.ToCsvString());
                }
            }
        }

        /// <summary>
        /// Adds a file path to the recent paths list.
        /// If a path is already in the list, it is moved to the top.
        /// Otherwise, it is added to the top.
        /// Keeps only the 5 most recent paths.
        /// </summary>
        /// <param name="path">The path.</param>
        public static void AddRecentPath(string path)
        {
            List<string> paths = new List<string>();
            if (File.Exists(recentPathsFile))
            {
                using (StreamReader reader = new StreamReader(recentPathsFile))
                {
                    string line;
                    while ((line = reader.ReadLine()) != null)
                    {
                        paths.Add(line);
                    }
                }
            }
            paths.Remove(path);
            paths.Insert(0, path);
            if (paths.Count > 5)
            {
                paths = paths.Take(5).ToList();
            }
            using (StreamWriter writer = new StreamWriter(recentPathsFile))
            {
                foreach (string p in paths)
                {
                    writer.WriteLine(p);
                }
            }
        }

        /// <summary>
        /// Gets the recently opened file paths.
        /// </summary>
        /// <returns>
        /// A <see cref="List{String}"/> containing the recent file paths.
        /// </returns>
        public static List<string> GetRecentPaths()
        {
            List<string> paths = new List<string>();
            if (File.Exists(recentPathsFile))
            {
                using (StreamReader reader = new StreamReader(recentPathsFile))
                {
                    string line;
                    while ((line = reader.ReadLine()) != null)
                    {
                        paths.Add(line);
                    }
                }
            }
            return paths;
        }
    }
}