using Forum.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

public class DataMapper
{
    private const string DATA_PATH = "../data/";
    private const string CONFIG_PATH = "config.ini";
    private const string DEFAULT_CONFIG = "users=users.csv\r\ncategories=categories.csv\r\nposts=posts.csv\r\nreplies=replies.csv";

    private static readonly Dictionary<string, string> config;

    static DataMapper()
    {
        Directory.CreateDirectory(DATA_PATH);
        config = LoadConfig(DATA_PATH + CONFIG_PATH);
    }



    private static void EnsureConfigFile(string configPath)
    {
        if (!File.Exists(configPath))
        {
            File.WriteAllText(configPath, DEFAULT_CONFIG);
        }
    }

    private static void EnsureFile(string path)
    {
        if (!File.Exists(path))
        {
            File.Create(path).Close();
        }
    }

    private static Dictionary<string,string> LoadConfig(string configPath)
    {
        EnsureConfigFile(configPath);

        var contents = ReadLines(configPath);
        var config = contents.Select(l => l.Split('=')).ToDictionary(t => t[0], t => DATA_PATH + t[1]);
        return config;
    }

    private static string[] ReadLines(string path)
    {
        EnsureFile(path);

        var lines = File.ReadAllLines(path);
        return lines;
    }

    private static void WriteLines(string path, string[] lines)
    {
        File.WriteAllLines(path, lines);
    }

    public static List<Category> LoadCategories()
    {
        List<Category> categories = new List<Category>();
        var dataLines = ReadLines(config["categories"]);

        foreach (var line in dataLines)
        {
            var args = line.Split(",");
            var id = int.Parse(args[0]);
            var name = args[1];
            var postIds = args[2].Split(',', StringSplitOptions.RemoveEmptyEntries).Select(int.Parse).ToArray();
            Category category = new Category(id, name, postIds);
            categories.Add(category);
        }
        return categories;
    }

    public static void SaveCategories(List<Category> categories)
    {
        List<string> lines = new List<string>();

        foreach (var category in categories)
        {
            const string categoryFormat = "{0},{1},{2}";
            string line = string.Format(categoryFormat, category.Id, category.Name, string.Join(",", category.Posts));
            lines.Add(line);
        }
        WriteLines(config["categories"], lines.ToArray());
    }

    public static List<User> LoadUsers()
    {
        List<User> users = new List<User>();
        var dataLines = ReadLines(config["users"]);

        foreach (var line in dataLines)
        {
            var args = line.Split(",");
            var id = int.Parse(args[0]);
            var userName = args[1];
            var password = args[2];
            var postIds = args[3].Split(',', StringSplitOptions.RemoveEmptyEntries).Select(int.Parse).ToArray();
            User user = new User(id, userName,password, postIds);
            users.Add(user);
        }
        return users;
    }
    public static void SaveUsers(List<User> users)
    {
        List<string> lines = new List<string>();

        foreach (var user in users)
        {
            const string categoryFormat = "{0},{1},{2},{3}";
            string line = string.Format(categoryFormat, user.Id, user.Username,user.Password, string.Join(",", user.PostIds));
            lines.Add(line);
        }
        WriteLines(config["users"], lines.ToArray());
    }

    public static List<Post> LoadPosts()
    {
        List<Post> posts = new List<Post>();
        var dataLines = ReadLines(config["posts"]);

        foreach (var line in dataLines)
        {
            var args = line.Split(",");
            var id = int.Parse(args[0]);
            var title = args[1];
            var content = args[2];
            var categoryId = int.Parse(args[3]);
            var authorId = int.Parse(args[4]);
            var replies = args[5].Split(',', StringSplitOptions.RemoveEmptyEntries).Select(int.Parse).ToArray();
            Post post = new Post(id, title, content, categoryId,authorId,replies);
            posts.Add(post);
        }
        return posts;
    }

    public static void SavePosts(List<Post> posts)
    {
        List<string> lines = new List<string>();

        foreach (var post in posts)
        {
            const string categoryFormat = "{0},{1},{2},{3},{4},{5}";
            string line = string.Format(categoryFormat, post.Id, post.Title, post.Content,post.CategoryId,post.AuthorId, string.Join(",", post.Replies));
            lines.Add(line);
        }
        WriteLines(config["posts"], lines.ToArray());
    }

    public static List<Reply> LoadReplies()
    {
        List<Reply> replies = new List<Reply>();
        var dataLines = ReadLines(config["replies"]);

        foreach (var line in dataLines)
        {
            var args = line.Split(",");
            var id = int.Parse(args[0]);
            var content = args[1];

            var authorId = int.Parse(args[3]);
            var postId = int.Parse(args[4]);
            Reply reply = new Reply(id,content, authorId, postId);
            replies.Add(reply);
        }
        return replies;
    }

    public static void SaveReplies(List<Reply> replies)
    {
        List<string> lines = new List<string>();

        foreach (var reply in replies)
        {
            const string categoryFormat = "{0},{1},{2},{3}";
            string line = string.Format(categoryFormat, reply.Id, reply.Content, reply.AuthorId,reply.PostId);
            lines.Add(line);
        }
        WriteLines(config["replies"], lines.ToArray());
    }
}