using System.IO;
using System.Text.Json;

namespace WpfSample.Models {
    internal class DemoItem {
        public int Id { get; set; } = 1;
        public int Order { get; set; } = 1;
        public string Name { get; set; } = string.Empty;
        public string Description { get; set; } = string.Empty;

        public DemoItem Parent { get; set; } = DemoRoot.Root;
        public List<DemoItem> Items { get; } = new List<DemoItem>();
        public List<DemoMessage> Messages { get; } = new List<DemoMessage>();

        private IncrementNumberGenerator IncrementIdentify = new IncrementNumberGenerator();
        public int NextId => IncrementIdentify.Value;
        public int NextOrder => Items.Count;


        static public DemoItem? Load(DemoItem parent, string path, string? name = null) {
            if (path == null || Directory.Exists(path) == false) {
                return null;
            }

            DirectoryInfo directoryInfo = new DirectoryInfo(path);
            if (name == null) {
                name = directoryInfo.Name;
            }
            if (parent == null) {
                parent = DemoRoot.Root;
            }

            DemoItem data = new DemoItem() {
                Name = name,
                Id = parent.NextId,
                Order = parent.NextOrder,
                Parent = parent,
            };

            // 加载 文件
            foreach (FileInfo messageFileInfo in directoryInfo.GetFiles("*.json")) {
                using StreamReader reader = new StreamReader(messageFileInfo.FullName);
                if (JsonSerializer.Deserialize<DemoMessage>(reader.ReadToEnd()) is DemoMessage message) {
                    data.Messages.Add(message);
                }
            }

            // 加载 子元素
            foreach (DirectoryInfo subItemDirectoryInfo in directoryInfo.GetDirectories()) {
                if (Load(data, subItemDirectoryInfo.FullName) is DemoItem subItem) {
                    data.Items.Add(subItem);
                }
            }

            return data;
        }

        static public bool Save(DemoItem data, string path, bool overwrite = false) {
            if (path == null) {
                return false;
            }

            if (overwrite == false && (Directory.Exists(path) || File.Exists(path))) {
                return false;
            }

            if (overwrite == true && Directory.Exists(path)) {
                try {
                    Directory.Delete(path, true);
                }
                catch {
                    return false;
                }
            }

            if (overwrite == true && File.Exists(path)) {
                try {
                    File.Delete(path);
                }
                catch {
                    return false;
                }
            }

            try {
                Directory.CreateDirectory(path);
            }
            catch {
                return false;
            }

            // 保存 文件
            foreach (DemoMessage message in data.Messages) {
                string messageFilePath = Path.Combine(path, $"{message.Name}.json");
                try {
                    using FileStream file = File.Create(messageFilePath);
                    JsonSerializer.Serialize(file, message);
                }
                catch {
                    continue;
                }
            }

            // 保存 子元素
            foreach (DemoItem subItem in data.Items) {
                string subItemPath = Path.Combine(path, subItem.Name);
                if (Save(subItem, subItemPath, overwrite) == false) {

                }
            }

            return true;
        }
    }
}