using System.Collections;
using System.Collections.Specialized;
using System.Net.Http.Formatting;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Text.RegularExpressions;

namespace YLErp
{
    [TestClass]
    public class UnitTestBase
    {
        protected OptUserInfo GetOptUser([CallerMemberName] string m_name = "")
        {
            if (string.IsNullOrEmpty(m_name) || m_name == ".ctor")
            {
                m_name = GetType().Name;
            }

            return new OptUserInfo(0, m_name, OptUserFrom.UnitTest, userGroup: null);
        }

        /// <summary>
        /// 读取资源文件所有文本
        /// </summary>
        protected static string ReadResourceFile(string relativeFilePath)
        {
            var path = Path.Combine(AppContext.BaseDirectory, "Resources\\" + relativeFilePath);
            return File.ReadAllText(path);
        }

        /// <summary>
        /// 读取资源文件所有行
        /// </summary>
        protected static string[] ReadResourceFileLines(string relativeFilePath)
        {
            var path = Path.Combine(AppContext.BaseDirectory, "Resources\\" + relativeFilePath);
            return File.ReadAllLines(path);
        }

        protected static T DeserializeFormData<T>(string resourceFileRelativePath) where T : new()
        {
            var list = new List<KeyValuePair<string, string>>();
            var lines = ReadResourceFileLines(resourceFileRelativePath);

            foreach (var line in lines)
            {
                if (string.IsNullOrWhiteSpace(line))
                {
                    continue;
                }
                var index = line.IndexOf(':');
                if (index < 0)
                {
                    continue;
                }

                list.Add(new KeyValuePair<string, string>(line.Substring(0, index).Trim(), line.Substring(index + 1).Trim()));
            }

            var fc = new FormDataCollection(list);

            return MapForm<T>(fc.ReadAsNameValueCollection(), "");
        }

        protected class OtcOptionTradeFullFormData
        {
            public IEnumerable<OtcOptionTradeFull> trades { get; set; }
        }

        private static readonly Regex _regex = new(@"\[(?<value>.*?)\]", RegexOptions.Compiled | RegexOptions.Singleline);

        private static T MapForm<T>(NameValueCollection nvc, string rootObjectName) where T : new()
        {
            var result = new T();

            foreach (var kvp in nvc.AllKeys)
            {
                if (!kvp.StartsWith(rootObjectName))
                {
                    throw new Exception("All keys should start with " + rootObjectName);
                }

                var match = _regex.Match(kvp.Remove(0, rootObjectName.Length));

                if (match.Success)
                {
                    // build path in a form of [Documents, 0, DocumentID]-like array
                    var path = new List<string>();
                    while (match.Success)
                    {
                        path.Add(match.Groups["value"].Value);
                        match = match.NextMatch();
                    }
                    // this is object we currently working on                                      
                    object currentObject = result;
                    for (var i = 0; i < path.Count; i++)
                    {
                        var last = i == path.Count - 1;
                        var propName = path[i];
                        if (int.TryParse(propName, out var index))
                        {
                            // index access, like [0]
                            var list = currentObject as IList;
                            if (list == null)
                            {
                                throw new Exception("Invalid index access expression"); // more info here
                            }
                            // get the type of item in that list (i.e. Document)
                            var args = list.GetType().GetGenericArguments();
                            var listItemType = args[0];
                            if (last)
                            {
                                // may need more sophisticated conversion from string to target type
                                list[index] = Convert.ChangeType(nvc[kvp], Nullable.GetUnderlyingType(listItemType) ?? listItemType);
                            }
                            else
                            {
                                // if not initialized - initalize
                                var next = index < list.Count ? list[index] : null;
                                if (next == null)
                                {
                                    // handle IList case in a special way here, since you cannot create instance of interface                                    
                                    next = Activator.CreateInstance(listItemType);
                                    // fill with nulls if not enough items yet
                                    while (index >= list.Count)
                                    {
                                        list.Add(null);
                                    }
                                    list[index] = next;
                                }
                                currentObject = next;
                            }
                        }
                        else
                        {
                            var prop = currentObject.GetType().GetProperty(propName, BindingFlags.Instance | BindingFlags.Public);
                            if (last)
                            {
                                // may need more sophisticated conversion from string to target type
                                prop.SetValue(currentObject, Convert.ChangeType(nvc[kvp], Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType));
                            }
                            else
                            {
                                // if not initialized - initalize
                                var next = prop.GetValue(currentObject);
                                if (next == null)
                                {
                                    // TODO: handle IList case in a special way here, since you cannot create instance of interface                                    
                                    next = Activator.CreateInstance(prop.PropertyType);
                                    prop.SetValue(currentObject, next);
                                }
                                currentObject = next;
                            }
                        }
                    }
                }
            }

            return result;
        }
    }
}