using AutoBet.ApiGenerator.Extensions;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Xml.Linq;

namespace AutoBet.ApiGenerator
{
    internal class ApiClientGenetaor
    {
        private string _inputXmlFile { get; }
        private string _outputFilesDirectory { get; }

        public ApiClientGenetaor(string inputXmlFile, string outputFilesDirectory)
        {
            _inputXmlFile = inputXmlFile;
            _outputFilesDirectory = outputFilesDirectory;
        }
    
        public void Process(string apiClientName, string namespaceValue)
        {
            var doc = XDocument.Load(_inputXmlFile);
            var sb = new StringBuilder();
            sb.AppendLine("using System;");
            sb.AppendLine("using System.Collections.Generic;");
            sb.AppendLine("using System.Net.Http;");
            sb.AppendLine("using System.Net.Http.Headers;");
            sb.AppendLine("using System.Text;");
            sb.AppendLine("using System.Threading.Tasks;");
            sb.AppendFormat("using {0}.{1}{2};", namespaceValue, apiClientName, "Models");
            sb.AppendLine();
            sb.AppendFormat("using {0}.{1}{2};", namespaceValue, apiClientName, "Models.Enums");
            sb.AppendLine();
            sb.AppendLine();
            sb.Append("namespace ");
            sb.Append(namespaceValue);
            sb.AppendLine();
            sb.AppendLine("{");
            sb.AppendWithIndent(4, "public class ");
            sb.Append(apiClientName);
            sb.Append("ApiClient");
            sb.AppendLine();
            sb.AppendWithIndent(4, "{\r\n");

            var nodes = doc.Root.Elements("operation");
            foreach(var node in nodes)
            {
                AppendDescription(sb, node);

                sb.AppendWithIndent(8, "public ");
                var paramaeters = node.Element("parameters");
                var response = paramaeters.Element("simpleResponse");
                sb.Append("async Task<");
                var returnType = CSharpClassBuilder.GetDataType(response.Attribute("type").Value);
                sb.Append(returnType);
                sb.Append("> ");
                var camelcaseMethodName = node.Attribute("name").Value;
                var methodName = GetMethodName(camelcaseMethodName);
                sb.Append(methodName);
                var parametersAppended = AppendParameters(sb, paramaeters.Element("request"));
                sb.AppendWithIndent(8, "{\r\n");
                AppendMethodBody(sb, returnType, camelcaseMethodName + "/", parametersAppended);
                sb.AppendWithIndent(8, "}\r\n\r\n");
            }
            sb.Remove(sb.Length - 2, 2);
            sb.AppendWithIndent(4, "}\r\n");
            sb.Append("}");
            File.WriteAllText(Path.Combine(_outputFilesDirectory, $"{apiClientName}ApiClient.cs"), sb.ToString());
        }

        private void AppendMethodBody(StringBuilder sb, string returnType, string endpoint, string[] paramaters)
        {
            var request = "";
            if(paramaters.Length > 0)
            {
                sb.AppendWithIndent(12, "var request = new\r\n");
                sb.AppendWithIndent(12, "{\r\n");
                foreach (var parameter in paramaters)
                {
                    sb.AppendWithIndent(16, parameter);
                    sb.Append(",\r\n");
                }
                sb.Remove(sb.Length - 3, 3);
                sb.Append("\r\n");
                sb.AppendWithIndent(12, "};\r\n");
                request = ", request";
            }
            sb.AppendWithIndent(12, "var result = await ExecuteRequest<");
            sb.Append(returnType);
            sb.Append(">(_endpoint + \"");
            sb.Append(endpoint);
            sb.Append("\"");
            sb.Append(request);
            sb.Append(");\r\n");
            sb.AppendWithIndent(12, "return result;\r\n");
        }

        private string[] AppendParameters(StringBuilder sb, XElement request)
        {
            var paramatersAppended = new List<string>();
            sb.Append("(");
            var parameters = request.Elements("parameter");
            foreach (var parameter in parameters)
            {
                var name = parameter.Attribute("name").Value;
                var type = CSharpClassBuilder.GetDataType(parameter.Attribute("type").Value);
                sb.Append(type);

                var mandatory = parameter.Attribute("mandatory");
                var isRequired = mandatory != null && mandatory.Value != null && mandatory.Value == "true";
                if (!isRequired && (type == "int" || type == "long" || type == "bool"))
                {
                    sb.Append("?");
                }

                sb.Append(" ");

                sb.Append(name);

                if (!isRequired)
                {
                    sb.Append(" = null");
                }

                paramatersAppended.Add(name);
                sb.Append(", ");
            }
            if(parameters.Any())
            {
                sb.Remove(sb.Length - 2, 2);
            }

            sb.Append(")\r\n");
            return paramatersAppended.ToArray();
        }

        private void AppendDescription(StringBuilder sb, XElement node)
        {
            var description = node.Element("description").Value;
            if (!String.IsNullOrWhiteSpace(description))
            {
                CSharpClassBuilder.Summary(sb, description);
            }
        }

        private static string GetMethodName(string methodName)
        {
            return Char.ToUpper(methodName[0]).ToString() + methodName.Substring(1, methodName.Length - 1);
        }
    }
}