using System;
using System.IO;
using System.Linq;
using System.Xml.Linq;
using JetBrains.Rider.Unity.Editor;
using UnityEditor;
using UnityEngine;

namespace Editor
{
  public class CsprojAssetPostprocessor : AssetPostprocessor
  {
    internal static string[] GetCsprojLinesInSln()
    {
      var projectDirectory = Directory.GetParent(Application.dataPath).FullName;

      var projectName = Path.GetFileName(projectDirectory);
      var slnFile = Path.GetFullPath(string.Format("{0}.sln", projectName));
      if (!File.Exists(slnFile))
        return new string[0];

      var slnAllText = File.ReadAllText(slnFile);
      var lines = slnAllText.Split(new[] {Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries)
        .Where(a => a.StartsWith("Project(")).ToArray();
      return lines;
    }

    public static void OnGeneratedCSProjectFiles()
    {
      if (!PluginEntryPoint.Enabled)
        return;

      try
      {
        // get only csproj files, which are mentioned in sln
        var lines = GetCsprojLinesInSln();
        var currentDirectory = Directory.GetCurrentDirectory();
        var projectFiles = Directory.GetFiles(currentDirectory, "*.csproj")
          .Where(csprojFile => lines.Any(line => line.Contains("\"" + Path.GetFileName(csprojFile) + "\""))).ToArray();

        foreach (var file in projectFiles)
        {
          UpgradeProjectFile(file);
        }
      }
      catch (Exception e)
      {
        // unhandled exception kills editor
        Debug.LogError(e);
      }
    }

    private static void UpgradeProjectFile(string projectFile)
    {
      XDocument doc;
      try
      {
        doc = XDocument.Load(projectFile);
      }
      catch (Exception)
      {
        return;
      }

      var projectContentElement = doc.Root;
      XNamespace xmlns = projectContentElement.Name.NamespaceName; // do not use var

      SetBooDllReference(projectContentElement, xmlns);

      doc.Save(projectFile);
    }

    private static void SetBooDllReference(XElement projectContentElement, XNamespace xmlns)
    {
      var unityAppBaseFolder = Path.GetDirectoryName(EditorApplication.applicationPath);
      if (string.IsNullOrEmpty(unityAppBaseFolder))
      {
        return;
      }

      var name = "Boo.Lang.dll";
      var booDllPath = Path.Combine(unityAppBaseFolder, Path.Combine("Data/MonoBleedingEdge/lib/mono/2.0-api", name));

      if (!File.Exists(booDllPath))
        return;

      var itemGroup = new XElement(xmlns + "ItemGroup");
      var reference = new XElement(xmlns + "Reference");
      reference.Add(new XAttribute("Include", Path.GetFileNameWithoutExtension(booDllPath)));
      reference.Add(new XElement(xmlns + "HintPath", booDllPath));
      itemGroup.Add(reference);
      projectContentElement.Add(itemGroup);
    }

    private static int ourScriptingRuntimeCached = -1;
    private static string SlnFile;
  }
}