using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using Tango.Core.Helpers;
using Tango.Core.IO;

namespace Tango.Protobuf.Compilers
{
    /// <summary>
    /// Represents a protobuf C Compiler.
    /// </summary>
    /// <seealso cref="Tango.Protobuf.ProtoCompiler" />
    public class CCompiler : ProtoCompiler
    {
        /// <summary>
        /// Gets or sets a value indicating whether this <see cref="CCompiler"/> will minimize the code by omitting hard coded strings.
        /// </summary>
        public bool Minimize { get; set; }

        /// <summary>
        /// Gets the compiler language.
        /// </summary>
        public override CompilerLanguage Language => CompilerLanguage.C;

        /// <summary>
        /// Gets the protobuf compiler CLI arguments (without input/output files!).
        /// </summary>
        /// <returns></returns>
        protected override string GetProtoArguments()
        {
            return "--c_out";
        }

        /// <summary>
        /// Gets the protobuf compiler CLI file name (override when using a compiler other than the default 'protoc.exe').
        /// </summary>
        /// <returns></returns>
        /// <remarks>
        /// The compiler program must be located in the compilers folder.
        /// </remarks>
        protected override string GetProtoCompilerName()
        {
            return "protoc-c";
        }

        /// <summary>
        /// Compiles all files in the specified folder recursively.
        /// </summary>
        /// <param name="sourceFolder">The source folder</param>
        /// <returns>
        /// Compilation result.
        /// </returns>
        public override CompilerFolderResult CompileFolder(string sourceFolder, params String[] includeFolders)
        {
            var temp = TemporaryManager.Default.CreateFolder();
            PathHelper.CopyDirectory(sourceFolder, temp.Path, true);

            List<String> directories = Directory.GetDirectories(sourceFolder, "*", SearchOption.AllDirectories).Where(x => includeFolders == null || includeFolders.Length == 0 || includeFolders.Contains(Path.GetFileName(x))).ToList();

            foreach (var dir in Directory.GetDirectories(temp.Path))
            {
                if (!directories.Select(x => Path.GetFileName(x)).Contains(Path.GetFileName(dir)))
                {
                    Directory.Delete(dir, true);
                }
            }

            foreach (var file in Directory.GetFiles(temp.Path, "*.proto", SearchOption.AllDirectories))
            {
                String str = File.ReadAllText(file);

                var lines = str.ToLines();

                lines.RemoveAll(x => x.Contains("package "));

                for (int i = 0; i < lines.Count; i++)
                {
                    if (!lines[i].Contains("import ") || lines[i].StartsWith("//"))
                    {
                        string[] wordsAndComments = lines[i].Split('/');

                        string lineWords = wordsAndComments.FirstOrDefault();

                        string[] words = lineWords.Split(' ');

                        for (int j = 0; j < words.Length; j++)
                        {
                            words[j] = words[j].Split('.').LastOrDefault();
                        }

                        lines[i] = String.Join(" ", words);
                    }
                }

                str = String.Join(Environment.NewLine, lines);
                File.WriteAllText(file, str);
            }

            var result = base.CompileFolder(temp.Path);

            if (Minimize)
            {
                MinimizeFolder(result);
            }

            return result;
        }

        private void MinimizeFolder(CompilerFolderResult folder)
        {
            foreach (var childFolder in folder.Results.OfType<CompilerFolderResult>())
            {
                MinimizeFolder(childFolder);
            }

            foreach (var childFile in folder.Results.OfType<CompilerFileResult>())
            {
                MinimizeFile(childFile);
            }
        }

        private void MinimizeFile(CompilerFileResult file)
        {
            file.Content = MinimizeCode(file.Content);
        }

        private String MinimizeCode(String code)
        {
            Regex reg = new Regex("(?<=\")(\\w{1,})(?=\")");
            return reg.Replace(code, "");
        }
    }
}