using System;

using System.Collections.Generic;

using System.ComponentModel.Composition;

using System.Diagnostics;

using System.Linq;

namespace ScriptCs

{

public class FilePreProcessor : IFilePreProcessor

{

private const string LoadString = "#load ";

private const string UsingString = "using ";

private readonly IFileSystem _fileSystem;

[ImportingConstructor]

public FilePreProcessor(IFileSystem fileSystem)

{

_fileSystem = fileSystem;

}

public string ProcessFile(string path)

{

var entryFile = _fileSystem.ReadFileLines(path);

var parsed = ParseFile(entryFile);

var result = string.Join(_fileSystem.NewLine, parsed.Item1);

result += _fileSystem.NewLine + parsed.Item2;

return result;

}

private Tuple<List<string>, string> ParseFile(IEnumerable<string> file)

{

var usings = new List<string>();

var fileList = file.ToList();

for (var i = 0; i < fileList.Count; i++)

{

var line = fileList[i];

if (IsUsingLine(line))

{

usings.Add(line);

}

if (IsLoadLine(line))

{

var filepath = line.Trim(' ').Replace(LoadString, "").Replace("\"", "").Replace(";","");

var filecontent = _fileSystem.IsPathRooted(filepath)

? _fileSystem.ReadFileLines(filepath)

: _fileSystem.ReadFileLines(_fileSystem.CurrentDirectory + @"\" + filepath);

if (filecontent != null)

{

var parsed = ParseFile(filecontent);

fileList[i] = parsed.Item2;

usings.AddRange(parsed.Item1);

}

}

}

var result = string.Join(_fileSystem.NewLine, fileList.Where(line => !IsUsingLine(line)));

var tuple = new Tuple<List<string>, string>(usings.Distinct().ToList(), result);

return tuple;

}

private static bool IsUsingLine(string line)

{

return line.TrimStart(' ').StartsWith(UsingString) && !line.Contains("{") && line.Contains(";");

}

private static bool IsLoadLine(string line)

{

return line.TrimStart(' ').StartsWith(LoadString);

}

}

}