using System;
using System.IO;
using System.Security;
using Microsoft.Build.Framework;

namespace GodotTools.BuildLogger
{
    public class GodotBuildLogger : ILogger
    {
        public string Parameters { get; set; }
        public LoggerVerbosity Verbosity { get; set; }

        private StreamWriter _logStreamWriter;
        private StreamWriter _issuesStreamWriter;
        private int _indent;

        public void Initialize(IEventSource eventSource)
        {
            if (null == Parameters)
                throw new LoggerException("Log directory parameter not specified.");

            string[] parameters = Parameters.Split(new[] { ';' });

            string logDir = parameters[0];

            if (string.IsNullOrEmpty(logDir))
                throw new LoggerException("Log directory parameter is empty.");

            if (parameters.Length > 1)
                throw new LoggerException("Too many parameters passed.");

            string logFile = Path.Combine(logDir, "msbuild_log.txt");
            string issuesFile = Path.Combine(logDir, "msbuild_issues.csv");

            try
            {
                if (!Directory.Exists(logDir))
                    Directory.CreateDirectory(logDir);

                _logStreamWriter = new StreamWriter(logFile);
                _issuesStreamWriter = new StreamWriter(issuesFile);
            }
            catch (Exception ex)
            {
                if (ex is UnauthorizedAccessException
                    || ex is ArgumentNullException
                    || ex is PathTooLongException
                    || ex is DirectoryNotFoundException
                    || ex is NotSupportedException
                    || ex is ArgumentException
                    || ex is SecurityException
                    || ex is IOException)
                {
                    throw new LoggerException("Failed to create log file: " + ex.Message);
                }

                // Unexpected failure
                throw;
            }

            eventSource.ProjectStarted += eventSource_ProjectStarted;
            eventSource.ProjectFinished += eventSource_ProjectFinished;
            eventSource.MessageRaised += eventSource_MessageRaised;
            eventSource.WarningRaised += eventSource_WarningRaised;
            eventSource.ErrorRaised += eventSource_ErrorRaised;
        }

        private void eventSource_ProjectStarted(object sender, ProjectStartedEventArgs e)
        {
            WriteLine(e.Message);
            _indent++;
        }

        private void eventSource_ProjectFinished(object sender, ProjectFinishedEventArgs e)
        {
            _indent--;
            WriteLine(e.Message);
        }

        private void eventSource_ErrorRaised(object sender, BuildErrorEventArgs e)
        {
            string line = $"{e.File}({e.LineNumber},{e.ColumnNumber}): error {e.Code}: {e.Message}";

            if (!string.IsNullOrEmpty(e.ProjectFile))
                line += $" [{e.ProjectFile}]";

            WriteLine(line);

            string errorLine = $@"error,{e.File.CsvEscape()},{e.LineNumber},{e.ColumnNumber}," +
                               $"{e.Code?.CsvEscape() ?? string.Empty},{e.Message.CsvEscape()}," +
                               $"{e.ProjectFile?.CsvEscape() ?? string.Empty}";
            _issuesStreamWriter.WriteLine(errorLine);
        }

        private void eventSource_WarningRaised(object sender, BuildWarningEventArgs e)
        {
            string line = $"{e.File}({e.LineNumber},{e.ColumnNumber}): warning {e.Code}: {e.Message}";

            if (!string.IsNullOrEmpty(e.ProjectFile))
                line += $" [{e.ProjectFile}]";

            WriteLine(line);

            string warningLine = $@"warning,{e.File.CsvEscape()},{e.LineNumber},{e.ColumnNumber}," +
                                 $"{e.Code?.CsvEscape() ?? string.Empty},{e.Message.CsvEscape()}," +
                                 $"{e.ProjectFile?.CsvEscape() ?? string.Empty}";
            _issuesStreamWriter.WriteLine(warningLine);
        }

        private void eventSource_MessageRaised(object sender, BuildMessageEventArgs e)
        {
            // BuildMessageEventArgs adds Importance to BuildEventArgs
            // Let's take account of the verbosity setting we've been passed in deciding whether to log the message
            if (e.Importance == MessageImportance.High && IsVerbosityAtLeast(LoggerVerbosity.Minimal)
                || e.Importance == MessageImportance.Normal && IsVerbosityAtLeast(LoggerVerbosity.Normal)
                || e.Importance == MessageImportance.Low && IsVerbosityAtLeast(LoggerVerbosity.Detailed))
            {
                WriteLineWithSenderAndMessage(string.Empty, e);
            }
        }

        /// <summary>
        /// Write a line to the log, adding the SenderName and Message
        /// (these parameters are on all MSBuild event argument objects)
        /// </summary>
        private void WriteLineWithSenderAndMessage(string line, BuildEventArgs e)
        {
            if (0 == string.Compare(e.SenderName, "MSBuild", StringComparison.OrdinalIgnoreCase))
            {
                // Well, if the sender name is MSBuild, let's leave it out for prettiness
                WriteLine(line + e.Message);
            }
            else
            {
                WriteLine(e.SenderName + ": " + line + e.Message);
            }
        }

        private void WriteLine(string line)
        {
            for (int i = _indent; i > 0; i--)
            {
                _logStreamWriter.Write("\t");
            }

            _logStreamWriter.WriteLine(line);
        }

        public void Shutdown()
        {
            _logStreamWriter.Close();
            _issuesStreamWriter.Close();
        }

        private bool IsVerbosityAtLeast(LoggerVerbosity checkVerbosity)
        {
            return Verbosity >= checkVerbosity;
        }
    }

    internal static class StringExtensions
    {
        public static string CsvEscape(this string value, char delimiter = ',')
        {
            bool hasSpecialChar = value.IndexOfAny(new[] { '\"', '\n', '\r', delimiter }) != -1;

            if (hasSpecialChar)
                return "\"" + value.Replace("\"", "\"\"") + "\"";

            return value;
        }
    }
}