using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using System.Linq;
using System.Drawing;

namespace SpritePacker
{
	enum ProgramMode
	{
		Normal,
		DisplayHelpText,
		DisplayVersionText
	}

	enum OutputFormat
	{
		Text,
		CSV
	}

	class Program
	{
		public static string Version = Utilities.GetEmbeddedResourceContent("SpritePacker.Version.txt").Trim();

		private static ProgramMode programMode = ProgramMode.Normal;

		private static string helpTextFilename = "SpritePacker.Resources.HelpText.txt";
		private static string versionTextFilename = "SpritePacker.Resources.VersionText.txt";
		private static string commitHashFilename = "SpritePacker.latest-commit-hash.txt";

		private static SpritePacker spritePacker;

		private static OutputFormat outputFormat = OutputFormat.Text;
		private static string outputFilename = "spritesheet.png";
		private static List<string> values = new List<string>();
		private static string rawSourceLocations = null;

		public static bool Verbose = false;

		public static int Main(string[] args)
		{
			string commitHash = Utilities.GetEmbeddedResourceContent(commitHashFilename).Trim();
			Version += "-" + commitHash.Substring(0, 7);

			for(int i = 0; i < args.Length; i++)
			{
				switch(args[i])
				{
					case "--help":
						programMode = ProgramMode.DisplayHelpText;
						break;
					case "--version":
						programMode = ProgramMode.DisplayVersionText;
						break;
					case "--verbose":
						Verbose = true;
						break;
					case "--preset":
						string presetFilename = args[++i];
						if (File.Exists(presetFilename))
							rawSourceLocations = File.ReadAllText(presetFilename);
						else {
							Console.Error.WriteLine("Warning: Couldn't find the preset csv file at {0}", presetFilename);
							return 1;
						}
						break;
					case "--csv":
						outputFormat = OutputFormat.CSV;
						break;
					default:
						if(args[i].StartsWith("-")) {
							Console.Error.WriteLine("Error: Unrecognised flag '{0}'.", args[i]);
							return 1;
						}
						values.Add(args[i]);
						break;
				}
			}

			switch(programMode)
			{
				case ProgramMode.Normal:
					if (values.Count == 0) {
						Console.Error.WriteLine("Error: No filenames specified!");
						return 1;
					}

					// Set the output filename to be equal to the first filename in the list
					outputFilename = values[0];
					values.RemoveAt(0);

					RunNormal();
					break;
				case ProgramMode.DisplayHelpText:
				case ProgramMode.DisplayVersionText:
					string textFileName = programMode == ProgramMode.DisplayHelpText ? helpTextFilename : versionTextFilename;
					string helpText = Utilities.GetEmbeddedResourceContent(textFileName);
					Dictionary<string, string> templateValues = new Dictionary<string, string>() {
						{ "version", Version },
						{ "build-date", Utilities.GetProgramBuildDate().ToString("dd/MM/yyyy h:mmtt") },
						{ "commit-hash", commitHash.Substring(commitHash.Length - 7) },
						{ "commit-url", string.Format("https://git.starbeamrainbowlabs.com/sbrl/SpritePacker/commit/{0}", commitHash) }
					};
					foreach (KeyValuePair<string, string> replacePair in templateValues)
						helpText = helpText.Replace(string.Format("{{{0}}}", replacePair.Key), replacePair.Value);

					Console.WriteLine(helpText);
					break;
			}

			return 0;
		}

		public static void RunNormal()
		{
			spritePacker = new SpritePacker(Verbose);
			List<Sprite> sprites = new List<Sprite>();
			addSprites(values, sprites);

			// Preset some locations if they were specified
			if (rawSourceLocations != null) {
				foreach (string[] line in parseCSV(rawSourceLocations).Skip(1)) { // Skip the header
					// index,filename,x,y,width,height
					Sprite currentSprite = sprites.Find((Sprite item) => item.Filename == line[1]);
					currentSprite.Area = new Rectangle(
						int.Parse(line[2]),
						int.Parse(line[3]),
						int.Parse(line[4]),
						int.Parse(line[5])
					);
					currentSprite.Placed = true;
					if(Verbose) Console.WriteLine("Pre-placing {0}", currentSprite);
				}
			}
			spritePacker.Add(sprites);

			spritePacker.Arrange();
			spritePacker.Output(outputFilename);
			switch(outputFormat)
			{
				case OutputFormat.CSV:
					Console.WriteLine(spritePacker.GetSpritePositionsCSV().Trim());
					break;
				case OutputFormat.Text:
					Console.WriteLine(spritePacker.ToString());
					break;
				default:
					Console.Error.WriteLine("Error: Invalid output format!");
					break;
			}
		}

		private static void addSprites(List<string> filenames, List<Sprite> outputSpriteList)
		{
			foreach(string filename in filenames)
			{
				// Make sure that the file actually exists (we don't want the packer to throw a tantrum)
				if (File.Exists(filename))
				{
					try {
						outputSpriteList.Add(new Sprite(filename));
					}
					catch(Exception error) {
						Console.Error.WriteLine("Error reading {0}: {1}", filename, error.Message);
					}

					if ((File.GetAttributes(filename) & FileAttributes.Directory) == FileAttributes.Directory)
					{
						// This filename is a directory - recurse over all the files in the directory
						string[] dirFiles = Directory.GetFiles(filename);
						addSprites(new List<string>(dirFiles), outputSpriteList);
					}
				}
				else
				{
					Console.Error.WriteLine("Warning: Ignoring non-existent file '{0}'.", filename);
				}
			}

		}

		private static IEnumerable<string[]> parseCSV(string source)
		{
			return Regex.Split(source.Trim(), @"\r?\n").Select((string line) => line.Split(','));
		}
	}
}