LfdFile.cs

/*
 * Idmr.LfdReader.dll, Library file to read and write LFD resource files
 * Copyright (C) 2009-2026 Michael Gaisser (mjgaisser@gmail.com)
 * Licensed under the MPL v2.0 or later
 * 
 * Full notice in help/Idmr.LfdReader.chm
 * Version: 3.0
 */

/* CHANGE LOG
 * v3.0, 260821
 * [ADD] Name
 * v2.5.2, 260517
 * [FIX] Resource modified flag reset during Write
 * v2.4, 250202
 * [ADD] Enabled Mtrx
 * v2.0, 210309
 * [UPD] cleanup
 * [ADD] Cplx, Crft, Ship to assignResource
 * v1.2, 160712
 * [UPD] Always zeroes out name before writing
 * [UPD] Only calls _encode on children if they report being modified
 * v1.1, 141215
 * [UPD] changed license to MPL
 * v1.0
 */

using System;
using System.IO;

namespace Idmr.LfdReader
{
	/// <summary>Object to manage LFD resource files.</summary>
	public class LfdFile
	{
		Rmap _rmp = null;
		static readonly string _cockpitRmapErrorMessage = "Cockpit LFDs do not contain RMAPs";

		string _tempPath => FilePath + ".tmp";
		LfdCategory _lfdCategory = LfdCategory.Normal;

		/// <summary>Preset Lfd structures.</summary>
		public enum LfdCategory : byte {
			/// <summary>Typical LFD file, unlocked structure, no restrictions.</summary>
			Normal,
			/// <summary>Cockpit view LFDs, locked structure, does not contain an RMAP.</summary>
			Cockpit,
			/// <summary>Battle#.LFD files, locked structure.</summary>
			Battle }
		
		#region constructors
		/// <summary>Populates with an existing *.lfd file.</summary>
		/// <param name="stream">Opened *.lfd.</param>
		public LfdFile(FileStream stream)
		{
			read(stream);
		}
		/// <summary>Populates with an existing *.lfd file.</summary>
		/// <param name="filePath">Full path to the unopened *.lfd.</param>
		public LfdFile(string filePath)
		{
			FileStream stream = File.OpenRead(filePath);
			read(stream);
			stream.Close();
		}
		/// <summary>Creates an empty file with the appropriate file structure.</summary>
		/// <param name="category">Preset type.</param>
		/// <remarks><see cref="Rmap"/> and <see cref="Resources"/> are initialized accordingly.</remarks>
		public LfdFile(LfdCategory category)
		{
			Resources = new ResourceCollection(category);
			if (category == LfdCategory.Battle) _rmp = new Rmap(category);
			_lfdCategory = category;
		}
		#endregion constructors

		#region public methods
		/// <summary>Initializes <see cref="Rmap"/> using the contents of the LfdFile. If Rmap is already defined, it is updated.</summary>
		/// <remarks>Processes individual <see cref="Resource.EncodeResource"/> functions, thus updating all <see cref="Resource.RawData"/> properties.</remarks>
		public void CreateRmap()
		{
			if (_lfdCategory == LfdCategory.Cockpit) throw new ArgumentException(_cockpitRmapErrorMessage);

			string name = null;
			if (_rmp != null) name = _rmp.Name;
			encodeResources();
			if (_lfdCategory == LfdCategory.Battle) _rmp = new Rmap(_lfdCategory);
			else _rmp = new Rmap(Resources.Count);
			for (int i = 0; i < _rmp.NumberOfHeaders; i++)
			{
				_rmp.SubHeaders[i].Type = Resources[i].Type;
				_rmp.SubHeaders[i].Name = Resources[i].Name;
				_rmp.SubHeaders[i].Length = Resources[i].Length;
				_rmp.SubHeaders[i].Offset = Resource.HeaderLength +
					(i > 0 ? _rmp.SubHeaders[i - 1].Offset + _rmp.SubHeaders[i - 1].Length : 0);
			}
			if (name != null) _rmp.Name = name;
			_rmp.EncodeResource();
		}

		/// <summary>Writes the file to disk.</summary>
		/// <exception cref="Common.SaveFileException">An error occured, file remains unchanged.</exception>
		public void Write()
		{
			System.Diagnostics.Debug.WriteLine("Encoding Lfd...");
			if (_rmp != null) CreateRmap();
			else encodeResources();
			FileStream stream = null;
			try
			{
				if (File.Exists(FilePath)) File.Copy(FilePath, _tempPath);	// create backup
				stream = File.OpenWrite(FilePath);
				BinaryWriter bw = new BinaryWriter(stream);
				System.Diagnostics.Debug.WriteLine("Writing...");
				if (_rmp != null)
				{
					bw.Write((int)_rmp.Type);
					bw.Write(_rmp.Name.ToCharArray());
					stream.Position = Resource.LengthOffset;
					bw.Write(_rmp.Length);
					bw.Write(_rmp.RawData);
					_rmp._isModified = false;
				}
				for(int i=0;i<Resources.Count;i++)
				{
					long pos = stream.Position;
					bw.Write((int)Resources[i].Type);
					bw.Write((long)0);
					stream.Position = pos + Resource.NameOffset;
					bw.Write(Resources[i].Name.ToCharArray());
					stream.Position = pos + Resource.LengthOffset;
					bw.Write(Resources[i].Length);
					bw.Write(Resources[i].RawData);
					Resources[i]._isModified = false;
				}
				stream.SetLength(stream.Position);
				stream.Close();
				File.Delete(_tempPath);	// delete backup if it exists
				System.Diagnostics.Debug.WriteLine("Completed");
			}
			catch (Exception x)
			{
				System.Diagnostics.Debug.WriteLine("Write failure");
				stream?.Close();
				if (File.Exists(_tempPath)) File.Copy(_tempPath, FilePath);	// restore backup if it exists
				File.Delete(_tempPath);	// delete backup if it exists
				throw new Common.SaveFileException(x);
			}
		}
		#endregion public methods

		#region public properties
		/// <summary>Resources contained within the file.</summary>
		/// <remarks>Does <u>not</u> contain <see cref="Rmap"/> if applicable.</remarks>
		public ResourceCollection Resources { get; set; } = new ResourceCollection();

		/// <summary>Gets the full path to the file.</summary>
		public string FilePath { get; private set; } = "resource.lfd";
		/// <summary>Gets the file name and extension of the file.</summary>
		public string FileName => Path.GetFileName(FilePath);
		/// <summary>Gets if <see cref="Rmap"/> is defined.</summary>
		public bool HasRmap => (_rmp != null);
		/// <summary>Gets the file name without extension.</summary>
		public string Name => Path.GetFileNameWithoutExtension(FilePath);
		/// <summary>Gets or sets the Rmap resource for the file.</summary>
		/// <exception cref="ArgumentException">Cannot set if file is defined by the <see cref="LfdCategory.Cockpit"/> preset.</exception>
		public Rmap Rmap
		{
			get => _rmp;
			set
			{
				if (_lfdCategory == LfdCategory.Cockpit) throw new ArgumentException(_cockpitRmapErrorMessage);
				_rmp = value;
			}
		}
		#endregion public properties

		#region private methods
		/// <summary>Loops through Resources and calls the individual EncodeResource() functions.</summary>
		void encodeResources() { for (int i = 0; i < Resources.Count; i++) if (Resources[i]._isModified) Resources[i].EncodeResource(); }

		void read(FileStream stream)
		{
			FilePath = stream.Name;
			if (Resource.GetType(stream, 0) == Resource.ResourceType.Rmap)
			{
				_rmp = new Rmap(stream);
				Resources = new ResourceCollection(_rmp.NumberOfHeaders);
				for (int i = 0; i < Resources.Count; i++)
					assignResource(i, _rmp.SubHeaders[i].Type, stream, _rmp.SubHeaders[i].Offset);
				if (Resources.Count == 2 && Resources[0].Name.StartsWith("battle") && Resources[1].Name.EndsWith("gal"))
					_lfdCategory = LfdCategory.Battle;
			}
			else if (Resource.GetType(stream, 0) == Resource.ResourceType.Panl)
			{
				_lfdCategory = LfdCategory.Cockpit;
				Resources = new ResourceCollection(3)
				{
					[0] = new Panl(stream, 0)
				};
				Resources[1] = new Mask(stream, Resource.HeaderLength + Resources[0].Length);
				Resources[2] = new Pltt(stream, Resource.HeaderLength * 2 + Resources[0].Length + Resources[1].Length);
			}
			else
			{
				Resources = new ResourceCollection(1);
				assignResource(0, Resource.GetType(stream, 0), stream, 0);
			}
		}

		void assignResource(int index, Resource.ResourceType type, FileStream stream, long offset)
		{
			// commented out types redirect to Resource to read and capture _rawData
			if (type == Resource.ResourceType.Anim) Resources[index] = new Anim(stream, offset);
			//TODO: else if (type == Resource.ResourceType.Adlb) Resources[index] = new Adlb(stream, offset);
			else if (type == Resource.ResourceType.Blas || type == Resource.ResourceType.Voic) Resources[index] = new Blas(stream, offset);
			//TODO: else if (type == Resource.ResourceType.Bmap) Resources[index] = new Bmap(stream, offset);
			//TODO: else if (type == Resource.ResourceType.Btmp) Resources[index] = new Btmp(stream, offset);
			else if (type == Resource.ResourceType.Cplx) Resources[index] = new Cplx(stream, offset);
			else if (type == Resource.ResourceType.Crft) Resources[index] = new Crft(stream, offset);
			//TODO: else if (type == Resource.ResourceType.Cust) Resources[index] = new Cust(stream, offset);
			else if (type == Resource.ResourceType.Delt) Resources[index] = new Delt(stream, offset);
			else if (type == Resource.ResourceType.Film) Resources[index] = new Film(stream, offset);
			else if (type == Resource.ResourceType.Font) Resources[index] = new Font(stream, offset);
			//TODO: else if (type == Resource.ResourceType.Gmid) Resources[index] = new Gmid(stream, offset);
			else if (type == Resource.ResourceType.Mask) Resources[index] = new Mask(stream, offset);
			else if (type == Resource.ResourceType.Mtrx) Resources[index] = new Mtrx(stream, offset);
			else if (type == Resource.ResourceType.Panl) Resources[index] = new Panl(stream, offset);
			else if (type == Resource.ResourceType.Pltt) Resources[index] = new Pltt(stream, offset);
			//TODO: else if (type == Resource.ResourceType.Rlnd) Resources[index] = new Rlnd(stream, offset);
			// skip Rmap
			else if (type == Resource.ResourceType.Ship) Resources[index] = new Ship(stream, offset);
			else if (type == Resource.ResourceType.Text) Resources[index] = new Text(stream, offset);
			else if (type == Resource.ResourceType.Xact) Resources[index] = new Xact(stream, offset);
			else Resources[index] = new Resource(stream, offset);
		}
		#endregion private methods

		/// <summary>Gets if any of the resources are known to have been modified.</summary>
        public bool IsModified
        {
            get
            {
                for (int i = 0; i < Resources.Count; i++)
                    if (Resources[i]._isModified) return true;

                return false;
            }
        }
	}
}