using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

namespace VirtualPhotoOrganizer.Photo
{
	/// <summary>
	/// Handles resizing, cropping, rotating, and the creation of thumbnails
	/// </summary>
	internal class Resizer
	{
		public Resizer() { }

		/// <summary>
		/// Resizes the specified image to the specified size with the specified InterpolationMode
		/// </summary>
		public Bitmap Resize(Bitmap image, int width, int height, InterpolationMode interpolationMode) {
			// create the resized Bitmap and its Graphics object
			Bitmap resizedImage = new Bitmap(width, height);
			Graphics g = Graphics.FromImage(resizedImage);
			g.InterpolationMode = interpolationMode;

			// fill the resized Bitmap with the resized image
			Rectangle destRect = new Rectangle(0, 0, width, height);
			g.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel);

			// dispose the unneeded objects and return the resized Bitmap
			g.Dispose();
			return resizedImage;
		}

		/// <summary>
		/// Returns a Bitmap containing the specified cropArea
		/// </summary>
		public Bitmap Crop(Bitmap image, Rectangle cropArea) {
			// create the resized Bitmap and its Graphics object
			Bitmap croppedImage = new Bitmap(cropArea.Width, cropArea.Height);
			Graphics g = Graphics.FromImage(croppedImage);

			// fill the resized Bitmap with the cropArea
			Rectangle destRect = new Rectangle(0, 0, cropArea.Width, cropArea.Height);
			g.DrawImage(image, destRect, cropArea, GraphicsUnit.Pixel);

			// dispose the unneeded objects and return the cropped Bitmap
			g.Dispose();
			return croppedImage;
		}

		/// <summary>
		/// Rotates the given image according to the specified RotateFlipType
		/// </summary>
		public Bitmap Rotate(Bitmap image, RotateFlipType flipType) {
			image.RotateFlip(flipType);
			return image;
		}

		public void Rotate(string path, RotateFlipType flipType, int quality) {
			Image image = Bitmap.FromFile(path);
			Bitmap b = new Bitmap(image);	// create the bitmap
			image.Dispose();

			// rotate and save the bitmap
			b.RotateFlip(flipType);
			JpegSaver js = new JpegSaver();
			js.SaveJpeg(path, b, quality);

			// dispose the bitmap
			b.Dispose();
		}

		/// <summary>
		/// Saves a thumbnail of the specified image in the specified path
		/// </summary>
		public void CreateThumbnail(string srcPath, string destPath) {
			// the defined constants for the max thumbnail dimensions
			const int cthWidth = 150;
			const int cthHeight = 113;

			// the aspect ratio and the newly calculated thumbnail dimensions
			int thWidth = 0;
			int thHeight = 0;

			// load the source image
			Image img = Bitmap.FromFile(srcPath);
			Bitmap srcImage = new Bitmap(img);

			// calculate the new tumbnail dimensions, based on the longer side of the image
			double ratio = srcImage.Height / srcImage.Width;
			if (ratio < cthHeight / cthWidth) {
				// Width is constant
				thWidth = cthWidth;
				thHeight = (srcImage.Height * cthWidth) / srcImage.Width;
			} else {
				// Height is constant
				thHeight = cthHeight;
				thWidth = (srcImage.Width * cthHeight) / srcImage.Height;
			}


			// create the thumbnail
			Image thumb = srcImage.GetThumbnailImage(thWidth, thHeight, null, IntPtr.Zero);

			// create a new bitmap for the border creation
			Bitmap finthumb = new Bitmap(cthWidth, cthHeight);
			Graphics g = Graphics.FromImage(finthumb);

			// draw thumb into finthumb
			Rectangle dest;
			double size;
			if (thumb.Width > thumb.Height) {
				size = (cthHeight - thumb.Height) / 2;
				if (size != cthHeight / 2)	// check if image does not have cthWidth
					dest = new Rectangle(0, (int) Math.Round(size, 0), thumb.Width, thumb.Height);
				else
					dest = new Rectangle(0, 0, thumb.Width, thumb.Height);
			} else {
				size = (cthWidth - thumb.Width) / 2;
				if (size != cthWidth / 2)	// check if image does not have cthWidth
					dest = new Rectangle((int) Math.Round(size, 0), 0, thumb.Width, thumb.Height);
				else
					dest = new Rectangle(0, 0, thumb.Width, thumb.Height);
			}

			g.DrawImage(thumb, dest);

			// save finthumb
			finthumb.Save(destPath);

			// dispose the gdi+ objects
			g.Dispose();
			img.Dispose();
			srcImage.Dispose();
			thumb.Dispose();
			finthumb.Dispose();
		}

		#region HTMLExport

		/// <summary>
		/// Saves a thumbnail (without borders) of the specified image in the specified path
		/// </summary>
		public void CreateThumbnailWoBorders(string srcPath, string destPath) {
			// the defined constants for the max thumbnail dimensions
			const int cthWidth = 150;
			const int cthHeight = 113;

			// the aspect ratio and the newly calculated thumbnail dimensions
			int thWidth = 0;
			int thHeight = 0;

			// load the source image
			Image img = Bitmap.FromFile(srcPath);
			Bitmap srcImage = new Bitmap(img);

			// calculate the new tumbnail dimensions, based on the longer side of the image
			double ratio = srcImage.Height / srcImage.Width;
			if (ratio < cthHeight / cthWidth) {
				// Width is constant
				thWidth = cthWidth;
				thHeight = (srcImage.Height * cthWidth) / srcImage.Width;
			} else {
				// Height is constant
				thHeight = cthHeight;
				thWidth = (srcImage.Width * cthHeight) / srcImage.Height;
			}


			// create the thumbnail
			Image thumb = srcImage.GetThumbnailImage(thWidth, thHeight, null, IntPtr.Zero);

			// save the thumbnail
			thumb.Save(destPath);

			// dispose the gdi+ objects
			thumb.Dispose();
			srcImage.Dispose();
			img.Dispose();
		}

		/// <summary>
		/// Resizes the specified image to the specified size with the specified InterpolationMode and then saves it with the specified quality
		/// </summary>
		public void Resize(string srcPath, string destPath, int width, int height, int quality, InterpolationMode interpolationMode) {
			// open the original image
			Image img = Bitmap.FromFile(srcPath);
			Bitmap image = new Bitmap(img);

			// calculate the right size for the destRect
			Rectangle destRect = new Rectangle(0, 0, width, height);
			// calculate the new tumbnail dimensions, based on the longer side of the image
			double ratio = image.Height / image.Width;
			if (ratio < height / width) {
				// Width is constant
				destRect.Width = width;
				destRect.Height = (image.Height * width) / image.Width;
			} else {
				// Height is constant
				destRect.Height = height;
				destRect.Width = (image.Width * height) / image.Height;
			}

			// create the resized Bitmap and its Graphics object
			Bitmap resizedImage = new Bitmap(destRect.Width, destRect.Height);
			Graphics g = Graphics.FromImage(resizedImage);
			g.InterpolationMode = interpolationMode;

			// fill the resized Bitmap with the resized image
			g.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel);

			// save the resized image
			JpegSaver js = new JpegSaver();
			js.SaveJpeg(destPath, resizedImage, quality);

			// dispose the unneeded objects
			g.Dispose();
			resizedImage.Dispose();
			img.Dispose();
			image.Dispose();
		}

		#endregion
	}
}