using System;
using System.IO;
using System.Threading;
 
namespace Microsoft.Maui.Graphics
{
	internal abstract class PdfExportContext : IDisposable
	{
		private readonly float _defaultWidth;
		private readonly float _defaultHeight;
 
		private float _currentPageWidth;
		private float _currentPageHeight;
		private int _pageCount;
 
		protected PdfExportContext(
			float defaultWidth = -1,
			float defaultHeight = -1)
		{
			if (defaultWidth <= 0 || defaultHeight <= 0)
			{
				if ("en-US".Equals(Thread.CurrentThread.CurrentCulture.Name, StringComparison.Ordinal))
				{
					// Letter
					defaultWidth = 612;
					defaultHeight = 792;
				}
				else
				{
					// A4
					defaultWidth = 595;
					defaultHeight = 842;
				}
			}
 
			_defaultWidth = defaultWidth;
			_defaultHeight = defaultHeight;
		}
 
		public float DefaultWidth => _defaultWidth;
 
		public float DefaultHeight => _defaultHeight;
 
		public int PageCount => _pageCount;
 
		public void AddPage(float width = -1, float height = -1)
		{
			if (width <= 0 || height <= 0)
			{
				_currentPageWidth = _defaultWidth;
				_currentPageHeight = _defaultHeight;
			}
			else
			{
				_currentPageWidth = width;
				_currentPageHeight = height;
			}
 
			AddPageImpl(_currentPageWidth, _currentPageHeight);
			_pageCount++;
		}
 
		public virtual void Dispose()
		{
		}
 
		protected abstract void AddPageImpl(float width, float height);
 
		public abstract ICanvas Canvas { get; }
 
		public abstract void WriteToStream(Stream stream);
	}
}