using System;

using System.Collections.Generic;

using System.Diagnostics.Contracts;

using System.Drawing;

using System.Drawing.Drawing2D;

using System.Drawing.Imaging;

using System.Linq;

namespace ReClassNET.UI

{

public static class BannerFactory

{

private const int StdHeight = 48; // 96 DPI

private const int StdIconDim = 32;

private const int MaxCacheEntries = 20;

private static readonly Dictionary<string, Image> imageCache = new Dictionary<string, Image>();

/// <summary>Creates a banner with the given <paramref name="icon"/>, <paramref name="title"/> and <paramref name="text"/>.</summary>

/// <param name="bannerWidth">Width of the banner.</param>

/// <param name="bannerHeight">Height of the banner.</param>

/// <param name="icon">The icon of the banner.</param>

/// <param name="title">The title of the banner.</param>

/// <param name="text">The text of the banner.</param>

/// <param name="skipCache">True to skip cache.</param>

/// <returns>The created banner.</returns>

public static Image CreateBanner(int bannerWidth, int bannerHeight, Image icon, string title, string text, bool skipCache)

{

Contract.Requires(title != null);

Contract.Requires(text != null);

var bannerId = $"{bannerWidth}x{bannerHeight}:{title}:{text}";

if (skipCache || !imageCache.TryGetValue(bannerId, out var image))

{

image = new Bitmap(bannerWidth, bannerHeight, PixelFormat.Format24bppRgb);

using (var g = Graphics.FromImage(image))

{

int xIcon = DpiScaleInt(10, bannerHeight);

var rect = new Rectangle(0, 0, bannerWidth, bannerHeight);

using (var brush = new LinearGradientBrush(rect, Color.FromArgb(151, 154, 173), Color.FromArgb(27, 27, 37), LinearGradientMode.Vertical))

{

g.FillRectangle(brush, rect);

}

int wIconScaled = StdIconDim;

if (icon != null)

{

var iconRel = icon.Width / (float)icon.Height;

wIconScaled = (int)Math.Round(DpiScaleFloat(iconRel * StdIconDim, bannerHeight));

var hIconScaled = DpiScaleInt(StdIconDim, bannerHeight);

int yIcon = (bannerHeight - hIconScaled) / 2;

if (hIconScaled == icon.Height)

{

g.DrawImageUnscaled(icon, xIcon, yIcon);

}

else

{

g.DrawImage(icon, xIcon, yIcon, wIconScaled, hIconScaled);

}

var attributes = new ImageAttributes();

attributes.SetColorMatrix(new ColorMatrix

{

Matrix33 = 0.1f

});

int w = wIconScaled * 2;

int h = hIconScaled * 2;

int x = bannerWidth - w - xIcon;

int y = (bannerHeight - h) / 2;

g.DrawImage(icon, new Rectangle(x, y, w, h), 0, 0, icon.Width, icon.Height, GraphicsUnit.Pixel, attributes);

}

int tx = 2 * xIcon;

int ty = DpiScaleInt(4, bannerHeight);

if (icon != null)

{

tx += wIconScaled;

}

float fontSize = DpiScaleFloat((12.0f * 96.0f) / g.DpiY, bannerHeight);

using (var font = new Font(FontFamily.GenericSansSerif, fontSize, FontStyle.Bold))

{

DrawText(g, title, tx, ty, font, Color.White);

}

tx += xIcon;

ty += xIcon * 2 + 2;

float fontSizeSmall = DpiScaleFloat((9.0f * 96.0f) / g.DpiY, bannerHeight);

using (var fontSmall = new Font(FontFamily.GenericSansSerif, fontSizeSmall, FontStyle.Regular))

{

DrawText(g, text, tx, ty, fontSmall, Color.White);

}

}

if (!skipCache)

{

while (imageCache.Count > MaxCacheEntries)

{

imageCache.Remove(imageCache.Keys.First());

}

imageCache[bannerId] = image;

}

}

return image;

}

private static void DrawText(Graphics g, string text, int x, int y, Font font, Color color)

{

using (var brush = new SolidBrush(color))

{

using (var format = new StringFormat(StringFormatFlags.FitBlackBox | StringFormatFlags.NoClip))

{

g.DrawString(text, font, brush, x, y, format);

}

}

}

private static int DpiScaleInt(int x, int height) => (int)Math.Round((x * height) / (double)StdHeight);

private static float DpiScaleFloat(float x, int height) => (x * height) / StdHeight;

}

}