// Copyright (c) Microsoft Corporation. All rights reserved.

using System.Collections.Generic;

using System.IO;

using ColorCode.Common;

using ColorCode.Parsing;

using System.Text;

using ColorCode.HTML.Common;

using ColorCode.Styling;

using System.Net;

namespace ColorCode

{

/// <summary>

/// Creates a <see cref="HtmlFormatter"/>, for creating HTML to display Syntax Highlighted code.

/// </summary>

public class HtmlFormatter : CodeColorizerBase

{

/// <summary>

/// Creates a <see cref="HtmlFormatter"/>, for creating HTML to display Syntax Highlighted code.

/// </summary>

/// <param name="Style">The Custom styles to Apply to the formatted Code.</param>

/// <param name="languageParser">The language parser that the <see cref="HtmlFormatter"/> instance will use for its lifetime.</param>

public HtmlFormatter(StyleDictionary Style = null, ILanguageParser languageParser = null) : base(Style, languageParser)

{

}

private TextWriter Writer { get; set; }

/// <summary>

/// Creates the HTML Markup, which can be saved to a .html file.

/// </summary>

/// <param name="sourceCode">The source code to colorize.</param>

/// <param name="language">The language to use to colorize the source code.</param>

/// <returns>Colorised HTML Markup.</returns>

public string GetHtmlString(string sourceCode, ILanguage language)

{

var buffer = new StringBuilder(sourceCode.Length * 2);

using (TextWriter writer = new StringWriter(buffer))

{

Writer = writer;

WriteHeader(language);

languageParser.Parse(sourceCode, language, (parsedSourceCode, captures) => Write(parsedSourceCode, captures));

WriteFooter(language);

writer.Flush();

}

return buffer.ToString();

}

protected override void Write(string parsedSourceCode, IList<Scope> scopes)

{

var styleInsertions = new List<TextInsertion>();

foreach (Scope scope in scopes)

GetStyleInsertionsForCapturedStyle(scope, styleInsertions);

styleInsertions.SortStable((x, y) => x.Index.CompareTo(y.Index));

int offset = 0;

foreach (TextInsertion styleInsertion in styleInsertions)

{

var text = parsedSourceCode.Substring(offset, styleInsertion.Index - offset);

Writer.Write(WebUtility.HtmlEncode(text));

if (string.IsNullOrEmpty(styleInsertion.Text))

BuildSpanForCapturedStyle(styleInsertion.Scope);

else

Writer.Write(styleInsertion.Text);

offset = styleInsertion.Index;

}

Writer.Write(WebUtility.HtmlEncode(parsedSourceCode.Substring(offset)));

}

private void WriteFooter(ILanguage language)

{

Writer.WriteLine();

WriteHeaderPreEnd();

WriteHeaderDivEnd();

}

private void WriteHeader(ILanguage language)

{

WriteHeaderDivStart();

WriteHeaderPreStart();

Writer.WriteLine();

}

private void GetStyleInsertionsForCapturedStyle(Scope scope, ICollection<TextInsertion> styleInsertions)

{

styleInsertions.Add(new TextInsertion

{

Index = scope.Index,

Scope = scope

});

foreach (Scope childScope in scope.Children)

GetStyleInsertionsForCapturedStyle(childScope, styleInsertions);

styleInsertions.Add(new TextInsertion

{

Index = scope.Index + scope.Length,

Text = "</span>"

});

}

private void BuildSpanForCapturedStyle(Scope scope)

{

string foreground = string.Empty;

string background = string.Empty;

bool italic = false;

bool bold = false;

if (Styles.Contains(scope.Name))

{

Style style = Styles[scope.Name];

foreground = style.Foreground;

background = style.Background;

italic = style.Italic;

bold = style.Bold;

}

WriteElementStart("span", foreground, background, italic, bold);

}

private void WriteHeaderDivEnd()

{

WriteElementEnd("div");

}

private void WriteElementEnd(string elementName)

{

Writer.Write("</{0}>", elementName);

}

private void WriteHeaderPreEnd()

{

WriteElementEnd("pre");

}

private void WriteHeaderPreStart()

{

WriteElementStart("pre");

}

private void WriteHeaderDivStart()

{

string foreground = string.Empty;

string background = string.Empty;

if (Styles.Contains(ScopeName.PlainText))

{

Style plainTextStyle = Styles[ScopeName.PlainText];

foreground = plainTextStyle.Foreground;

background = plainTextStyle.Background;

}

WriteElementStart("div", foreground, background);

}

private void WriteElementStart(string elementName, string foreground = null, string background = null, bool italic = false, bool bold = false)

{

Writer.Write("<{0}", elementName);

if (!string.IsNullOrWhiteSpace(foreground) || !string.IsNullOrWhiteSpace(background) || italic || bold)

{

Writer.Write(" style=\"");

if (!string.IsNullOrWhiteSpace(foreground))

Writer.Write("color:{0};", foreground.ToHtmlColor());

if (!string.IsNullOrWhiteSpace(background))

Writer.Write("background-color:{0};", background.ToHtmlColor());

if (italic)

Writer.Write("font-style: italic;");

if (bold)

Writer.Write("font-weight: bold;");

Writer.Write("\"");

}

Writer.Write(">");

}

}

}