From f98f44365fe6fe10d719910e42bf59544ff00377 Mon Sep 17 00:00:00 2001
From: Roberto Alsina <roberto.alsina@gmail.com>
Date: Fri, 9 Aug 2024 14:00:42 -0300
Subject: [PATCH] HTML formatter option: line_numbers / highlight_lines

---
 scripts/token_abbrevs.py |  2 +-
 src/constants.cr         |  1 +
 src/formatters/html.cr   | 14 ++++++++++----
 src/main.cr              |  3 ++-
 src/styles.cr            |  1 +
 5 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/scripts/token_abbrevs.py b/scripts/token_abbrevs.py
index 2b0c91b..e8b7f11 100644
--- a/scripts/token_abbrevs.py
+++ b/scripts/token_abbrevs.py
@@ -8,7 +8,7 @@ def abbr(line):
     return "".join(c for c in line if c in string.ascii_uppercase).lower()
 
 abbrevs = {}
-tokens = set([])
+tokens = {"Highlight"}
 for line in sys.stdin:
     if "<token" not in line:
         continue
diff --git a/src/constants.cr b/src/constants.cr
index 8657359..cc3f14e 100644
--- a/src/constants.cr
+++ b/src/constants.cr
@@ -1,6 +1,7 @@
 module Tartrazine
   Abbreviations = {
     "Background"               => "b",
+    "Highlight"                => "h",
     "Text"                     => "t",
     "CommentSingle"            => "cs",
     "CommentSpecial"           => "cs",
diff --git a/src/formatters/html.cr b/src/formatters/html.cr
index e552d50..d477d56 100644
--- a/src/formatters/html.cr
+++ b/src/formatters/html.cr
@@ -12,13 +12,13 @@ module Tartrazine
 
     # property surrounding_pre : Bool = true
     # property wrap_long_lines : Bool = false
-    # property line_numbers : Bool = false
+    property? line_numbers : Bool = false
     property line_number_start : Int32 = 1
     property line_number_id_prefix : String = "line-"
 
     # property line_number_in_table : Bool = false
     # property linkable_line_numbers : Bool = false
-    # property highlight_lines : Array(Range(Int32, Int32)) = [] of Range(Int32, Int32)
+    property highlight_lines : Array(Range(Int32, Int32)) = [] of Range(Int32, Int32)
 
     def format(text : String, lexer : Lexer, theme : Theme) : String
       text = format_text(text, lexer, theme)
@@ -45,12 +45,14 @@ module Tartrazine
       output = String.build do |outp|
         outp << "<pre class=\"#{get_css_class("Background", theme)}\"><code class=\"#{get_css_class("Background", theme)}\">"
         lines.each_with_index(offset: line_number_start - 1) do |line, i|
-          outp << "<span id=\"#{line_number_id_prefix}#{i + 1}\">"
+          line_label = line_numbers? ? "#{i + 1}".rjust(4).ljust(5) : ""
+
+          line_class = highlighted?(i + 1) ? "class=\"#{get_css_class("Highlight", theme)}\"" : ""
+          outp << "<span id=\"#{line_number_id_prefix}#{i + 1}\" #{line_class}>#{line_label}</span>"
           line.each do |token|
             fragment = "<span class=\"#{get_css_class(token[:type], theme)}\">#{token[:value]}</span>"
             outp << fragment
           end
-          outp << "</span>"
         end
         outp << "</code></pre>"
       end
@@ -96,6 +98,10 @@ module Tartrazine
       }]
     end
 
+    def highlighted?(line : Int) : Bool
+      highlight_lines.any?(&.includes?(line))
+    end
+
     def group_tokens_in_lines(tokens : Array(Token)) : Array(Array(Token))
       split_tokens = [] of Token
       tokens.each do |token|
diff --git a/src/main.cr b/src/main.cr
index 949aa0e..fecdcf8 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -6,5 +6,6 @@ formatter = Tartrazine::Html.new
 formatter.standalone = true
 formatter.class_prefix = "hl-"
 formatter.line_number_id_prefix = "ln-"
-formatter.line_number_start = 3
+formatter.line_numbers = true
+formatter.highlight_lines = [3..7, 20..30]
 puts formatter.format(File.read(ARGV[0]), lexer, theme)
diff --git a/src/styles.cr b/src/styles.cr
index f9c2a9e..2120223 100644
--- a/src/styles.cr
+++ b/src/styles.cr
@@ -104,6 +104,7 @@ module Tartrazine
       # https://github.com/mohd-akram/base16-pygments/
 
       theme.styles["Background"] = Style.new(color: t["base05"], background: t["base00"])
+      theme.styles["Highlight"] = Style.new(color: t["base0D"], background: t["base01"])
       theme.styles["Text"] = Style.new(color: t["base05"])
       theme.styles["Error"] = Style.new(color: t["base08"])
       theme.styles["Comment"] = Style.new(color: t["base03"])