From 60b733783c5e9f267377d8dbadeb5982e7566418 Mon Sep 17 00:00:00 2001
From: xdrm-brackets <doowap31@gmail.com>
Date: Sun, 27 Jan 2019 16:39:34 +0100
Subject: [PATCH] allow escaping special characters (*, _, $, [) | fix: append
 last character when cursor is len-1 after all matches | add
 transform/markdown/hyperlink format

---
 clifmt.go                                | 26 ++++++++++--
 internal/transform/color/color.go        |  2 +-
 internal/transform/markdown/bold.go      |  2 +-
 internal/transform/markdown/hyperlink.go | 50 ++++++++++++++++++++++++
 internal/transform/markdown/italic.go    |  2 +-
 internal/transform/markdown/markdown.go  | 10 ++++-
 internal/transform/markdown/underline.go |  2 +-
 7 files changed, 85 insertions(+), 9 deletions(-)
 create mode 100644 internal/transform/markdown/hyperlink.go

diff --git a/clifmt.go b/clifmt.go
index 2054f17..f2c6134 100644
--- a/clifmt.go
+++ b/clifmt.go
@@ -5,28 +5,48 @@ import (
 	"git.xdrm.io/go/clifmt/internal/color"
 	colorTransform "git.xdrm.io/go/clifmt/internal/transform/color"
 	mdTransform "git.xdrm.io/go/clifmt/internal/transform/markdown"
+	"strings"
 )
 
 var theme = color.DefaultTheme()
 
+var (
+	dollarToken        = `e4d097183ab04e49f25cb7b0956fb9eb25b90c0316a32cb5afcbcdd9a6692e8d2974919035789d5632b10d799db5b3e5bf8539592c904497f5c356f117ef37382`
+	asteriskToken      = `253c3cd0a904d28abc3e601e3557d59ea69da2616079ceef4987d58d55c9820c83026be92a917ee19a298e613ea0b393cc70d4e55dc614a9afc6a020d8f08f37`
+	underscoreToken    = `2b08e24b7833e90c74ed8e6c27b7b3cd5fe949e0f18b28af813d5f2df863d55f97b0ed7f8fbb26a152eda55ac073331ce11ac10702caca5b3ea4a29f722840b9`
+	squareBracketToken = `51b06edd58f36003844941916cd3b313979fece55824d89ba02af052a229b2673aafffa541b703472c1a21d8e6a1bb3e844d236fb0e8bf5d62902b24042f4fb5`
+)
+
 // Sprintf returns a terminal-colorized output following the coloring format
 func Sprintf(format string, a ...interface{}) (string, error) {
 	// 1. Pre-process format with 'fmt'
 	formatted := fmt.Sprintf(format, a...)
 
-	// 2. Colorize
+	// 2. Protect escaped characters with tokens
+	formatted = strings.Replace(formatted, "\\$", dollarToken, -1)
+	formatted = strings.Replace(formatted, "\\*", asteriskToken, -1)
+	formatted = strings.Replace(formatted, "\\_", underscoreToken, -1)
+	formatted = strings.Replace(formatted, "\\[", squareBracketToken, -1)
+
+	// 3. Colorize
 	colorized, err := colorTransform.Transform(formatted, theme)
 	if err != nil {
 		return "", err
 	}
 
-	// 3. Markdown format
+	// 4. Markdown format
 	markdown, err := mdTransform.Transform(colorized)
 	if err != nil {
 		return "", err
 	}
 
-	// 3. return final output
+	// 5. Restore token-protected characters
+	markdown = strings.Replace(markdown, dollarToken, "$", -1)
+	markdown = strings.Replace(markdown, asteriskToken, "*", -1)
+	markdown = strings.Replace(markdown, underscoreToken, "_", -1)
+	markdown = strings.Replace(markdown, squareBracketToken, "[", -1)
+
+	// 6. return final output
 	return markdown, nil
 }
 
diff --git a/internal/transform/color/color.go b/internal/transform/color/color.go
index ad66299..2595b99 100644
--- a/internal/transform/color/color.go
+++ b/internal/transform/color/color.go
@@ -83,7 +83,7 @@ func Transform(input string, theme color.Theme) (string, error) {
 	}
 
 	// 2. Add end of input
-	if cursor < len(input)-1 {
+	if cursor < len(input) {
 		output += input[cursor:]
 	}
 
diff --git a/internal/transform/markdown/bold.go b/internal/transform/markdown/bold.go
index 1be4c1b..32f8dc8 100644
--- a/internal/transform/markdown/bold.go
+++ b/internal/transform/markdown/bold.go
@@ -38,7 +38,7 @@ func boldTransform(input string) (string, error) {
 	}
 
 	// 2. Add end of input
-	if cursor < len(input)-1 {
+	if cursor < len(input) {
 		output += input[cursor:]
 	}
 
diff --git a/internal/transform/markdown/hyperlink.go b/internal/transform/markdown/hyperlink.go
new file mode 100644
index 0000000..e1f2842
--- /dev/null
+++ b/internal/transform/markdown/hyperlink.go
@@ -0,0 +1,50 @@
+package markdown
+
+import (
+	"fmt"
+	"regexp"
+)
+
+var hyperlinkRe = regexp.MustCompile(`(?m)\[([^\[]+)\]\(([^\)]+)\)`)
+
+// linkify returns the terminal-formatted hyperlink for @url with the text : @label
+func linkify(url, label string) string {
+	return fmt.Sprintf("\x1b]8;;%s\x1b\\%s\x1b]8;;\x1b\\", url, label)
+}
+
+// hyperlinkTransform the @input text using markdown-like syntax :
+// - "normal [link label](link url) normal"
+func hyperlinkTransform(input string) (string, error) {
+	output := ""
+	cursor := int(0)
+
+	// 1. Replace for each match
+	for _, match := range hyperlinkRe.FindAllStringSubmatchIndex(input, -1) {
+
+		// (1) add gap between input start OR previous match
+		output += input[cursor:match[0]]
+		cursor = match[1]
+
+		// (2) extract features
+		var label, url string
+
+		if match[3]-match[2] > 0 {
+			label = input[match[2]:match[3]]
+		}
+		if match[5]-match[4] > 0 {
+			url = input[match[4]:match[5]]
+		}
+
+		// (3) replace with hyperlink
+		output += linkify(url, label)
+	}
+
+	// 2. Add end of input
+	if cursor < len(input) {
+		output += input[cursor:]
+	}
+
+	// 3. print final output
+	return output, nil
+
+}
diff --git a/internal/transform/markdown/italic.go b/internal/transform/markdown/italic.go
index f2bec0c..66a0b92 100644
--- a/internal/transform/markdown/italic.go
+++ b/internal/transform/markdown/italic.go
@@ -38,7 +38,7 @@ func italicTransform(input string) (string, error) {
 	}
 
 	// 2. Add end of input
-	if cursor < len(input)-1 {
+	if cursor < len(input) {
 		output += input[cursor:]
 	}
 
diff --git a/internal/transform/markdown/markdown.go b/internal/transform/markdown/markdown.go
index c583a17..94df0c1 100644
--- a/internal/transform/markdown/markdown.go
+++ b/internal/transform/markdown/markdown.go
@@ -14,11 +14,17 @@ func Transform(input string) (string, error) {
 		return "", err
 	}
 
-	// 3. italic
+	// 3. underline
 	underline, err := underlineTransform(italic)
 	if err != nil {
 		return "", err
 	}
 
-	return underline, nil
+	// 4. hyperlink
+	hyperlinked, err := hyperlinkTransform(underline)
+	if err != nil {
+		return "", err
+	}
+
+	return hyperlinked, nil
 }
diff --git a/internal/transform/markdown/underline.go b/internal/transform/markdown/underline.go
index af2aafb..926669d 100644
--- a/internal/transform/markdown/underline.go
+++ b/internal/transform/markdown/underline.go
@@ -38,7 +38,7 @@ func underlineTransform(input string) (string, error) {
 	}
 
 	// 2. Add end of input
-	if cursor < len(input)-1 {
+	if cursor < len(input) {
 		output += input[cursor:]
 	}