From d2d5846b0eaffa615048a86bb634fd4f8a99f742 Mon Sep 17 00:00:00 2001
From: makeworld <colecmac@protonmail.com>
Date: Mon, 1 Mar 2021 19:05:26 -0500
Subject: [PATCH] ANSI and plain renderers done but untested, gemtext started

---
 render/gemtext.go  | 71 ++++++++++++++++++++++++++++++++++++
 render/render.go   |  3 +-
 render/renderer.go | 91 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 163 insertions(+), 2 deletions(-)
 create mode 100644 render/gemtext.go
 create mode 100644 render/renderer.go

diff --git a/render/gemtext.go b/render/gemtext.go
new file mode 100644
index 0000000..b13368d
--- /dev/null
+++ b/render/gemtext.go
@@ -0,0 +1,71 @@
+package render
+
+import (
+	"bufio"
+	"io"
+)
+
+// Renderer for gemtext. Other Renderers are in renderer.go.
+
+type GemtextRenderer struct {
+	r *io.PipeReader
+	w *io.PipeWriter
+
+	// scanner is used to process line by line.
+	scanner *bufio.Scanner
+
+	// scanWriter is used to send data to the scanner, which reads out of the other
+	// end of the pipe.
+	scanWriter *io.PipeWriter
+
+	// lineEnd holds the rest of line when the Read call cuts off the line being returned.
+	lineEnd []byte
+
+	links chan string
+
+	// numLinks is the number of links that exist so far.
+	numLinks int
+	// width is the number of columns to wrap to.
+	width int
+	// proxied is whether the request is through the gemini:// scheme.
+	proxied bool
+
+	// pre indicates whether the renderer is currently in a preformatted block
+	// or not.
+	pre bool
+}
+
+// NewGemtextRenderer.
+//
+// width is the number of columns to wrap to.
+//
+// proxied is whether the request is through the gemini:// scheme.
+// If it's not a gemini:// page, set this to true.
+func NewGemtextRenderer(width int, proxied bool) *GemtextRenderer {
+	pr, pw := io.Pipe()
+	scanReader, scanWriter := io.Pipe()
+	scanner := bufio.NewScanner(scanReader)
+	links := make(chan string, 10)
+
+	return &GemtextRenderer{
+		r:          pr,
+		w:          pw,
+		scanner:    scanner,
+		scanWriter: scanWriter,
+		lineEnd:    make([]byte, 0),
+		links:      links,
+		numLinks:   0,
+		width:      width,
+		proxied:    proxied,
+		pre:        false,
+	}
+}
+
+func (r *GemtextRenderer) Links() <-chan string {
+	return r.links
+}
+
+func (r *GemtextRenderer) Write(p []byte) (n int, err error) {
+	// Just write to the scanner, all logic is in Read()
+	return r.scanWriter.Write(p)
+}
diff --git a/render/render.go b/render/render.go
index d21bcc2..9036220 100644
--- a/render/render.go
+++ b/render/render.go
@@ -41,7 +41,7 @@ func RenderPlainText(s string) string {
 	// It used to add a left margin, now this is done elsewhere.
 	// The function is kept for convenience and in case rendering
 	// is needed in the future.
-	return s
+	return cview.Escape(s)
 }
 
 // wrapLine wraps a line to the provided width, and adds the provided prefix and suffix to each wrapped line.
@@ -270,7 +270,6 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 // It also returns a slice of link URLs.
 //
 // width is the number of columns to wrap to.
-// leftMargin is the number of blank spaces to prepend to each line.
 //
 // proxied is whether the request is through the gemini:// scheme.
 // If it's not a gemini:// page, set this to true.
diff --git a/render/renderer.go b/render/renderer.go
new file mode 100644
index 0000000..68278f2
--- /dev/null
+++ b/render/renderer.go
@@ -0,0 +1,91 @@
+package render
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"github.com/makeworld-the-better-one/amfora/config"
+	"github.com/spf13/viper"
+	"gitlab.com/tslocum/cview"
+)
+
+// Renderer renderers network bytes into something that can be displayed on a
+// cview.TextView.
+type Renderer interface {
+	io.ReadWriter
+
+	// Links returns a channel that yields Link URLs as they are parsed.
+	// It is buffered. The channel might be closed to indicate links are supported
+	// for this renderer.
+	Links() <-chan string
+}
+
+type PlaintextRenderer struct {
+	*io.PipeReader
+	w *io.PipeWriter
+}
+
+func NewPlaintextRenderer() *PlaintextRenderer {
+	pr, pw := io.Pipe()
+	return &PlaintextRenderer{pr, pw}
+}
+
+func (r *PlaintextRenderer) Write(p []byte) (n int, err error) {
+	// TODO: The escaping will fail if the Write bytes end in the middle of a tag
+	// How can this be avoided by users of this func?
+	return r.w.Write(cview.EscapeBytes(p))
+}
+
+func (r *PlaintextRenderer) Links() <-chan string {
+	ch := make(chan string)
+	close(ch)
+	return ch
+}
+
+type ANSIRenderer struct {
+	*io.PipeReader
+	pw         *io.PipeWriter
+	ansiWriter io.Writer // cview.ANSIWriter
+	buf        bytes.Buffer
+}
+
+func NewANSIRenderer() *ANSIRenderer {
+	pr, pw := io.Pipe()
+
+	var ansiWriter io.Writer = nil // When ANSI is disabled
+	var buf bytes.Buffer
+
+	if viper.GetBool("a-general.color") && viper.GetBool("a-general.ansi") {
+		// ANSI enabled
+		ansiWriter = cview.ANSIWriter(&buf)
+	}
+	return &ANSIRenderer{pr, pw, ansiWriter, buf}
+}
+
+func (r *ANSIRenderer) Write(p []byte) (n int, err error) {
+	if r.ansiWriter == nil {
+		// ANSI disabled
+		return r.pw.Write(ansiRegex.ReplaceAll(p, []byte{}))
+	}
+	// ANSI enabled
+
+	r.buf.Reset()
+	r.ansiWriter.Write(p) // Shouldn't error because everything it writes to are all bytes.Buffer
+	return r.pw.Write(
+		// The ANSIWriter injects tags like [-:-:-]
+		// but this will reset the background to use the user's terminal color.
+		// These tags need to be replaced with resets that use the theme color.
+		bytes.ReplaceAll(
+			r.buf.Bytes(),
+			[]byte("[-:-:-]"),
+			[]byte(fmt.Sprintf("[-:%s:-]", config.GetColorString("bg"))),
+		),
+	)
+}
+
+func (r *ANSIRenderer) Links() <-chan string {
+	ch := make(chan string)
+	close(ch)
+	return ch
+}