web/mastosan: add markdown and plain text modes

Signed-off-by: Xe <me@christine.website>

3 files changed, 52 insertions, 12 deletions

diff --git a/web/mastosan/mastosan.go b/web/mastosan/mastosan.go
index 7e0d539..ea0db58 100644
--- a/web/mastosan/mastosan.go
+++ b/web/mastosan/mastosan.go
@@ -54,18 +54,12 @@ func init() {
 	}
 }
 
-// HTML2Slackdown converts a string full of HTML text to slack-flavored markdown.
-//
-// Internally this works by taking that HTML and piping it to a small Rust program
-// using lol_html to parse the HTML and rejigger it into slack-flavored markdown.
-// This has an added latency of about 0.2 seconds per invocation, but this is as
-// fast as I can make it for now.
-func HTML2Slackdown(ctx context.Context, text string) (string, error) {
+func runWASM(ctx context.Context, text, mode string) (string, error) {
 	fout := &bytes.Buffer{}
 	fin := bytes.NewBufferString(text)
 
 	name := strconv.Itoa(rand.Int())
-	config := wazero.NewModuleConfig().WithStdout(fout).WithStdin(fin).WithArgs("mastosan").WithName(name)
+	config := wazero.NewModuleConfig().WithStdout(fout).WithStdin(fin).WithArgs("mastosan", mode).WithName(name)
 
 	mod, err := r.InstantiateModule(ctx, code, config)
 	if err != nil {
@@ -75,3 +69,27 @@ func HTML2Slackdown(ctx context.Context, text string) (string, error) {
 
 	return strings.TrimSpace(fout.String()), nil
 }
+
+// Slackdown converts a string full of HTML text to slack-flavored markdown.
+//
+// Internally this works by taking that HTML and piping it to a small Rust program
+// using lol_html to parse the HTML and rejigger it into slack-flavored markdown.
+func Slackdown(ctx context.Context, text string) (string, error) {
+	return runWASM(ctx, text, "slackdown")
+}
+
+// Text converts a string with HTML content into an approximation of plain text.
+//
+// Internally this works by taking that HTML and piping it to a small Rust program
+// using lol_html to parse the HTML and rejigger it into plain text.
+func Text(ctx context.Context, text string) (string, error) {
+	return runWASM(ctx, text, "text")
+}
+
+// Markdown converts a string with HTML content into an approximation of plain text.
+//
+// Internally this works by taking that HTML and piping it to a small Rust program
+// using lol_html to parse the HTML and rejigger it into generic markdown.
+func Markdown(ctx context.Context, text string) (string, error) {
+	return runWASM(ctx, text, "markdown")
+}
diff --git a/web/mastosan/src/main.rs b/web/mastosan/src/main.rs
index a69e24a..80658b0 100644
--- a/web/mastosan/src/main.rs
+++ b/web/mastosan/src/main.rs
@@ -1,7 +1,18 @@
 use lol_html::{element, html_content::ContentType, HtmlRewriter, Settings};
+use std::env::args;
 use std::io::{self, prelude::*, stdin, stdout};
 
 fn main() -> io::Result<()> {
+    let mode = match args().nth(1) {
+        None => {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "usage: mastosan [markdown|slackdown|text]",
+            ))
+        }
+        Some(mode) => mode,
+    };
+
     let mut output = Vec::new();
     let mut rewriter = HtmlRewriter::new(
         Settings {
@@ -22,10 +33,21 @@ fn main() -> io::Result<()> {
                 }),
                 element!("a[href]", |el| {
                     let href = el.get_attribute("href").unwrap();
-                    el.prepend("|", ContentType::Html);
-                    el.prepend(&href, ContentType::Html);
-                    el.prepend("<", ContentType::Html);
-                    el.append(">", ContentType::Html);
+                    match mode.as_str() {
+                        "slackdown" => {
+                            el.prepend("|", ContentType::Html);
+                            el.prepend(&href, ContentType::Html);
+                            el.prepend("<", ContentType::Html);
+                            el.append(">", ContentType::Html);
+                        }
+                        "markdown" => {
+                            el.prepend("](", ContentType::Html);
+                            el.prepend(&href, ContentType::Html);
+                            el.prepend("[", ContentType::Html);
+                            el.append(")", ContentType::Html);
+                        }
+                        _ => {}
+                    }
                     el.remove_and_keep_content();
 
                     Ok(())
diff --git a/web/mastosan/testdata/mastosan.wasm b/web/mastosan/testdata/mastosan.wasm
index 218ee48..c03f403 100644..100755
--- a/web/mastosan/testdata/mastosan.wasm
+++ b/web/mastosan/testdata/mastosan.wasm