From d3803f892c8f2fea714628390579ed2dbaa92940 Mon Sep 17 00:00:00 2001
From: Joseph LaFreniere <joseph@lafreniere.xyz>
Date: Fri, 23 Dec 2022 18:35:37 -0600
Subject: [PATCH] fixup! Implement async `postproc_pagebreaks`

---
 src/adapters/postproc.rs | 52 +++++++++++++++++++++++++---------------
 1 file changed, 33 insertions(+), 19 deletions(-)

diff --git a/src/adapters/postproc.rs b/src/adapters/postproc.rs
index 6e311ac..0ccfae6 100644
--- a/src/adapters/postproc.rs
+++ b/src/adapters/postproc.rs
@@ -146,40 +146,54 @@ pub fn postproc_prefix(line_prefix: &str, inp: impl AsyncRead + Send) -> impl As
 /// Adds the prefix "Page N:" to each line,
 /// where N starts at one and is incremented for each ASCII Form Feed character in the input stream.
 /// ASCII form feeds are the page delimiters output by `pdftotext`.
-pub fn postproc_pagebreaks(line_prefix: &str, inp: impl AsyncRead) -> impl AsyncRead {
-    let form_feed = b'\x0c';
-    let regex = regex::bytes::Regex::new("\n").unwrap();
-    let mut page_count = 1;
-    let mut line_prefix = format!("\n{}Page {}:", line_prefix, page_count);
+pub fn postproc_pagebreaks(input: impl AsyncRead + Send) -> impl AsyncRead + Send {
+    let regex_linefeed = regex::bytes::Regex::new(r"\x0c").unwrap();
+    let regex_newline = regex::bytes::Regex::new("\n").unwrap();
+    let mut page_count: i32 = 1;
+    let mut page_prefix: String = format!("\nPage {}:", page_count);
 
-    let inp_stream = ReaderStream::new(inp);
-    let oup_stream = stream! {
-        for await chunk in inp_stream {
+    let input_stream = ReaderStream::new(input);
+    let output_stream = stream! {
+        for await chunk in input_stream {
             match chunk {
                 Err(e) => yield Err(e),
                 Ok(chunk) => {
-                    let chunk_iter = chunk.split_inclusive(|byte| byte == &form_feed);
-                    for sub_chunk in chunk_iter {
-                        if sub_chunk == [form_feed] {
-                            page_count += 1;
-                            line_prefix = format!("\n{}Page {}:", line_prefix, page_count);
-                        } else {
-                            yield Ok(Bytes::copy_from_slice(&regex.replace_all(&sub_chunk, line_prefix.as_bytes())));
-                        }
+                    let sub_chunks = regex_linefeed.split(&chunk);
+                    for sub_chunk in sub_chunks {
+                        // println!("{}", String::from_utf8_lossy(page_prefix.as_bytes()));
+                        yield Ok(Bytes::copy_from_slice(page_prefix.as_bytes()));
+                        yield Ok(Bytes::copy_from_slice(&regex_newline.replace_all(&sub_chunk, page_prefix.as_bytes())));
+                        page_count += 1;
+                        page_prefix = format!("\nPage {}:", page_count);
                     }
                 }
             }
         }
     };
-    StreamReader::new(oup_stream)
+    Box::pin(StreamReader::new(output_stream))
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
     use anyhow::Result;
-    use std::io::Read;
-    use tokio::pin;
+    use tokio_test::io::Builder;
+    use tokio_test::io::Mock;
+
+    #[tokio::test]
+    async fn test_with_pagebreaks() {
+        let mut output: Vec<u8> = Vec::new();
+        let mock: Mock = Builder::new()
+            .read(b"Hello\nWorld\x0cFoo Bar\n\x0cTest")
+            .build();
+        let res = postproc_pagebreaks(mock).read_to_end(&mut output).await;
+        println!("{}", String::from_utf8_lossy(&output));
+        assert!(matches!(res, Ok(_)));
+        assert_eq!(
+            output,
+            b"\nPage 1:Hello\nPage 1:World\nPage 2:Foo Bar\nPage 2:\nPage 3:Test"
+        );
+    }
 
     async fn test_from_strs(
         pagebreaks: bool,