From 51a8e1ff88a5a0fbddc08b2c0db137f00ebd3be1 Mon Sep 17 00:00:00 2001
From: Leonora Tindall <nora@nora.codes>
Date: Tue, 1 Nov 2022 14:50:14 -0500
Subject: [PATCH] Add post-slurping (get markdown source for post)

---
 src/main.rs       | 43 +++++++++++++++++++++++++++++++++++++++++--
 static/index.html |  5 +++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 11b18a3..3359029 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -12,7 +12,7 @@ mod cohost_posts;
 mod syndication;
 mod webfinger;
 use cohost_account::{CohostAccount, COHOST_ACCOUNT_API_URL};
-use cohost_posts::{cohost_posts_api_url, CohostPostsPage};
+use cohost_posts::{cohost_posts_api_url, CohostPost, CohostPostsPage};
 use webfinger::CohostWebfingerResource;
 
 #[derive(Parser, Debug)]
@@ -46,6 +46,12 @@ fn index() -> RawHtml<&'static str> {
     RawHtml(include_str!("../static/index.html"))
 }
 
+#[derive(Responder)]
+#[response(content_type = "text/markdown")]
+struct MdResponse {
+    inner: String,
+}
+
 #[derive(Responder)]
 #[response(content_type = "application/rss+xml")]
 struct RssResponse {
@@ -61,6 +67,28 @@ enum ErrorResponse {
     InternalError(String),
 }
 
+async fn get_post_from_page(
+    client: &mut Client,
+    project_id: &str,
+    post_id: u64,
+) -> Result<CohostPost, ErrorResponse> {
+    let mut page = 0;
+    loop {
+        let new_page = get_page_data(client, project_id, page).await?;
+        if new_page.items.is_empty() {
+            // Once there are no posts, we're done.
+            return Err(ErrorResponse::NotFound(
+                "End of posts reached, ID not found.".into(),
+            ));
+        } else {
+            page += 1;
+            if let Some(post) = new_page.items.into_iter().find(|post| post.id == post_id) {
+                return Ok(post);
+            }
+        }
+    }
+}
+
 async fn get_full_post_data(
     client: &mut Client,
     project_id: &str,
@@ -130,6 +158,17 @@ async fn syndication_rss_route(project: &str) -> Result<RssResponse, ErrorRespon
     })
 }
 
+#[get("/<project>/<id>")]
+async fn post_md_route(project: &str, id: u64) -> Result<MdResponse, ErrorResponse> {
+    let mut client = get_client()?;
+
+    let _project_data = get_project_data(&mut client, project).await?;
+    let post_data = get_post_from_page(&mut client, project, id).await?;
+    Ok(MdResponse {
+        inner: post_data.plain_body,
+    })
+}
+
 async fn get_project_data(
     client: &mut Client,
     project_id: &str,
@@ -213,7 +252,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
     let _rocket = rocket::build()
         .mount(
             &ARGS.base_url,
-            routes![index, webfinger_route, syndication_rss_route],
+            routes![index, webfinger_route, syndication_rss_route, post_md_route],
         )
         .ignite()
         .await?
diff --git a/static/index.html b/static/index.html
index fe650cf..409021f 100644
--- a/static/index.html
+++ b/static/index.html
@@ -30,6 +30,11 @@
         Go to <code>/project_name/feed.rss</code> to get a feed for a project.
         For example, <a href="/noracodes/feed.rss"><code>/noracodes/feed.rss</code></a> will give you the feed for my page.
     </p>
+    <p>
+        You can also get a particular post's original plain-text body at <code>/project_name/post_id/</code>, such as
+        <a href="/noracodes/169186/"><code>/noracodes/169186/</code></a>. (In a Cohost post URL, the ID is the numerical part after <code>/post/</code>.
+        For instance, in <code>https://cohost.org/noracodes/post/169186-october-update</code>, the ID is "169186".)
+    </p>
     <p>
         Webfinger resources for accounts are provided at the Webfinger well-known URL <code>/.well-known/webfinger?project_name</code>.
     </p>