From 968fe675cd83c825dbebff9e5c1c999a92f4f2dc Mon Sep 17 00:00:00 2001
From: projectmoon <projectmoon@agnos.is>
Date: Fri, 29 Mar 2024 20:00:02 +0100
Subject: [PATCH] Also attempt to verify from meta

---
 src/main.rs | 70 ++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 59 insertions(+), 11 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 933f0b7..d31e7c0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,8 @@
+use std::fmt::Display;
+
 use fluffer::{App, AppErr, Client, Fluff};
 use germ::ast::{Ast as GeminiAst, Node as GemtextNode};
+use germ::meta::Meta as GeminiMetadata;
 use germ::request::request as germ_request;
 use thiserror::Error;
 use url::Url;
@@ -17,19 +20,39 @@ enum GementionError {
 }
 
 enum VerificationStatus {
-    Verified(String),
+    Verified {
+        endpoint: String,
+        source: VerificationSource,
+    },
+
     NotVerified(VerificationFailureReason),
 }
 
 impl ToString for VerificationStatus {
     fn to_string(&self) -> String {
         match self {
-            Self::Verified(url) => format!("verified: {}", url),
+            Self::Verified { endpoint, source } => format!("verified: {} [{}]", endpoint, source),
             Self::NotVerified(failure) => failure.to_string(),
         }
     }
 }
 
+#[derive(Debug, Clone, Copy)]
+enum VerificationSource {
+    Meta,
+    Page,
+}
+
+impl Display for VerificationSource {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Meta => write!(f, "source=meta"),
+            Self::Page => write!(f, "source=page"),
+        }
+
+    }
+}
+
 enum VerificationFailureReason {
     /// No titan link to our endpoint exists on this page.
     NoMentionLinkFound,
@@ -58,25 +81,48 @@ fn is_mention_link(gemtext_link: &str) -> Result<bool, GementionError> {
     Ok(gemtext_link.starts_with(OUR_ENDPOINT))
 }
 
-fn scan_for_mentions(ast: GeminiAst) -> Vec<String> {
-    ast.inner()
+fn scan_for_mentions(meta: GeminiMetadata, ast: GeminiAst) -> (VerificationSource, Vec<String>) {
+    // Check metadata of the page for a gemention endpoint.
+    println!("meta is {:?}", meta);
+    if let Some(endpoint) = meta.parameters().get("gemention") {
+        let endpoint = endpoint.trim_start_matches("=");
+        return (VerificationSource::Meta, vec![endpoint.to_owned()]);
+    }
+
+    // If that fails, check the page itself for the first available
+    // link that matches.
+    let endpoints = ast
+        .inner()
         .into_iter()
         .filter_map(|node| match node {
             GemtextNode::Link { ref to, .. } if is_mention_link(to).unwrap_or(false) => Some(to),
             _ => None,
         })
         .cloned()
-        .collect()
+        .collect();
+
+    (VerificationSource::Page, endpoints)
 }
 
-fn verify_mentions<S: AsRef<str>>(expected_link: S, mentions: Vec<String>) -> VerificationStatus {
+fn verify_mentions<S: AsRef<str>>(
+    expected_link: S,
+    source_and_mentions: (VerificationSource, Vec<String>),
+) -> VerificationStatus {
+    let (verification_source, mentions) = source_and_mentions;
     let expected_link = expected_link.as_ref();
+
     if mentions.len() > 0 {
+        // We have links that go to our endpoint. Scan links for the
+        // one we expect (i.e. for the target), otherwise we say
+        // incorrect link.
         mentions
             .into_iter()
             .find_map(|link| {
                 if link == expected_link {
-                    Some(VerificationStatus::Verified(link))
+                    Some(VerificationStatus::Verified {
+                        source: verification_source,
+                        endpoint: link,
+                    })
                 } else {
                     None
                 }
@@ -89,18 +135,20 @@ fn verify_mentions<S: AsRef<str>>(expected_link: S, mentions: Vec<String>) -> Ve
     }
 }
 
-async fn verify_mention(target: &str) -> Result<VerificationStatus, GementionError> {
-    let url = Url::parse(&format!("gemini://{}", target))?;
-    let expected_link = Url::parse(OUR_ENDPOINT)?.join(target)?;
+async fn verify_mention(target_page: &str) -> Result<VerificationStatus, GementionError> {
+    let url = Url::parse(&format!("gemini://{}", target_page))?;
+    let expected_link = Url::parse(OUR_ENDPOINT)?.join(target_page)?;
 
     let resp = germ_request(&url).await?;
+    let meta = GeminiMetadata::from_string(resp.meta());
+
     let content = resp
         .content()
         .as_deref()
         .ok_or(GementionError::NoContentFoundForTarget)?;
 
     let ast = GeminiAst::from_string(content);
-    let mentions = scan_for_mentions(ast);
+    let mentions = scan_for_mentions(meta, ast);
     Ok(verify_mentions(expected_link, mentions))
 }