Show BibTeX entry when hovering over citations

src/hover/latex_citation.rs

@@ -0,0 +1,73 @@
+use crate::feature::FeatureRequest;
+use crate::formatting::{BibtexFormatter, BibtexFormattingOptions};
+use crate::syntax::bibtex::{BibtexDeclaration, BibtexEntry};
+use crate::syntax::latex::{LatexCitationAnalyzer, LatexToken, LatexVisitor};
+use crate::syntax::text::SyntaxNode;
+use crate::workspace::SyntaxTree;
+use lsp_types::{Hover, HoverContents, MarkupContent, MarkupKind, TextDocumentPositionParams};
+use std::borrow::Cow;
+
+pub struct LatexCitationHoverProvider;
+
+impl LatexCitationHoverProvider {
+    pub async fn execute(request: &FeatureRequest<TextDocumentPositionParams>) -> Option<Hover> {
+        let entry = Self::get_entry(request)?;
+        if entry.is_comment() {
+            None
+        } else {
+            let mut formatter = BibtexFormatter::new(BibtexFormattingOptions::new(4, true, 80));
+            formatter.format_entry(entry);
+            Some(Hover {
+                contents: HoverContents::Markup(MarkupContent {
+                    kind: MarkupKind::Markdown,
+                    value: Cow::from(format!("```bibtex\n{}\n```", formatter.output)),
+                }),
+                range: None,
+            })
+        }
+    }
+
+    fn get_entry(request: &FeatureRequest<TextDocumentPositionParams>) -> Option<&BibtexEntry> {
+        let key = Self::get_key(request)?;
+        for document in &request.related_documents {
+            if let SyntaxTree::Bibtex(tree) = &document.tree {
+                for declaration in &tree.root.children {
+                    if let BibtexDeclaration::Entry(entry) = &declaration {
+                        if let Some(current_key) = &entry.key {
+                            if current_key.text() == key {
+                                return Some(entry);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        None
+    }
+
+    fn get_key(request: &FeatureRequest<TextDocumentPositionParams>) -> Option<&str> {
+        match &request.document.tree {
+            SyntaxTree::Latex(tree) => {
+                let mut analyzer = LatexCitationAnalyzer::new();
+                analyzer.visit_root(&tree.root);
+                analyzer
+                    .citations
+                    .iter()
+                    .find(|citation| citation.command.range.contains(request.params.position))
+                    .map(|citation| citation.key.text())
+            }
+            SyntaxTree::Bibtex(tree) => {
+                for declaration in &tree.root.children {
+                    if let BibtexDeclaration::Entry(entry) = &declaration {
+                        if let Some(key) = &entry.key {
+                            if key.range().contains(request.params.position) {
+                                return Some(key.text());
+                            }
+                        }
+                    }
+                }
+                None
+            }
+        }
+    }
+}

src/hover/mod.rs

@@ -1,14 +1,20 @@
 mod bibtex_field;
+mod latex_citation;
 
+use self::bibtex_field::BibtexFieldHoverProvider;
+use self::latex_citation::LatexCitationHoverProvider;
 use crate::choice_feature;
 use crate::feature::FeatureRequest;
-use crate::hover::bibtex_field::BibtexFieldHoverProvider;
 use lsp_types::{Hover, TextDocumentPositionParams};
 
 pub struct HoverProvider;
 
 impl HoverProvider {
     pub async fn execute(request: &FeatureRequest<TextDocumentPositionParams>) -> Option<Hover> {
-        choice_feature!(&request, BibtexFieldHoverProvider)
+        choice_feature!(
+            &request,
+            BibtexFieldHoverProvider,
+            LatexCitationHoverProvider
+        )
     }
 }