Add search functions

Signed-off-by: trivernis <trivernis@protonmail.com>

Cargo.toml

@@ -12,6 +12,7 @@ scraper = "0.12.0"
 thiserror = "1.0.24"
 lazy_static = "1.4.0"
 serde = {version = "1.0.125", features = ["serde_derive"]}
+trigram = "0.4.4"
 
 [dev-dependencies]
 tokio = {version = "1.5.0", features = ["macros", "rt-multi-thread"]}

src/lib.rs

@@ -2,8 +2,10 @@ mod archive;
 mod comic;
 mod error;
 
+mod search;
 #[cfg(test)]
 mod tests;
 
 pub use archive::*;
 pub use comic::*;
+pub use search::*;

src/search.rs

@@ -0,0 +1,53 @@
+use crate::error::XKCDResult;
+use crate::get_archive;
+use std::cmp::Ordering;
+
+/// Searches for a comic containing the words from the query
+pub async fn search(query: &str) -> XKCDResult<Vec<(String, u32)>> {
+    let archive = get_archive().await?;
+    let words: Vec<String> = query
+        .split(" ")
+        .into_iter()
+        .map(|s| s.to_lowercase())
+        .collect();
+    let entries = archive
+        .into_iter()
+        .filter(|(key, _)| {
+            words
+                .iter()
+                .find(|w| key.to_lowercase().contains(*w))
+                .is_some()
+        })
+        .collect();
+
+    Ok(entries)
+}
+
+/// Searches for a comic with a fuzzy compare function that assigns a score
+/// to each match.
+/// The Threshold defines what still counts as a match
+pub async fn search_fuzzy(query: &str, threshold: f32) -> XKCDResult<Vec<(String, u32)>> {
+    let archive = get_archive().await?;
+    let query = query.to_lowercase();
+
+    let mut entries: Vec<(f32, String, u32)> = archive
+        .into_iter()
+        .map(|(key, id)| (trigram::similarity(&query, &key.to_lowercase()), key, id))
+        .filter(|(score, _, _)| score >= &threshold)
+        .collect();
+    entries.sort_by(|(s1, _, _), (s2, _, _)| {
+        if s1 > s2 {
+            Ordering::Greater
+        } else if s1 < s2 {
+            Ordering::Less
+        } else {
+            Ordering::Equal
+        }
+    });
+    entries.reverse();
+
+    Ok(entries
+        .into_iter()
+        .map(|(_, title, id)| (title, id))
+        .collect())
+}

src/tests.rs

@@ -1,4 +1,4 @@
-use crate::{get_archive, get_comic, get_latest_comic};
+use crate::{get_archive, get_comic, get_latest_comic, search, search_fuzzy};
 
 #[tokio::test]
 async fn it_retrieves_the_archive() {
@@ -15,3 +15,17 @@ async fn it_retrieves_a_comic() {
 async fn it_retrieves_the_latest_comic() {
     assert!(get_latest_comic().await.is_ok())
 }
+
+#[tokio::test]
+async fn it_searches_for_comics() {
+    let search_results = search("Phone").await.unwrap();
+    assert!(!search_results.is_empty());
+    assert!(search_results.len() < 1000);
+}
+
+#[tokio::test]
+async fn it_fuzzy_searches_for_comics() {
+    let search_results = search_fuzzy("Phone", 0.5).await.unwrap();
+    assert!(!search_results.is_empty());
+    assert!(search_results.len() < 1000);
+}