Refactor Meilisearch, update to latest SDK, and implement faceted search (#44)

* feat(indexing): Reindex curseforge & local database at an interval

* fix(indexing): Use strings for meilisearch primary key

Fixes #17 by prefixing curseforge ids with "curse-" and local ids
with "local-".

* feat(indexing): Add newly created mods to the index more quickly

* feat(indexing): Implement faceted search, update to meilisearch master

Fixes #9, but only uses faceted search for categories.  It should
be reasonably simple to add support for versions, but it may not
be as useful due to the large number of versions and the large
number of supported versions for each mod.

* feat(indexing): Allow skipping initial indexing

Co-authored-by: Geometrically <18202329+Geometrically@users.noreply.github.com>

src/search/mod.rs

@@ -6,6 +6,7 @@ use meilisearch_sdk::client::Client;
 use meilisearch_sdk::document::Document;
 use meilisearch_sdk::search::Query;
 use serde::{Deserialize, Serialize};
+use std::borrow::Cow;
 use thiserror::Error;
 
 pub mod indexing;
@@ -13,7 +14,7 @@ pub mod indexing;
 #[derive(Error, Debug)]
 pub enum SearchError {
     #[error("Error while connecting to the MeiliSearch database")]
-    IndexDBError(meilisearch_sdk::errors::Error),
+    IndexDBError(#[from] meilisearch_sdk::errors::Error),
     #[error("Error while serializing or deserializing JSON: {0}")]
     SerDeError(#[from] serde_json::Error),
     #[error("Error while parsing an integer: {0}")]
@@ -45,36 +46,75 @@ impl actix_web::ResponseError for SearchError {
     }
 }
 
+/// A mod document used for uploading mods to meilisearch's indices.
+/// This contains some extra data that is not returned by search results.
 #[derive(Serialize, Deserialize, Debug, Clone)]
-pub struct SearchMod {
-    pub mod_id: i64,
+pub struct UploadSearchMod {
+    pub mod_id: String,
     pub author: String,
     pub title: String,
     pub description: String,
-    pub keywords: Vec<String>,
+    pub categories: Vec<String>,
     pub versions: Vec<String>,
     pub downloads: i32,
     pub page_url: String,
     pub icon_url: String,
     pub author_url: String,
-    pub date_created: String,
-    pub created: i64,
-    pub date_modified: String,
-    pub updated: i64,
     pub latest_version: String,
-    pub empty: String,
+
+    /// RFC 3339 formatted creation date of the mod
+    pub date_created: String,
+    /// Unix timestamp of the creation date of the mod
+    pub created_timestamp: i64,
+    /// RFC 3339 formatted date/time of last major modification (update)
+    pub date_modified: String,
+    /// Unix timestamp of the last major modification
+    pub modified_timestamp: i64,
+
+    /// Must be "{}{}{}", a hack until meilisearch supports searches
+    /// with empty queries (https://github.com/meilisearch/MeiliSearch/issues/729)
+    // This is a Cow to prevent unnecessary allocations for a static
+    // string
+    pub empty: Cow<'static, str>,
 }
 
-impl Document for SearchMod {
-    type UIDType = i64;
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct ResultSearchMod {
+    pub mod_id: String,
+    pub author: String,
+    pub title: String,
+    pub description: String,
+    pub categories: Vec<String>,
+    // TODO: more efficient format for listing versions, without many repetitions
+    pub versions: Vec<String>,
+    pub downloads: i32,
+    pub page_url: String,
+    pub icon_url: String,
+    pub author_url: String,
+    /// RFC 3339 formatted creation date of the mod
+    pub date_created: String,
+    /// RFC 3339 formatted modification date of the mod
+    pub date_modified: String,
+    pub latest_version: String,
+}
+
+impl Document for UploadSearchMod {
+    type UIDType = String;
 
     fn get_uid(&self) -> &Self::UIDType {
         &self.mod_id
     }
 }
 
-pub fn search_for_mod(info: &SearchRequest) -> Result<Vec<SearchMod>, SearchError> {
-    use std::borrow::Cow;
+impl Document for ResultSearchMod {
+    type UIDType = String;
+
+    fn get_uid(&self) -> &Self::UIDType {
+        &self.mod_id
+    }
+}
+
+pub async fn search_for_mod(info: &SearchRequest) -> Result<Vec<ResultSearchMod>, SearchError> {
     let address = &*dotenv::var("MEILISEARCH_ADDR")?;
     let client = Client::new(address, "");
 
@@ -98,11 +138,15 @@ pub fn search_for_mod(info: &SearchRequest) -> Result<Vec<SearchMod>, SearchErro
     if !filters.is_empty() {
         query = query.with_filters(&filters);
     }
+    if let Some(facets) = &info.facets {
+        let facets = serde_json::from_str::<Vec<Vec<&str>>>(facets)?;
+        query = query.with_facet_filters(facets);
+    }
 
     Ok(client
         .get_index(format!("{}_mods", index).as_ref())
-        .map_err(SearchError::IndexDBError)?
-        .search::<SearchMod>(&query)
-        .map_err(SearchError::IndexDBError)?
+        .await?
+        .search::<ResultSearchMod>(&query)
+        .await?
         .hits)
 }