From e81809aae70d19a32a1c1708f68b774a0ccaf70e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <clement@meilisearch.com>
Date: Wed, 26 Apr 2023 11:55:43 +0200
Subject: [PATCH] Make the search for facet work

---
 meilisearch/src/routes/indexes/facet_search.rs |  2 +-
 meilisearch/src/search.rs                      | 15 ++++++++++-----
 milli/src/search/mod.rs                        | 12 ++++++------
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/meilisearch/src/routes/indexes/facet_search.rs b/meilisearch/src/routes/indexes/facet_search.rs
index be3af4f3e..16479c755 100644
--- a/meilisearch/src/routes/indexes/facet_search.rs
+++ b/meilisearch/src/routes/indexes/facet_search.rs
@@ -119,7 +119,7 @@ pub async fn search(
 ) -> Result<HttpResponse, ResponseError> {
     let index_uid = IndexUid::try_from(index_uid.into_inner())?;
 
-    let mut query = params.into_inner();
+    let query = params.into_inner();
     debug!("facet search called with params: {:?}", query);
 
     let facet_query = query.facet_query.clone();
diff --git a/meilisearch/src/search.rs b/meilisearch/src/search.rs
index 2093a27ef..cd6a0bc54 100644
--- a/meilisearch/src/search.rs
+++ b/meilisearch/src/search.rs
@@ -14,7 +14,9 @@ use meilisearch_types::error::deserr_codes::*;
 use meilisearch_types::heed::RoTxn;
 use meilisearch_types::index_uid::IndexUid;
 use meilisearch_types::milli::score_details::{ScoreDetails, ScoringStrategy};
-use meilisearch_types::milli::{dot_product_similarity, FacetSearchResult, InternalError};
+use meilisearch_types::milli::{
+    dot_product_similarity, facet, FacetSearchResult, InternalError, SearchForFacetValue,
+};
 use meilisearch_types::settings::DEFAULT_PAGINATION_MAX_TOTAL_HITS;
 use meilisearch_types::{milli, Document};
 use milli::tokenizer::TokenizerBuilder;
@@ -575,16 +577,19 @@ pub fn perform_search(
 pub fn perform_facet_search(
     index: &Index,
     search_query: SearchQuery,
-    facet_query: Option<String>,
+    mut facet_query: Option<String>,
     facet_name: String,
 ) -> Result<Vec<FacetSearchResult>, MeilisearchHttpError> {
     let before_search = Instant::now();
     let rtxn = index.read_txn()?;
 
-    let (search, is_finite_pagination, max_total_hits, offset) =
-        prepare_search(index, &rtxn, &search_query)?;
+    let (search, _, _, _) = prepare_search(index, &rtxn, &search_query)?;
+    let mut facet_search = SearchForFacetValue::new(facet_name, search);
+    if let Some(facet_query) = facet_query.take() {
+        facet_search.query(facet_query);
+    }
 
-    todo!("Execute the search")
+    facet_search.execute().map_err(Into::into)
 }
 
 fn insert_geo_distance(sorts: &[String], document: &mut Document) {
diff --git a/milli/src/search/mod.rs b/milli/src/search/mod.rs
index 85ba3df3a..bc88a0ff8 100644
--- a/milli/src/search/mod.rs
+++ b/milli/src/search/mod.rs
@@ -248,25 +248,25 @@ pub struct SearchForFacetValue<'a> {
 }
 
 impl<'a> SearchForFacetValue<'a> {
-    fn new(facet: String, search_query: Search<'a>) -> SearchForFacetValue<'a> {
+    pub fn new(facet: String, search_query: Search<'a>) -> SearchForFacetValue<'a> {
         SearchForFacetValue { query: None, facet, search_query }
     }
 
-    fn query(&mut self, query: impl Into<String>) -> &mut Self {
+    pub fn query(&mut self, query: impl Into<String>) -> &mut Self {
         self.query = Some(query.into());
         self
     }
 
-    fn execute(&self) -> Result<Vec<FacetSearchResult>> {
+    pub fn execute(&self) -> Result<Vec<FacetSearchResult>> {
         let index = self.search_query.index;
         let rtxn = self.search_query.rtxn;
 
-        let sortable_fields = index.sortable_fields(rtxn)?;
-        if !sortable_fields.contains(&self.facet) {
+        let filterable_fields = index.filterable_fields(rtxn)?;
+        if !filterable_fields.contains(&self.facet) {
             // TODO create a new type of error
             return Err(UserError::InvalidSortableAttribute {
                 field: self.facet.clone(),
-                valid_fields: sortable_fields.into_iter().collect(),
+                valid_fields: filterable_fields.into_iter().collect(),
             })?;
         }