From 927444a010597d22ccb08fe3d5111bb92070cbbe Mon Sep 17 00:00:00 2001
From: Francisco Salgueiro <fgcdbs@gmail.com>
Date: Fri, 10 Nov 2023 13:34:15 +0000
Subject: [PATCH] allow for reversed game analysis

---
 src-tauri/src/chess.rs                        | 23 +++++++++++++++----
 src/bindings.ts                               |  2 +-
 .../panels/analysis/ReportModal.tsx           |  8 +++++++
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src-tauri/src/chess.rs b/src-tauri/src/chess.rs
index eb661287..f84cf017 100644
--- a/src-tauri/src/chess.rs
+++ b/src-tauri/src/chess.rs
@@ -423,6 +423,7 @@ pub struct AnalysisOptions {
     pub fen: String,
     pub annotate_novelties: bool,
     pub reference_db: Option<PathBuf>,
+    pub reversed: bool,
 }
 
 #[tauri::command]
@@ -452,6 +453,10 @@ pub async fn analyze_game(
         fens.push(Fen::from_position(chess.clone(), EnPassantMode::Legal));
     });
 
+    if options.reversed {
+        fens.reverse();
+    }
+
     let mut novelty_found = false;
 
     for (i, fen) in fens.iter().enumerate() {
@@ -463,7 +468,6 @@ pub async fn analyze_game(
                 finished: false,
             },
         )?;
-        let query = PositionQuery::exact_from_fen(&fen.to_string())?;
 
         process
             .set_options(EngineOptions {
@@ -490,19 +494,28 @@ pub async fn analyze_game(
                 _ => {}
             }
         }
+        analysis.push(current_analysis);
+    }
+
+    if options.reversed {
+        analysis.reverse();
+        fens.reverse();
+    }
+
+    for (i, analysis) in analysis.iter_mut().enumerate() {
+        let fen = &fens[i];
+        let query = PositionQuery::exact_from_fen(&fen.to_string())?;
 
         if options.annotate_novelties && !novelty_found {
             if let Some(reference) = options.reference_db.clone() {
-                current_analysis.novelty =
-                    !is_position_in_db(reference, query, state.clone()).await?;
-                if current_analysis.novelty {
+                analysis.novelty = !is_position_in_db(reference, query, state.clone()).await?;
+                if analysis.novelty {
                     novelty_found = true;
                 }
             } else {
                 return Err(Error::MissingReferenceDatabase);
             }
         }
-        analysis.push(current_analysis);
     }
     app.emit_all(
         "report_progress",
diff --git a/src/bindings.ts b/src/bindings.ts
index 08b4813d..7c15cbb1 100644
--- a/src/bindings.ts
+++ b/src/bindings.ts
@@ -62,7 +62,7 @@ bestMovesPayload: "plugin:tauri-specta:best-moves-payload"
 
 /** user-defined types **/
 
-export type AnalysisOptions = { fen: string; annotateNovelties: boolean; referenceDb: string | null }
+export type AnalysisOptions = { fen: string; annotateNovelties: boolean; referenceDb: string | null; reversed: boolean }
 export type BestMoves = { depth: number; score: Score; uciMoves: string[]; sanMoves: string[]; multipv: number; nps: number }
 export type BestMovesPayload = { bestLines: BestMoves[]; engine: string; tab: string }
 export type EngineOption = { name: string; value: string }
diff --git a/src/components/panels/analysis/ReportModal.tsx b/src/components/panels/analysis/ReportModal.tsx
index 052add06..23a823d8 100644
--- a/src/components/panels/analysis/ReportModal.tsx
+++ b/src/components/panels/analysis/ReportModal.tsx
@@ -39,6 +39,7 @@ function ReportModal({
       engine: engines[0]?.path ?? "",
       millisecondsPerMove: 500,
       novelty: true,
+      reversed: true
     },
 
     validate: {
@@ -70,6 +71,7 @@ function ReportModal({
           annotateNovelties: form.values.novelty,
           fen: initialFen,
           referenceDb,
+          reversed: form.values.reversed
         }
       )
       .then((analysis) => {
@@ -111,6 +113,12 @@ function ReportModal({
             {...form.getInputProps("millisecondsPerMove")}
           />
 
+          <Checkbox
+            label="Reversed analysis"
+            description="Analyze the game in starting from the last move."
+            {...form.getInputProps("reversed", { type: "checkbox" })}
+          />
+
           <Checkbox
             label="Annotate Novelties"
             description="Add a comment to the first position that is not in the reference database."