From c4031449fb38bed27b43152e5d9e048c4588b6f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pierre=20No=C3=ABl?= <petersg83@gmail.com>
Date: Wed, 7 Sep 2022 18:21:54 +0200
Subject: [PATCH] implement 2 columns + adapt attachRelations

---
 .../core/database/lib/entity-manager/index.js | 27 ++++++++++--
 .../core/database/lib/metadata/relations.js   | 41 +++++++++++++++++--
 2 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/packages/core/database/lib/entity-manager/index.js b/packages/core/database/lib/entity-manager/index.js
index 79fa8af92d..15618b2126 100644
--- a/packages/core/database/lib/entity-manager/index.js
+++ b/packages/core/database/lib/entity-manager/index.js
@@ -475,26 +475,45 @@ const createEntityManager = (db) => {
           // need to set the column on the target
 
           const { joinTable } = attribute;
-          const { joinColumn, inverseJoinColumn } = joinTable;
+          const { joinColumn, inverseJoinColumn, orderColumnName, inverseOrderColumnName } =
+            joinTable;
 
           if (isOneToAny(attribute) && isBidirectional(attribute)) {
             await this.createQueryBuilder(joinTable.name)
               .delete()
-              .where({ [inverseJoinColumn.name]: castArray(data[attributeName]) })
+              .where({ [inverseJoinColumn.name]: castArray(data[attributeName]) }) // TODO: would break with connect
               .where(joinTable.on || {})
               .execute();
           }
 
           const assocs = toAssocs(data[attributeName]);
 
-          const relationsToAdd = assocs.connect || assocs;
+          const relationsToAdd = uniqBy('id', assocs.connect || assocs);
+
+          const maxMap = {};
+          if (inverseOrderColumnName) {
+            await Promise.all(
+              relationsToAdd.map(async (rel) => {
+                const { max } = await this.createQueryBuilder(joinTable.name)
+                  .max(inverseOrderColumnName)
+                  .where({ [inverseJoinColumn.name]: rel.id })
+                  .where(joinTable.on || {})
+                  .first()
+                  .execute();
+
+                maxMap[rel.id] = max;
+              })
+            );
+          }
+
           const insert = relationsToAdd.map((data, idx) => {
             return {
               [joinColumn.name]: id,
               [inverseJoinColumn.name]: data.id,
               ...(joinTable.on || {}),
               ...(data.__pivot || {}),
-              order: idx + 1,
+              [orderColumnName]: idx + 1,
+              ...(inverseOrderColumnName ? { [inverseOrderColumnName]: maxMap[data.id] + 1 } : {}),
             };
           });
 
diff --git a/packages/core/database/lib/metadata/relations.js b/packages/core/database/lib/metadata/relations.js
index 2dfcb0e5ff..b3b9896949 100644
--- a/packages/core/database/lib/metadata/relations.js
+++ b/packages/core/database/lib/metadata/relations.js
@@ -398,12 +398,14 @@ const createJoinTable = (metadata, { attributeName, attribute, meta }) => {
   const joinColumnName = _.snakeCase(`${meta.singularName}_id`);
   let inverseJoinColumnName = _.snakeCase(`${targetMeta.singularName}_id`);
 
+  const orderColumnName = _.snakeCase(`${meta.singularName}_order`);
+
   // if relation is slef referencing
   if (joinColumnName === inverseJoinColumnName) {
     inverseJoinColumnName = `inv_${inverseJoinColumnName}`;
   }
 
-  metadata.add({
+  const metadataSchema = {
     uid: joinTableName,
     tableName: joinTableName,
     attributes: {
@@ -422,7 +424,7 @@ const createJoinTable = (metadata, { attributeName, attribute, meta }) => {
           unsigned: true,
         },
       },
-      order: {
+      [orderColumnName]: {
         type: 'integer',
         column: {
           unsigned: true,
@@ -440,6 +442,10 @@ const createJoinTable = (metadata, { attributeName, attribute, meta }) => {
         name: `${joinTableName}_inv_fk`,
         columns: [inverseJoinColumnName],
       },
+      {
+        name: `${joinTableName}_order_fk`,
+        columns: [orderColumnName],
+      },
     ],
     foreignKeys: [
       {
@@ -457,7 +463,7 @@ const createJoinTable = (metadata, { attributeName, attribute, meta }) => {
         onDelete: 'CASCADE',
       },
     ],
-  });
+  };
 
   const joinTable = {
     name: joinTableName,
@@ -469,8 +475,35 @@ const createJoinTable = (metadata, { attributeName, attribute, meta }) => {
       name: inverseJoinColumnName,
       referencedColumn: 'id',
     },
+    orderColumnName,
   };
 
+  if (isBidirectional(attribute)) {
+    let inverseOrderColumnName = _.snakeCase(`${targetMeta.singularName}_order`);
+
+    // if relation is slef referencing
+    if (joinColumnName === inverseJoinColumnName) {
+      inverseOrderColumnName = `inv_${inverseOrderColumnName}`;
+    }
+
+    metadataSchema.attributes[inverseOrderColumnName] = {
+      type: 'integer',
+      column: {
+        unsigned: true,
+        defaultTo: 0,
+      },
+    };
+
+    metadataSchema.indexes.push({
+      name: `${joinTableName}_order_inv_fk`,
+      columns: [inverseOrderColumnName],
+    });
+
+    joinTable.inverseOrderColumnName = inverseOrderColumnName;
+  }
+
+  metadata.add(metadataSchema);
+
   attribute.joinTable = joinTable;
 
   if (isBidirectional(attribute)) {
@@ -486,6 +519,8 @@ const createJoinTable = (metadata, { attributeName, attribute, meta }) => {
       name: joinTableName,
       joinColumn: joinTable.inverseJoinColumn,
       inverseJoinColumn: joinTable.joinColumn,
+      orderColumnName: joinTable.inverseOrderColumnName,
+      inverseOrderColumnName: joinTable.orderColumnName,
     };
   }
 };