fix inventory slot and stacked items

src/entity/gateway/postgres/migrations/V0001__initial.sql

@@ -79,9 +79,9 @@ create table item_location (
   created_at timestamptz default current_timestamp not null
 );
 
-create table inventory_slots (
-  pchar integer references player_character not null,
-  items integer[30] /* references item (id) */
+create table inventory_slot (
+  item integer references item not null unique,
+  slot integer not null
 );
 
 create table weapon_modifier (

src/entity/gateway/postgres/postgres.rs

@@ -172,7 +172,6 @@ impl EntityGateway for PostgresGateway {
                   ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31)
                   returning *;"#;
         let character = sqlx::query_as::<_, PgCharacter>(q)
-        //sqlx::query(q)
             .bind(char.user_id.0)
             .bind(char.slot as i16)
             .bind(char.name)
@@ -206,9 +205,6 @@ impl EntityGateway for PostgresGateway {
             .bind(char.option_flags as i32)
             .fetch_one(&self.pool).await?;
 
-        sqlx::query("insert into inventory_slots (pchar) values ($1)")
-            .bind(character.id)
-            .execute(&self.pool).await?;
         Ok(character.into())
     }
 
@@ -280,23 +276,22 @@ impl EntityGateway for PostgresGateway {
         let new_item = sqlx::query_as::<_, PgItem>("insert into item (item) values ($1) returning *;")
             .bind(sqlx::types::Json(PgItemDetail::from(item.item)))
             .fetch_one(&mut tx).await?;
-        let location = if let ItemLocation::Inventory{character_id, slot, ..} = &item.location {
+        let location = if let ItemLocation::Inventory{slot, ..} = &item.location {
             sqlx::query("insert into item_location (item, location) values ($1, $2)")
                 .bind(new_item.id)
                 .bind(sqlx::types::Json(PgItemLocationDetail::from(item.location.clone())))
                 .execute(&mut tx).await?;
-            sqlx::query("update inventory_slots set items[$2] = $1 where pchar = $3")
+            sqlx::query("insert into inventory_slot (item, slot) values ($1, $2)")
                 .bind(new_item.id)
                 .bind(*slot as i32)
-                .bind(character_id.0 as i32)
                 .execute(&mut tx).await?;
             sqlx::query_as::<_, PgItemLocation>(r#"select
                                                        item_location.item,
-                                                       jsonb_set(item_location.location, '{Inventory,slot}', (array_position(inventory_slots.items, item.id))::text::jsonb) as location,
+                                                       jsonb_set(item_location.location, '{Inventory,slot}', inventory_slot.slot::text::jsonb) as location,
                                                        item_location.created_at
                                                    from item_location
                                                    join item on item.id = item_location.item
-                                                   join inventory_slots on inventory_slots.pchar = cast (item_location.location -> 'Inventory' ->> 'character_id' as integer)
+                                                   join inventory_slot on inventory_slot.item = item.id
                                                    where item.id = $1
                                                    order by item_location.created_at
                                                    limit 1"#)
@@ -319,15 +314,13 @@ impl EntityGateway for PostgresGateway {
 
     async fn change_item_location(&mut self, item_id: &ItemEntityId, item_location: ItemLocation) -> Result<(), GatewayError> {
         let mut tx = self.pool.begin().await?;
-        if let ItemLocation::Inventory{character_id, slot, ..} = &item_location {
-            sqlx::query("update inventory_slots set items[array_position(items, $1)] = null where pchar = $2 and items[array_position(items, $1)] is not null")
+        if let ItemLocation::Inventory{slot, ..} = &item_location {
+            sqlx::query("delete from inventory_slot where item = $1")
                 .bind(item_id.0 as i32)
-                .bind(character_id.0 as i32)
                 .execute(&mut tx).await?;
-            sqlx::query("update inventory_slots set items[$2] = $1 where pchar = $3")
-                .bind(item_id.0 as i32)
+            sqlx::query("insert into inventory_slot (item, slot) values ($1, $2)")
+                .bind(item_id.0)
                 .bind(*slot as i32)
-                .bind(character_id.0 as i32)
                 .execute(&mut tx).await?;
             sqlx::query(r#"insert into item_location (item, location)
                            select $1, $2
@@ -377,14 +370,14 @@ impl EntityGateway for PostgresGateway {
                           item.id,
                           case
                               when item_location.location -> 'Inventory' is not null then
-                                  jsonb_set(item_location.location, '{Inventory,slot}', (array_position(inventory_slots.items, item.id))::text::jsonb)
+                                  jsonb_set(item_location.location, '{Inventory,slot}', inventory_slot.slot::text::jsonb)
                               else
                                   item_location.location
                           end,
                           item.item
                       from item_location
                       join item on item.id = item_location.item
-                      join inventory_slots on inventory_slots.pchar = $1
+                      join inventory_slot on inventory_slot.item = item.id
                       order by item_location.item, item_location.created_at desc
                   ) as i
                   where cast (location -> 'Inventory' ->> 'character_id' as integer) = $1