Init commit

server/core/models/shared/position.ts

@@ -0,0 +1,78 @@
+import { forceNumber } from '@peertube/peertube-core-utils'
+import { AggregateOptions, Attributes, Model, ModelStatic, Op, Sequelize, Transaction, WhereOptions } from 'sequelize'
+
+export async function getNextPositionOf<T extends Model> (options: {
+  model: ModelStatic<T>
+  columnName: keyof Attributes<T>
+  where: WhereOptions<Attributes<T>>
+  transaction: Transaction
+}) {
+  const { columnName, model, where, transaction } = options
+
+  const query: AggregateOptions<number> = {
+    where,
+    transaction
+  }
+
+  const position = await model.max(columnName, query)
+
+  return position
+    ? position + 1
+    : 1
+}
+
+export function reassignPositionOf<T extends Model> (options: {
+  model: ModelStatic<T>
+  columnName: keyof Attributes<T>
+  where: WhereOptions<Attributes<T>>
+  transaction: Transaction
+
+  firstPosition: number
+  endPosition: number
+  newPosition: number
+}) {
+  const { firstPosition, endPosition, newPosition, model, where, columnName, transaction } = options
+
+  const query = {
+    where: {
+      ...where,
+
+      [columnName]: {
+        [Op.gte]: firstPosition,
+        [Op.lte]: endPosition
+      }
+    },
+    transaction,
+    validate: false // We use a literal to update the position
+  }
+
+  const escapedColumnName = model.sequelize.escape(columnName as string).replace(/'/g, '')
+  const positionQuery = Sequelize.literal(`${forceNumber(newPosition)} + "${escapedColumnName}" - ${forceNumber(firstPosition)}`)
+
+  return model.update({ [columnName]: positionQuery } as Record<typeof columnName, typeof positionQuery>, query)
+}
+
+export function increasePositionOf<T extends Model> (options: {
+  model: ModelStatic<T>
+  columnName: keyof Attributes<T>
+  where: WhereOptions<Attributes<T>>
+  transaction: Transaction
+
+  fromPosition: number
+  by: number
+}) {
+  const { model, where, transaction, fromPosition, by, columnName } = options
+
+  const query = {
+    where: {
+      ...where,
+
+      [columnName]: {
+        [Op.gte]: fromPosition
+      }
+    },
+    transaction
+  }
+
+  return model.increment({ [columnName]: by } as Record<typeof columnName, number>, query)
+}