Add: series migration to be unique

server/migrations/changelog.md

@@ -2,6 +2,6 @@
 
 Please add a record of every database migration that you create to this file. This will help us keep track of changes to the database schema over time.
 
-| Server Version | Migration Script Name | Description |
-| -------------- | --------------------- | ----------- |
-|                |                       |             |
+| Server Version | Migration Script Name        | Description                                       |
+| -------------- | ---------------------------- | ------------------------------------------------- |
+| v2.13.5        | v2.13.5-series-column-unique | Series must have unique names in the same library |

server/migrations/v2.13.5-series-column-unique.js

@@ -0,0 +1,200 @@
+const Logger = require('../Logger')
+
+/**
+ * @typedef MigrationContext
+ * @property {import('sequelize').QueryInterface} queryInterface - a suquelize QueryInterface object.
+ * @property {import('../Logger')} logger - a Logger object.
+ *
+ * @typedef MigrationOptions
+ * @property {MigrationContext} context - an object containing the migration context.
+ */
+
+/**
+ * This upward migration script cleans any duplicate series in the `Series` table and
+ * adds a unique index on the `name` and `libraryId` columns.
+ *
+ * @param {MigrationOptions} options - an object containing the migration context.
+ * @returns {Promise<void>} - A promise that resolves when the migration is complete.
+ */
+async function up({ context: { queryInterface, logger } }) {
+  // Upwards migration script
+  logger.info('UPGRADE BEGIN: 2.13.5-series-column-unique ')
+
+  // The steps taken to deduplicate the series are as follows:
+  // 1. Find all duplicate series in the `Series` table.
+  // 2. Iterate over the duplicate series and find all book IDs that are associated with the duplicate series in `bookSeries` table.
+  //    2.a For each book ID, check if the ID occurs multiple times for the duplicate series.
+  //    2.b If so, keep only one of the rows that has this bookId and seriesId.
+  // 3. Update `bookSeries` table to point to the most recent series.
+  // 4. Delete the older series.
+
+  // Use the queryInterface to get the series table and find duplicates in the `name` and `libraryId` column
+  const [duplicates] = await queryInterface.sequelize.query(`
+    SELECT name, libraryId, MAX(updatedAt) AS latestUpdatedAt, COUNT(name) AS count
+    FROM Series
+    GROUP BY name, libraryId
+    HAVING COUNT(name) > 1
+  `)
+
+  // Print out how many duplicates were found
+  logger.info(`[2.13.5 migration] Found ${duplicates.length} duplicate series`)
+
+  // Iterate over each duplicate series
+  for (const duplicate of duplicates) {
+    // Report the series name that is being deleted
+    logger.info(`[2.13.5 migration] Deduplicating series "${duplicate.name}" in library ${duplicate.libraryId}`)
+
+    // Determine any duplicate book IDs in the `bookSeries` table for the same series
+    const [duplicateBookIds] = await queryInterface.sequelize.query(
+      `
+        SELECT bookId, COUNT(bookId) AS count
+        FROM BookSeries
+        WHERE seriesId IN (
+          SELECT id
+          FROM Series
+          WHERE name = :name AND libraryId = :libraryId
+        )
+        GROUP BY bookId
+        HAVING COUNT(bookId) > 1
+        `,
+      {
+        replacements: {
+          name: duplicate.name,
+          libraryId: duplicate.libraryId
+        }
+      }
+    )
+
+    // Iterate over the duplicate book IDs if there is at least one and only keep the first row that has this bookId and seriesId
+    for (const { bookId } of duplicateBookIds) {
+      logger.info(`[2.13.5 migration] Deduplicating bookId ${bookId} in series "${duplicate.name}" of library ${duplicate.libraryId}`)
+      // Get all rows of `BookSeries` table that have the same `bookId` and `seriesId`. Sort by `sequence` with nulls sorted last
+      const [duplicateBookSeries] = await queryInterface.sequelize.query(
+        `
+            SELECT id
+            FROM BookSeries
+            WHERE bookId = :bookId
+            AND seriesId IN (
+              SELECT id
+              FROM Series
+              WHERE name = :name AND libraryId = :libraryId
+            )
+            ORDER BY sequence NULLS LAST
+            `,
+        {
+          replacements: {
+            bookId,
+            name: duplicate.name,
+            libraryId: duplicate.libraryId
+          }
+        }
+      )
+
+      // remove the first element from the array
+      duplicateBookSeries.shift()
+
+      // Delete the remaining duplicate rows
+      if (duplicateBookSeries.length > 0) {
+        const [deletedBookSeries] = await queryInterface.sequelize.query(
+          `
+              DELETE FROM BookSeries
+              WHERE id IN (:ids)
+              `,
+          {
+            replacements: {
+              ids: duplicateBookSeries.map((row) => row.id)
+            }
+          }
+        )
+      }
+      logger.info(`[2.13.5 migration] Finished cleanup of bookId ${bookId} in series "${duplicate.name}" of library ${duplicate.libraryId}`)
+    }
+
+    // Get all the most recent series which matches the `name` and `libraryId`
+    const [mostRecentSeries] = await queryInterface.sequelize.query(
+      `
+        SELECT id
+        FROM Series
+        WHERE name = :name AND libraryId = :libraryId
+        ORDER BY updatedAt DESC
+        LIMIT 1
+        `,
+      {
+        replacements: {
+          name: duplicate.name,
+          libraryId: duplicate.libraryId
+        },
+        type: queryInterface.sequelize.QueryTypes.SELECT
+      }
+    )
+
+    if (mostRecentSeries) {
+      // Update all BookSeries records for this series to point to the most recent series
+      const [seriesUpdated] = await queryInterface.sequelize.query(
+        `
+          UPDATE BookSeries
+          SET seriesId = :mostRecentSeriesId
+          WHERE seriesId IN (
+            SELECT id
+            FROM Series
+            WHERE name = :name AND libraryId = :libraryId
+            AND id != :mostRecentSeriesId
+          )
+          `,
+        {
+          replacements: {
+            name: duplicate.name,
+            libraryId: duplicate.libraryId,
+            mostRecentSeriesId: mostRecentSeries.id
+          }
+        }
+      )
+
+      // Delete the older series
+      const seriesDeleted = await queryInterface.sequelize.query(
+        `
+          DELETE FROM Series
+          WHERE name = :name AND libraryId = :libraryId
+          AND id != :mostRecentSeriesId
+          `,
+        {
+          replacements: {
+            name: duplicate.name,
+            libraryId: duplicate.libraryId,
+            mostRecentSeriesId: mostRecentSeries.id
+          }
+        }
+      )
+    }
+  }
+
+  logger.info(`[2.13.5 migration] Deduplication complete`)
+
+  // Create a unique index based on the name and library ID for the `Series` table
+  await queryInterface.addIndex('Series', ['name', 'libraryId'], {
+    unique: true,
+    name: 'unique_series_name_per_library'
+  })
+  logger.info('Added unique index on Series.name and Series.libraryId')
+
+  logger.info('UPGRADE END: 2.13.5-series-column-unique ')
+}
+
+/**
+ * This removes the unique index on the `Series` table.
+ *
+ * @param {MigrationOptions} options - an object containing the migration context.
+ * @returns {Promise<void>} - A promise that resolves when the migration is complete.
+ */
+async function down({ context: { queryInterface, logger } }) {
+  // Downward migration script
+  logger.info('DOWNGRADE BEGIN: 2.13.5-series-column-unique ')
+
+  // Remove the unique index
+  await queryInterface.removeIndex('Series', 'unique_series_name_per_library')
+  logger.info('Removed unique index on Series.name and Series.libraryId')
+
+  logger.info('DOWNGRADE END: 2.13.5-series-column-unique ')
+}
+
+module.exports = { up, down }

server/models/Series.js

@@ -84,6 +84,12 @@ class Series extends Model {
           //     collate: 'NOCASE'
           //   }]
           // },
+          {
+            // unique constraint on name and libraryId
+            fields: ['name', 'libraryId'],
+            unique: true,
+            name: 'unique_series_name_per_library'
+          },
           {
             fields: ['libraryId']
           }