/**
 * Migration: Link Device to InventoryDevice
 *
 * Fixes: InventoryDevice and Device have no explicit relationship
 * Changes:
 * - Add inventory_device_id FK to devices table
 * - Migrate existing data by matching hardware_id
 *
 * @type {import('node-pg-migrate').ColumnDefinitions | undefined}
 */
export const shorthands = undefined;

/**
 * @param pgm {import('node-pg-migrate').MigrationBuilder}
 * @param run {() => void | undefined}
 * @returns {Promise<void> | void}
 */
export const up = (pgm) => {
  console.log('Linking Device to InventoryDevice...');

  // Add inventory_device_id column
  pgm.addColumn('devices', {
    inventory_device_id: {
      type: 'uuid',
      notNull: false,
      comment: 'FK to inventory_devices - the inventory record for this device',
    },
  });

  // Migrate data by matching hardware_id
  pgm.sql(`
    UPDATE devices d
    SET inventory_device_id = inv.id
    FROM inventory_devices inv
    WHERE d.hardware_id = inv.hardware_id;
  `);

  // Add FK constraint
  pgm.addConstraint('devices', 'devices_inventory_device_id_fkey', {
    foreignKeys: {
      columns: 'inventory_device_id',
      references: 'inventory_devices(id)',
      onDelete: 'SET NULL',
    },
  });

  // Add unique constraint - one device per inventory record
  pgm.createIndex('devices', 'inventory_device_id', {
    name: 'idx_devices_inventory_device_id_unique',
    unique: true,
    where: 'inventory_device_id IS NOT NULL',
  });

  // Update inventory_devices.is_claimed based on linked devices
  pgm.sql(`
    UPDATE inventory_devices inv
    SET is_claimed = true
    WHERE EXISTS (
      SELECT 1 FROM devices d WHERE d.inventory_device_id = inv.id
    );
  `);

  console.log('Device to InventoryDevice link added.');
};

/**
 * @param pgm {import('node-pg-migrate').MigrationBuilder}
 * @param run {() => void | undefined}
 * @returns {Promise<void> | void}
 */
export const down = (pgm) => {
  console.log('Rolling back Device to InventoryDevice link...');

  // Drop unique index
  pgm.dropIndex('devices', 'inventory_device_id', {
    name: 'idx_devices_inventory_device_id_unique',
    ifExists: true,
  });

  // Drop FK constraint
  pgm.dropConstraint('devices', 'devices_inventory_device_id_fkey', {
    ifExists: true,
  });

  // Drop column
  pgm.dropColumn('devices', 'inventory_device_id', { ifExists: true });

  console.log('Device to InventoryDevice link rollback complete.');
};