"use strict";

module.exports.up = function(knex, Promise) {
	// Get rid of existing duplicate entries
	return knex.raw(`
		DELETE FROM srap_tags
		WHERE id IN (
			SELECT
				id
			FROM (
				SELECT
					id,
					row_number() OVER w as rnum
				FROM srap_tags
				WINDOW w AS (
					PARTITION BY name, item_id
					ORDER BY id
				)
		
			) t
		WHERE t.rnum > 1);
	`).then(() => {
		return knex.schema
			.alterTable("srap_tags", (table) => {
				table.dropPrimary();
				table.dropIndex("name");
				table.dropColumn("id");
				table.primary([ "name", "item_id" ]);
			});
	});
};
	
module.exports.down = function(knex, Promise) {
	return knex.schema
		.alterTable("srap_tags", (table) => {
			table.dropPrimary();
			table.bigIncrements("id").primary();
		});
};