'use strict';

const helpers = require('../app/migration_helpers');

exports.up = function(knex, Promise) {
	const dbType = helpers.getDbType(knex);

	// Defer has the promise resulting from creating the initial tables
	let defer = knex.schema.createTableIfNotExists('users', (table) => {
		table.comment('User authentication table');
		table.increments()
			.unsigned();
		table.string('user');
		table.binary('password_hash');
		table.timestamp('created_at')
			.defaultTo(knex.fn.now());
		table.timestamp('updated_at')
			.defaultTo(knex.fn.now());
	}).then(() => {
		return knex.schema.createTableIfNotExists('posts', (table) => {
			table.comment('Blog post table');
			table.increments()
				.unsigned();
			table.integer('created_by')
				.unsigned()
				.references('users.id');
			table.string('uri')
				.index()
				.comment('The uri segment of the blog post');
			table.string('title')
				.comment('The title of the blog post');
			table.text('content')
				.comment('The content of the blog post');
			table.timestamp('created_at')
				.defaultTo(knex.fn.now());
			table.timestamp('updated_at')
				.defaultTo(knex.fn.now());
		});
	});

	if ('pg' === dbType) {
		// Create the function to update
		return knex.schema.raw(helpers.pgTimestampUpdateFunction())
			// Create the tables
			.then(() => defer)

			// Add trigger for tables
			.then(() => knex.schema.raw(helpers.pgCreateTimestampUpdateTrigger('users')))
			.then(() => knex.schema.raw(helpers.pgCreateTimestampUpdateTrigger('posts')));
	} else if ('sqlite3' === dbType) {
		return defer.then(() => knex.schema.raw(helpers.sqlite3CreateTimestampUpdateTrigger('users')))
			.then(() => knex.schema.raw(helpers.sqlite3CreateTimestampUpdateTrigger('posts')));
	} else {
		return defer;
	}
};

exports.down = function(knex, Promise) {
	const dbType = helpers.getDbType(knex);
	let defer = knex.schema.dropTableIfExists('posts')
		.then(() => knex.schema.dropTableIfExists('users'));

	if ('pg' === dbType) {
		return knex.schema.raw(helpers.pgDeleteTimestampUpdateTrigger('users'))
			.then(() => knex.schema.raw(helpers.pgDeleteTimestampUpdateTrigger('posts')))
			.then(() => defer);
	} else if ('sqlite3' === dbType) {
		return knex.schema.raw(helpers.sqlite3DeleteTimestampUpdateTrigger('users'))
			.then(() => knex.schema.raw(helpers.sqlite3DeleteTimestampUpdateTrigger('posts')))
			.then(() => defer);
	} else {
		return defer;
	}
};