'use strict';

exports.__esModule = true;

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError('Cannot call a class as a function'); } }

// Migrator
// -------
'use strict';

var fs = require('fs');
var path = require('path');
var _ = require('lodash');
var mkdirp = require('mkdirp');
var Promise = require('../promise');
var helpers = require('../helpers');
var assign = require('lodash/object/assign');

// The new migration we're performing, typically called from the `knex.migrate`
// interface on the main `knex` object. Passes the `knex` instance performing
// the migration.

var Migrator = (function () {
  function Migrator(knex) {
    _classCallCheck(this, Migrator);

    this.knex = knex;
    this.config = this.setConfig(knex.client.config.migrations);
  }

  // Migrators to the latest configuration.

  Migrator.prototype.latest = function latest(config) {
    var _this = this;

    this.config = this.setConfig(config);
    return this._migrationData().tap(validateMigrationList).spread(function (all, completed) {
      return _this._runBatch(_.difference(all, completed), 'up');
    });
  };

  // Rollback the last "batch" of migrations that were run.

  Migrator.prototype.rollback = function rollback(config) {
    var _this2 = this;

    return Promise['try'](function () {
      _this2.config = _this2.setConfig(config);
      return _this2._migrationData().tap(validateMigrationList).then(function (val) {
        return _this2._getLastBatch(val);
      }).then(function (migrations) {
        return _this2._runBatch(_.pluck(migrations, 'name'), 'down');
      });
    });
  };

  // Retrieves and returns the current migration version
  // we're on, as a promise. If there aren't any migrations run yet,
  // return "none" as the value for the `currentVersion`.

  Migrator.prototype.currentVersion = function currentVersion(config) {
    this.config = this.setConfig(config);
    return this._listCompleted(config).then(function (completed) {
      var val = _.chain(completed).map(function (value) {
        return value.split('_')[0];
      }).max().value();
      return val === -Infinity ? 'none' : val;
    });
  };

  // Creates a new migration, with a given name.

  Migrator.prototype.make = function make(name, config) {
    var _this3 = this;

    this.config = this.setConfig(config);
    if (!name) Promise.rejected(new Error('A name must be specified for the generated migration'));
    return this._ensureFolder(config).then(function (val) {
      return _this3._generateStubTemplate(val);
    }).then(function (val) {
      return _this3._writeNewMigration(name, val);
    });
  };

  // Lists all available migration versions, as a sorted array.

  Migrator.prototype._listAll = function _listAll(config) {
    this.config = this.setConfig(config);
    return Promise.promisify(fs.readdir, fs)(this._absoluteConfigDir()).then(function (migrations) {
      return _.filter(migrations, function (value) {
        var extension = path.extname(value);
        return _.contains(['.co', '.coffee', '.iced', '.js', '.litcoffee', '.ls'], extension);
      }).sort();
    });
  };

  // Ensures a folder for the migrations exist, dependent on the
  // migration config settings.

  Migrator.prototype._ensureFolder = function _ensureFolder() {
    var dir = this._absoluteConfigDir();
    return Promise.promisify(fs.stat, fs)(dir)['catch'](function () {
      return Promise.promisify(mkdirp)(dir);
    });
  };

  // Ensures that the proper table has been created,
  // dependent on the migration config settings.

  Migrator.prototype._ensureTable = function _ensureTable() {
    var _this4 = this;

    var table = this.config.tableName;
    return this.knex.schema.hasTable(table).then(function (exists) {
      if (!exists) return _this4._createMigrationTable(table);
    });
  };

  // Create the migration table, if it doesn't already exist.

  Migrator.prototype._createMigrationTable = function _createMigrationTable(tableName) {
    return this.knex.schema.createTable(tableName, function (t) {
      t.increments();
      t.string('name');
      t.integer('batch');
      t.timestamp('migration_time');
    });
  };

  // Run a batch of current migrations, in sequence.

  Migrator.prototype._runBatch = function _runBatch(migrations, direction) {
    var _this5 = this;

    return Promise.all(_.map(migrations, this._validateMigrationStructure, this)).then(function () {
      return _this5._latestBatchNumber();
    }).then(function (batchNo) {
      if (direction === 'up') batchNo++;
      return batchNo;
    }).then(function (batchNo) {
      return _this5._waterfallBatch(batchNo, migrations, direction);
    })['catch'](function (error) {
      helpers.warn('migrations failed with error: ' + error.message);
      throw error;
    });
  };

  // Validates some migrations by requiring and checking for an `up` and `down` function.

  Migrator.prototype._validateMigrationStructure = function _validateMigrationStructure(name) {
    var migration = require(path.join(this._absoluteConfigDir(), name));
    if (typeof migration.up !== 'function' || typeof migration.down !== 'function') {
      throw new Error('Invalid migration: ' + name + ' must have both an up and down function');
    }
    return name;
  };

  // Lists all migrations that have been completed for the current db, as an array.

  Migrator.prototype._listCompleted = function _listCompleted() {
    var _this6 = this;

    var tableName = this.config.tableName;
    return this._ensureTable(tableName).then(function () {
      return _this6.knex(tableName).orderBy('id').select('name');
    }).then(function (migrations) {
      return _.pluck(migrations, 'name');
    });
  };

  // Gets the migration list from the specified migration directory,
  // as well as the list of completed migrations to check what
  // should be run.

  Migrator.prototype._migrationData = function _migrationData() {
    return Promise.all([this._listAll(), this._listCompleted()]);
  };

  // Generates the stub template for the current migration, returning a compiled template.

  Migrator.prototype._generateStubTemplate = function _generateStubTemplate() {
    var stubPath = this.config.stub || path.join(__dirname, 'stub', this.config.extension + '.stub');
    return Promise.promisify(fs.readFile, fs)(stubPath).then(function (stub) {
      return _.template(stub.toString(), null, { variable: 'd' });
    });
  };

  // Write a new migration to disk, using the config and generated filename,
  // passing any `variables` given in the config to the template.

  Migrator.prototype._writeNewMigration = function _writeNewMigration(name, tmpl) {
    var config = this.config;
    var dir = this._absoluteConfigDir();
    if (name[0] === '-') name = name.slice(1);
    var filename = yyyymmddhhmmss() + '_' + name + '.' + config.extension;
    return Promise.promisify(fs.writeFile, fs)(path.join(dir, filename), tmpl(config.variables || {}))['return'](path.join(dir, filename));
  };

  // Get the last batch of migrations, by name, ordered by insert id
  // in reverse order.

  Migrator.prototype._getLastBatch = function _getLastBatch() {
    var tableName = this.config.tableName;
    return this.knex(tableName).where('batch', function (qb) {
      qb.max('batch').from(tableName);
    }).orderBy('id', 'desc');
  };

  // Returns the latest batch number.

  Migrator.prototype._latestBatchNumber = function _latestBatchNumber() {
    return this.knex(this.config.tableName).max('batch as max_batch').then(function (obj) {
      return obj[0].max_batch || 0;
    });
  };

  // Runs a batch of `migrations` in a specified `direction`,
  // saving the appropriate database information as the migrations are run.

  Migrator.prototype._waterfallBatch = function _waterfallBatch(batchNo, migrations, direction) {
    var knex = this.knex;
    var _config = this.config;
    var tableName = _config.tableName;
    var disableTransactions = _config.disableTransactions;

    var directory = this._absoluteConfigDir();
    var current = Promise.bind({ failed: false, failedOn: 0 });
    var log = [];
    _.each(migrations, function (migration) {
      var name = migration;
      migration = require(directory + '/' + name);

      // We're going to run each of the migrations in the current "up"
      current = current.then(function () {
        if (disableTransactions) {
          return warnPromise(migration[direction](knex, Promise), 'migration ' + name + ' did not return a promise');
        }
        return knex.transaction(function (trx) {
          return warnPromise(migration[direction](trx, Promise), 'migration ' + name + ' did not return a promise');
        });
      }).then(function () {
        log.push(path.join(directory, name));
        if (direction === 'up') {
          return knex(tableName).insert({
            name: name,
            batch: batchNo,
            migration_time: new Date()
          });
        }
        if (direction === 'down') {
          return knex(tableName).where({ name: name }).del();
        }
      });
    });

    return current.thenReturn([batchNo, log]);
  };

  Migrator.prototype._absoluteConfigDir = function _absoluteConfigDir() {
    return path.resolve(process.cwd(), this.config.directory);
  };

  Migrator.prototype.setConfig = function setConfig(config) {
    return assign({
      extension: 'js',
      tableName: 'knex_migrations',
      directory: './migrations'
    }, this.config || {}, config);
  };

  return Migrator;
})();

exports['default'] = Migrator;

// Validates that migrations are present in the appropriate directories.
function validateMigrationList(migrations) {
  var all = migrations[0];
  var completed = migrations[1];
  var diff = _.difference(completed, all);
  if (!_.isEmpty(diff)) {
    throw new Error('The migration directory is corrupt, the following files are missing: ' + diff.join(', '));
  }
}

function warnPromise(value, message) {
  if (!value || typeof value.then !== 'function') {
    helpers.warn(message);
  }
  return value;
}

// Ensure that we have 2 places for each of the date segments
function padDate(segment) {
  segment = segment.toString();
  return segment[1] ? segment : '0' + segment;
}

// Get a date object in the correct format, without requiring
// a full out library like "moment.js".
function yyyymmddhhmmss() {
  var d = new Date();
  return d.getFullYear().toString() + padDate(d.getMonth() + 1) + padDate(d.getDate()) + padDate(d.getHours()) + padDate(d.getMinutes()) + padDate(d.getSeconds());
}
module.exports = exports['default'];