'use strict';

// SQLite3: Column Builder & Compiler
// -------
module.exports = function(client) {

var _        = require('lodash');
var inherits = require('inherits');
var Schema   = require('../../../schema');

// Table Builder
// -------

function TableBuilder_SQLite3() {
  this.client = client;
  Schema.TableBuilder.apply(this, arguments);
}
inherits(TableBuilder_SQLite3, Schema.TableBuilder);

// Table Compiler
// -------

function TableCompiler_SQLite3() {
  this.client = client;
  this.Formatter = client.Formatter;
  this.SQLite3_DDL = client.SQLite3_DDL;
  this.primaryKey = void 0;
  Schema.TableCompiler.apply(this, arguments);
}
inherits(TableCompiler_SQLite3, Schema.TableCompiler);

// Create a new table.
TableCompiler_SQLite3.prototype.createQuery = function(columns, ifNot) {
  var createStatement = ifNot ? 'create table if not exists ' : 'create table ';
  var sql = createStatement + this.tableName() + ' (' + columns.sql.join(', ');

  // SQLite forces primary keys to be added when the table is initially created
  // so we will need to check for a primary key commands and add the columns
  // to the table's declaration here so they can be created on the tables.
  sql += this.foreignKeys() || '';
  sql += this.primaryKeys() || '';
  sql += ')';

  this.pushQuery(sql);
};

TableCompiler_SQLite3.prototype.addColumns = function(columns) {
  for (var i = 0, l = columns.sql.length; i < l; i++) {
    this.pushQuery({
      sql: 'alter table ' + this.tableName() + ' add column ' + columns.sql[i],
      bindings: columns.bindings[i]
    });
  }
};

// Compile a drop unique key command.
TableCompiler_SQLite3.prototype.dropUnique = function(columns, indexName) {
  indexName = indexName || this._indexCommand('unique', this.tableNameRaw, columns);
  this.pushQuery('drop index ' + indexName);
};

TableCompiler_SQLite3.prototype.dropIndex = function(columns, indexName) {
  indexName = indexName || this._indexCommand('index', this.tableNameRaw, columns);
  this.pushQuery('drop index ' + indexName);
};

// Compile a unique key command.
TableCompiler_SQLite3.prototype.unique = function(columns, indexName) {
  indexName = indexName || this._indexCommand('unique', this.tableNameRaw, columns);
  columns = this.formatter.columnize(columns);
  this.pushQuery('create unique index ' + indexName + ' on ' + this.tableName() + ' (' + columns + ')');
};

// Compile a plain index key command.
TableCompiler_SQLite3.prototype.index = function(columns, indexName) {
  indexName = indexName || this._indexCommand('index', this.tableNameRaw, columns);
  columns = this.formatter.columnize(columns);
  this.pushQuery('create index ' + indexName + ' on ' + this.tableName() + ' (' + columns + ')');
};

TableCompiler_SQLite3.prototype.primary =
TableCompiler_SQLite3.prototype.foreign = function() {
  if (this.method !== 'create') {
    console.warn('SQLite3 Foreign & Primary keys may only be added on create');
  }
};

TableCompiler_SQLite3.prototype.primaryKeys = function() {
  var pks = _.where(this.grouped.alterTable || [], {method: 'primary'});
  if (pks.length > 0 && pks[0].args.length > 0) {
    var args = _.isArray(pks[0].args[0]) ? pks[0].args[0] : pks[0].args;
    return ', primary key (' + this.formatter.columnize(args) + ')';
  }
};

TableCompiler_SQLite3.prototype.foreignKeys = function() {
  var sql = '';
  var foreignKeys = _.where(this.grouped.alterTable || [], {method: 'foreign'});
  for (var i = 0, l = foreignKeys.length; i < l; i++) {
    var foreign       = foreignKeys[i].args[0];
    var column        = this.formatter.columnize(foreign.column);
    var references    = this.formatter.columnize(foreign.references);
    var foreignTable  = this.formatter.wrap(foreign.inTable);
    sql += ', foreign key(' + column + ') references ' + foreignTable + '(' + references + ')';
    if (foreign.onDelete) sql += ' on delete ' + foreign.onDelete;
    if (foreign.onUpdate) sql += ' on update ' + foreign.onUpdate;
  }
  return sql;
};

TableCompiler_SQLite3.prototype.createTableBlock = function() {
  return this.getColumns().concat().join(',');
};

// Compile a rename column command... very complex in sqlite
TableCompiler_SQLite3.prototype.renameColumn = function(from, to) {
  var compiler = this;
  this.pushQuery({
    sql: 'PRAGMA table_info(' + this.tableName() + ')',
    output: function(pragma) {
      return new compiler.SQLite3_DDL(this, compiler, pragma).renameColumn(from, to);
    }
  });
};

TableCompiler_SQLite3.prototype.dropColumn = function(column) {
  var compiler = this;
  this.pushQuery({
    sql: 'PRAGMA table_info(' + this.tableName() + ')',
    output: function(pragma) {
      return new compiler.SQLite3_DDL(this, compiler, pragma).dropColumn(column);
    }
  });
};

client.TableBuilder = TableBuilder_SQLite3;
client.TableCompiler = TableCompiler_SQLite3;

};