// PostgreSQL Table Builder & Compiler
// -------
module.exports = function(client) {

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

// Table
// ------

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

function TableCompiler_PG() {
  this.client = client;
  this.Formatter = client.Formatter;
  Schema.TableCompiler.apply(this, arguments);
}
inherits(TableCompiler_PG, Schema.TableCompiler);

// Compile a rename column command.
TableCompiler_PG.prototype.renameColumn = function(from, to) {
  return {
    sql: 'alter table ' + this.tableName + ' rename '+ this.formatter.wrap(from) + ' to ' + this.formatter.wrap(to)
  };
};

TableCompiler_PG.prototype.compileAdd = function(builder) {
  var table = this.formatter.wrap(builder);
  var columns = this.prefixArray('add column', this.getColumns(builder));
  return {
    sql: 'alter table ' + table + ' ' + columns.join(', ')
  };
};

// Adds the "create" query to the query sequence.
TableCompiler_PG.prototype.createQuery = function(columns) {
  this.pushQuery({
    sql: 'create table ' + this.tableName() + ' (' + columns.sql.join(', ') + ')',
    bindings: columns.bindings
  });
  var hasComment = _.has(this._single, 'comment');
  if (hasComment) {
    this.pushQuery('comment on table ' + this.tableName() + ' is ' + "'" + this.attributes.comment + "'");
  }
};

// Compile a foreign key command.
TableCompiler_PG.prototype.foreignKey = function(foreignData) {
  var sql = '';
  if (foreignData.inTable && foreignData.references) {
    var keyName    = this._indexCommand('foreign', this.tableNameRaw, foreignData.column);
    var column     = this.formatter.columnize(foreignData.column);
    var references = this.formatter.columnize(foreignData.references);
    var inTable    = this.formatter.wrap(foreignData.inTable);

    sql = 'alter table ' + this.tableName + ' add constraint ' + keyName + ' ';
    sql += 'foreign key (' + column + ') references ' + inTable + ' (' + references + ')';
  }
  return {
    sql: sql
  };
};

// Indexes:
// -------

TableCompiler_PG.prototype.primary = function(columns) {
  this.pushQuery('alter table ' + this.tableName() + " add primary key (" + this.formatter.columnize(columns) + ")");
};
TableCompiler_PG.prototype.unique = function(columns, indexName) {
  indexName = indexName || this._indexCommand('unique', this.tableNameRaw, columns);
  this.pushQuery('alter table ' + this.tableName() + ' add constraint ' + indexName +
    ' unique (' + this.formatter.columnize(columns) + ')');
};
TableCompiler_PG.prototype.index = function(columns, indexName) {
  indexName = indexName || this._indexCommand('index', this.tableNameRaw, columns);
  this.pushQuery('create index ' + indexName + ' on ' + this.tableName() +
    ' (' + this.formatter.columnize(columns) + ')');
};
TableCompiler_PG.prototype.dropPrimary = function() {
  this.pushQuery('alter table ' + this.tableName() + " drop constraint " + this.tableNameRaw + "_pkey");
};
TableCompiler_PG.prototype.dropIndex = function(index) {
  this.pushQuery('drop index ' + index);
};
TableCompiler_PG.prototype.dropUnique = function(index) {
  this.pushQuery('alter table ' + this.tableName() + ' drop constraint ' + index);
};
TableCompiler_PG.prototype.dropForeign = function(index) {
  this.pushQuery('alter table ' + this.tableName() + ' drop constraint ' + index);
};

client.TableBuilder = TableBuilder_PG;
client.TableCompiler = TableCompiler_PG;

};