import inherits from 'inherits';
import TableCompiler from '../../../schema/tablecompiler';
import * as helpers from '../../../helpers';

import { filter } from 'lodash'

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

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

// Create a new table.
TableCompiler_SQLite3.prototype.createQuery = function(columns, ifNot) {
  const createStatement = ifNot ? 'create table if not exists ' : 'create table ';
  let 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, prefix) {
  if (prefix) {
    throw new Error("Sqlite does not support alter column.");
  }
  for (let 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.formatter.wrap(indexName)
    : this._indexCommand('unique', this.tableNameRaw, columns);
  this.pushQuery(`drop index ${indexName}`);
};

TableCompiler_SQLite3.prototype.dropIndex = function(columns, indexName) {
  indexName = indexName
    ? this.formatter.wrap(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.formatter.wrap(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.formatter.wrap(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' && this.method !== 'createIfNot') {
    helpers.warn('SQLite3 Foreign & Primary keys may only be added on create');
  }
};

TableCompiler_SQLite3.prototype.primaryKeys = function() {
  const pks = filter(this.grouped.alterTable || [], {method: 'primary'});
  if (pks.length > 0 && pks[0].args.length > 0) {
    const args = Array.isArray(pks[0].args[0]) ? pks[0].args[0] : pks[0].args;
    return `, primary key (${this.formatter.columnize(args)})`;
  }
};

TableCompiler_SQLite3.prototype.foreignKeys = function() {
  let sql = '';
  const foreignKeys = filter(this.grouped.alterTable || [], {method: 'foreign'});
  for (let i = 0, l = foreignKeys.length; i < l; i++) {
    const foreign = foreignKeys[i].args[0];
    const column = this.formatter.columnize(foreign.column);
    const references = this.formatter.columnize(foreign.references);
    const 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) {
  const compiler = this;
  this.pushQuery({
    sql: `PRAGMA table_info(${this.tableName()})`,
    output(pragma) {
      return compiler.client.ddl(compiler, pragma, this.connection).renameColumn(from, to);
    }
  });
};

TableCompiler_SQLite3.prototype.dropColumn = function(column) {
  const compiler = this;
  this.pushQuery({
    sql: `PRAGMA table_info(${this.tableName()})`,
    output(pragma) {
      return compiler.client.ddl(compiler, pragma, this.connection).dropColumn(column);
    }
  });
};

export default TableCompiler_SQLite3;