// Column Compiler
// Used for designating column definitions
// during the table "create" / "alter" statements.
// -------
const helpers = require('./internal/helpers');
const groupBy = require('lodash/groupBy');
const first = require('lodash/first');
const has = require('lodash/has');
const tail = require('lodash/tail');
const { toNumber } = require('../util/helpers');
const { formatDefault } = require('../formatter/formatterUtils');
const { operator: operator_ } = require('../formatter/wrappingFormatter');

class ColumnCompiler {
  constructor(client, tableCompiler, columnBuilder) {
    this.client = client;
    this.tableCompiler = tableCompiler;
    this.columnBuilder = columnBuilder;
    this._commonBuilder = this.columnBuilder;
    this.args = columnBuilder._args;
    this.type = columnBuilder._type.toLowerCase();
    this.grouped = groupBy(columnBuilder._statements, 'grouping');
    this.modified = columnBuilder._modifiers;
    this.isIncrements = this.type.indexOf('increments') !== -1;

    this.formatter = client.formatter(columnBuilder);
    this.bindings = [];
    this.formatter.bindings = this.bindings;
    this.bindingsHolder = this;

    this.sequence = [];
    this.modifiers = [];

    this.checksCount = 0;
  }

  _addCheckModifiers() {
    this.modifiers.push(
      'check',
      'checkPositive',
      'checkNegative',
      'checkIn',
      'checkNotIn',
      'checkBetween',
      'checkLength',
      'checkRegex'
    );
  }

  defaults(label) {
    if (Object.prototype.hasOwnProperty.call(this._defaultMap, label)) {
      return this._defaultMap[label].bind(this)();
    } else {
      throw new Error(
        `There is no default for the specified identifier ${label}`
      );
    }
  }

  // To convert to sql, we first go through and build the
  // column as it would be in the insert statement
  toSQL() {
    this.pushQuery(this.compileColumn());
    if (this.sequence.additional) {
      this.sequence = this.sequence.concat(this.sequence.additional);
    }
    return this.sequence;
  }

  // Compiles a column.
  compileColumn() {
    return (
      this.formatter.wrap(this.getColumnName()) +
      ' ' +
      this.getColumnType() +
      this.getModifiers()
    );
  }

  // Assumes the autoincrementing key is named `id` if not otherwise specified.
  getColumnName() {
    const value = first(this.args);
    return value || this.defaults('columnName');
  }

  getColumnType() {
    // Column type is cached so side effects (such as in pg native enums) are only run once
    if (!this._columnType) {
      const type = this[this.type];
      this._columnType =
        typeof type === 'function' ? type.apply(this, tail(this.args)) : type;
    }

    return this._columnType;
  }

  getModifiers() {
    const modifiers = [];

    for (let i = 0, l = this.modifiers.length; i < l; i++) {
      const modifier = this.modifiers[i];

      //Cannot allow 'nullable' modifiers on increments types
      if (!this.isIncrements || (this.isIncrements && modifier === 'comment')) {
        if (has(this.modified, modifier)) {
          const val = this[modifier].apply(this, this.modified[modifier]);
          if (val) modifiers.push(val);
        }
      }
    }

    return modifiers.length > 0 ? ` ${modifiers.join(' ')}` : '';
  }

  // Types
  // ------
  varchar(length) {
    return `varchar(${toNumber(length, 255)})`;
  }

  floating(precision, scale) {
    return `float(${toNumber(precision, 8)}, ${toNumber(scale, 2)})`;
  }

  decimal(precision, scale) {
    if (precision === null) {
      throw new Error(
        'Specifying no precision on decimal columns is not supported for that SQL dialect.'
      );
    }
    return `decimal(${toNumber(precision, 8)}, ${toNumber(scale, 2)})`;
  }

  // Used to support custom types
  specifictype(type) {
    return type;
  }

  // Modifiers
  // -------

  nullable(nullable) {
    return nullable === false ? 'not null' : 'null';
  }

  notNullable() {
    return this.nullable(false);
  }

  defaultTo(value) {
    return `default ${formatDefault(value, this.type, this.client)}`;
  }

  increments(options = { primaryKey: true }) {
    return (
      'integer not null' +
      (this.tableCompiler._canBeAddPrimaryKey(options) ? ' primary key' : '') +
      ' autoincrement'
    );
  }

  bigincrements(options = { primaryKey: true }) {
    return this.increments(options);
  }

  _pushAlterCheckQuery(checkPredicate, constraintName) {
    let checkName = constraintName;
    if (!checkName) {
      this.checksCount++;
      checkName =
        this.tableCompiler.tableNameRaw +
        '_' +
        this.getColumnName() +
        '_' +
        this.checksCount;
    }
    this.pushAdditional(function () {
      this.pushQuery(
        `alter table ${this.tableCompiler.tableName()} add constraint ${checkName} check(${checkPredicate})`
      );
    });
  }

  _checkConstraintName(constraintName) {
    return constraintName ? `constraint ${constraintName} ` : '';
  }

  _check(checkPredicate, constraintName) {
    if (this.columnBuilder._method === 'alter') {
      this._pushAlterCheckQuery(checkPredicate, constraintName);
      return '';
    }
    return `${this._checkConstraintName(
      constraintName
    )}check (${checkPredicate})`;
  }

  checkPositive(constraintName) {
    return this._check(
      `${this.formatter.wrap(this.getColumnName())} ${operator_(
        '>',
        this.columnBuilder,
        this.bindingsHolder
      )} 0`,
      constraintName
    );
  }

  checkNegative(constraintName) {
    return this._check(
      `${this.formatter.wrap(this.getColumnName())} ${operator_(
        '<',
        this.columnBuilder,
        this.bindingsHolder
      )} 0`,
      constraintName
    );
  }

  _checkIn(values, constraintName, not) {
    return this._check(
      `${this.formatter.wrap(this.getColumnName())} ${
        not ? 'not ' : ''
      }in (${values.map((v) => this.client._escapeBinding(v)).join(',')})`,
      constraintName
    );
  }

  checkIn(values, constraintName) {
    return this._checkIn(values, constraintName);
  }

  checkNotIn(values, constraintName) {
    return this._checkIn(values, constraintName, true);
  }

  checkBetween(intervals, constraintName) {
    if (
      intervals.length === 2 &&
      !Array.isArray(intervals[0]) &&
      !Array.isArray(intervals[1])
    ) {
      intervals = [intervals];
    }
    const intervalChecks = intervals
      .map((interval) => {
        return `${this.formatter.wrap(
          this.getColumnName()
        )} between ${this.client._escapeBinding(
          interval[0]
        )} and ${this.client._escapeBinding(interval[1])}`;
      })
      .join(' or ');
    return this._check(intervalChecks, constraintName);
  }

  checkLength(operator, length, constraintName) {
    return this._check(
      `length(${this.formatter.wrap(this.getColumnName())}) ${operator_(
        operator,
        this.columnBuilder,
        this.bindingsHolder
      )} ${toNumber(length)}`,
      constraintName
    );
  }
}

ColumnCompiler.prototype.binary = 'blob';
ColumnCompiler.prototype.bool = 'boolean';
ColumnCompiler.prototype.date = 'date';
ColumnCompiler.prototype.datetime = 'datetime';
ColumnCompiler.prototype.time = 'time';
ColumnCompiler.prototype.timestamp = 'timestamp';
ColumnCompiler.prototype.geometry = 'geometry';
ColumnCompiler.prototype.geography = 'geography';
ColumnCompiler.prototype.point = 'point';
ColumnCompiler.prototype.enu = 'varchar';
ColumnCompiler.prototype.bit = ColumnCompiler.prototype.json = 'text';
ColumnCompiler.prototype.uuid = ({
  useBinaryUuid = false,
  primaryKey = false,
} = {}) => (useBinaryUuid ? 'binary(16)' : 'char(36)');
ColumnCompiler.prototype.integer =
  ColumnCompiler.prototype.smallint =
  ColumnCompiler.prototype.mediumint =
    'integer';
ColumnCompiler.prototype.biginteger = 'bigint';
ColumnCompiler.prototype.text = 'text';
ColumnCompiler.prototype.tinyint = 'tinyint';

ColumnCompiler.prototype.pushQuery = helpers.pushQuery;
ColumnCompiler.prototype.pushAdditional = helpers.pushAdditional;
ColumnCompiler.prototype.unshiftQuery = helpers.unshiftQuery;

ColumnCompiler.prototype._defaultMap = {
  columnName: function () {
    if (!this.isIncrements) {
      throw new Error(
        `You did not specify a column name for the ${this.type} column.`
      );
    }
    return 'id';
  },
};

module.exports = ColumnCompiler;