// Raw
// -------
const { inherits } = require('util');
const { EventEmitter } = require('events');
const debug = require('debug');
const assign = require('lodash/assign');
const isPlainObject = require('lodash/isPlainObject');
const reduce = require('lodash/reduce');

const helpers = require('./helpers');
const saveAsyncStack = require('./util/save-async-stack');
const { nanoid } = require('./util/nanoid');
const { isNumber, isObject } = require('./util/is');

const debugBindings = debug('knex:bindings');

function Raw(client) {
  this.client = client;

  this.sql = '';
  this.bindings = [];

  // Todo: Deprecate
  this._wrappedBefore = undefined;
  this._wrappedAfter = undefined;
  if (client && client.config) {
    this._debug = client.config.debug;
    saveAsyncStack(this, 4);
  }
}

inherits(Raw, EventEmitter);

assign(Raw.prototype, {
  set(sql, bindings) {
    this.sql = sql;
    this.bindings =
      (isObject(bindings) && !bindings.toSQL) || bindings === undefined
        ? bindings
        : [bindings];

    return this;
  },

  timeout(ms, { cancel } = {}) {
    if (isNumber(ms) && ms > 0) {
      this._timeout = ms;
      if (cancel) {
        this.client.assertCanCancelQuery();
        this._cancelOnTimeout = true;
      }
    }
    return this;
  },

  // Wraps the current sql with `before` and `after`.
  wrap(before, after) {
    this._wrappedBefore = before;
    this._wrappedAfter = after;
    return this;
  },

  // Calls `toString` on the Knex object.
  toString() {
    return this.toQuery();
  },

  // Returns the raw sql for the query.
  toSQL(method, tz) {
    let obj;
    const formatter = this.client.formatter(this);

    if (Array.isArray(this.bindings)) {
      obj = replaceRawArrBindings(this, formatter);
    } else if (this.bindings && isPlainObject(this.bindings)) {
      obj = replaceKeyBindings(this, formatter);
    } else {
      obj = {
        method: 'raw',
        sql: this.sql,
        bindings: this.bindings === undefined ? [] : [this.bindings],
      };
    }

    if (this._wrappedBefore) {
      obj.sql = this._wrappedBefore + obj.sql;
    }
    if (this._wrappedAfter) {
      obj.sql = obj.sql + this._wrappedAfter;
    }

    obj.options = reduce(this._options, assign, {});

    if (this._timeout) {
      obj.timeout = this._timeout;
      if (this._cancelOnTimeout) {
        obj.cancelOnTimeout = this._cancelOnTimeout;
      }
    }

    obj.bindings = obj.bindings || [];
    if (helpers.containsUndefined(obj.bindings)) {
      const undefinedBindingIndices = helpers.getUndefinedIndices(
        this.bindings
      );
      debugBindings(obj.bindings);
      throw new Error(
        `Undefined binding(s) detected for keys [${undefinedBindingIndices}] when compiling RAW query: ${obj.sql}`
      );
    }

    obj.__knexQueryUid = nanoid();

    return obj;
  },
});

function replaceRawArrBindings(raw, formatter) {
  const expectedBindings = raw.bindings.length;
  const values = raw.bindings;
  let index = 0;

  const sql = raw.sql.replace(/\\?\?\??/g, function (match) {
    if (match === '\\?') {
      return match;
    }

    const value = values[index++];

    if (match === '??') {
      return formatter.columnize(value);
    }
    return formatter.parameter(value);
  });

  if (expectedBindings !== index) {
    throw new Error(`Expected ${expectedBindings} bindings, saw ${index}`);
  }

  return {
    method: 'raw',
    sql,
    bindings: formatter.bindings,
  };
}

function replaceKeyBindings(raw, formatter) {
  const values = raw.bindings;
  const regex = /\\?(:(\w+):(?=::)|:(\w+):(?!:)|:(\w+))/g;

  const sql = raw.sql.replace(regex, function (match, p1, p2, p3, p4) {
    if (match !== p1) {
      return p1;
    }

    const part = p2 || p3 || p4;
    const key = match.trim();
    const isIdentifier = key[key.length - 1] === ':';
    const value = values[part];

    if (value === undefined) {
      if (Object.prototype.hasOwnProperty.call(values, part)) {
        formatter.bindings.push(value);
      }

      return match;
    }

    if (isIdentifier) {
      return match.replace(p1, formatter.columnize(value));
    }

    return match.replace(p1, formatter.parameter(value));
  });

  return {
    method: 'raw',
    sql,
    bindings: formatter.bindings,
  };
}

// Allow the `Raw` object to be utilized with full access to the relevant
// promise API.
require('./interface')(Raw);
helpers.addQueryContext(Raw);

module.exports = Raw;
