param.ts

/** @publicapi @module params */ /** */
import { extend, filter, map, allTrueR, find } from '../common/common';
import { prop } from '../common/hof';
import { isInjectable, isDefined, isString, isArray, isUndefined } from '../common/predicates';
import { RawParams, ParamDeclaration } from '../params/interface';
import { services } from '../common/coreservices';
import { ParamType } from './paramType';
import { ParamTypes } from './paramTypes';
import { StateDeclaration } from '../state';
import { UrlConfig } from '../url';

/** @hidden */
const hasOwn = Object.prototype.hasOwnProperty;

/** @hidden */
const isShorthand = (cfg: ParamDeclaration) =>
  ['value', 'type', 'squash', 'array', 'dynamic'].filter(hasOwn.bind(cfg || {})).length === 0;

/** @internalapi */
enum DefType {
  PATH,
  SEARCH,
  CONFIG,
}
export { DefType };

/** @internalapi */
function getParamDeclaration(paramName: string, location: DefType, state: StateDeclaration): ParamDeclaration {
  const noReloadOnSearch = (state.reloadOnSearch === false && location === DefType.SEARCH) || undefined;
  const dynamic = find([state.dynamic, noReloadOnSearch], isDefined);
  const defaultConfig = isDefined(dynamic) ? { dynamic } : {};
  const paramConfig = unwrapShorthand(state && state.params && state.params[paramName]);
  return extend(defaultConfig, paramConfig);
}

/** @hidden */
function unwrapShorthand(cfg: ParamDeclaration): ParamDeclaration {
  cfg = isShorthand(cfg) ? ({ value: cfg } as ParamDeclaration) : cfg;

  getStaticDefaultValue['__cacheable'] = true;
  function getStaticDefaultValue() {
    return cfg.value;
  }

  const $$fn = isInjectable(cfg.value) ? cfg.value : getStaticDefaultValue;
  return extend(cfg, { $$fn });
}

/** @hidden */
function getType(cfg: ParamDeclaration, urlType: ParamType, location: DefType, id: string, paramTypes: ParamTypes) {
  if (cfg.type && urlType && urlType.name !== 'string') throw new Error(`Param '${id}' has two type configurations.`);
  if (cfg.type && urlType && urlType.name === 'string' && paramTypes.type(cfg.type as string))
    return paramTypes.type(cfg.type as string);
  if (urlType) return urlType;
  if (!cfg.type) {
    const type =
      location === DefType.CONFIG
        ? 'any'
        : location === DefType.PATH
          ? 'path'
          : location === DefType.SEARCH
            ? 'query'
            : 'string';
    return paramTypes.type(type);
  }
  return cfg.type instanceof ParamType ? cfg.type : paramTypes.type(cfg.type as string);
}

/**
 * @internalapi
 * returns false, true, or the squash value to indicate the "default parameter url squash policy".
 */
function getSquashPolicy(config: ParamDeclaration, isOptional: boolean, defaultPolicy: boolean | string) {
  const squash = config.squash;
  if (!isOptional || squash === false) return false;
  if (!isDefined(squash) || squash == null) return defaultPolicy;
  if (squash === true || isString(squash)) return squash;
  throw new Error(`Invalid squash policy: '${squash}'. Valid policies: false, true, or arbitrary string`);
}

/** @internalapi */
function getReplace(config: ParamDeclaration, arrayMode: boolean, isOptional: boolean, squash: string | boolean) {
  const defaultPolicy = [
    { from: '', to: isOptional || arrayMode ? undefined : '' },
    { from: null, to: isOptional || arrayMode ? undefined : '' },
  ];

  const replace = isArray(config.replace) ? config.replace : [];
  if (isString(squash)) replace.push({ from: squash, to: undefined });

  const configuredKeys = map(replace, prop('from'));
  return filter(defaultPolicy, item => configuredKeys.indexOf(item.from) === -1).concat(replace);
}

/** @internalapi */
export class Param {
  id: string;
  type: ParamType;
  location: DefType;
  isOptional: boolean;
  dynamic: boolean;
  raw: boolean;
  squash: boolean | string;
  replace: [{ to: any; from: any }];
  inherit: boolean;
  array: boolean;
  config: any;
  /** Cache the default value if it is a static value */
  _defaultValueCache: {
    defaultValue: any;
  };

  static values(params: Param[], values: RawParams = {}): RawParams {
    const paramValues = {} as RawParams;
    for (const param of params) {
      paramValues[param.id] = param.value(values[param.id]);
    }
    return paramValues;
  }

  /**
   * Finds [[Param]] objects which have different param values
   *
   * Filters a list of [[Param]] objects to only those whose parameter values differ in two param value objects
   *
   * @param params: The list of Param objects to filter
   * @param values1: The first set of parameter values
   * @param values2: the second set of parameter values
   *
   * @returns any Param objects whose values were different between values1 and values2
   */
  static changed(params: Param[], values1: RawParams = {}, values2: RawParams = {}): Param[] {
    return params.filter(param => !param.type.equals(values1[param.id], values2[param.id]));
  }

  /**
   * Checks if two param value objects are equal (for a set of [[Param]] objects)
   *
   * @param params The list of [[Param]] objects to check
   * @param values1 The first set of param values
   * @param values2 The second set of param values
   *
   * @returns true if the param values in values1 and values2 are equal
   */
  static equals(params: Param[], values1 = {}, values2 = {}): boolean {
    return Param.changed(params, values1, values2).length === 0;
  }

  /** Returns true if a the parameter values are valid, according to the Param definitions */
  static validates(params: Param[], values: RawParams = {}): boolean {
    return params.map(param => param.validates(values[param.id])).reduce(allTrueR, true);
  }

  constructor(id: string, type: ParamType, location: DefType, urlConfig: UrlConfig, state: StateDeclaration) {
    const config: ParamDeclaration = getParamDeclaration(id, location, state);
    type = getType(config, type, location, id, urlConfig.paramTypes);
    const arrayMode = getArrayMode();
    type = arrayMode ? type.$asArray(arrayMode, location === DefType.SEARCH) : type;
    const isOptional = config.value !== undefined || location === DefType.SEARCH;
    const dynamic = isDefined(config.dynamic) ? !!config.dynamic : !!type.dynamic;
    const raw = isDefined(config.raw) ? !!config.raw : !!type.raw;
    const squash = getSquashPolicy(config, isOptional, urlConfig.defaultSquashPolicy());
    const replace = getReplace(config, arrayMode, isOptional, squash);
    const inherit = isDefined(config.inherit) ? !!config.inherit : !!type.inherit;

    // array config: param name (param[]) overrides default settings.  explicit config overrides param name.
    function getArrayMode() {
      const arrayDefaults = { array: location === DefType.SEARCH ? 'auto' : false };
      const arrayParamNomenclature = id.match(/\[\]$/) ? { array: true } : {};
      return extend(arrayDefaults, arrayParamNomenclature, config).array;
    }

    extend(this, { id, type, location, isOptional, dynamic, raw, squash, replace, inherit, array: arrayMode, config });
  }

  isDefaultValue(value: any): boolean {
    return this.isOptional && this.type.equals(this.value(), value);
  }

  /**
   * [Internal] Gets the decoded representation of a value if the value is defined, otherwise, returns the
   * default value, which may be the result of an injectable function.
   */
  value(value?: any): any {
    /**
     * [Internal] Get the default value of a parameter, which may be an injectable function.
     */
    const getDefaultValue = () => {
      if (this._defaultValueCache) return this._defaultValueCache.defaultValue;

      if (!services.$injector) throw new Error('Injectable functions cannot be called at configuration time');

      const defaultValue = services.$injector.invoke(this.config.$$fn);

      if (defaultValue !== null && defaultValue !== undefined && !this.type.is(defaultValue))
        throw new Error(
          `Default value (${defaultValue}) for parameter '${this.id}' is not an instance of ParamType (${
            this.type.name
          })`
        );

      if (this.config.$$fn['__cacheable']) {
        this._defaultValueCache = { defaultValue };
      }

      return defaultValue;
    };

    const replaceSpecialValues = (val: any) => {
      for (const tuple of this.replace) {
        if (tuple.from === val) return tuple.to;
      }
      return val;
    };

    value = replaceSpecialValues(value);

    return isUndefined(value) ? getDefaultValue() : this.type.$normalize(value);
  }

  isSearch(): boolean {
    return this.location === DefType.SEARCH;
  }

  validates(value: any): boolean {
    // There was no parameter value, but the param is optional
    if ((isUndefined(value) || value === null) && this.isOptional) return true;

    // The value was not of the correct ParamType, and could not be decoded to the correct ParamType
    const normalized = this.type.$normalize(value);
    if (!this.type.is(normalized)) return false;

    // The value was of the correct type, but when encoded, did not match the ParamType's regexp
    const encoded = this.type.encode(normalized);
    return !(isString(encoded) && !this.type.pattern.exec(<string>encoded));
  }

  toString() {
    return `{Param:${this.id} ${this.type} squash: '${this.squash}' optional: ${this.isOptional}}`;
  }
}