/** @module validate */
/** @hidden */ 
let _ = require('lodash');

import { IValidationRule } from './IValidationRule';
import { ValidationResult } from './ValidationResult';
import { ValidationResultType } from './ValidationResultType';
import { Schema } from './Schema';
import { ObjectReader } from '../reflect/ObjectReader';
import { TypeCode } from '../convert/TypeCode';
import { TypeConverter } from '../convert/TypeConverter';
import { StringConverter } from '../convert/StringConverter';

/**
 * Schema to validate maps.
 * 
 * ### Example ###
 * 
 *     let schema = new MapSchema(TypeCode.String, TypeCode.Integer);
 *     
 *     schema.validate({ "key1": "A", "key2": "B" });       // Result: no errors
 *     schema.validate({ "key1": 1, "key2": 2 });           // Result: element type mismatch
 *     schema.validate([ 1, 2, 3 ]);                        // Result: type mismatch
 */
export class MapSchema extends Schema {
    private _keyType: any;
    private _valueType: any;
    
    /**
     * Creates a new instance of validation schema and sets its values.
     * 
     * @param keyType       a type of map keys. Null means that keys may have any type.
     * @param valueType     a type of map values. Null means that values may have any type.
     * @param required      (optional) true to always require non-null values.
     * @param rules         (optional) a list with validation rules.
     * 
     * @see [[IValidationRule]]
     * @see [[TypeCode]]
     */
    public constructor(keyType?: any, valueType?: any, required?: boolean, rules?: IValidationRule[]) {
        super(required, rules);

        this._keyType = keyType;
        this._valueType = valueType;
    }

    /**
     * Gets the type of map keys.
     * Null means that keys may have any type.
     * 
     * @returns the type of map keys.
     */
    public getKeyType(): any {
        return this._keyType; 
    }

    /**
     * Sets the type of map keys.
     * Null means that keys may have any type.
     * 
     * @param value     a type of map keys.
     */
    public setKeyType(value: any) {
        this._keyType = value; 
    }

    /**
     * Gets the type of map values.
     * Null means that values may have any type.
     * 
     * @returns the type of map values.
     */
    public getValueType(): any {
        return this._valueType; 
    }

    /**
     * Sets the type of map values.
     * Null means that values may have any type.
     * 
     * @param value     a type of map values.
     */
    public setValueType(value: any) {
        this._valueType = value; 
    }

    /**
     * Validates a given value against the schema and configured validation rules.
     * 
     * @param path      a dot notation path to the value.
     * @param value     a value to be validated.
     * @param results   a list with validation results to add new results.
     */
    protected performValidation(path: string, value: any, results: ValidationResult[]): void {
        value = ObjectReader.getValue(value);

        super.performValidation(path, value, results);

        if (!value) return;

        let name = path || "value";
        let valueType: TypeCode = TypeConverter.toTypeCode(value);
        let map: any = valueType === TypeCode.Map ? value : null;

        if (map) {
            for (var key in map) {
                var elementPath = path != "" ? path + "." + key : StringConverter.toString(key);

                this.performTypeValidation(elementPath, this.getKeyType(), key, results);
                this.performTypeValidation(elementPath, this.getValueType(), map[key], results);
            }
        } else {
            if (this.isRequired) {
                results.push(new ValidationResult(
                    path,
                    ValidationResultType.Error,
                    "VALUE_ISNOT_MAP",
                    name + " type must be Map",
                    TypeCode.Map,
                    valueType
                ));
            }
        }
    }

}