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

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

/**
 * Schema to validate arrays.
 * 
 * ### Example ###
 * 
 *     let schema = new ArraySchema(TypeCode.String);
 *     
 *     schema.validate(["A", "B", "C"]);    // Result: no errors
 *     schema.validate([1, 2, 3]);          // Result: element type mismatch
 *     schema.validate("A");                // Result: type mismatch            
 */
export class ArraySchema extends Schema {
    private _valueType: any;

    /**
     * Creates a new instance of validation schema and sets its values.
     * 
     * @param valueType     a type of array elements. Null means that elements may have any type.
     * @param required      (optional) true to always require non-null values.
     * @param rules         (optional) a list with validation rules.
     * 
     * @see [[TypeCode]]
     */
    public constructor(valueType?: any, required?: boolean, rules?: IValidationRule[]) {
        super(required, rules);

        this._valueType = valueType;
    }

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

    /**
     * Sets the type of array elements.
     * Null means that elements may have any type.
     * 
     * @param value     a type of array elements.
     */
    public setValueType(value: any): void {
        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 {
        let name = path || "value";
        value = ObjectReader.getValue(value);

        super.performValidation(path, value, results);

        if (!value) return;

        if (_.isArray(value)) {
            for (let index = 0; index < value.length; index++) {
                let elementPath = path != "" ? path + "." + index : index.toString();
                this.performTypeValidation(elementPath, this.getValueType(), value[index], results);
            }
        } else {
            results.push(
                new ValidationResult(
                    path,
                    ValidationResultType.Error,
                    "VALUE_ISNOT_ARRAY",
                    name + " type must to be List or Array",
                    TypeCode.Array,
                    TypeConverter.toTypeCode(value)
                )
            );
        }
    }

}