package com.diagnose.common.validation;

import com.google.common.collect.Sets;

import javax.validation.Constraint;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import java.util.Set;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Documented
@Constraint(validatedBy = IntArrayChecker.class)
@Target({METHOD, FIELD, ANNOTATION_TYPE, PARAMETER, CONSTRUCTOR})
@Retention(RUNTIME)
public @interface IntArrayValidator {

    String message() default "不符合取值范围";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    int[] value();

}

class IntArrayChecker implements ConstraintValidator<IntArrayValidator, Integer> {

    private Set<Integer> AVAILABLE_VALUES;

    @Override
    public void initialize(IntArrayValidator validator) {
        int[] values = validator.value();
        Set<Integer> valuesSet = Sets.newHashSetWithExpectedSize(values.length);
        for (int value : values) {
            valuesSet.add(value);
        }
        AVAILABLE_VALUES = valuesSet;
    }

    @Override
    public boolean isValid(Integer value, ConstraintValidatorContext context) {
        if (value == null) {
            return true;
        } else {
            return AVAILABLE_VALUES.contains(value);
        }
    }

}