co.streamx.fluent.JPA.DSLInterpreterHelpers Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of fluent-jpa Show documentation
Fluent query implementation for JPA repositories
The newest version!
package co.streamx.fluent.JPA;

import static co.streamx.fluent.JPA.JPAHelpers.wrap;

import java.lang.annotation.Annotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

import co.streamx.fluent.extree.expression.ConstantExpression;
import co.streamx.fluent.extree.expression.Expression;
import co.streamx.fluent.extree.expression.ExpressionType;
import co.streamx.fluent.extree.expression.InvocationExpression;
import co.streamx.fluent.extree.expression.LambdaExpression;
import co.streamx.fluent.extree.expression.ParameterExpression;
import co.streamx.fluent.notation.Context;
import co.streamx.fluent.notation.ParameterContext;
import lombok.Getter;
import lombok.RequiredArgsConstructor;

interface DSLInterpreterHelpers {
    @RequiredArgsConstructor
    final class DynamicConstant implements UnboundCharSequence {

        private CharSequence string;
        @Getter
        private final Object value;
        private final DSLInterpreter dsl;

        private void lazyInit() {
            if (string == null) {
                if (value instanceof CharSequence || value instanceof Character) {
                    // wrap with quotes and escape existing quotes
                    StringBuilder out = new StringBuilder().append(DSLInterpreter.SINGLE_QUOTE_CHAR);
                    if (value instanceof CharSequence)
                        out.append((CharSequence) value);
                    else
                        out.append((char) value);
                    for (int i = out.length() - 1; i > 0; i--) {
                        if (out.charAt(i) == DSLInterpreter.SINGLE_QUOTE_CHAR)
                            out.insert(i, DSLInterpreter.SINGLE_QUOTE_CHAR);
                    }
                    string = out.append(DSLInterpreter.SINGLE_QUOTE_CHAR);
                } else
                    string = String.valueOf(value);
            }
        }

        public CharSequence registerAsParameter() {
            return dsl.registerParameter(value);
        }

        @Override
        public boolean isEmpty() {
            return false;
        }

        @Override
        public int length() {
            lazyInit();
            return string.length();
        }

        @Override
        public char charAt(int index) {
            lazyInit();
            return string.charAt(index);
        }

        @Override
        public CharSequence subSequence(int start,
                                        int end) {
            lazyInit();
            return string.subSequence(start, end);
        }

        @Override
        public String toString() {
            lazyInit();
            return string.toString();
        }
    }

    @RequiredArgsConstructor
    @Getter
    final class PackedInitializers implements UnboundCharSequence {

        private final List expressions;
        List> compiled;
        private final List, CharSequence>> producers;
        private final List it;
        private List itDecoded;
        private final DSLInterpreter dsl;

        public List getInitializers() {
            if (itDecoded != null)
                return itDecoded;
            return itDecoded = getInitializers(it, 0);
        }

        public List getInitializers(CharSequence seq,
                                                  int limit) {
            CharSequence[] seqs = new CharSequence[it.size()];
            Arrays.fill(seqs, seq);
            return getInitializers(Arrays.asList(seqs), limit);
        }

        public List getInitializers(Object value,
                                                  int limit) {
            if (limit <= 0)
                limit = producers.size() + limit;
            Object[] t = { value };
            return compiled().stream()
                    .limit(limit)
                    .map(f -> f.apply(t))
                    .map(p -> dsl.registerParameter(p))
                    .collect(Collectors.toList());
        }

        private List getInitializers(List it,
                                                   int limit) {
            if (limit <= 0)
                limit = producers.size() + limit;
            return producers.stream().limit(limit).map(pe -> pe.apply(it)).collect(Collectors.toList());
        }

        private List> compiled() {
            if (compiled == null)
                compiled = expressions.stream()
                        .map(e -> ((InvocationExpression) e).getTarget())
                        .map(ie -> ie instanceof LambdaExpression ? ((LambdaExpression) ie).compile()
                                : LambdaExpression.compile(ie))
                        .collect(Collectors.toList());

            return compiled;
        }

        @Override
        public boolean isEmpty() {
            return false;
        }

        @Override
        public int length() {
            throw new IllegalStateException();
        }

        @Override
        public char charAt(int index) {
            throw new IllegalStateException();
        }

        @Override
        public CharSequence subSequence(int start,
                                        int end) {
            throw new IllegalStateException();
        }

        @Override
        public String toString() {
            throw new IllegalStateException();
        }
    }

    @Getter
    @RequiredArgsConstructor
    final class RequiresParenthesesInAS implements Wrapped {
        private final CharSequence wrapped;

        @Override
        public String toString() {
            return getWrapped().toString();
        }
    }

    @Getter
    @RequiredArgsConstructor
    final class View {

        private final PackedInitializers packed;
        private CharSequence columns;
        private List allColumns;
        private CharSequence selfSelect;

        public CharSequence getColumn(CharSequence p,
                                      int i) {
            getColumns();
            try {
                if (i < 0)
                    i += allColumns.size();
                return new StringBuilder(p).append(DSLInterpreter.SEP_AS_SEP).append(allColumns.get(i));
            } catch (IndexOutOfBoundsException ioobe) {
                throw TranslationError.ALIAS_NOT_SPECIFIED.getError(ioobe, i);
            }
        }

        public CharSequence getColumns() {
            if (this.columns != null)
                return this.columns;
            allColumns = packed.getInitializers("", 0);
            return this.columns = join(allColumns, false);
        }

        private String join(List columns, boolean aliased) {
            Iterable it = aliased
                    ? () -> IntStream.range(0, columns.size()).mapToObj(i -> getColumn(columns.get(i), i)).iterator()
                    : columns;
            return String.join(DSLInterpreter.COMMA_CHAR + DSLInterpreter.KEYWORD_DELIMITER, it);
        }

        public CharSequence getSelect() {
            if (selfSelect != null)
                return selfSelect;
            return selfSelect = join(packed.getInitializers(), false);
        }

        public CharSequence getSelect(CharSequence seq,
                                      int limit,
                                      boolean aliased) {
            return join(packed.getInitializers(seq, limit), aliased);
        }

        public CharSequence getSelect(Object value,
                                      int limit,
                                      boolean aliased) {
            return join(packed.getInitializers(value, limit), aliased);
        }

    }

    interface Wrapped extends UnboundCharSequence {

        CharSequence getWrapped();

        @Override
        default boolean isEmpty() {
            return length() != 0;
        }

        @Override
        default int length() {
            return getWrapped().length();
        }

        @Override
        default char charAt(int index) {
            return getWrapped().charAt(index);
        }

        @Override
        default CharSequence subSequence(int start,
                                        int end) {
            return getWrapped().subSequence(start, end);
        }
    }

    @RequiredArgsConstructor
    @Getter
    final class ParameterRef implements Wrapped {

        private CharSequence seq;
        private final Object value;
        private final List