/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Other licenses:
 * -----------------------------------------------------------------------------
 * Commercial licenses for this work are available. These replace the above
 * Apache-2.0 license and offer limited warranties, support, maintenance, and
 * commercial database integrations.
 *
 * For more information, please visit: https://www.jooq.org/legal/licensing
 *
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 */
package org.jooq.impl;

// ...
// ...
// ...
// ...
// ...
import static org.jooq.SQLDialect.CUBRID;
// ...
// ...
// ...
import static org.jooq.SQLDialect.MARIADB;
// ...
import static org.jooq.SQLDialect.MYSQL;
// ...
// ...
import static org.jooq.SQLDialect.SQLITE;
// ...
// ...
// ...
import static org.jooq.impl.DSL.nvl2;
import static org.jooq.impl.DSL.one;
import static org.jooq.impl.DSL.zero;
import static org.jooq.impl.Keywords.K_NULLS_FIRST;
import static org.jooq.impl.Keywords.K_NULLS_LAST;

import java.util.Set;

import org.jooq.Context;
import org.jooq.Field;
// ...
import org.jooq.QueryPart;
// ...
import org.jooq.SQLDialect;
import org.jooq.SortField;
import org.jooq.SortOrder;
// ...
import org.jooq.impl.QOM.NullOrdering;


final class SortFieldImpl<T> extends AbstractQueryPart implements SortField<T>, SimpleCheckQueryPart {

    // DB2 supports NULLS FIRST/LAST only in OLAP (window) functions
    private static final Set<SQLDialect> NO_SUPPORT_NULLS = SQLDialect.supportedUntil(CUBRID, MARIADB, MYSQL);

    final Field<T>                       field;
    final SortOrder                      order;
    NullOrdering                         nullOrdering;

    SortFieldImpl(Field<T> field, SortOrder order) {
        this(field, order, null);
    }

    SortFieldImpl(Field<T> field, SortOrder order, NullOrdering nullOrdering) {
        this.field = field;
        this.order = order;
        this.nullOrdering = nullOrdering;
    }

    @Override
    public boolean isSimple(Context<?> ctx) {
        return nullOrdering == null && Tools.isSimple(ctx, field);
    }

    @Override
    public final String getName() {
        return field.getName();
    }

    @Override
    public final SortOrder getOrder() {
        return order;
    }

    @Override
    public final SortField<T> nullsFirst() {
        nullOrdering = NullOrdering.NULLS_FIRST;
        return this;
    }

    @Override
    public final SortField<T> nullsLast() {
        nullOrdering = NullOrdering.NULLS_LAST;
        return this;
    }

    @Override
    public final void accept(Context<?> ctx) {







        if (nullOrdering != null) {
            if (NO_SUPPORT_NULLS.contains(ctx.dialect())) {
                Field<Integer> ifNull = nullOrdering == NullOrdering.NULLS_FIRST ? zero() : one();
                Field<Integer> ifNotNull = nullOrdering == NullOrdering.NULLS_FIRST ? one() : zero();

                ctx.visit(nvl2(field, ifNotNull, ifNull))
                   .sql(", ");

                acceptFieldAndOrder(ctx, false);
            }
            else
                acceptFieldAndOrder(ctx, true);
        }
        else
            acceptFieldAndOrder(ctx, false);
    }


















    private final void acceptFieldAndOrder(Context<?> ctx, boolean includeNulls) {
        String separator = "";

        for (Field<?> f : Tools.flatten(field)) {
            ctx.sql(separator).visit(f);

            if (order != SortOrder.DEFAULT)
               ctx.sql(' ')
                  .visit(order.toKeyword());

            if (includeNulls)
                if (nullOrdering == NullOrdering.NULLS_FIRST)
                    ctx.sql(' ').visit(K_NULLS_FIRST);
                else
                    ctx.sql(' ').visit(K_NULLS_LAST);

            separator = ", ";
        }
    }

    // -------------------------------------------------------------------------
    // XXX: Query Object Model
    // -------------------------------------------------------------------------

    @Override
    public final Field<T> $field() {
        return field;
    }

    @SuppressWarnings("unchecked")
    @Override
    public final <U> SortField<U> $field(Field<U> newField) {
        if (newField == field)
            return (SortField<U>) this;
        else
            return new SortFieldImpl<>(newField, order, nullOrdering);
    }

    @Override
    public final SortOrder $sortOrder() {
        return order;
    }

    @Override
    public final SortField<T> $sortOrder(SortOrder newOrder) {
        if (newOrder == order)
            return this;
        else
            return new SortFieldImpl<>(field, newOrder, nullOrdering);
    }

    @Override
    public final NullOrdering $nullOrdering() {
        return nullOrdering;
    }

    @Override
    public final SortField<T> $nullOrdering(NullOrdering newOrdering) {
        if (newOrdering == nullOrdering)
            return this;
        else
            return new SortFieldImpl<>(field, order, newOrdering);
    }



















}
