/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */
package org.elasticsearch.rest.action.search;

import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.SearchType;
import org.elasticsearch.rest.RestRequest;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.term.TermSuggestionBuilder;
import org.elasticsearch.search.vectors.KnnSearchBuilder;
import org.elasticsearch.test.rest.FakeRestChannel;
import org.elasticsearch.test.rest.FakeRestRequest;
import org.elasticsearch.test.rest.RestActionTestCase;
import org.elasticsearch.usage.UsageService;
import org.junit.Before;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static org.mockito.Mockito.mock;

public final class RestSearchActionTests extends RestActionTestCase {
    private RestSearchAction action;

    @Before
    public void setUpAction() {
        action = new RestSearchAction(new UsageService().getSearchUsageHolder(), nf -> false);
        controller().registerHandler(action);
        verifyingClient.setExecuteVerifier((actionType, request) -> mock(SearchResponse.class));
        verifyingClient.setExecuteLocallyVerifier((actionType, request) -> mock(SearchResponse.class));
    }

    /**
     * The "enable_fields_emulation" flag on search requests is a no-op but should not raise an error
     */
    public void testEnableFieldsEmulationNoErrors() throws Exception {
        Map<String, String> params = new HashMap<>();
        params.put("enable_fields_emulation", "true");

        RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withMethod(RestRequest.Method.GET)
            .withPath("/some_index/_search")
            .withParams(params)
            .build();

        action.handleRequest(request, new FakeRestChannel(request, randomBoolean(), 1), verifyingClient);
    }

    public void testValidateSearchRequest() {
        {
            Map<String, String> params = new HashMap<>();
            params.put("rest_total_hits_as_int", "true");

            RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withMethod(RestRequest.Method.GET)
                .withPath("/some_index/_search")
                .withParams(params)
                .build();

            SearchRequest searchRequest = new SearchRequest();
            searchRequest.source(new SearchSourceBuilder().trackTotalHitsUpTo(100));

            Exception ex = expectThrows(
                IllegalArgumentException.class,
                () -> RestSearchAction.validateSearchRequest(request, searchRequest)
            );
            assertEquals("[rest_total_hits_as_int] cannot be used if the tracking of total hits is not accurate, got 100", ex.getMessage());
        }
        {
            Map<String, String> params = new HashMap<>();
            params.put("search_type", randomFrom(SearchType.values()).name());

            RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withMethod(RestRequest.Method.GET)
                .withPath("/some_index/_search")
                .withParams(params)
                .build();

            SearchRequest searchRequest = new SearchRequest();
            KnnSearchBuilder knnSearch = new KnnSearchBuilder("vector", new float[] { 1, 1, 1 }, 10, 100, null, null);
            searchRequest.source(new SearchSourceBuilder().knnSearch(List.of(knnSearch)));

            Exception ex = expectThrows(
                IllegalArgumentException.class,
                () -> RestSearchAction.validateSearchRequest(request, searchRequest)
            );
            assertEquals(
                "cannot set [search_type] when using [knn] search, since the search type is determined automatically",
                ex.getMessage()
            );
        }
    }

    /**
     * Using an illegal search type on the request should throw an error
     */
    public void testIllegalSearchType() {
        Map<String, String> params = new HashMap<>();
        params.put("search_type", "some_search_type");

        RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withMethod(RestRequest.Method.GET)
            .withPath("/some_index/_search")
            .withParams(params)
            .build();

        Exception ex = expectThrows(IllegalArgumentException.class, () -> action.prepareRequest(request, verifyingClient));
        assertEquals("No search type for [some_search_type]", ex.getMessage());
    }

    public void testParseSuggestParameters() {
        assertNull(RestSearchAction.parseSuggestUrlParameters(new FakeRestRequest()));

        RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withParams(
            Map.of("suggest_field", "field", "suggest_text", "text", "suggest_size", "3", "suggest_mode", "missing")
        ).build();
        SuggestBuilder suggestBuilder = RestSearchAction.parseSuggestUrlParameters(request);
        TermSuggestionBuilder builder = (TermSuggestionBuilder) suggestBuilder.getSuggestions().get("field");
        assertNotNull(builder);
        assertEquals("text", builder.text());
        assertEquals("field", builder.field());
        assertEquals(3, builder.size().intValue());
        assertEquals(TermSuggestionBuilder.SuggestMode.MISSING, builder.suggestMode());
    }

    public void testParseSuggestParametersError() {
        RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withParams(
            Map.of("suggest_text", "text", "suggest_size", "3", "suggest_mode", "missing")
        ).build();
        IllegalArgumentException iae = expectThrows(
            IllegalArgumentException.class,
            () -> RestSearchAction.parseSuggestUrlParameters(request)
        );
        assertEquals(
            "request [/] contains parameters [suggest_text, suggest_size, suggest_mode] but missing 'suggest_field' parameter.",
            iae.getMessage()
        );
    }
}