BingSearchHelper.cs

// 
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license.
// 
// Microsoft Cognitive Services: http://www.microsoft.com/cognitive
// 
// Microsoft Cognitive Services Github:
// https://github.com/Microsoft/Cognitive
// 
// Copyright (c) Microsoft Corporation
// All rights reserved.
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// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
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// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
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using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace ServiceHelpers
{
    public class BingSearchHelper
    {
        private static string ImageSearchEndPoint = "https://api.cognitive.microsoft.com/bing/v7.0/images/search";
        private static string ImageInsightsEndPoint = "https://api.cognitive.microsoft.com/bing/v7.0/images/details";
        private static string AutoSuggestionEndPoint = "https://api.cognitive.microsoft.com/bing/v7.0/suggestions";
        private static string NewsSearchEndPoint = "https://api.cognitive.microsoft.com/bing/v7.0/news/search";

        private static int RetryCountOnQuotaLimitError = 6;
        private static int RetryDelayOnQuotaLimitError = 500;

        private static HttpClient autoSuggestionClient { get; set; }
        private static HttpClient searchClient { get; set; }

        private static string autoSuggestionApiKey;
        public static string AutoSuggestionApiKey
        {
            get { return autoSuggestionApiKey; }
            set
            {
                var changed = autoSuggestionApiKey != value;
                autoSuggestionApiKey = value;
                if (changed)
                {
                    InitializeBingClients();
                }
            }
        }

        private static string searchApiKey;
        public static string SearchApiKey
        {
            get { return searchApiKey; }
            set
            {
                var changed = searchApiKey != value;
                searchApiKey = value;
                if (changed)
                {
                    InitializeBingClients();
                }
            }
        }

        private static void InitializeBingClients()
        {
            autoSuggestionClient = new HttpClient();
            autoSuggestionClient.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", AutoSuggestionApiKey);

            searchClient = new HttpClient();
            searchClient.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", SearchApiKey);
        }

        private static async Task<HttpResponseMessage> RequestAndAutoRetryWhenThrottled(Func<Task<HttpResponseMessage>> action)
        {
            int retriesLeft = BingSearchHelper.RetryCountOnQuotaLimitError;
            int delay = BingSearchHelper.RetryDelayOnQuotaLimitError;

            HttpResponseMessage response = null;

            while (true)
            {
                response = await action();

                if ((int)response.StatusCode == 429 && retriesLeft > 0)
                {
                    await Task.Delay(delay);
                    retriesLeft--;
                    delay *= 2;
                    continue;
                }
                else
                {
                    break;
                }
            }

            return response;
        }

        public static async Task<IEnumerable<string>> GetImageSearchResults(string query, string imageContent = "Face", int count = 20, int offset = 0)
        {
            List<string> urls = new List<string>();

            var result = await RequestAndAutoRetryWhenThrottled(() => searchClient.GetAsync(string.Format("{0}?q={1}&safeSearch=Strict&imageType=Photo&color=ColorOnly&count={2}&offset={3}{4}", ImageSearchEndPoint, WebUtility.UrlEncode(query), count, offset, string.IsNullOrEmpty(imageContent) ? "" : "&imageContent=" + imageContent)));
            result.EnsureSuccessStatusCode();
            var json = await result.Content.ReadAsStringAsync();
            dynamic data = JObject.Parse(json);
            if (data.value != null && data.value.Count > 0)
            {
                for (int i = 0; i < data.value.Count; i++)
                {
                    urls.Add(data.value[i].contentUrl.Value);
                }
            }

            return urls;
        }

        public static async Task<IEnumerable<string>> GetAutoSuggestResults(string query, string market = "en-US")
        {
            List<string> suggestions = new List<string>();

            var result = await RequestAndAutoRetryWhenThrottled(() => autoSuggestionClient.GetAsync(string.Format("{0}/?q={1}&mkt={2}", AutoSuggestionEndPoint, WebUtility.UrlEncode(query), market)));
            result.EnsureSuccessStatusCode();
            var json = await result.Content.ReadAsStringAsync();
            dynamic data = JObject.Parse(json);
            if (data.suggestionGroups != null && data.suggestionGroups.Count > 0 &&
                data.suggestionGroups[0].searchSuggestions != null)
            {
                for (int i = 0; i < data.suggestionGroups[0].searchSuggestions.Count; i++)
                {
                    suggestions.Add(data.suggestionGroups[0].searchSuggestions[i].displayText.Value);
                }
            }

            return suggestions;
        }


        public static async Task<IEnumerable<NewsArticle>> GetNewsSearchResults(string query, int count = 20, int offset = 0, string market = "en-US")
        {
            List<NewsArticle> articles = new List<NewsArticle>();

            var result = await RequestAndAutoRetryWhenThrottled(() => searchClient.GetAsync(string.Format("{0}/?q={1}&count={2}&offset={3}&mkt={4}", NewsSearchEndPoint, WebUtility.UrlEncode(query), count, offset, market)));
            result.EnsureSuccessStatusCode();
            var json = await result.Content.ReadAsStringAsync();
            dynamic data = JObject.Parse(json);

            if (data.value != null && data.value.Count > 0)
            {
                for (int i = 0; i < data.value.Count; i++)
                {
                    articles.Add(new NewsArticle
                    {
                        Title = data.value[i].name,
                        Url = data.value[i].url,
                        Description = data.value[i].description,
                        ThumbnailUrl = data.value[i].image?.thumbnail?.contentUrl,
                        Provider = data.value[i].provider?[0].name
                    });
                }
            }
            return articles;
        }

        private static async Task<HttpResponseMessage> CallBingImageInsightsAsync(string imgUrl, string module)
        {
            var result = await RequestAndAutoRetryWhenThrottled(() => searchClient.GetAsync(string.Format("{0}?imgUrl={1}&modules={2}", ImageInsightsEndPoint, WebUtility.UrlEncode(imgUrl), module)));
            result.EnsureSuccessStatusCode();
            return result;
        }

        private static async Task<HttpResponseMessage> CallBingImageInsightsAsync(Stream stream, string module)
        {
            var strContent = new StreamContent(stream);
            strContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data") { FileName = "AnyNameWorks" };

            var content = new MultipartFormDataContent();
            content.Add(strContent);

            var result = await RequestAndAutoRetryWhenThrottled(() => searchClient.PostAsync(string.Format("{0}?modules={1}", ImageInsightsEndPoint, module), content));
            result.EnsureSuccessStatusCode();
            return result;
        }

        public static async Task<IEnumerable<VisualSearchCelebrityResult>> GetVisuallySimilarCelebrities(string imgUrl)
        {
            var result = await CallBingImageInsightsAsync(imgUrl, "RecognizedEntities");
            return ParseCelebrityResults(await result.Content.ReadAsStringAsync());
        }

        public static async Task<IEnumerable<VisualSearchCelebrityResult>> GetVisuallySimilarCelebrities(Stream stream)
        {
            var result = await CallBingImageInsightsAsync(stream, "RecognizedEntities");
            return ParseCelebrityResults(await result.Content.ReadAsStringAsync());
        }

        private static List<VisualSearchCelebrityResult> ParseCelebrityResults(string json)
        {
            List<VisualSearchCelebrityResult> results = new List<VisualSearchCelebrityResult>();

            dynamic data = JObject.Parse(json);
            if (data.recognizedEntityGroups != null && data.recognizedEntityGroups.value.Count > 0)
            {
                for (int i = 0; i < data.recognizedEntityGroups.value.Count; i++)
                {
                    for (int j = 0; j < data.recognizedEntityGroups.value[i].recognizedEntityRegions.Count; j++)
                    {
                        for (int k = 0; k < data.recognizedEntityGroups.value[i].recognizedEntityRegions[j].matchingEntities.Count; k++)
                        {
                            dynamic entity = data.recognizedEntityGroups.value[i].recognizedEntityRegions[j].matchingEntities[k];
                            results.Add(new VisualSearchCelebrityResult
                            {
                                Name = entity.entity.name.Value,
                                SimilarityScore = Math.Round(entity.matchConfidence.Value, 2),
                                Occupation = entity.entity.jobTitle != null ? entity.entity.jobTitle.Value : "",
                                ReferenceUrl = entity.entity.image.hostPageUrl.Value,
                                ImageUrl = entity.entity.image.contentUrl.Value
                            });
                        }
                    }
                }
            }
            return results;
        }

        public static async Task<IEnumerable<VisualSearchPhotoResult>> GetVisuallySimilarImages(string imgUrl)
        {
            var result = await CallBingImageInsightsAsync(imgUrl, "SimilarImages");
            return ParsePhotoResults(await result.Content.ReadAsStringAsync());
        }

        public static async Task<IEnumerable<VisualSearchPhotoResult>> GetVisuallySimilarImages(Stream stream)
        {
            var result = await CallBingImageInsightsAsync(stream, "SimilarImages");
            return ParsePhotoResults(await result.Content.ReadAsStringAsync());
        }

        private static List<VisualSearchPhotoResult> ParsePhotoResults(string json)
        {
            List<VisualSearchPhotoResult> results = new List<VisualSearchPhotoResult>();

            dynamic data = JObject.Parse(json);
            if (data.visuallySimilarImages != null && data.visuallySimilarImages.value.Count > 0)
            {
                for (int i = 0; i < data.visuallySimilarImages.value.Count; i++)
                {
                    results.Add(new VisualSearchPhotoResult
                    {
                        ImageUrl = data.visuallySimilarImages.value[i].thumbnailUrl.Value
                    });
                }
            }

            return results;
        }

        public static async Task<IEnumerable<VisualSearchProductResult>> GetVisuallySimilarProducts(string imgUrl)
        {
            var result = await CallBingImageInsightsAsync(imgUrl, "SimilarProducts");
            return ParseProductResults(await result.Content.ReadAsStringAsync());
        }

        public static async Task<IEnumerable<VisualSearchProductResult>> GetVisuallySimilarProducts(Stream stream)
        {
            var result = await CallBingImageInsightsAsync(stream, "SimilarProducts");
            return ParseProductResults(await result.Content.ReadAsStringAsync());
        }

        private static List<VisualSearchProductResult> ParseProductResults(string json)
        {
            List<VisualSearchProductResult> products = new List<VisualSearchProductResult>();

            dynamic data = JObject.Parse(json);
            if (data.visuallySimilarProducts != null && data.visuallySimilarProducts.value.Count > 0)
            {
                for (int i = 0; i < data.visuallySimilarProducts.value.Count; i++)
                {
                    dynamic prod = data.visuallySimilarProducts.value[i];
                    if (prod?.insightsMetadata?.aggregateOffer?.priceCurrency != null && prod?.insightsMetadata?.aggregateOffer?.lowPrice != null)
                    {
                        products.Add(new VisualSearchProductResult
                        {
                            Name = prod.insightsMetadata.aggregateOffer.name.Value,
                            ImageUrl = prod.thumbnailUrl.Value,
                            ReferenceUrl = prod.hostPageUrl.Value,
                            Price = string.Format("{0} {1}", prod.insightsMetadata.aggregateOffer.priceCurrency.Value, prod.insightsMetadata.aggregateOffer.lowPrice.Value)
                        });
                    }
                }
            }

            return products;
        }
    }

    public class NewsArticle
    {
        public string Title { get; set; }
        public string Description { get; set; }
        public string Url { get; set; }
        public string ThumbnailUrl { get; set; }
        public string Provider { get; set; }
    }

    public abstract class VisualSearchResult
    {
        public string ImageUrl { get; set; }
        public string ReferenceUrl { get; set; }
    }

    public class VisualSearchPhotoResult : VisualSearchResult
    {
    }

    public class VisualSearchProductResult : VisualSearchResult
    {
        public string Name { get; set; }
        public string Price { get; set; }
    }

    public class VisualSearchCelebrityResult : VisualSearchResult
    {
        public string Name { get; set; }
        public string Occupation { get; set; }
        public double SimilarityScore { get; set; }
    }
}