/// <summary>
/// Gets images from DuckDuckGo.
/// </summary>
/// <remarks>This method returns at most 100 image results.</remarks>
/// <param name="query">The search query.</param>
/// <param name="safeSearch">The safe search level.</param>
/// <param name="time">The image time.</param>
/// <param name="size">The image size.</param>
/// <param name="color">The image color.</param>
/// <param name="type">The image type.</param>
/// <param name="layout">The image layout.</param>
/// <param name="license">The image license.</param>
/// <param name="region">The region. <see cref="DuckDuckGoRegions"/> contains the regions that can be used here.</param>
/// <returns>A task representing the asynchronous operation. The result contains an <see cref="IEnumerable{T}"/> of <see cref="DuckDuckGoImageResult"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="query"/> is null or empty.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="query"/> is larger than <see cref="MaxQueryLength"/>.</exception>
/// <exception cref="GScraperException">An error occurred during the scraping process.</exception>
public async Task <IEnumerable <DuckDuckGoImageResult> > GetImagesAsync(string query, SafeSearchLevel safeSearch = SafeSearchLevel.Moderate,
DuckDuckGoImageTime time = DuckDuckGoImageTime.Any, DuckDuckGoImageSize size = DuckDuckGoImageSize.All, DuckDuckGoImageColor color = DuckDuckGoImageColor.All,
DuckDuckGoImageType type = DuckDuckGoImageType.All, DuckDuckGoImageLayout layout = DuckDuckGoImageLayout.All, DuckDuckGoImageLicense license = DuckDuckGoImageLicense.All,
string region = DuckDuckGoRegions.UsEnglish)
{
GScraperGuards.NotNull(query, nameof(query));
GScraperGuards.NotNullOrEmpty(region, nameof(region));
GScraperGuards.ArgumentInRange(query.Length, MaxQueryLength, nameof(query), $"The query cannot be larger than {MaxQueryLength}.");
string token = await GetTokenAsync(query);
var uri = new Uri($"i.js{BuildImageQuery(token, query, safeSearch, time, size, color, type, layout, license, region)}", UriKind.Relative);
byte[] bytes;
using (var request = new HttpRequestMessage())
{
request.Method = HttpMethod.Get;
request.RequestUri = uri;
if (safeSearch == SafeSearchLevel.Strict)
{
request.Headers.Add("cookie", "p=1");
}
else if (safeSearch == SafeSearchLevel.Off)
{
request.Headers.Add("cookie", "p=-2");
}
var response = await _httpClient.SendAsync(request).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
bytes = await response.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
}
var document = JsonDocument.Parse(bytes);
var results = document.RootElement.GetPropertyOrDefault("results");
return(EnumerateResults(results));
}
private static string BuildImageQuery(string token, string query, SafeSearchLevel safeSearch, DuckDuckGoImageTime time, DuckDuckGoImageSize size,
DuckDuckGoImageColor color, DuckDuckGoImageType type, DuckDuckGoImageLayout layout, DuckDuckGoImageLicense license, string region)
{
string url = $"?l={region}" +
"&o=json" +
$"&q={Uri.EscapeDataString(query)}" +
$"&vqd={token}" +
"&f=";
url += time == DuckDuckGoImageTime.Any ? ',' : $"time:{time},";
url += size == DuckDuckGoImageSize.All ? ',' : $"size:{size},";
url += color == DuckDuckGoImageColor.All ? ',' : $"color:{color.ToString().ToLowerInvariant()},";
url += type == DuckDuckGoImageType.All ? ',' : $"type:{type},";
url += layout == DuckDuckGoImageLayout.All ? ',' : $"layout:{layout},";
url += license == DuckDuckGoImageLicense.All ? "" : $"license:{license}";
url += $"&p={(safeSearch == SafeSearchLevel.Off ? "-1" : "1")}";
return(url);
}