/// <summary>
/// Tries to find the license id from the project itself.
/// </summary>
private async Task <(License?, string)> TryGetLicenseFromProject(Uri?projectUrl)
{
// A random sample of packages shows that many are missing a license
// URL, but having a github project URL shows that around 20% will
// have a LICENSE file.
if (projectUrl == null)
{
return(null, string.Empty);
}
var licenseUrls = GetPotentialLicenseUrls(projectUrl);
if (!licenseUrls.Any())
{
return(null, string.Empty);
}
Uri?validUri = null;
foreach (var licenseUrl in licenseUrls)
{
try
{
var _ = await SharedHttpClient.GetStringAsync(licenseUrl);
validUri = licenseUrl;
}
catch
{
// Expected. Only one in five will statistically have a license
// at the guessed URL.
}
}
if (validUri == null)
{
return(null, string.Empty);
}
return(await this.licenseParsing.TryGetLicenseFromLicenseFile(validUri));
}
/// <summary>
/// Tries to find the license identifier based on the text in the
/// license file.
/// </summary>
public async Task <(License?, string)> TryGetLicenseFromLicenseFile(Uri licenseUrl)
{
string path = Path.Combine(licenceFileDirectory, Normalize(licenseUrl), "LICENSE");
if (!DiskCache.TryGetValue(path, this.config.DiskCache.LicenseFiles, out string?licenseText))
{
try
{
licenseText = await SharedHttpClient.GetStringAsync(licenseUrl).ConfigureAwait(false);
}
catch (Exception e)
{
string message = $"Error getting license file from {licenseUrl}: {e.Message}";
Log.Warning(message);
return(null, message);
}
DiskCache.CacheData(path, licenseText);
}
return(await this.licenseDetector.Detect(Path.GetDirectoryName(path)).ConfigureAwait(false));
}