/// <summary>
/// Reads the specified stream.
/// </summary>
/// <param name="stream">The stream.</param>
/// <returns>
/// A hydrated safety data sheet.
/// </returns>
/// <remarks>
/// The algorithm for this method loops on each page of the given PDF until it can match the section headers.
/// Once it finds section 3 and copies the CAS numbers out, it will exit to avoid unnecessary processing time.
/// </remarks>
public SafetyDataSheet Read(Stream stream)
{
using var pdfReader = new PdfReader(stream);
using var pdfDocument = new PdfDocument(pdfReader);
var section3 = new SafetyDataSheetSection(new RegExTokenMatcher(Section3Regex), new RegExTokenMatcher(Section4Regex));
var numberOfPages = pdfDocument.GetNumberOfPages();
var pageNumber = 1;
while (pageNumber <= numberOfPages && !section3.Completed)
{
var page = pdfDocument.GetPage(pageNumber++);
var pageText = PdfTextExtractor.GetTextFromPage(page);
pageText = Encoding.UTF8.GetString(Encoding.Convert(Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(pageText)));
section3.ExtractMatchingContent(pageText);
}
var sectionCasNumbers = GetCasNumbersFromSection(section3).ToList();
var successfullyParsed = sectionCasNumbers.Any();
var matchedProp65Ingredients = _prop65Cache.GetProp65Ingredients(sectionCasNumbers);
var result = new SafetyDataSheet
{
ParsedSuccessfully = successfullyParsed,
Ingredients = matchedProp65Ingredients
};
return(result);
}
private static IEnumerable <string> GetCasNumbersFromSection(SafetyDataSheetSection section)
{
return(CasNumberRegex.Matches(section.Text)
.Select(m => m.Value));
}
