static async Task <string> CompareFiles(string ofi, string nfi, PathMatchLevel matchLevel)
{
FileComparer cmp = GetComparerForFile(ofi);
string diff = await cmp.Compare(ofi, nfi);
if (!String.IsNullOrWhiteSpace(diff) || matchLevel != PathMatchLevel.FullMatch)
{
StringBuilder output = new StringBuilder();
output.AppendLine("Diff " + ofi + " vs " + nfi + ":");
switch (matchLevel)
{
case PathMatchLevel.CaseInsensitiveMatch:
output.AppendLine("(NOTE: File paths differ in case)");
break;
case PathMatchLevel.SubstitutionMatch:
output.AppendLine("(NOTE: New file has no exact counterpart in old tree, using a substitution)");
break;
}
output.AppendLine(diff);
return(output.ToString());
}
return(String.Empty);
}
static string FindOldFile(FileInfo nfi, string rootOld, string rootNew, out PathMatchLevel matchLevel)
{
int rootLength = rootNew.Length;
if (!rootNew.EndsWith(Path.DirectorySeparatorChar.ToString()))
{
rootLength++;
}
string nameOnly = nfi.FullName.Substring(rootLength);
// try exact match first
string ofi = Path.Combine(rootOld, nameOnly);
if (File.Exists(ofi))
{
string exactName = Tools.GetProperFilePathCapitalization(ofi);
if (ofi == exactName)
{
matchLevel = PathMatchLevel.FullMatch;
}
else
{
matchLevel = PathMatchLevel.CaseInsensitiveMatch;
}
return(exactName);
}
// try a substitution if exact/case-insensitive match failed
foreach (var subst in substitutions)
{
if (nameOnly.ToLower().StartsWith(subst.Key.ToLower()))
{
string substNameOnly = subst.Value + nameOnly.Substring(subst.Key.Length);
ofi = Path.Combine(rootOld, substNameOnly);
if (File.Exists(ofi))
{
matchLevel = PathMatchLevel.SubstitutionMatch;
return(ofi);
}
}
}
// give up, there's no good old file to diff this new file against
matchLevel = PathMatchLevel.None;
return(null);
}
