implement 'apt-get files' to access index targets

Downloading additional files is only half the job. We still need a way
to allow external tools to know where the files are they requested for
download given that we don't want them to choose their own location.

'apt-get files' is our answer to this showing by default in a deb822
format information about each IndexTarget with the potential to filter
the records based on lines and an option to change the output format.

The command serves also as an example on how to get to this information
via libapt.

1 files changed, 87 insertions, 0 deletions

diff --git a/cmdline/apt-get.cc b/cmdline/apt-get.cc
index c1f78523c..0fff2db58 100644
--- a/cmdline/apt-get.cc
+++ b/cmdline/apt-get.cc
@@ -86,6 +86,7 @@
 #include <algorithm>
 #include <fstream>
 #include <iostream>
+#include <sstream>
 #include <set>
 #include <string>
 #include <vector>
@@ -1602,6 +1603,91 @@ static bool DoChangelog(CommandLine &CmdL)
    return true;
 }
 									/*}}}*/
+// DoFiles - Lists all IndexTargets					/*{{{*/
+static std::string format_key(std::string key)
+{
+   // deb822 is case-insensitive, but the human eye prefers candy
+   std::transform(key.begin(), key.end(), key.begin(), ::tolower);
+   key[0] = ::toupper(key[0]);
+   size_t found = key.find("_uri");
+   if (found != std::string::npos)
+      key.replace(found, 4, "-URI");
+   while ((found = key.find('_')) != std::string::npos)
+   {
+      key[found] = '-';
+      key[found + 1] = ::toupper(key[found + 1]);
+   }
+   return key;
+}
+static bool DoFiles(CommandLine &CmdL)
+{
+   pkgCacheFile CacheFile;
+   pkgSourceList *SrcList = CacheFile.GetSourceList();
+
+   if (SrcList == NULL)
+      return false;
+
+   std::string const Format = _config->Find("APT::Get::Files::Format");
+   bool Filtered = CmdL.FileSize() > 1;
+   for (pkgSourceList::const_iterator S = SrcList->begin(); S != SrcList->end(); ++S)
+   {
+      std::vector<IndexTarget> const targets = (*S)->GetIndexTargets();
+      std::map<std::string, string> AddOptions;
+      AddOptions.insert(std::make_pair("TRUSTED", ((*S)->IsTrusted() ? "yes" : "no")));
+
+      for (std::vector<IndexTarget>::const_iterator T = targets.begin(); T != targets.end(); ++T)
+      {
+	 std::ostringstream stanza;
+	 if (Filtered || Format.empty())
+	 {
+	    stanza << "MetaKey: " << T->MetaKey << "\n"
+	       << "ShortDesc: " << T->ShortDesc << "\n"
+	       << "Description: " << T->Description << "\n"
+	       << "URI: " << T->URI << "\n"
+	       << "Filename: " << T->Option(IndexTarget::FILENAME) << "\n"
+	       << "Optional: " << (T->IsOptional ? "yes" : "no") << "\n";
+	    for (std::map<std::string,std::string>::const_iterator O = AddOptions.begin(); O != AddOptions.end(); ++O)
+	       stanza << format_key(O->first) << ": " << O->second << "\n";
+	    for (std::map<std::string,std::string>::const_iterator O = T->Options.begin(); O != T->Options.end(); ++O)
+	       stanza << format_key(O->first) << ": " << O->second << "\n";
+	    stanza << "\n";
+
+	    if (Filtered)
+	    {
+	       // that is a bit crude, but good enough for now
+	       bool found = true;
+	       std::string haystack = std::string("\n") + stanza.str() + "\n";
+	       std::transform(haystack.begin(), haystack.end(), haystack.begin(), ::tolower);
+	       size_t const filesize = CmdL.FileSize() - 1;
+	       for (size_t i = 0; i != filesize; ++i)
+	       {
+		  std::string needle = std::string("\n") + CmdL.FileList[i + 1] + "\n";
+		  std::transform(needle.begin(), needle.end(), needle.begin(), ::tolower);
+		  if (haystack.find(needle) != std::string::npos)
+		     continue;
+		  found = false;
+		  break;
+	       }
+	       if (found == false)
+		  continue;
+	    }
+	 }
+
+	 if (Format.empty())
+	    cout << stanza.str();
+	 else
+	 {
+	    std::string out = T->Format(Format);
+	    for (std::map<std::string,std::string>::const_iterator O = AddOptions.begin(); O != AddOptions.end(); ++O)
+	       out = SubstVar(out, std::string("$(") + O->first + ")", O->second);
+	    cout << out << std::endl;
+	 }
+      }
+   }
+
+   return true;
+}
+									/*}}}*/
 // ShowHelp - Show a help screen					/*{{{*/
 // ---------------------------------------------------------------------
 /* */
@@ -1716,6 +1802,7 @@ int main(int argc,const char *argv[])					/*{{{*/
 				   {"source",&DoSource},
                                    {"download",&DoDownload},
                                    {"changelog",&DoChangelog},
+				   {"files",&DoFiles},
 				   {"moo",&DoMoo},
 				   {"help",&ShowHelp},
                                    {0,0}};