-- this is the standard set of lua hooks for monotone;
-- user-provided files can override it or add to it.

function temp_file()
   local tdir
   tdir = os.getenv("TMPDIR")
   if tdir == nil then tdir = os.getenv("TMP") end
   if tdir == nil then tdir = os.getenv("TEMP") end
   if tdir == nil then tdir = "/tmp" end
   return mkstemp(string.format("%s/mt.XXXXXX", tdir))
end

function execute(path, ...)   
   local pid = posix.fork()
   local ret = -1
   if pid == 0 then
      posix.exec(path, unpack(arg))
   else
      ret, pid = posix.wait(pid)
   end
   return ret
end



-- attributes are persistent metadata about files (such as execute
-- bit, ACLs, various special flags) which we want to have set and
-- re-set any time the files are modified. the attributes themselves
-- are stored in a file .mt-attrs, in the working copy (and
-- manifest). each (f,k,v) triple in an atribute file turns into a
-- call to attr_functions[k](f,v) in lua.

if (attr_functions == nil) then
   attr_functions = {}
end


attr_functions["execute"] = 
   function(filename, value) 
      if (value == "true") then
         posix.chmod(filename, "u+x")
      end
   end


function ignore_file(name)
   if (string.find(name, "%.a$")) then return true end
   if (string.find(name, "%.so$")) then return true end
   if (string.find(name, "%.o$")) then return true end
   if (string.find(name, "%.la$")) then return true end
   if (string.find(name, "%.lo$")) then return true end
   if (string.find(name, "%.aux$")) then return true end
   if (string.find(name, "%.bak$")) then return true end
   if (string.find(name, "%.orig$")) then return true end
   if (string.find(name, "%.rej$")) then return true end
   if (string.find(name, "%~$")) then return true end
   if (string.find(name, "/core$")) then return true end
   if (string.find(name, "^CVS/")) then return true end
   if (string.find(name, "/CVS/")) then return true end
   if (string.find(name, "^%.svn/")) then return true end
   if (string.find(name, "/%.svn/")) then return true end
   if (string.find(name, "^SCCS/")) then return true end
   if (string.find(name, "/SCCS/")) then return true end
   return false;
end


function edit_comment(basetext)
   local exe = "vi"
   local visual = os.getenv("VISUAL")
   if (visual ~= nil) then exe = visual end
   local editor = os.getenv("EDITOR")
   if (editor ~= nil) then exe = editor end

   local tmp, tname = temp_file()
   if (tmp == nil) then return nil end
   basetext = "MT: " .. string.gsub(basetext, "\n", "\nMT: ") .. "\n"
   tmp:write(basetext)
   io.close(tmp)

   if (execute(exe, tname) ~= 0) then
      os.remove(tname)
      return nil
   end

   tmp = io.open(tname, "r")
   if (tmp == nil) then os.remove(tname); return nil end
   local res = ""
   local line = tmp:read()
   while(line ~= nil) do 
      if (not string.find(line, "^MT:")) then
         res = res .. line .. "\n"
      end
      line = tmp:read()
   end
   io.close(tmp)
   os.remove(tname)
   return res
end


function non_blocking_rng_ok()
   return true
end


function persist_phrase_ok()
   return true
end

-- trust evaluation hooks

function intersection(a,b)
   local s={}
   local t={}
   for k,v in pairs(a) do s[v] = 1 end
   for k,v in pairs(b) do if s[v] ~= nil then table.insert(t,v) end end
   return t
end

function get_revision_cert_trust(signers, id, name, val)
   return true
end

function get_manifest_cert_trust(signers, id, name, val)
   return true
end

function get_file_cert_trust(signers, id, name, val)
   return true
end

function accept_testresult_change(old_results, new_results)
   for test,res in pairs(old_results)
   do
      if res == true and new_results[test] ~= true
      then
         return false
      end
   end
   return true
end

-- merger support

function merge2_meld_cmd(lfile, rfile)
   return 
   function()
      return execute("meld", lfile, rfile)
   end
end

function merge3_meld_cmd(lfile, afile, rfile)
   return 
   function()
      return execute("meld", lfile, afile, rfile)
   end
end


function merge2_emacs_cmd(emacs, lfile, rfile, outfile)
   local elisp = "(ediff-merge-files \"%s\" \"%s\" nil \"%s\")"
   return 
   function()
      return execute(emacs, "-no-init-file", "-eval", 
		     string.format(elisp, lfile, rfile, outfile))
   end
end

function merge3_emacs_cmd(emacs, lfile, afile, rfile, outfile)
   local elisp = "(ediff-merge-files-with-ancestor \"%s\" \"%s\" \"%s\" nil \"%s\")"
   local cmd_fmt = "%s -no-init-file -eval " .. elisp
   return 
   function()
      execute(emacs, "-no-init-file", "-eval", 
	      string.format(elisp, lfile, rfile, afile, outfile))
   end
end

function merge2_xxdiff_cmd(left_path, right_path, merged_path, lfile, rfile, outfile)
   return 
   function()
      return execute("xxdiff", 
		     "--title1", left_path,
		     "--title2", right_path,
		     lfile, rfile, 
		     "--merged-filename", outfile)
   end
end

function merge3_xxdiff_cmd(left_path, anc_path, right_path, merged_path, 
                           lfile, afile, rfile, outfile)
   return 
   function()
      return execute("xxdiff", 
		     "--title1", left_path,
		     "--title2", right_path,
		     "--title3", merged_path,
		     lfile, afile, rfile, 
		     "--merge", 
		     "--merged-filename", outfile)
   end
end
   
function write_to_temporary_file(data)
   tmp, filename = temp_file()
   if (tmp == nil) then 
      return nil 
   end;
   tmp:write(data)
   io.close(tmp)
   return filename
end

function read_contents_of_file(filename)
   tmp = io.open(filename, "r")
   if (tmp == nil) then
      return nil
   end
   local data = tmp:read("*a")
   io.close(tmp)
   return data
end

function program_exists_in_path(program)
   return execute("which", program) == 0
end

function merge2(left_path, right_path, merged_path, left, right)
   local lfile = nil
   local rfile = nil
   local outfile = nil
   local data = nil
   local meld_exists = false

   lfile = write_to_temporary_file(left)
   rfile = write_to_temporary_file(right)
   outfile = write_to_temporary_file("")

   if lfile ~= nil and
      rfile ~= nil and
      outfile ~= nil 
   then 
      local cmd = nil
      if program_exists_in_path("meld") then
         meld_exists = true
         io.write(string.format("\nWARNING: 'meld' was choosen to perform external 2-way merge.\n" .. 
				"You should merge all changes to *LEFT* file due to limitation of program\n" ..
				   "arguments.\n\n"))
         cmd = merge2_meld_cmd(lfile, rfile) 
      elseif program_exists_in_path("xxdiff") then
         cmd = merge2_xxdiff_cmd(left_path, right_path, merged_path, 
                                 lfile, rfile, outfile)
      elseif program_exists_in_path("emacs") then
         cmd = merge2_emacs_cmd("emacs", lfile, rfile, outfile)
      elseif program_exists_in_path("xemacs") then
         cmd = merge2_emacs_cmd("xemacs", lfile, rfile, outfile)
      end

      if cmd ~= nil
      then
         io.write(string.format("executing external 2-way merge command\n"))
         cmd()
	 if meld_exists then
            data = read_contents_of_file(lfile)
         else
            data = read_contents_of_file(outfile)
         end
	 if string.len(data) == 0 
	 then 
	    data = nil
	 end
      else
         io.write("no external 2-way merge command found\n")
      end
   end
   
   os.remove(lfile)
   os.remove(rfile)
   os.remove(outfile)

   return data
end

function merge3(anc_path, left_path, right_path, merged_path, ancestor, left, right)
   local afile = nil
   local lfile = nil
   local rfile = nil
   local outfile = nil
   local data = nil
   local meld_exists = false

   lfile = write_to_temporary_file(left)
   afile = write_to_temporary_file(ancestor)
   rfile = write_to_temporary_file(right)
   outfile = write_to_temporary_file("")

   if lfile ~= nil and
      rfile ~= nil and
      afile ~= nil and
      outfile ~= nil 
   then 
      local cmd = nil
      if program_exists_in_path("meld") then
         meld_exists = true
         io.write(string.format("\nWARNING: 'meld' was choosen to perform external 3-way merge.\n" .. 
				"You should merge all changes to *CENTER* file due to limitation of program\n" ..
				   "arguments.\n\n"))
         cmd = merge3_meld_cmd(lfile, afile, rfile)
      elseif program_exists_in_path("xxdiff") then
         cmd = merge3_xxdiff_cmd(left_path, anc_path, right_path, merged_path, 
                                 lfile, afile, rfile, outfile)
      elseif program_exists_in_path("emacs") then
         cmd = merge3_emacs_cmd("emacs", lfile, afile, rfile, outfile)
      elseif program_exists_in_path("xemacs") then
         cmd = merge3_emacs_cmd("xemacs", lfile, afile, rfile, outfile)
      end
      
      if cmd ~= nil
      then
         io.write(string.format("executing external 3-way merge command\n"))
         cmd()
         if meld_exists then
            data = read_contents_of_file(afile)
         else
            data = read_contents_of_file(outfile)
         end
	 if string.len(data) == 0 
	 then 
	    data = nil
	 end
      else
         io.write("no external 3-way merge command found\n")
      end
   end
   
   os.remove(lfile)
   os.remove(rfile)
   os.remove(afile)
   os.remove(outfile)
   
   return data
end


-- expansion of values used in selector completion

function expand_selector(str)

   -- simple date patterns
   if string.find(str, "^19%d%d%-%d%d")
      or string.find(str, "^20%d%d%-%d%d")
   then
      return ("d:" .. str)
   end

   -- something which looks like an email address
   if string.find(str, "[%w%-_]+@[%w%-_]+")
   then
      return ("a:" .. str)
   end

   -- something which looks like a branch name
   if string.find(str, "[%w%-]+%.[%w%-]+")
   then
      return ("b:" .. str)
   end

   -- a sequence of nothing but hex digits
   if string.find(str, "^%x+$")
   then
      return ("i:" .. str)
   end

   -- "yesterday", the source of all hangovers
   if str == "yesterday"
   then
      local t = os.time(os.date('!*t'))
      return os.date("d:%F", t - 86400)
   end
   
   -- "CVS style" relative dates such as "3 weeks ago"
   local trans = { 
      minute = 60; 
      hour = 3600; 
      day = 86400; 
      week = 604800; 
      month = 2678400; 
      year = 31536000 
   }
   local pos, len, n, type = string.find(str, "(%d+) ([minutehordaywk]+)s? ago")
   if trans[type] ~= nil
   then
      local t = os.time(os.date('!*t'))
      return os.date("d:%F", t - (n * trans[type]))
   end

   return nil
end