local SpecFormatter = {}

local utils = {}

function SpecFormatter.init( us )
  utils = us
end

function trim( s )
   return ( s:gsub( "^%s*(.-)%s*$", "%1" ) )
end

local function rawpairs( t )
  return next, t, nil
end

-- The code this is based off of is here:
-- https://swarm.workshop.perforce.com/files/guest/jason_gibson/misc/spec_printer.pl
--
-- Note that this function expects the forms to be as the server produces
-- them, not as processed by another trigger/Extension.

function SpecFormatter.Format( type, formFile, keepComments )
  local form = ""
  local body = {}
  local inBody = false
  local bodyKey = "View" -- Everything but protections.
  local space = 0
  local plusminus = 0
  local quote_len = 0
  local spaces = { 1, 0, 2, 0, 3, 0, 4, 0 }

  function protectBody( line )
     -- A comment is not formatted.
     if string.find( line, "^%s+##" ) then
	table.insert( body, line )
	return
     end

     local _, _, pp, put, pu, pip, ppa = string.find( line, "^%s(%S*) (%S*) (%S*) (%S*) (.*)" )

     if string.len( pp ) > spaces[ 1 ] then
	spaces[ 1 ] = string.len( pp )
     end
     if string.len( put ) > spaces[ 2 ] then
	spaces[ 2 ] = string.len( put )
     end
     if string.len( pu ) > spaces[ 3 ] then
	spaces[ 3 ] = string.len( pu )
     end
     if string.len( pip ) > spaces[ 4 ] then
	spaces[ 4 ] = string.len( pip )
     end

     table.insert( body, line )
  end

  function viewBody( line )
     local tline = trim( line ) -- todo: should be utils.trim

     local _, _, lhs, rhs = string.find( tline, "(.*) (\"?//.*)" )
     local len = string.len( lhs )
     if len > space then
        space = len
     end

     local quote = 0

     if string.match( tline, "^\"[%+-&]" ) then
        quote = 2
     elseif string.match( tline, "^[%+-&]" ) or string.match( tline, "^\"" ) then
        quote = 1
     end

     if quote > quote_len then
        quote_len = quote
     end

     table.insert( body, { ["line"] = tline, ["quote"] = quote } )
  end

  if type == "protect" then
    bodyKey = "Protections"
  end

  for line in io.lines( formFile ) do
     line = line .. "\n"

    if string.match( line, "^#" ) and keepComments then
      form = form .. line
      goto continue
    end

    if not inBody then
      form = form .. line
    end

    if string.match( line, "^" .. bodyKey .. ":" ) then
      inBody = true
      goto continue
    end

    if inBody then
       if type == "protect" then
	  protectBody( line )
       else
	  viewBody( line )
       end
    else
       assert( "how?" )
    end

    ::continue::
  end

  function formatProtect()
     for i, line in ipairs( body ) do
	if string.find( line, "^%s+##" ) then
	   form = form .. line .. "\n"
	   goto next
	end

	form = form .. "\t"
	local _, _, pp, put, pu, pip, ppa = string.find( line, "^%s(%S*) (%S*) (%S*) (%S*) (.*)" )

	form = form .. string.rep( " ", 1 + spaces[ 1 ] - string.len( pp  ) ) .. pp
	form = form .. string.rep( " ", 1 + spaces[ 2 ] - string.len( put ) ) .. put
	form = form .. string.rep( " ", 1 + spaces[ 3 ] - string.len( pu  ) ) .. pu
	form = form .. string.rep( " ", 1 + spaces[ 4 ] - string.len( pip ) ) .. pip

	local quote = 0
	if string.match( ppa, "^\"[%+-&]" ) then
	   quote = 2
	elseif string.match( ppa, "^[%+-&]" ) or string.match( line, "^\"" ) then
	   quote = 1
	end

	form = form .. " " .. string.rep( " ", 2 - quote ) .. ppa .. "\n"
	form = form .. "\n"

	::next::
     end
  end

  function formatView()
     for i, t in ipairs( body ) do
	local line = t[ "line" ]
	local quote = t[ "quote" ]
	local tbl = {}
	local _, _, lhs, rhs = string.find( line, "(.*) (\"?//.*)" )
	local ql = quote_len - quote
	local sp1 = ""

	if quote_len > 0 then
	   sp1 = sp1 .. string.rep( " ", ql - #sp1 )
	end

	local sp2 = ""
	local lhsQ = 0

	if string.match( rhs, "^\"" ) then
	   lhsQ = ql
	else
	   lhsQ = ql - 1
	end

	sp2 = sp2 .. string.rep( " ", space - lhsQ - string.len( lhs ) + 3)
	form = form .. "\t" .. sp1 .. lhs .. sp2 .. rhs .. "\n"

	::continue::
     end
  end

  if type == "protect" then
     formatProtect()
  else
     formatView()
  end

  utils.writeFile( formFile, form )

  return true, "no message"

end

return SpecFormatter