#!/usr/bin/env lua

-- Perl-like split/join functions by http://lua-users.org/wiki/PeterPrade

-- Concat the contents of the parameter list,
-- separated by the string delimiter (just like in perl)
-- example: strjoin(", ", {"Anna", "Bob", "Charlie", "Dolores"})
function strjoin(delimiter, list)
  local len = #list
  if len == 0 then
    return ""
  end
  local string = list[1]
  for i = 2, len do
    string = string .. delimiter .. list[i]
  end
  return string
end

-- Split text into a list consisting of the strings in text,
-- separated by strings matching delimiter (which may be a pattern).
-- example: strsplit(",%s*", "Anna, Bob, Charlie,Dolores")
function strsplit(delimiter, text)
  local list = {}
  local pos = 1
  if string.find("", delimiter, 1) then -- this would result in endless loops
    error("delimiter matches empty string!")
  end
  while 1 do
    local first, last = string.find(text, delimiter, pos)
    if first then -- found?
      table.insert(list, string.sub(text, pos, first-1))
      pos = last+1
    else
      table.insert(list, string.sub(text, pos))
      break
    end
  end
  return list
end

function lowercase_textpattern_categories(request_uri)
  local uri_parts = strsplit("/", request_uri)
  if #uri_parts >= 3 then
    uri_parts[3] = uri_parts[3]:lower()
  end
  return strjoin("/", uri_parts)
end

lighty.env["request.orig-uri"] = lighty.env["request.uri"]
lighty.env["request.uri"] = lowercase_textpattern_categories(lighty.env["request.orig-uri"])
if lighty.env["request.uri"] ~= lighty.env["request.orig-uri"] then
  print("SCHMONZ: redirecting " .. lighty.env["request.orig-uri"] .. " to " .. lighty.env["request.uri"])
  lighty.header["Location"] = lighty.env["request.uri"]
  return 302
else
  print("SCHMONZ: unneeded Lua invocation, no redirect needed for " .. lighty.env["request.orig-uri"])
end