CSV Lookup

local CsvLookup = advancedMacros.inherit()

local function readHeader( file )
  assert( file, "File handle missing")
  local line = file.readLine()
  local out = {}
  local i = 1
  for a in line:gmatch("[^,]+") do
    out[a] = i
    out[i] = a
    i = i+1
  end
  return out
end

local function isQuote(x)
  return x=='"' or x=='"'
end

local function xnor(a, b)
  return a and b or not a and not b
end

local _new = CsvLookup.new
function CsvLookup:new( fileName , ...)
  local obj = _new( self )
  assert(filesystem.exists(filename), "Could not find the file!")
  obj.file = filesystem.open(fileName,"r")
  obj.header = readHeader( obj.file )
  obj.data = {}
  return obj
end

function CsvLookup:indexFor( propName )
  if not self.file then
    self.file = filesystem.open(fileName,"r")
    self.header = readHeader( obj.file )
  end
  local k = self.header[propName]
  assert( k , "property '"..propName.."' is not defined in the header")
  self.data = {}
  lineNum = 1
  while self.file.available() > 0 do
    local line = self.file.readLine()
    local i = 1

    local x;
    local values = {}
    local t =""
    for a in line:gmatch("[^,]+") do
      if i == k then
        x = a
      else
        --log(self.header[i])
        --log(values)
        t = t..a
      end
      if xnor(isQuote(t:sub(1,1)), isQuote(t:sub(#t, #t)))  then
        if i~=k then values[self.header[i]] = t end
        t = ""
        i = i+1
      end
    end
    if #t>0 then error("Unfinished quote on line "..lineNum..":&6"..line) end
    self.data[x] = values
    lineNum = lineNum+1
  end
  self.file.close()
  self.file = nil
end


function CsvLookup:find( x )
  return self.data[ x ]
end

return CsvLookup