require"imlua"
require"lfs"

function serialize (o, indent)
-- this function enables most types of data to be printed
-- it is based on examples in "Programming in Lua" 2nd edition
-- by Roberto Ierusalimschy
  indent = indent or 0
  if type(o) == "number" then
    io.write(string.rep(" ",indent),o) -- string.rep repeats argument
  elseif type(o) == "string" then
    io.write(string.rep(" ",indent),string.format("%q",o))
  elseif type(o) == "table" then
    io.write(string.rep(" ",indent-2),"{\n")
    for k,v in pairs(o) do -- pairs gets the key and value for the next
                          -- element of the table
      io.write(string.rep(" ",indent), k, " = ")
      serialize(v, indent+2)
      io.write(string.rep(" ",indent),",\n")
    end
    io.write(string.rep(" ",indent-2),"}\n")
  else
    error("cannot serialize a " ..type(o))
  end
end

function PrintError(error)
  print(im.ErrorStr(error))
end

function FindZero(data)
 if (not data) then return false end
  for i = 1, table.getn(data) do
    if data[i] == 0 then
      return true
    end
  end
  return false
end

function AttribData2Str(data, data_type)
  local data_str

  if data_type == im.BYTE then
    data_str = string.format("%3d", data[1])
  elseif data_type == im.USHORT then
    data_str = string.format("%5d", data[1])
  elseif data_type == im.INT then
    data_str = string.format("%5d", data[1])
  elseif data_type == im.FLOAT then
    data_str = string.format("%5.2f", data[1])
  elseif data_type == im.CFLOAT then
    data_str = string.format("%5.2f, %5.2f", data[1], data[2])
  end

  return data_str
end

function GetSizeDesc(size)
  local size_desc

  if size < 1024 then
    size_desc = "b"
  else
    size = size / 1024

    if size < 1024 then
      size_desc = "Kb"
    else
      size = size / 1024
      size_desc = "Mb"
    end
  end

  return size, size_desc
end

function FileSize(file_name)
  if lfs then
    local attr = lfs.attributes(file_name)
    return attr.size
  else
    return 0
  end
end

function PrintImageInfo(file_name)
  print("IM Info")
  print(string.format("  File Name:\n    %s", file_name))

  local ifile, error = im.FileOpen(file_name)
  if not ifile then
    PrintError(error)
    return nil
  end

  local file_size = FileSize(file_name)

  print(string.format("  File Size: %.2f %s", GetSizeDesc(file_size)))

  local format, compression, image_count = ifile:GetInfo()

  local error, format_desc = im.FormatInfo(format)
  print(string.format("  Format: %s - %s", format, format_desc))
  print(string.format("  Compression: %s", compression))
  print(string.format("  Image Count: %d", image_count))
  for i = 1, image_count do
    local error, width, height, color_mode, data_type = ifile:ReadImageInfo(i-1)
    if width == nil then
      PrintError(error)
      ifile:Close()
      return nil
    end

    print(string.format("  Image #%d", i))
    print(string.format("    Width: %d", width))
    print(string.format("    Height: %d", height))
    print(string.format("    Color Space: %s", im.ColorModeSpaceName(color_mode)))
    print(string.format("      Has Alpha: %s", im.ColorModeHasAlpha(color_mode) and "Yes" or "No"))
    print(string.format("      Is Packed: %s", im.ColorModeIsPacked(color_mode) and "Yes" or "No"))
    print(string.format("      Is Top Down: %s", im.ColorModeIsTopDown(color_mode) and "Yes" or "No"))
    print(string.format("    Data Type: %s", im.DataTypeName(data_type)))

    local image_size = im.ImageDataSize(width, height, color_mode, data_type)
    print(string.format("    Data Size: %.2f %s", GetSizeDesc(image_size)))

    local attrib_list = ifile:GetAttributeList()
    for a = 1, table.getn(attrib_list) do
      if a == 1 then
        print("    Attributes:")
      end

      local attrib_data, attrib_data_type = ifile:GetAttribute(attrib_list[a])
      if table.getn(attrib_data) == 1 then
        print(string.format("      %s: %s", attrib_list[a], AttribData2Str(attrib_data, attrib_data_type)))
      elseif attrib_data_type == im.BYTE and FindZero(attrib_data) then
        attrib_data = ifile:GetAttribute(attrib_list[a], true)
        print(string.format("      %s: %s", attrib_list[a], attrib_data))
      else
        --print(string.format("      %s: %s ...", attrib_list[a], AttribData2Str(attrib_data, attrib_data_type)))
        print(string.format("      %s: ", attrib_list[a] ))

        serialize(attrib_data, 8)
      end
    end
  end

  ifile:Close()
end

function main(arg)
  if (not arg or table.getn(arg) < 1) then
    print("Invalid number of arguments.")
    return nil
  end

  PrintImageInfo(arg[1])
  return 1
end

main(arg)