local PathObj = {}

local posix_separator = '/'
local windows_separator = '\\'

local function split( s, sep, include_sep )
    local include = include_sep or false
    local fields, index = {}, 1
    repeat
        local occurence = s:find(sep, index, true)
        if include == true then
            fields[#fields + 1] = s:sub(index - 1, occurence and occurence - 1)
        else
            fields[#fields + 1] = s:sub(index, occurence and occurence - 1)
        end
        index = occurence and occurence + #sep
    until not index
    return fields
end

local function slice( t, first, last, step )
    local sliced = {}

    local first_index = first or 1
    local last_index = last or #t
    local step_size = step or 1

    for i = first_index, last_index, step_size do
        sliced[#sliced + 1] = t[i]
    end

    return sliced
end

function PathObj:new( path )
    local obj = {}
    local path_blocks = split(path, posix_separator)

    local slash_count = 0
    for i, part in ipairs(path_blocks) do
        if part == '' then
            slash_count = slash_count + 1
        else
            break
        end
    end

    if slash_count == 0 then
        obj.root = ''
    elseif slash_count == 2 then
        obj.root = posix_separator .. posix_separator
        path_blocks = slice(path_blocks, 3)
    else
        obj.root = posix_separator
        path_blocks = slice(path_blocks, slash_count + 1)
    end

    if obj.root ~= '' then
        obj.parts = {obj.root, table.unpack(path_blocks)}
    else
        obj.parts = path_block
    end

    obj.drive = ''
    obj.anchor = obj.drive .. obj.root
    obj._segments = path_blocks
    obj.name = path_blocks[#path_blocks]

    local suffices = slice(split(obj.name, ".", true), 2)

    obj.suffix = suffices[#suffices]
    obj.suffices = suffices

    setmetatable(obj, self)
    self.__index = self

    return obj
end

function PathObj:to_string()
    local out = self.drive .. self.root

    for i = 1, #self._segments - 1 do
        out = out .. self._segments[i] .. '/'
    end

    out = out .. self._segments[#self._segments]

    return out
end

function PathObj:data_repr()
    print("root = " .. self.root)
    local segments = "segments = ["
    for _, seg in ipairs(self.parts) do
        segments = segments .. seg .. ","
    end
    segments = segments .. "]"
    print(segments)

    print("name = " .. self.name)
    print("suffix = " .. self.suffix)

    local suffices = "suffices = ["
    for _, seg in ipairs(self.suffices) do
        suffices = suffices .. seg .. ","
    end
    suffices = suffices .. "]"
    print(suffices)
end

function PathObj:is_absolute()
    return self.root ~= ''
end

print(PathObj:new( "home/folkert/test.ads" ):to_string())
print(PathObj:new( "/home/folkert/test.ads" ):to_string())
print(PathObj:new( "//home/folkert/test.ads" ):to_string())
print(PathObj:new( "///home/folkert/test.ads" ):is_absolute())

local x = PathObj:new( "/home/foo/bar/baz.c" )
print(x:to_string())

return PathObj