-- This file is part of a Liberty Eiffel library.
-- See the full copyright at the end.
--
class POSIX_PATH_NAME
   -- Operating system path name, POSIX notation

inherit
   UNIXISH_PATH_NAME
      rename
         path as to_string
      export {ANY}
         to_string
      redefine copy, is_equal
      end

create {ANY}
   make_empty, make_root, make_current, make_from_string

feature {ANY} -- Creation
   make_empty
      do
         if to_string = Void then
            to_string := ""
         else
            to_string.clear_count
         end
      end

   make_root
      do
         make_empty
         to_string.extend('/')
      ensure then
         to_string.is_equal(once "/")
      end

   make_current
      do
         make_empty
         to_string.extend('.')
      ensure then
         to_string.is_equal(once ".")
      end

   make_from_string (s: STRING)
      do
         if to_string = Void then
            to_string := s.twin
         elseif to_string /= s then
            to_string.copy(s)
         end
      end

feature {ANY} -- Constants
   extension_separator: CHARACTER '.'

   directory_separator: CHARACTER '/'

   up_directory: STRING ".."

   this_directory: STRING "."

feature {ANY} -- Access
   drive_specification: STRING
      do
      ensure then
         Result = Void
      end

   count: INTEGER
      local
         p: INTEGER; sep: BOOLEAN
      do
         from
            p := 1
            sep := True
         until
            p > to_string.count
         loop
            if not sep and to_string.item(p) = '/' then
               sep := True
            elseif sep and to_string.item(p) /= '/' then
               sep := False
               Result := Result + 1
            end
            p := p + 1
         end
         if sep and Result > 0 then
            -- trailing /
            Result := Result + 1
         end
      end

   last: STRING
      local
         p: INTEGER
      do
        p := to_string.last_index_of(directory_separator) + 1
        -- check to_string.is_valid_index(p) end
        Result := to_string.substring(p, to_string.upper)
      ensure then
         to_string.has_suffix(Result)
      end

   extension: STRING
      local
         p: INTEGER -- the position of the eventual (last) separator (usually a point)
         as_string: like to_string
      do
         -- A naive implementation, requiring an hidden allocation could be
         -- Result := last; Result := Result.right(Result.last_index_of(extension_separator))
         -- beside requiring "right"
         Result := once ""
         as_string := to_string -- let's cache the complete path as a string in the eventuality that an heir of POSIX_PATH_NAME redefine to_string into a computed feature (a function)
         p := as_string.last_index_of(extension_separator)
         if p > as_string.lower then
            if p > as_string.last_index_of(directory_separator) then
               Result := as_string.substring(p, as_string.upper)
            else
               check
                  not last.has(extension_separator) -- Current is like "xxx.d/we"
               end
            end
         else
            -- path should be like "./without_extension" or like "../asd/./qwerty"
            check
               Result.is_empty
            end
         end
      end

   is_absolute: BOOLEAN
      do
         Result := not to_string.is_empty and then to_string.first = '/'
      ensure
         definition: Result = (not to_string.is_empty and then to_string.first = '/')
      end

   is_normalized: BOOLEAN
      local
         elem: STRING; scan: STRING
      do
         elem := once "path_element"
         scan := once ""
         scan.copy(to_string)
         -- Check for emptiness or too many slashes
         Result := not scan.is_empty and then not scan.has_prefix(once "///")
         -- zero, one or two slashes allowed by POSIX
         -- Remove initial slashes
         from
         until
            scan.is_empty or else scan.first /= '/'
         loop
            scan.remove_head(1)
         end
         -- Check for trailing slashes, double slashes
         Result := Result and then (scan.is_empty or else scan.last /= '/') and then not scan.has_substring(double_slash)
         -- Remove initial sequences of ".."
         if not is_absolute and Result then
            from
            until
               scan.is_empty or else not scan.has_prefix(up_directory)
            loop
               if scan.count >= 3 and then scan.item(3) = '/' then
                  scan.remove_head(3)
               else
                  scan.remove_head(2)
               end
            end
         else
            Result := Result and then not scan.has_prefix(once "../") and then not scan.is_equal(up_directory)
         end
         -- Make sure that there is no '..' remaining
         Result := Result and then not scan.has_substring(once "/../") and then not scan.has_suffix(once "/..")
         -- Make sure that there is no '.' remaining except alones
         Result := Result and then not scan.has_substring(once "/./") and then not scan.has_suffix(once "/.") and then not scan.has_prefix(once "./")
         Result := Result and then (is_absolute implies not scan.is_equal(this_directory))
      ensure
         Result implies not to_string.has_substring(once "/./")
         Result implies not to_string.has_suffix(once "/.")
         Result implies not to_string.is_empty
         Result implies to_string.last /= '/' or else to_string.is_equal(once "/") or else to_string.is_equal(once "//")
      end

   is_valid_path (path: STRING): BOOLEAN
      do
         --|*** Not nearly strict enough <FM-24/03/2003>
         Result := not path.is_empty
      end

feature {ANY} -- Operations
   to_absolute
      local
         bd: BASIC_DIRECTORY
      do
         if not is_absolute then
            tmp.copy(Current)
            to_string := bd.current_working_directory.out.twin
            join(tmp)
            tmp.to_string.make_empty
         end
         normalize
      end

   normalize
      do
         tmp.copy(Current)
         make_from_path_name(tmp)
         if to_string.is_empty then
            make_current
         end
      end

   normalize_case
      do
         -- POSIX filesystem is case-sensitive
         -- There are no secondary separators
      ensure
         to_string.is_equal(old to_string.twin)
      end

   remove_last
      local
         p: INTEGER
      do
         -- Find last separator
         p := to_string.reverse_index_of('/', to_string.count)
         -- Remove all trailing slashes, leaving one if it is root
         from
         until
            p <= 1 or else to_string.item(p) /= '/'
         loop
            p := p - 1
         end
         to_string.keep_head(p)
      ensure then
         (old to_string.twin).has_prefix(to_string)
      end

   add_last (elem: STRING)
      do
         if not is_empty then
            to_string.extend_unless('/')
         end
         to_string.append(elem)
      end

   expand_user
      local
         user_home: STRING; sys: SYSTEM; p: INTEGER
      do
         if not is_empty and then to_string.first = '~' then
            if to_string.count = 1 or else to_string.has_prefix(once "~/") then
               user_home := sys.get_environment_variable(once "HOME")
            else
               -- FIXME: Expansion of some other user's home: not done yet
               not_yet_implemented
            end
            if user_home /= Void then
               p := to_string.first_index_of('/')
               if p = 0 then
                  p := to_string.count + 1
               end
               to_string.remove_head(p - 1)
               to_string.prepend(user_home)
            end
         end
      end

   expand_shellouts
      do
         not_yet_implemented
      end

feature {ANY} -- Copying, comparison
   copy (other: like Current)
      do
         if Current /= other then
            if to_string = Void then
               to_string := other.to_string.twin
            else
               to_string.copy(other.to_string)
            end
         end
      end

   is_equal (other: like Current): BOOLEAN
      do
         Result := to_string.is_equal(other.to_string)
      end

feature {PATH_JOINER}
   start_join (drive: STRING; absoluteness: INTEGER)
      do
         inspect absoluteness
         when 0 then
         when 1 then
            make_root
         else
            make_from_string(double_slash)
         end
      end

feature {} -- Auxiliary constants/onces
   tmp: POSIX_PATH_NAME
      once
         create Result.make_empty
      end

   double_slash: STRING "//"

   start_join_to (other: PATH_JOINER): INTEGER
      local
         slash_count: INTEGER
      do
         from
            Result := to_string.lower
         until
            Result > to_string.upper or else not is_separator(to_string.item(Result))
         loop
            Result := Result + 1
         end
         slash_count := Result - to_string.lower
         if slash_count > 2 then
            slash_count := 1
         end
         if Result <= to_string.upper then
            other.start_join(drive_specification, slash_count)
         elseif slash_count > 0 then
            other.start_join(drive_specification, slash_count)
            other.end_join
         end
      end

end -- class POSIX_PATH_NAME
--
-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in
-- all copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-- THE SOFTWARE.