-- See the Copyright notice at the end of this file.
--
class XML_DTD_VALIDATOR
   --
   -- Helps the parser to validate an XML file using a DTD
   --

inherit
   XML_VALIDATOR
   BACKTRACKING
      rename
         current_node as backtrack_node,
         set_current_node as set_backtrack_node
      end

insert
   XML_DTD_MEMORY
   RECYCLABLE

create {XML_DTD_MEMORY}
   make

feature {XML_PARSER}
   attributes: HASHED_DICTIONARY[UNICODE_STRING, UNICODE_STRING]

   root: XML_DTD_NODE

   point: XML_DTD_NODE

   with_attribute (attribute_name, attribute_value: UNICODE_STRING; line, column: INTEGER)
      do
         attributes.add(new_string(attribute_value), new_string(attribute_name))
      end

   is_valid_open_node (node_name: UNICODE_STRING; line, column: INTEGER): BOOLEAN
      do
         if point = Void then
            Result := root_element.name.is_equal(node_name)
         else
            Result := point.is_valid_child(Current, node_name)
         end
         if Result then
            Result := get_element(node_name).is_valid_attributes(attributes)
         end
      end

   is_valid_close_node (node_name: UNICODE_STRING; line, column: INTEGER): BOOLEAN
      do
         if point = Void then
            -- not valid!
         else
            Result := point.name.is_equal(node_name)
               and then point.is_valid_child(Current, Void)
         end
      end

   is_valid_open_close_node (node_name: UNICODE_STRING; line, column: INTEGER): BOOLEAN
      do
         Result := is_valid_open_node(node_name, line, column)
      end

   current_node: UNICODE_STRING
      do
         if point /= Void then
            Result := point.name
         end
      end

   open_node (node_name: UNICODE_STRING; line, column: INTEGER)
      local
         e: XML_DTD_ELEMENT
      do
         clear_attributes
         e := elements.at(node_name)
         point := new_node(e, point)
         if root = Void then
            root := point
         end
      end

   close_node (node_name: UNICODE_STRING; line, column: INTEGER)
      local
         p: like point
      do
         p := point.parent
         if p = Void then
            check
               root = point
            end
            free_node(root)
            root := Void
         end
         point := p
      end

   open_close_node (node_name: UNICODE_STRING; line, column: INTEGER)
      do
         open_node(node_name, line, column)
         close_node(node_name, line, column)
      end

   entity (a_entity: UNICODE_STRING; line, column: INTEGER): UNICODE_STRING
      do
         Result := entities.reference_at(a_entity)
      end

   entity_url (a_entity: UNICODE_STRING; line, column: INTEGER): UNICODE_STRING
         -- When the parser reads an '''&entity;'''. Returns the entity URL if it is a SYSTEM entity.
      do
         Result := entity_urls.reference_at(a_entity)
      end

   is_valid_data (a_data: UNICODE_STRING; line, column: INTEGER): BOOLEAN
      do
         if point /= Void then
            Result := point.is_valid_data(Current, a_data)
         end
      end

   data (a_data: UNICODE_STRING; line, column: INTEGER)
      do
         -- DTD does not validate data, so we don't keep it
      end

   the_end
      do
         recycle_dtd_validator(Current)
      end

feature {} -- Nodes management, for validation
   nodes_pool: RECYCLING_POOL[XML_DTD_NODE]
      once
         create Result.make
      end

   new_node (element: XML_DTD_ELEMENT; parent: XML_DTD_NODE): XML_DTD_NODE
      do
         if nodes_pool.is_empty then
            create Result.make
         else
            Result := nodes_pool.item
         end
         check
            Result.parent = Void
         end
         Result.element := element
         if parent /= Void then
            Result.parent := parent
         end
      ensure
         Result.is_empty
         Result.element = element
         Result.parent = parent
      end

   free_node (a_node: XML_DTD_NODE)
      local
         node: XML_DTD_NODE
      do
         from
         until
            a_node.is_empty
         loop
            node := a_node.last
            free_node(node)
            check
               not a_node.fast_has(node)
            end
         end
         nodes_pool.recycle(a_node)
      end

feature {} -- Attributes string management
   clear_attributes
      local
         key, item: UNICODE_STRING
      do
         from
         until
            attributes.is_empty
         loop
            key := attributes.key(attributes.lower)
            item := attributes.item(attributes.lower)
            attributes.fast_remove(key)
            free_string(key)
            free_string(item)
         end
      end

feature {XML_DTD_PARSER}
   parse_done
         -- Called when done parsing the DTD
      do
         debug
            io.put_string(root_element.out)
            io.put_new_line
         end
      end

feature {XML_DTD_PARSER} -- <!ELEMENT . . .>
   elements: HASHED_DICTIONARY[XML_DTD_ELEMENT, UNICODE_STRING]

   current_element: XML_DTD_ELEMENT

   element_built (element_name: UNICODE_STRING): BOOLEAN
      do
         Result := get_element(element_name).is_built
      end

   adding_element (element_name: UNICODE_STRING): BOOLEAN
      do
         Result := current_element /= Void and then current_element.name.is_equal(element_name)
      ensure
         Result implies not element_built(element_name)
         Result implies building_element
      end

   building_element: BOOLEAN
      do
         Result := current_element /= Void
      end

   add_element (element_name: UNICODE_STRING)
      require
         not element_built(element_name)
         not building_element
      do
         current_element := get_element(element_name)
         current_element.build
      ensure
         adding_element(element_name)
      end

   commit_element (element_name: UNICODE_STRING)
      require
         adding_element(element_name)
      do
         current_element.commit
         current_element := Void
      ensure
         element_built(element_name)
         not building_element
      end

   close_fix
      require
         building_element
      do
         current_element.close_fix
      end

   close_exactly_one
      require
         building_element
      do
         current_element.close_exactly_one
      end

   close_zero_or_one
      require
         building_element
      do
         current_element.close_zero_or_one
      end

   close_zero_or_more
      require
         building_element
      do
         current_element.close_zero_or_more
      end

   close_one_or_more
      require
         building_element
      do
         current_element.close_one_or_more
      end

   add_list
      require
         building_element
      do
         current_element.add_list
      end

   add_alt
      require
         building_element
      do
         current_element.add_alt
      end

   child_pcdata
      require
         building_element
      do
         current_element.child_pcdata
      end

   child_any
      require
         building_element
      do
         current_element.child_any
      end

   child_empty
      require
         building_element
      do
         current_element.child_empty
      end

   child_one_or_more (node: UNICODE_STRING)
      require
         building_element
      do
         current_element.child_one_or_more(get_element(node))
      end

   child_zero_or_more (node: UNICODE_STRING)
      require
         building_element
      do
         current_element.child_zero_or_more(get_element(node))
      end

   child_zero_or_one (node: UNICODE_STRING)
      require
         building_element
      do
         current_element.child_zero_or_one(get_element(node))
      end

   child_exactly_one (node: UNICODE_STRING)
      require
         building_element
      do
         current_element.child_exactly_one(get_element(node))
      end

feature {}
   root_element: XML_DTD_ELEMENT
      do
         Result := get_element(root_name)
      end

   get_element (element_name: UNICODE_STRING): XML_DTD_ELEMENT
      local
         eltname: UNICODE_STRING
      do
         Result := elements.reference_at(element_name)
         if Result = Void then
            eltname := element_name.twin
            if elements_pool.is_empty then
               create Result.make(eltname)
            else
               Result := elements_pool.item
               Result.make(eltname)
            end
            elements.add(Result, eltname)
         end
      ensure
         Result.name.is_equal(element_name)
      end

   elements_pool: RECYCLING_POOL[XML_DTD_ELEMENT]
      once
         create Result.make
      end

feature {XML_DTD_PARSER} -- <!ATTLIST . . .>
   attlist_element: XML_DTD_ELEMENT

   building_attlist: BOOLEAN
      do
         Result := attlist_element /= Void
         check
            Result implies attlist_element.building_attlist
         end
      end

   has_attlist (element_name, attribute_name: UNICODE_STRING): BOOLEAN
      local
         elt: XML_DTD_ELEMENT
      do
         elt := elements.reference_at(element_name)
         if elt /= Void then
            Result := elt.has_attlist(attribute_name)
         end
      ensure
         Result implies building_attlist
      end

   adding_attlist (element_name, attribute_name: UNICODE_STRING): BOOLEAN
      do
         Result := attlist_element /= Void and then attlist_element.name.is_equal(element_name) and then attlist_element.adding_attlist(attribute_name)
      ensure
         Result implies building_attlist
      end

   add_attlist (element_name, attribute_name: UNICODE_STRING)
      require
         element_built(element_name)
         not building_element
         not building_attlist
      do
         attlist_element := elements.at(element_name)
         attlist_element.add_attlist(attribute_name)
      ensure
         building_attlist
      end

   commit_attlist (element_name, attribute_name: UNICODE_STRING)
      require
         adding_attlist(element_name, attribute_name)
      do
         attlist_element.commit_attlist(attribute_name)
         attlist_element := Void
      ensure
         not building_attlist
      end

   addlist_list_value (value: UNICODE_STRING)
      require
         building_attlist
      do
         attlist_element.attlist_list_value(value)
      end

   attlist_cdata
      require
         building_attlist
      do
         attlist_element.attlist_cdata
      end

   attlist_id
      require
         building_attlist
      do
         attlist_element.attlist_id
      end

   attlist_idref
      require
         building_attlist
      do
         attlist_element.attlist_idref
      end

   attlist_idrefs
      require
         building_attlist
      do
         attlist_element.attlist_idrefs
      end

   attlist_nmtoken
      require
         building_attlist
      do
         attlist_element.attlist_nmtoken
      end

   attlist_nmtokens
      require
         building_attlist
      do
         attlist_element.attlist_nmtokens
      end

   attlist_entity
      require
         building_attlist
      do
         attlist_element.attlist_entity
      end

   attlist_entities
      require
         building_attlist
      do
         attlist_element.attlist_entities
      end

   attlist_notation
      require
         building_attlist
      do
         attlist_element.attlist_notation
      end

   attlist_required
      require
         building_attlist
      do
         attlist_element.attlist_required
      end

   attlist_implied
      require
         building_attlist
      do
         attlist_element.attlist_implied
      end

   attlist_valid_fixed (value: UNICODE_STRING): BOOLEAN
      require
         building_attlist
      do
         Result := attlist_element.attlist_valid_fixed(value)
      end

   attlist_fixed (value: UNICODE_STRING)
      require
         building_attlist
         attlist_valid_fixed(value)
      do
         attlist_element.attlist_fixed(value)
      end

   attlist_default_value (value: UNICODE_STRING)
      require
         building_attlist
      do
         attlist_element.attlist_default_value(value)
      end

feature {XML_DTD_PARSER} -- <!ENTITY . . .>
   entities: HASHED_DICTIONARY[UNICODE_STRING, UNICODE_STRING]
   entity_urls: HASHED_DICTIONARY[UNICODE_STRING, UNICODE_STRING]

   has_entity (entity_name: UNICODE_STRING): BOOLEAN
      do
         Result := entities.has(entity_name)
      end

   add_entity (entity_name, entity_value, entity__url: UNICODE_STRING)
      require
         not has_entity(entity_name)
      do
         entities.add(entity_value, entity_name)
         if entity__url /= Void then
            entity_urls.add(entity__url, entity_name)
         end
      ensure
         has_entity(entity_name)
         entity(entity_name, 0, 0) = entity_value
         entity_url(entity_name, 0, 0) = entity__url
      end

feature {XML_DTD_ELEMENT}
   backtrack_valid_data (a_children: FAST_ARRAY[XML_DTD_NODE]; a_node: like backtrack_node; a_data: like backtrack_pcdata): BOOLEAN
      require
         a_node /= Void
      do
         --| std_output.put_line("backtrack_valid_data: #(1) -> #(2) / #(3)" # a_node.out # a_children.out # (if a_data = Void then "" else a_data.out end))
         set_backtrack_node(a_node)
         backtrack_pcdata := a_data
         backtrack_children := a_children
         backtrack_index := a_children.lower
         backtrack_next := backtrack_next_pcdata_marker
         backtrack_ok := False
         search_first
         Result := backtrack_ok
         if not Result then
            sedb_breakpoint
         end
      end

   backtrack_is_valid (a_children: like backtrack_children; a_node: like backtrack_node; a_next: like backtrack_next): BOOLEAN
      require
         a_node /= Void
         --| `a_next' can be Void, it means we are trying to close the node
      do
         --| std_output.put_line("backtrack_is_valid: #(1) -> #(2) / #(3)" # a_node.out # a_children.out # (if a_next = Void then "<none>" else a_next.out end))
         set_backtrack_node(a_node)
         backtrack_pcdata := Void
         backtrack_children := a_children
         backtrack_index := a_children.lower
         backtrack_next := a_next
         backtrack_ok := False
         search_first
         Result := backtrack_ok
         if not Result then
            sedb_breakpoint
         end
      end

feature {XML_DTD_ELEMENT}
   backtrack_valid_child (elt: XML_DTD_ELEMENT)
      require
         elt /= Void
      do
         --| std_output.put_line("    backtrack_valid_child: #(1)" # elt.out)
         if backtrack_next = backtrack_next_pcdata_marker then
            --| std_output.put_line("        backtrack, expected PCDATA")
            backtrack
         elseif backtrack_children.valid_index(backtrack_index) then
            if elt = backtrack_children.item(backtrack_index).element then
               backtrack_index := backtrack_index + 1
               --| std_output.put_line("        continue")
               continue
            else
               --| std_output.put_line("        backtrack, actual #(1) but expected #(2)" # elt.out # backtrack_children.item(backtrack_index).element.out)
               backtrack
            end
         else
            if backtrack_next = Void then
               --| std_output.put_line("        backtrack, unexpected next child" # backtrack_next.out)
               backtrack
            elseif elt.name.is_equal(backtrack_next) then
               --| std_output.put_line("        FOUND")
               backtrack_ok := True
               stop_search_loop := True
            else
               --| std_output.put_line("        backtrack, next child is #(1) not #(2)" # backtrack_next.out # elt.name.out)
               backtrack
            end
         end
      end

feature {XML_DTD_PCDATA_NODE}
   backtrack_valid_pcdata
      do
         --| std_output.put_line("    backtrack_valid_pcdata")
         if backtrack_children.valid_index(backtrack_index) then
            backtrack_index := backtrack_index + 1
            --| std_output.put_line("        continue")
            continue
         elseif backtrack_next = backtrack_next_pcdata_marker or else backtrack_next = Void then
            --| std_output.put_line("        FOUND")
            backtrack_ok := True
            stop_search_loop := True
         else
            sedb_breakpoint
            --| std_output.put_line("        backtrack")
            backtrack
         end
      end

feature {XML_DTD_ANY_NODE}
   backtrack_valid_any
      do
         --| std_output.put_line("    backtrack_valid_any")
         --| std_output.put_line("        FOUND")
         backtrack_ok := True
         stop_search_loop := True
      end

feature {XML_DTD_EMPTY_NODE}
   backtrack_valid_empty
      do
         --| std_output.put_line("    backtrack_valid_empty")
         if backtrack_children.is_empty and then (context.is_empty implies backtrack_next = Void) then
            --| std_output.put_line("        FOUND")
            backtrack_ok := True
            stop_search_loop := True
         else
            --| std_output.put_line("        backtrack")
            backtrack
         end
      end

feature {XML_DTD_END_NODE}
   backtrack_valid_end
      do
         --| std_output.put_line("    backtrack_valid_end")
         if not backtrack_children.valid_index(backtrack_index) and then (context.is_empty implies backtrack_next = Void) then
            --| std_output.put_line("        FOUND")
            backtrack_ok := True
            stop_search_loop := True
         else
            --| std_output.put_line("        backtrack")
            backtrack
         end
      end

feature {} -- Backtracking internals
   backtrack_pcdata: UNICODE_STRING
   backtrack_children: FAST_ARRAY[XML_DTD_NODE]
   backtrack_index: INTEGER
   backtrack_ok: BOOLEAN
   backtrack_next: UNICODE_STRING
   context: FAST_ARRAY[INTEGER]

   context_clear
      do
         context.clear_count
      end

   context_push
      do
         --| std_output.put_line("                context push " + backtrack_index.out)
         context.add_last(backtrack_index)
      end

   context_restore
      do
         backtrack_index := context.last
         --| std_output.put_line("                context restore " + backtrack_index.out)
      end

   context_restore_and_pop
      do
         context_restore
         context_cut
      end

   context_cut
      do
         --| std_output.put_line("                context cut ")
         context.remove_last
      end

feature {XML_DTD_MEMORY}
   root_name: UNICODE_STRING

   make (root_node_name: like root_name)
      require
         not root_node_name.is_empty
      do
         root_name := root_node_name
         if attributes = Void then
            create attributes.make
            create elements.make
            create entities.make
            create entity_urls.make
            create context.make(0)
         end
      ensure
         root_name = root_node_name
      end

feature {RECYCLING_POOL}
   recycle
      do
         attributes.clear_count
         recycle_elements
         entities.clear_count
         recycle_entity_urls
         context.clear_count
      end

feature {}
   recycle_elements
      local
         i: INTEGER
      do
         from
            i := elements.lower
         until
            i > elements.upper
         loop
            elements_pool.recycle(elements.item(i))
            i := i + 1
         end
         elements.clear_count
      ensure
         elements.is_empty
      end

   recycle_entity_urls
      local
         i: INTEGER
      do
         from
            i := entity_urls.lower
         until
            i > entity_urls.upper
         loop
            free_string(entity_urls.item(i))
            i := i + 1
         end
         entity_urls.clear_count
      ensure
         entity_urls.is_empty
      end

   backtrack_next_pcdata_marker: UNICODE_STRING once then U"__#PCDATA__" end

invariant
   not root_name.is_empty

end -- class XML_DTD_VALIDATOR
--
-- 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.