# Copyritght (c) 2002 TANIGUCHI Takaki
# This program is distributed under the GNU GPL 2 or later.

require 'strscan'
require 'uri/common'
require 'delegate'

# require 'obaq/htmlgen'

require 'aswiki/scanner'
require 'aswiki/node'
require 'aswiki/util'
require 'aswiki/plugin'
require "aswiki/i18n/#{$LANG}"

module AsWiki
  class Parser
#    include Obaq::HtmlGen
    include AsWiki::Util
    include AsWiki::I18N
    WORD  = [:SPACE, :OTHER, :WORD]
    TAG = [:ENDPERIOD, :INTERWIKINAME, :WIKINAME1, :WIKINAME2, :URI,:MOINHREF,
    :MOINHREFIMG]
    DECORATION = [:EM, :STRONG]
    ESCAPE = [:ESCAPE_BEGIN, :ESCAPE_END]
    TEXTLINE = WORD + TAG + [:EOL] + ESCAPE
    PLAINTEXT = TEXTLINE + DECORATION
    ELEMENT = PLAINTEXT + [:UL, :OL]
    D_TAG = {:EM => 'Em' ,  :STRONG => 'Strong'}

    def initialize(scanner, name='')
      @name = name
      @s = scanner
      @rawwikinames = []
      @plugin = AsWiki::Plugin.new(@name)

      @tocdata = []
      @tocnum  = 0

      @tocdata = [{:number => "##{@tocnum}", :text => '', 
	  :msg_edit => msg_edit,
	  :partialedit => cgiurl([['c', 'e'],
				   ['ebol',1],
				   ['eeol',0]], @name)}]
      @lastbol = 1
      
      @tree = parse
    end
    attr_reader :tree, :tocdata
    def wikinames
      @rawwikinames.collect{|n|
	expandwikiname(n,@name)
      }
    end

    private 
    def next_token
      @token = @s.next_token
    end
    def current_indent       # To handle indents of ul and ol at onece
      indent = 0
      indent = $1.size if @token[1] =~ /^(\s*)/

      ## Original
      ## indent = @token[1].size
      return indent
    end
    def parse
      @line = 1
      node = Node.new('Root')
      next_token
      while true
	case @token[0]
	when *PLAINTEXT
	  node << paragraph
	when :UL
	  node << simple_list('Ul')
	when :OL
	  node << simple_list('Ol')
	when :BLANK       
	  node << blank
	when :DL          
	  node << dl
	when :EOL         
	  eol  
	  node << "\n"
	when :HN_BEGIN    
	  node << hn
	when :HR          
	  node << Node.new('Hr')
	  next_token
	when :PLUGIN  
	  node << plugin
	when :PLUGIN_BEGIN
	  node << plugin_block
	when :PRE_BEGIN   
	  node << preblock
	when :TABLE_BEGIN 
	  node << table
	when :EOF         
	  break
	else 
	  node << syntax_error
	end
      end 
      return node
    end
    def blank
      next_token
      while true
	case  @token[0]
	when :BLANK
	  next_token
	when :EOL  
	  eol
	else 
	  break
	end
      end
      return "\n"
    end
    def hn
      level = @token[1].size
      lineno = @line
      node = Node.new("H#{level}")
      next_token
      ret = textline
      if level == 2
	@tocnum = @tocnum + 1
	@tocdata[-1][:partialedit] = cgiurl([['c', 'e'],
                                             ['ebol',@lastbol],
                                             ['eeol',lineno-1]],@name)
	@lastbol = lineno
	@tocdata << {:number => "##{@tocnum}", :text => ret,
	  :msg_edit => msg_edit,
	  :partialedit => cgiurl([['c', 'e'],['ebol',@lastbol]],
                                 @name)
	}
	node << {:number => @tocnum, :text=> ret, }
      else
	node << {:number => nil, :text=> ret}
      end
      return node
    end
    def plugin_block
      block = [] << (@token[1]+"\n")
      block_b = @line
      if :EOL == next_token[0] then eol else node << syntax_error end
      block += textblock(:PLUGIN_END)
      while true
	case @token[0] 
	when :PLUGIN_END 
	  block << @token[1] 
	  next_token
	when :EOL 
	  eol 
	  break
	when :EOF
	  break
	else node << syntax_error
	end
      end
      block_e = @line 
      return @plugin.onview(block, block_b, block_e)
    end
    def plugin
      node = @token[1]
      next_token
      return @plugin.onview(node.to_a, @line, 0)
    end

    def dl
      node = Node.new('Dl')
      while true
	next_token
	node << { :title => textline,  :doc => element}
	case @token[0]
	when :DL 
	  next
	else
	  break
	end
      end
      return node
    end
    def simple_list(kind = 'Ol') # kind = 'Ol' or 'Ul'
      node = Node.new(kind)
      indent = current_indent
      next_token
      node << catch(:simple_list_end) do
	while true
	  case @token[0]
	  when *ELEMENT
	    node << element(indent)
	  else
	    break
	  end
	end
      end
      return node
    end
    def table
      node = Node.new('Table')
      while true
	case @token[0]
	when :TABLE_BEGIN
	  next_token
	  node << table_tr
	when :EOL
	  eol
	when :EOF
	  break
	else 
	  break
	end
      end
      return node
    end
    def table_tr
      col = []
      while true
	col << plaintext
	case @token[0]
	when :TABLE_END
	  eol
	  break  # XXX
	when :TABLE
	  next_token
	  next
	else 
	  break
	end
      end
      return {:col => col}
    end
    def paragraph
      node = Node.new('Paragraph')
      node << plaintext
      return node
    end
    def plaintext
      node = Node.new('Plaintext')
      while true
	case @token[0]
	when *TEXTLINE
	  node << textline
	when :STRONG
	  node << decorate(:STRONG)
	when :EM
	  node << decorate(:EM)
	else
	  break
	end
      end
      return node
    end
    def element(indent=0)
      node = Node.new('Element')
      while true
	case @token[0]
	when *PLAINTEXT
	  node << plaintext
	when :UL
          cur_indent = current_indent
	  if indent == cur_indent
	    next_token
	    break
	  elsif indent < cur_indent
	    node << simple_list('Ul')
	  elsif indent > cur_indent
	    throw :simple_list_end, node
	  else
	    raise RangeError
	  end
	when :OL          
          cur_indent = current_indent
	  if indent == cur_indent
	    next_token
	    break
	  elsif indent < cur_indent
	    node << simple_list('Ol')
	  elsif indent > cur_indent
	    throw :simple_list_end, node
	  else
	    raise RangeError
	  end
	else
	  break
	end
      end
      return node
    end
    def decorate(tag)
      next_token
      node = Node.new(D_TAG[tag])
      node  << textline
      if @token[0] == tag 
	next_token
      else                
	node << syntax_error
      end
      return node
    end

    def textline
      node = Node.new('Textline')
      while true
	case @token[0]
	when :ESCAPE_BEGIN
	  next_token
	  ret  = textblock(:ESCAPE_END)
	  node << ret
	when :ESCAPE_END
	  node << @token[1]
	when :OTHER, :SPACE, :WORD
	  node << @token[1]
	when :WIKINAME1,:INTERWIKINAME
	  @rawwikinames << @token[1]
	  # node << wikilink(@token[1], @name) # XXX
	  node << wikilink(expandwikiname(@token[1], @name))
	when :WIKINAME2
	  name = @token[1][2..-3]
	  @rawwikinames << name 
	  # node << wikilink(name, @name) # XXX
	  node << wikilink(expandwikiname(name, @name))
	when :URI
	  tn = Node.new('Url')
	  tn << {:url=>@token[1],:text=>@token[1]}
	  node << tn
	when :MOINHREFIMG
	  tn = Node.new('MoinhrefImg')
	  urlt, key = @token[1][1..-2].split(/\s+/, 2)
	  url = Amrita::Sanitizer::sanitize_url(urlt[4..-1], {'http' => true, 'https' => true})
 	  tn << {:url => url, :alt => key}
	  node << tn
	when :MOINHREF
	  allowedscheme = {'http' => true, 'https' => true, 'file' => true, 
	    'news' => true, 'ftp' => true, 'mailto' => true }
	  tn = Node.new('Moinhref')
	  url, key = @token[1][1..-2].split(/\s+/, 2)
	  url = Amrita::Sanitizer::sanitize_url(url,allowedscheme)

	  tn << {:url => url, :text => key }
	  node << tn
	when :ENDPERIOD
	  node << Node.new('Br')
	when :EOL
	  node << "\n"
	  eol
	  break
	else
	  break
	end
	next_token
      end
      return node
    end
    def textblock(endtag)
      node = []
      line = ""
      while true
	case @token[0]
	when :EOF   
	  break
	when :EOL   
	  line << "\n" 
	  node << line 
	  line = ""
	  eol 
	when endtag 
	  if not line.empty?
	    node << line
	  end
	  break
	else line << @token[1] 
	  next_token
	end
      end
      return node
    end
    def preblock
      next_token
      ret = Amrita::e(:pre, :class=>"code") { Amrita::CompactSpace.new(false) { textblock(:PRE_END).join  } } # XXX use template ???
      next_token
      return ret 
    end
    def eol
      @line +=1
      next_token
      return 
    end
    def syntax_error
      s = "(Syntax error at line #{@line}. ; #{@token.inspect})\n" 
	next_token 
      return s
    end
  end
end