class UrlMount

# File lib/url_mount.rb, line 10
def initialize(path, opts = {}, &blk)
  @raw_path, @options = path, opts
  @url_split_regex = Regexp.new("[^#{DELIMETERS.collect{|d| Regexp.quote(d)}.join}]+|[#{DELIMETERS.collect{|d| Regexp.quote(d)}.join}]")
  @host, @scheme = opts[:host], opts[:scheme]
  @callbacks = []
  @callbacks << blk if blk
end

# File lib/url_mount.rb, line 18
def callback(&blk)
  @callbacks << blk if blk
  @callbacks
end

# File lib/url_mount.rb, line 23
def local_segments
  @local_segments || parse_local_segments
end

# File lib/url_mount.rb, line 49
def optional_variable_segments
  @optional_variable_segments ||= begin
    local_segments.map{|s| s.optional_variable_segments}.flatten.compact
  end
end

# File lib/url_mount.rb, line 37
def optional_variables
  @optional_variables ||= begin
    optional_variable_segments.map{|s| s.name}
  end
end

# File lib/url_mount.rb, line 43
def required_variable_segments
  @required_variable_segments ||= begin
    local_segments.map{|s| s.required_variable_segments}.flatten.compact
  end
end

# File lib/url_mount.rb, line 31
def required_variables
  @required_variables ||= begin
    required_variable_segments.map{|s| s.name}
  end
end

# File lib/url_mount.rb, line 64
def url(env = {}, opts = {})
  unless env.key?('rack.version')
    opts = env
    env  = nil
  end

  @callbacks.each{|blk| blk.call(env,opts)} if env

  requirements_met =  (local_required_variables - (opts.keys + options.keys)).empty?

  if !required_to_generate? && !requirements_met
    nil
  else
    raise Ungeneratable, "Missing required variables" if !requirements_met
    path = local_segments.inject([]){|url, segment| str = segment.to_s(opts); url << str if str; url}.join
    match = /(.*?)\/?$/.match(path)
    result = match[1]
    path = url_mount.nil? ? result : File.join(url_mount.to_s(opts), result)
    _host   = opts.delete(:host)    || host
    _scheme = opts.delete(:scheme)  || scheme
    if _host || _scheme
      _scheme ||= "http"
      raise Ungeneratable, "Missing host when generating absolute url" if _scheme && !_host
      uri = URI.parse(path)
      uri.host    = _host
      uri.scheme  = _scheme || "http"
      uri.to_s
    else
      path
    end
  end
end

# File lib/url_mount.rb, line 27
def variables
  required_variables + local_variables
end

# File lib/url_mount.rb, line 99
def local_required_variables
  local_segments.select{|s| s.instance_of?(Segment::Variable)}.map{|s| s.name}
end

# File lib/url_mount.rb, line 107
def parse_local_segments
  stack = []
  @local_segments = []
  buffer = ""
  raw_path.scan(@url_split_regex).each do |segment|
    case segment
    when '/'
      if stack.empty?
        @local_segments << Segment::Delimeter.new
      else
        buffer << segment
      end
    when '('
      buffer << '(' unless stack.empty?
      stack << segment
    when ')'
      stack.pop
      if stack.empty?
        @local_segments << Segment::Conditional.new(buffer, options)
        buffer = ""
      else
        buffer << ')'
      end
    when /^\:(.*)/
      if stack.empty?
        @local_segments << Segment::Variable.new($1, options)
      else
        buffer << segment
      end
    else
      if stack.empty?
        @local_segments << Segment::Static.new(segment)
      else
        buffer << segment
      end
    end
  end
  @local_segments
end

# File lib/url_mount.rb, line 103
def required_to_generate?
  true
end