class Trace < ActiveRecord::Base
  self.table_name = "gpx_files"

  belongs_to :user, :counter_cache => true
  has_many :tags, :class_name => 'Tracetag', :foreign_key => 'gpx_id', :dependent => :delete_all
  has_many :points, :class_name => 'Tracepoint', :foreign_key => 'gpx_id', :dependent => :delete_all

  scope :visible, -> { where(:visible => true) }
  scope :visible_to, ->(u) { visible.where("visibility IN ('public', 'identifiable') OR user_id = ?", u) }
  scope :visible_to_all, -> { where(:visibility => ["public", "identifiable"]) }
  scope :tagged, ->(t) { joins(:tags).where(:gpx_file_tags => { :tag => t }) }

  validates_presence_of :user_id, :name, :timestamp
  validates_presence_of :description, :on => :create
  validates_length_of :name, :maximum => 255
  validates_length_of :description, :maximum => 255
#  validates_numericality_of :latitude, :longitude
  validates_inclusion_of :inserted, :in => [ true, false ]
  validates_inclusion_of :visibility, :in => ["private", "public", "trackable", "identifiable"]

  def destroy
    super
    FileUtils.rm_f(trace_name)
    FileUtils.rm_f(icon_picture_name)
    FileUtils.rm_f(large_picture_name)
  end

  def tagstring
    return tags.collect {|tt| tt.tag}.join(", ")
  end

  def tagstring=(s)
    if s.include? ','
      self.tags = s.split(/\s*,\s*/).select {|tag| tag !~ /^\s*$/}.collect {|tag|
        tt = Tracetag.new
        tt.tag = tag
        tt
      }
    else
      #do as before for backwards compatibility:
      self.tags = s.split().collect {|tag|
        tt = Tracetag.new
        tt.tag = tag
        tt
      }
    end
  end

  def public?
    visibility == "public" || visibility == "identifiable"
  end

  def trackable?
    visibility == "trackable" || visibility == "identifiable"
  end

  def identifiable?
    visibility == "identifiable"
  end

  def large_picture= (data)
    f = File.new(large_picture_name, "wb")
    f.syswrite(data)
    f.close
  end
  
  def icon_picture= (data)
    f = File.new(icon_picture_name, "wb")
    f.syswrite(data)
    f.close
  end

  def large_picture
    f = File.new(large_picture_name, "rb")
    logger.info "large picture file: '#{f.path}', bytes: #{File.size(f.path)}"
    data = f.sysread(File.size(f.path))
    logger.info "have read data, bytes: '#{data.length}'"
    f.close
    data
  end
  
  def icon_picture
    f = File.new(icon_picture_name, "rb")
    logger.info "icon picture file: '#{f.path}'"
    data = f.sysread(File.size(f.path))
    f.close
    data
  end
  
  def large_picture_name
    "#{GPX_IMAGE_DIR}/#{id}.gif"
  end

  def icon_picture_name
    "#{GPX_IMAGE_DIR}/#{id}_icon.gif"
  end

  def trace_name
    "#{GPX_TRACE_DIR}/#{id}.gpx"
  end

  def mime_type
    filetype = `/usr/bin/file -bz #{trace_name}`.chomp
    gzipped = filetype =~ /gzip compressed/
    bzipped = filetype =~ /bzip2 compressed/
    zipped = filetype =~ /Zip archive/

    if gzipped then
      mimetype = "application/x-gzip"
    elsif bzipped then
      mimetype = "application/x-bzip2"
    elsif zipped
      mimetype = "application/x-zip"
    else
      mimetype = "application/gpx+xml"
    end

    return mimetype
  end

  def extension_name
    filetype = `/usr/bin/file -bz #{trace_name}`.chomp
    gzipped = filetype =~ /gzip compressed/
    bzipped = filetype =~ /bzip2 compressed/
    zipped = filetype =~ /Zip archive/
    tarred = filetype =~ /tar archive/

    if tarred and gzipped then
      extension = ".tar.gz"
    elsif tarred and bzipped then
      extension = ".tar.bz2"
    elsif tarred
      extension = ".tar"
    elsif gzipped
      extension = ".gpx.gz"
    elsif bzipped
      extension = ".gpx.bz2"
    elsif zipped
      extension = ".zip"
    else
      extension = ".gpx"
    end

    return extension
  end

  def to_xml
    doc = OSM::API.new.get_xml_doc
    doc.root << to_xml_node()
    return doc
  end

  def to_xml_node
    el1 = XML::Node.new 'gpx_file'
    el1['id'] = self.id.to_s
    el1['name'] = self.name.to_s
    el1['lat'] = self.latitude.to_s if self.inserted
    el1['lon'] = self.longitude.to_s if self.inserted
    el1['user'] = self.user.display_name
    el1['visibility'] = self.visibility
    el1['pending'] = (!self.inserted).to_s
    el1['timestamp'] = self.timestamp.xmlschema

    el2 = XML::Node.new 'description'
    el2 << self.description
    el1 << el2

    self.tags.each do |tag|
      el2 = XML::Node.new('tag')
      el2 << tag.tag
      el1 << el2
    end

    return el1
  end

  # Read in xml as text and return it's Node object representation
  def self.from_xml(xml, create=false)
    begin
      p = XML::Parser.string(xml)
      doc = p.parse

      doc.find('//osm/gpx_file').each do |pt|
        return Trace.from_xml_node(pt, create)
      end

      raise OSM::APIBadXMLError.new("trace", xml, "XML doesn't contain an osm/gpx_file element.")
    rescue LibXML::XML::Error, ArgumentError => ex
      raise OSM::APIBadXMLError.new("trace", xml, ex.message)
    end
  end

  def self.from_xml_node(pt, create=false)
    trace = Trace.new
    
    raise OSM::APIBadXMLError.new("trace", pt, "visibility missing") if pt['visibility'].nil?
    trace.visibility = pt['visibility']

    unless create
      raise OSM::APIBadXMLError.new("trace", pt, "ID is required when updating.") if pt['id'].nil?
      trace.id = pt['id'].to_i
      # .to_i will return 0 if there is no number that can be parsed. 
      # We want to make sure that there is no id with zero anyway
      raise OSM::APIBadUserInput.new("ID of trace cannot be zero when updating.") if trace.id == 0
    end

    # We don't care about the time, as it is explicitly set on create/update/delete
    # We don't care about the visibility as it is implicit based on the action
    # and set manually before the actual delete
    trace.visible = true

    description = pt.find('description').first
    raise OSM::APIBadXMLError.new("trace", pt, "description missing") if description.nil?
    trace.description = description.content

    pt.find('tag').each do |tag|
      trace.tags.build(:tag => tag.content)
    end

    return trace
  end

  def xml_file
    # TODO *nix specific, could do to work on windows... would be functionally inferior though - check for '.gz'
    filetype = `/usr/bin/file -bz #{trace_name}`.chomp
    gzipped = filetype =~ /gzip compressed/
    bzipped = filetype =~ /bzip2 compressed/
    zipped = filetype =~ /Zip archive/
    tarred = filetype =~ /tar archive/

    if gzipped or bzipped or zipped or tarred then
      tmpfile = Tempfile.new("trace.#{id}");

      if tarred and gzipped then
        system("tar -zxOf #{trace_name} > #{tmpfile.path}")
      elsif tarred and bzipped then
        system("tar -jxOf #{trace_name} > #{tmpfile.path}")
      elsif tarred
        system("tar -xOf #{trace_name} > #{tmpfile.path}")
      elsif gzipped
        system("gunzip -c #{trace_name} > #{tmpfile.path}")
      elsif bzipped
        system("bunzip2 -c #{trace_name} > #{tmpfile.path}")
      elsif zipped
        system("unzip -p #{trace_name} -x '__MACOSX/*' > #{tmpfile.path}")
      end

      tmpfile.unlink

      file = tmpfile.file
    else
      file = File.open(trace_name)
    end

    return file
  end

  def import
    logger.info("GPX Import importing #{name} (#{id}) from #{user.email}")

    gpx = GPX::File.new(self.xml_file)

    f_lat = 0
    f_lon = 0
    first = true

    # If there are any existing points for this trace then delete
    # them - we check for existing points first to avoid locking
    # the table in the common case where there aren't any.
    if Tracepoint.where(:gpx_id => self.id).exists?
      Tracepoint.delete_all(:gpx_id => self.id)
    end

    gpx.points do |point|
      if first
        f_lat = point.latitude
        f_lon = point.longitude
        first = false
      end

      tp = Tracepoint.new
      tp.lat = point.latitude
      tp.lon = point.longitude
      tp.altitude = point.altitude
      tp.timestamp = point.timestamp
      tp.gpx_id = id
      tp.trackid = point.segment
      tp.save!
    end

    if gpx.actual_points > 0
      max_lat = Tracepoint.where(:gpx_id => id).maximum(:latitude)
      min_lat = Tracepoint.where(:gpx_id => id).minimum(:latitude)
      max_lon = Tracepoint.where(:gpx_id => id).maximum(:longitude)
      min_lon = Tracepoint.where(:gpx_id => id).minimum(:longitude)

      max_lat = max_lat.to_f / 10000000
      min_lat = min_lat.to_f / 10000000
      max_lon = max_lon.to_f / 10000000
      min_lon = min_lon.to_f / 10000000

      self.latitude = f_lat
      self.longitude = f_lon
      self.large_picture = gpx.picture(min_lat, min_lon, max_lat, max_lon, gpx.actual_points)
      self.icon_picture = gpx.icon(min_lat, min_lon, max_lat, max_lon)
      self.size = gpx.actual_points
      self.inserted = true
      self.save!
    end

    logger.info "done trace #{id}"

    return gpx
  end
end