###############################################################################
# Codestriker: Copyright (c) 2001, 2002 David Sitsky.  All rights reserved.
# sits@users.sourceforge.net
#
# This program is free software; you can redistribute it and modify it under
# the terms of the GPL.

# Object for handling the computation of a delta for displaying to HTML.

package Codestriker::Http::DeltaRenderer;

use strict;

use Codestriker::Http::HtmlEntityLineFilter;
use Codestriker::Http::TabToNbspLineFilter;
use Codestriker::Http::HighlightLineFilter;
use Codestriker::Http::HighlightedLxrLineFilter;
use Codestriker::Http::NonHighlightedLxrLineFilter;

# Constructor.
sub new {
    my ($type, $topic, $comments, $deltas, $query, $mode,
        $tabwidth, $repository) = @_;

    my $self = {};
    $self->{topic} = $topic;
    $self->{comments} = $comments;
    $self->{deltas} = $deltas;
    $self->{query} = $query;
    $self->{mode} = $mode;
    $self->{tabwidth} = $tabwidth;

    # Build a hash from filenumber|fileline|new -> comment array, so that
    # when rendering, lines can be coloured appropriately.  Also build a list
    # of what points in the review have a comment.  Also record a mapping
    # from filenumber|fileline|new -> the comment number.
    my %comment_hash = ();
    my @comment_locations = ();
    my %comment_location_map = ();
    for (my $i = 0; $i <= $#$comments; $i++) {
        my $comment = $$comments[$i];
        my $key = $comment->{filenumber} . "|" . $comment->{fileline} . "|" .
          $comment->{filenew};
        if (! exists $comment_hash{$key}) {
            push @comment_locations, $key;
            $comment_location_map{$key} = $#comment_locations;
        }
        push @{ $comment_hash{$key} }, $comment;
    }
    $self->{comment_hash} = \%comment_hash;
    $self->{comment_locations} = \@comment_locations;
    $self->{comment_location_map} = \%comment_location_map;

    # Determine the LXR configuration.
    my $lxr_config = defined $repository ?
      $Codestriker::lxr_map->{$repository->toString()} : undef;

    # If the highlighter has been configured, use that for converting the
    # code to html.
    @{$self->{line_filters}} = ();
    if (defined $Codestriker::highlighter && $Codestriker::highlighter ne '') {
        push @{$self->{line_filters}}, Codestriker::Http::HighlightLineFilter->new($Codestriker::highlighter, $tabwidth);
        if (defined $lxr_config) {
            push @{$self->{line_filters}}, Codestriker::Http::HighlightedLxrLineFilter->new($lxr_config);
        }
    } else {
        push @{$self->{line_filters}}, Codestriker::Http::HtmlEntityLineFilter->new();
        push @{$self->{line_filters}}, Codestriker::Http::TabToNbspLineFilter->new($tabwidth);
        if (defined $lxr_config) {
            push @{$self->{line_filters}}, Codestriker::Http::NonHighlightedLxrLineFilter->new($lxr_config);
        }
    }

    bless $self, $type;
}

# Add a line filter to this delta-renderer, which will be called for each
# line that is to be rendered.
sub add_line_filter
  {
      my ($self, $line_filter) = @_;
      push @{$self->{line_filters}}, $line_filter;
  }

# Render $text with the appropriate anchor attributes set for
# displaying any existing comments and a link for adding new ones.
sub comment_link
  {
      my ($self, $filenumber, $line, $new, $text) = @_;

      # Determine the anchor and edit URL for this line number.
      my $anchor = "$filenumber|$line|$new";
      my $edit_url = "javascript:eo('$filenumber','$line','$new')";

      # Set the anchor to this line number.
      my $params = {};
      $params->{name} = $anchor;

      # Only set the href attribute if the comment is in open state.
      if (!Codestriker::topic_readonly($self->{topic}->{topic_state})) {
          $params->{href} = $edit_url;
      }

      # If a comment exists on this line, set span and the overlib hooks onto
      # it.
      my %comment_hash = %{ $self->{comment_hash} };
      my %comment_location_map = %{ $self->{comment_location_map} };
      my $query = $self->{query};
      if (exists $comment_hash{$anchor}) {
          $params->{class} = "comment";

          # Determine what the next comment in line is.
          my $index = -1;
          my @comment_locations = @{ $self->{comment_locations} };
          for ($index = 0; $index <= $#comment_locations; $index++) {
              last if $anchor eq $comment_locations[$index];
          }

          $params->{onmouseover} =
            "return overlib(comment_text[$index],STICKY,DRAGGABLE,ALTCUT);";
          $params->{onmouseout} = "return nd();";
      } else {
          $params->{class} = "nocom";
      }

      return $query->a($params, $text);
  }

# Go through all of the deltas, and append a line array for each delta with
# enough information to render it easily.
sub annotate_deltas
  {
      my ($self) = @_;

      foreach my $delta (@{ $self->{deltas} }) {

          # Split the delta into the left and right side so that text filtering
          # can be applied.
          my @diff_lines = split /\n/, $delta->{text};
          $delta->{diff_old_lines} = "";
          $delta->{diff_new_lines} = "";
          for (my $i = 0; $i <= $#diff_lines; $i++) {
              my $data = $diff_lines[$i];

              if ($data =~ /^\-(.*)$/o) {
                  # Line corresponding to old code.
                  $delta->{diff_old_lines} .= "$1\n";
              } elsif ($data =~ /^\+(.*)$/o) {
                  # Line corresponding to new code.
                  $delta->{diff_new_lines} .= "$1\n";
              } elsif ($data =~ /^\\/) {
                  # A diff comment such as "No newline at end of file" - ignore it.
              } else {
                  # Line corresponding to both sides. Strip the first space off
                  # the diff for proper alignment.
                  $data =~ s/^\s//;
                  $delta->{diff_old_lines} .= "$data\n";
                  $delta->{diff_new_lines} .= "$data\n";
              }
          }

          # Apply the line filters through the delta text.
          $self->_apply_line_filters($delta);

          # Now go through the delta text again to determine what lines are to be
          # rendered.
          my $old_linenumber = $delta->{old_linenumber};
          my $new_linenumber = $delta->{new_linenumber};
          @{$self->{lines}} = ();
          @{$self->{diff_old_lines}} = ();
          @{$self->{diff_old_lines_numbers}} = ();
          @{$self->{diff_new_lines}} = ();
          @{$self->{diff_new_lines_numbers}} = ();
          $self->{current_filename} = "";
          my $old_index = 0;
          my $new_index = 0;
          my @filtered_old_lines = split /\n/, $delta->{diff_old_lines};
          my @filtered_new_lines = split /\n/, $delta->{diff_new_lines};
          for (my $i = 0; $i <= $#diff_lines; $i++) {
              my $data = $diff_lines[$i];

              if ($data =~ /^\-/o) {
                  # Line corresponding to old code.
                  push @{ $self->{diff_old_lines} }, $filtered_old_lines[$old_index++];
                  push @{ $self->{diff_old_lines_numbers} }, $old_linenumber;
                  $old_linenumber++;
              } elsif ($data =~ /^\+(.*)$/o) {
                  # Line corresponding to new code.
                  push @{ $self->{diff_new_lines} }, $filtered_new_lines[$new_index++];
                  push @{ $self->{diff_new_lines_numbers} }, $new_linenumber;
                  $new_linenumber++;
              } elsif ($data =~ /^\\/) {
                  # A diff comment such as "No newline at end of file" - ignore it.
              } else {
                  # Line corresponding to both sides.
                  $data = $filtered_old_lines[$old_index++];
                  $new_index++;

                  # Render what has been currently recorded.
                  $self->_render_changes($delta->{filenumber});

                  # Now that the diff changeset has been rendered, remove the state data.
                  @{$self->{diff_old_lines}} = ();
                  @{$self->{diff_old_lines_numbers}} = ();
                  @{$self->{diff_new_lines}} = ();
                  @{$self->{diff_new_lines_numbers}} = ();

                  # Now render the line which is present on both sides.
                  my $line = {};
                  my $data_class =
                    $self->{mode} == $Codestriker::COLOURED_MODE ? "n" : "msn";
                  $line->{old_data} = $data;
                  $line->{old_data_line} =
                    $self->comment_link($delta->{filenumber}, $old_linenumber,
                                        0, $old_linenumber);
                  $line->{old_data_class} = $data_class;
                  $line->{new_data} = $data;
                  $line->{new_data_line} =
                    $self->comment_link($delta->{filenumber}, $new_linenumber,
                                        1, $new_linenumber);
                  $line->{new_data_class} = $data_class;
                  push @{$self->{lines}}, $line;
                  $old_linenumber++;
                  $new_linenumber++;
              }

              # Check if the delta corresponds to a new file.  This is true
              # if there is only one delta for the whole file, there are no
              # old lines, and the diff strarts at 0,1.
              $delta->{new_file} =
                $delta->{only_delta_in_file} &&    $old_linenumber == 0 &&
                  $delta->{old_linenumber} == 0 && $delta->{new_linenumber} == 1;
              if ($delta->{new_file}) {
                  $delta->{new_file_class} =
                    $self->{mode} == $Codestriker::COLOURED_MODE ? "n" : "msn";
              }
          }

          # Render any remaining diff segments.
          $self->_render_changes($delta->{filenumber});

          # Store the processed lines with the delta object for rendering.
          @{$delta->{lines}} = @{$self->{lines}};

          if ($self->{current_filename} ne $delta->{filename}) {
              # Keep track of the current filename being processed.
              $self->{current_filename} = $delta->{filename};
          }
      }
  }

# Annotate any accumlated diff changes.
sub _render_changes
  {
      my ($self, $filenumber) = @_;

      # Determine the class to use for displaying the comments.
      my ($old_col, $old_notpresent_col, $new_col, $new_notpresent_col);
      if (@{$self->{diff_new_lines}} > 0 && @{$self->{diff_old_lines}} > 0) {
          # Lines have been added and removed.
          if ($self->{mode} == $Codestriker::COLOURED_MODE) {
              $old_col = "c";
              $old_notpresent_col = "cb";
              $new_col = "c";
              $new_notpresent_col = "cb";
          } else {
              $old_col = "msc";
              $old_notpresent_col = "mscb";
              $new_col = "msc";
              $new_notpresent_col = "mscb";
          }
      } elsif (@{$self->{diff_new_lines}} > 0 && @{$self->{diff_old_lines}} == 0) {
          # New lines have been added.
          if ($self->{mode} == $Codestriker::COLOURED_MODE) {
              $old_col = "a";
              $old_notpresent_col = "ab";
              $new_col = "a";
              $new_notpresent_col = "ab";
          } else {
              $old_col = "msa";
              $old_notpresent_col = "msab";
              $new_col = "msa";
              $new_notpresent_col = "msab";
          }
      } else {
          # Lines have been removed.
          if ($self->{mode} == $Codestriker::COLOURED_MODE) {
              $old_col = "r";
              $old_notpresent_col = "rb";
              $new_col = "r";
              $new_notpresent_col = "rb";
          } else {
              $old_col = "msr";
              $old_notpresent_col = "msrb";
              $new_col = "msr";
              $new_notpresent_col = "msrb";
          }
      }

      my ($old_data, $new_data, $old_data_line, $new_data_line);
      while (@{$self->{diff_old_lines}} > 0 || @{$self->{diff_new_lines}} > 0) {

          # Retrieve the next lines which were removed (if any).
          if (@{$self->{diff_old_lines}} > 0) {
              $old_data = shift @{$self->{diff_old_lines}};
              $old_data_line = shift @{$self->{diff_old_lines_numbers}};
          } else {
              undef($old_data);
              undef($old_data_line);
          }

          # Retrieve the next lines which were added (if any).
          if (@{$self->{diff_new_lines}} > 0) {
              $new_data = shift @{$self->{diff_new_lines}};
              $new_data_line = shift @{$self->{diff_new_lines_numbers}};
          } else {
              undef($new_data);
              undef($new_data_line);
          }

          # Set the colours to use appropriately depending on what is defined.
          my $render_old_colour = $old_col;
          my $render_new_colour = $new_col;
          if (defined $old_data && ! defined $new_data) {
              $render_new_colour = $new_notpresent_col;
          } elsif (! defined $old_data && defined $new_data) {
              $render_old_colour = $old_notpresent_col;
          }

          my %comment_location_map = %{ $self->{comment_location_map} };
          my $line = {};
          if (defined $old_data) {
              $line->{old_data} = $old_data;
              $line->{old_data_line} =
                $self->comment_link($filenumber, $old_data_line, 0, $old_data_line);
          }
          $line->{old_data_class} = $render_old_colour;
          if (defined $new_data) {
              $line->{new_data} = $new_data;
              $line->{new_data_line} =
                $self->comment_link($filenumber, $new_data_line, 1, $new_data_line);
          }
          $line->{new_data_class} = $render_new_colour;
          push @{$self->{lines}}, $line;
      }

      # Apply all of the line filters to the line of text supplied.
      sub _apply_line_filters {
          my ($self, $delta) = @_;

          # TODO: perform syntax highlighting.
          foreach my $line_filter (@{$self->{line_filters}}) {
              $line_filter->filter($delta);
          }

          # Unconditionally add a &nbsp; at the start for better alignment.
          # Fix so count isn't stuffed.
          # return "&nbsp;" . $text;
      }
  }

1;