#!/bin/bash

# "assemble-all-pages" inserts the constant parts into all HTML templates
# in the working directory and creates the OS-specific pages by removing
# the irrelevant text from a common file which contains the OS-variable
# parts.

# The page is NAME.html and the template is NAME.t.html. The template has
# inclusion markers (similar to SSI directives, except for the lack of "#")
# to indicate where the constant parts are to be inserted, and deletion
# markers to identify the borders of each deletion and indicate which
# page(s) the text between them belongs to.

# All the ingredients are is in [...]/enc/[lang]/kitchen/:

# Script:     assemble-all-pages

# Templates:  confirmation.t.html
#             index.t.html  (contains variable parts for mac and windows)
#             infographic.t.html
#             next_steps.t.html

# Includes:   footer.html
#             head1.html
#             head2.html
#             javascript.html
#             translist.html

# To regenerate the pages in [...]/enc/[lang]/:
# - In the terminal, cd to [...]/enc/[lang]/kitchen/ and enter:
#                     $ ./assemble-all-pages
# - Or, in the file browser, display the directory [...]/kitchen/ (not its
#   parent) and double-click on the script.

# And if anything goes wrong, you can do a git reset, right?    ;-)

# ==========================================================================

set -e

# Create temporary files.
before=$(mktemp -t h2p.XXXXXX) || exit 1
after=$(mktemp -t h2p.XXXXXX) || exit 1
templates=$(mktemp -t h2p.XXXXXX) || exit 1
list=$(mktemp -t h2p.XXXXXX) || exit 1    # includes, then deletion markers
deletions=$(mktemp -t h2p.XXXXXX) || exit 1
trap 'rm -f "$before" "$after" "$templates" "$list" "$deletions"' EXIT

# List all the templates in the working directory.
if ! ls *.t.html > $templates  2>/dev/null; then
  echo "There is no template in this directory." && exit 1
fi

# Process each template in the list.
while read template; do

  page=${template/.t/}
  echo $page

  # Make sure there is a blank line before the first include, otherwise
  # it will not be added properly.
  cp $template ../$page && sed -i '1i\\n' ../$page

  # List the includes.
  grep '^<!-- include virtual="' ../$page |
  sed 's%^.*include virtual="\([^"]\+\).*$%\1%' > $list

  # Add the includes.
  while read include; do
    sed "1,/^<!-- include virtual=\"$include\"/!d" ../$page > $before
    sed "1,/^<!-- include virtual=\"$include\"/d" ../$page > $after
    if [ -f "$include" ]; then
      cat $before $include $after > ../$page
    else
      echo "$include is missing." && exit 1
    fi
    sed -i "/^<!-- include virtual=\"$include\"/d" ../$page
  done < $list

  # Create mac.html and windows.html from index.html and delete the
  # irrelevant parts.
  if [ $page == "index.html" ]; then
    cp ../$page ../mac.html
    cp ../$page ../windows.html
    # List the deletion markers.
    grep '^<!-- START DELETION' ../index.html > $list
    # Process each page separately.
    for variant in index mac windows; do
      # Find out which deletions should be made.
      grep -v "$variant"  $list \
      | sed 's%^<!-- START DELETION \([0-9][0-9]\?\),.*$%\1%' > $deletions
      # Delete.
      while read deletion; do
        sed -i "/^<!-- START DELETION $deletion/,\
        /^<!-- END DELETION $deletion/d" ../$variant.html
      done < $deletions
      sed -i '/^<!-- [A-Z]* DELETION/d' ../$variant.html
    done
  fi
  # Delete any extra blank lines at the end of the page.
  sed -i ':a /^\n*$/ {$d; N; ba}' ../*.html

done < $templates
exit 0