#!/usr/bin/ruby

# BB_POSTINDEX.RB makes a neat post collection index for Xenforo2 forum
# posts. Write the post summary text followed by the post URL in
# any (raw) text editor, with a single newline separating the summary
# from the URL, but as many blank lines as you want separating each
# post summary. Optionally, prefix the summary with specific commands
# to force different output formatting:
#   - !extra categorizes the comment as an extra to be placed at
#     the end of the post collection for the day,
#   - !daystart specifies that the following posts should be placed
#     inside spoiler tags given by the specified day (see example).
#   - !dayend similarly signals the end of the spoiler tags.
#
#  Example: So the text files I write to sort posts look like:
#
#    !daystart Saturday, 15 February 2020
#
#    Oh, snap! Things just got real ((@UserName) post)
#    https://blahblahblah/page-12#post-3456789
#
#    !extra (@WinnerPoster) made an interesting comment
#    https://blahblahblah/page-13#post-4214133
#
#    !dayend
#
# Then running this script with formats the posts with hyperlinks
# to the posts, @'s for the credited users, and puts everything
# behind spoiler tags separating the days. Within each day, the
# normal posts are formatted with bullet points and a sans serif
# font for whimsy, and the extra posts appear in a separate section
# "Informative takes and extras:" at the end of the spoiler.

# For whimsy, use Arial san serif font for the main post list.
LIST_FORMAT_FONT = "arial"

# Use text macros to dictate the format of the post collection index.
# !daystart begins a spoiler tag for a given day
DAY_START = "!daystart"

# !dayend ends the spoiler tag for a given day
DAY_END = "!dayend"

# !extra specifies that the post is an informative extra, to appear
# separately in a list at the end
EXTRA = "!extra"


# A class to represent an INDEXEDPOST with a given summary, user,
# and post hyperlink. Optionally, the post may be specified as
# an 'extra', in which case no list-style bullet point and sans
# serif formatting is applied.
#
# Example:
#   # Create a new indexed post and print it in default list format
#   post1 = IndexedPost.new("List post (@User post)", "@User", "www.blah#p-1")
#   puts post1  #=> [FONT=arial][URL='www.blah#p-1']○ List post ([/URL]
#               #   @User[URL='www.blah#p-1'] post)[/URL][/FONT]
#
#   # Create a new indexed post and print it in extra format
#   post2 = IndexedPost.new("@User's extra post", "@User", "www.blah", true)
#   puts post2  #=> @User[URL='www.blah']'s extra post[/URL]
#   # And in list form:
#   puts post2.list_format  #=> [FONT=arial][URL='www.blah']○ [/URL]
#                           #@User[URL='www.blah']'s extra post[/URL][/FONT]
#
class IndexedPost

  # Create a new indexed post with the given SUMMARY, USER and
  # POST_HYPERLINK. If EXTRA is true, formats the post as an
  # informative extra without any explicit list formatting.
  def initialize(summary, user, post_hyperlink, extra=false)
    @summary = summary
    @user = user
    @post_hyperlink = post_hyperlink
    @extra = extra
  end

  # Return a string representation for this post in extra format,
  # i.e. in the regular font with just the hyperlink and no
  # additional formatting.
  def extra_format()
    text = @summary.split(@user).map do |part|
      if (part.length > 0)
        "[URL='" + @post_hyperlink + "']" + part + "[/URL]"
      end
    end
    text.join(" " + @user + " ")
  end
  
  # Return a string representation for this post in list format,
  # i.e. in sans serif font with an ASCII bullet point prepended.
  # TODO: These methods are very similar. Refactor to get rid of the
  #       code duplication at some point later?
  def list_format()
    text = ("○ " + @summary).split(@user).map do |part|
      if (part.length > 0)
        "[URL='" + @post_hyperlink + "']" + part + "[/URL]"
      end
    end
    "[FONT=" + LIST_FORMAT_FONT + "]" + text.join(" " + @user + " ") + "[/FONT]"
  end
  
  # Return the printable string representation for this indexed post.
  def to_s()
    if (@extra)
      self.extra_format
    else
      self.list_format
    end
  end
  
end


# Assume that the file full of posts is the first command line arg
if (ARGV.length < 1)
  raise(ArgumentError, "No post file specified in command line args")
else
  posts_file = File.open(ARGV.join(""))
end

# Read lines from the post collection file (ignoring blank lines), and
# generate the index structure.
list_posts = []
extra_posts = []
day_active = false

line = posts_file.gets.strip

while (line)
  # Skip any preceding white space or blank lines
  line.strip!
  if (not line.empty?)
    case
    when line.start_with?(DAY_START)
      # Start the spoiler tag and refresh the post lists
      puts "[SPOILER=\"" + line.split(DAY_START)[1].strip! + "\"]"
      list_posts = []
      extra_posts = []
      day_active = true
      
    when line.start_with?(DAY_END)
      # Print all of the collected list posts
      list_posts.map { |post| puts post.list_format }
      
      # Print all of the collected extra posts in a separate section
      puts "\nInformative takes and extras:"
      extra_posts.map { |post| puts post.extra_format }

      # Finally, end the spoiler tag
      puts "[/SPOILER]"
      day_active = false

    else
      # If the line begins with !extra, it's an extra/informative post
      extra = line.start_with?(EXTRA)
      if (extra)
        line = line.split(EXTRA)[1].strip
      end

      # Parse the user name (assumed to be between a pair of parentheses
      # for simplicity)
      user_with_parens = line.scan(/\(@.+\)(?=['\s])/)[0].strip
      user = user_with_parens[1..-2]

      # And remove the extra parentheses in the formatted summary
      summary = line.gsub(user_with_parens, user)
      
      # Grab the next line too for the hyperlink
      post_hyperlink = posts_file.gets.strip

      # Instantiate a new post index and add it to the list.
      indexed_post = IndexedPost.new(summary, user, post_hyperlink, extra)
      if (extra)
        extra_posts << indexed_post
      else
        list_posts << indexed_post
      end
    end
  end

  # Read in the next line
  line = posts_file.gets
end

# Done reading! Close the collected posts file.
posts_file.close()

# Check: at the end here, if we still have collected posts for the day,
# print them all now and close the spoiler tag.
if (day_active)
  # TODO: Duplicate code from the case. Refactor?
  # Print all of the collected list posts
  list_posts.map { |post| puts post.list_format }
  
  # Print all of the collected extra posts in a separate section
  puts "\nInformative takes and extras:"
  extra_posts.map { |post| puts post.extra_format }
  
  # Finally, end the spoiler tag
  puts "[/SPOILER]"
end