require 'redis'
require 'securerandom'
require 'json'


class CommentsRepository
  
  def initialize
    @redis = Redis.new
  end
  
  
  def save itemId, comment, parentId = nil
    now = Time.now.utc.to_i
    id = @redis.incr 1
    comment = {id: id, comment: comment, time: now}
    childsOfKey = parentId ? subCommentsKey(parentId) : commentsKey(itemId)
    @redis.multi do |multi|
      @redis.del jsonKey itemId
      @redis.hmset commentKey(id), comment.map{|k,v| [k,v]}.flatten(1)
      @redis.zadd childsOfKey, now, id
    end
    id
  end
  
  
  def get id
    jsonId = jsonKey id
    jsonComments = @redis.get jsonId
    if jsonComments
      JSON.parse jsonComments
    else
      comments = multiFetch commentsKey id
      @redis.set jsonId, comments.to_json
      comments
    end
  end
  

  def leaf id
    comment = @redis.hgetall commentKey id
    comment['comments'] = multiFetch subCommentsKey id
    comment
  end

  
  def delete comment, parentId, itemId, isMainThread = true
    innerDelete comment, parentId, isMainThread
    @redis.del jsonKey itemId
  end
  
  
  private
  
  
  def multiFetch key
    commentIds = @redis.zrange key, 0, -1
    comments = @redis.multi do |multi|
      commentIds.map { |id| multi.hgetall(commentKey id)}
    end
    processComments comments
  end
  
  
  def processComments comments
    comments.each do |comment|
      subCommentsId = subCommentsKey comment['id']
      if @redis.zcard(subCommentsId) > 0
        comment['comments'] = multiFetch subCommentsId
      end
    end
  end
  
  
  def innerDelete comment, parentId, isMainThread
    if comment.kind_of? Array
      comment.each {|c| innerDelete c, parentId, isMainThread}
    else
      id = comment['id']
      comments = comment['comments']
      childsKey = isMainThread ? commentsKey(parentId) : subCommentsKey(parentId)
      @redis.del commentKey id
      @redis.zrem childsKey, id
      innerDelete comments, id, false if comments
    end
  end
  
  
  def jsonKey id
    "comment:#{id}:json"
  end
  
  
  def commentKey id
    "comment:#{id}"
  end
  
  
  def commentsKey id
    "comments:#{id}"
  end
  
  
  def subCommentsKey id
    "comment:#{id}:sub"
  end
  
end



def printComments comments, tabs = 0
  comments.each do |comment|
    tabs.times { putc "\t" }
    puts "#{comment['comment']}"
    if comment['comments']
      printComments comment['comments'], tabs + 1
    end
  end
end


def saveDummy cr, id
  tree = cr.save id, 'Tree'
  root = cr.save id, 'Root', tree
  trunk = cr.save id, 'Trunk', tree
  branch = cr.save id, 'Branch', trunk
  leaf = cr.save id, 'Leaf', branch
  top = cr.save id, 'Top', tree
end


command = ARGV[0]
id = ARGV[1]
cr = CommentsRepository.new


case command
when 's' 
  saveDummy cr, id
when 'p' 
  printComments cr.get id
when 'l'
  printComments [cr.leaf(id)]
when 'd' 
  cr.delete cr.get(id), id, id
when 'r'
  cr.delete cr.leaf(ARGV[2]), ARGV[3], id, false
when 'j' 
  puts cr.get(id).to_json
end