require 'flydata/source_mysql/plugin_support/alter_table_query_handler'
require 'flydata/source_mysql/plugin_support/truncate_table_query_handler'
require 'flydata/source_mysql/plugin_support/drop_database_query_handler'

module Flydata
module SourceMysql

module PluginSupport
  class BinlogQueryDispatcher
    def initialize
      @handlers = []
    end

    def dispatch(record)
      normalize_query(record["query"]) do |query|
        @handlers.each do |handler|
          if (handler.pattern.match(query))
            handler.process(record.merge({"normalized_query" => query}))
            break
          end
        end
      end
    end

    private

    PLACEMENT = '{}'
    def normalize_query(queries)
      q = queries.dup
      strings = []
      # \/\*.*?\*\/        /* */ style comment
      # `.*?`              `resource_name`
      # '(?:\\.|.)*?'      'string'
      # "(?:\\.|.)*?"      "string"
      # --\s+.*?(?:\n|$)   -- style comment
      # #\s+.*?(?:\n|$)    # style comment
      q.gsub!(/(\/\*.*?\*\/|`.*?`|'(?:\\.|.)*?'|"(?:\\.|.)*?"|--\s+.*?(?:\n|$)|#.*?(?:\n|$))/m) do |m|
        comment_or_quoted = $&
        if comment_or_quoted.start_with?("/*") || comment_or_quoted.start_with?("--") ||
           comment_or_quoted.start_with?("#")
          # comment. replace with a space
          ' '
        else
          # string.  save the original and replace with an temporary placement
          strings << comment_or_quoted
          PLACEMENT
        end
      end
      q = q.gsub(/\s+/, ' ') # replace multiple spaces with a space
      q.split(';').each do |query|
        query = query.lstrip
        query.gsub!(PLACEMENT) do |m|
          strings.shift
        end
        yield(query + ";") if block_given? && !query.empty?
      end
    end
  end

  class FlydataBinlogQueryDispatcher < BinlogQueryDispatcher
    def initialize(context)
      @handlers = [
        AlterTableQueryHandler.new(context),
        TruncateTableQueryHandler.new(context),
        DropDatabaseQueryHandler.new(context),
      ]
    end
  end
end

end
end