require 'rubygems'
require 'active_record'
require 'faster_csv'
require 'net/ftp'
require 'net/smtp'
require 'fileutils'
require 'uuidtools'

class Logger
  #Change the logging format to include a timestamp
  def format_message(severity, timestamp, progname, msg)
    "#{timestamp} (#{$$}) #{msg}\n" 
  end
end

module EchiConverter
  def connect_database
    databaseconfig = $workingdir + '/../config/database.yml'
    dblogfile = $workingdir + '/../log/database.log'
    ActiveRecord::Base.logger = Logger.new(dblogfile, $config["log_number"], $config["log_length"])  
    case $config["log_level"]
      when 'FATAL'
        ActiveRecord::Base.logger.level = Logger::FATAL
      when 'ERROR'
        ActiveRecord::Base.logger.level = Logger::ERROR
      when 'WARN'
        ActiveRecord::Base.logger.level = Logger::WARN
      when 'INFO'
        ActiveRecord::Base.logger.level = Logger::INFO
      when 'DEBUG'
        ActiveRecord::Base.logger.level = Logger::DEBUG
    end
    begin
      ActiveRecord::Base.establish_connection(YAML::load(File.open(databaseconfig))) 
      @log.info "Successfully connected to the database"
    rescue => err
      @log.fatal "Could not connect to the database - " + err
      send_email_alert "DATABASE"
    end
  end
  
  #Method to open our application log
  def initiate_logger
    logfile = $workingdir + '/../log/application.log'
    @log = Logger.new(logfile, $config["log_number"], $config["log_length"])
    case $config["log_level"]
      when 'FATAL'
        @log.level = Logger::FATAL
      when 'ERROR'
        @log.level = Logger::ERROR
      when 'WARN'
        @log.level = Logger::WARN
      when 'INFO'
        @log.level = Logger::INFO
      when 'DEBUG'
        @log.level = Logger::DEBUG
    end
  end
  
  #Method to send alert emails
  def send_email_alert reason
    begin
      Net::SMTP.start($config["smtp_server"], $config["smtp_port"]) do |smtp|
        smtp.open_message_stream('donotreply@echi-converter.rubyforge.org', [$config["alert_email_address"]]) do |f|
          f.puts "From: donotreply@echi-converter.rubyforge.org"
          f.puts "To: " + $config['alert_email_address']
          f.puts "Subject: ECHI-Converter Failure"
          case reason 
          when "DATABASE"
            f.puts "Failed to connect to the database."
          when "FTP"
            f.puts "Failed to connect to the ftp server."
          end
            f.puts " "
            f.puts "Please check the ECHI-Converter environment as soon as possible."
        end
      end
    rescue => err
      @log.warn err
    end
  end
  
  #Set the working directory to copy processed files to, if it does not exist creat it
  #Directory names based on year/month so as not to exceed 5K files in a single directory
  def set_directory working_directory
    time = Time.now
    directory_year = working_directory + "/../files/processed/" + time.year.to_s 
    directory_month = directory_year + "/" + time.month.to_s
    
    if File.exists?(directory_month) == false
      if File.exists?(directory_year) == false
        Dir.mkdir(directory_year)
      end
      Dir.mkdir(directory_month)
    end      
    
    return directory_month
  end
  
  #Method for parsing the various datatypes from the ECH file
  def dump_binary type, length
    case type
    when 'int' 
      #Process integers, assigning appropriate profile based on length
      #such as long int, short int and tiny int.
      case length
      when 4
        value = @binary_file.read(length).unpack("l").first.to_i
      when 2
        value = @binary_file.read(length).unpack("s").first.to_i
      when 1
        value = @binary_file.read(length).unpack("U").first.to_i
      end
    #Process appropriate intergers into datetime format in the database
    when 'datetime'
      case length 
      when 4
        value = @binary_file.read(length).unpack("l").first.to_i
        value = Time.at(value)
      end
    #Process strings
    when 'str'
      value = @binary_file.read(length).unpack("M").first.to_s.rstrip
    #Process individual bits that are booleans
    when 'bool'
      value = @binary_file.read(length).unpack("b8").last.to_s
    #Process that one wierd boolean that is actually an int, instead of a bit
    when 'boolint'
      value = @binary_file.read(length).unpack("U").first.to_i
      #Change the values of the field to Y/N for the varchar(1) representation of BOOLEAN
      if value == 1
        value = 'Y'
      else
        value = 'N'
      end
    end
    return value
  end
  
  #Mehtod that performs the conversions
  def convert_binary_file filename
    #Open the file to process
    echi_file = $workingdir + "/../files/to_process/" + filename
    @binary_file = open(echi_file,"rb")
    @log.debug "File size: " + @binary_file.stat.size.to_s
    
    #Read header information first
    filenumber = dump_binary 'int', 4
    @log.debug "File_number " + filenumber.to_s
    fileversion = dump_binary 'int', 4
    @log.debug "Version " + fileversion.to_s

    if $config["echi_process_log"] == "Y"
      #Log the file
      echi_log = EchiLog.new
      echi_log.filename = filename
      echi_log.filenumber = filenumber
      echi_log.version = fileversion
    end
    
    #Perform a transaction for each file, including the log table
    #in order to commit as one atomic action upon success
    EchiRecord.transaction do
      bool_cnt = 0
      @record_cnt = 0
      while @binary_file.eof == FALSE do 
        @log.debug '<====================START RECORD ' + @record_cnt.to_s + ' ====================>'
        echi_record = EchiRecord.new
        @echi_schema["fields"].each do | field |
          #We handle the 'boolean' fields differently, as they are all encoded as bits in a single 8-bit byte
          if field["type"] == 'bool'
            if bool_cnt == 0
              bytearray = dump_binary field["type"], field["length"]
            end
            #Ensure we parse the bytearray and set the appropriate flags
            #We need to make sure the entire array is not nil, in order to do Y/N
            #if Nil we then set all no
            if bytearray != nil
              if bytearray.slice(bool_cnt,1) == 1
                value = 'Y'
              else
                value = 'N'
              end
            else 
              value = 'N'
            end
            bool_cnt += 1
            if bool_cnt == 8
              bool_cnt = 0
            end
          else
            #Process 'standard' fields
            value = dump_binary field["type"], field["length"]
            @log.debug field["name"] + " { type => #{field["type"]} & length => #{field["length"]} } value => " + value.to_s
          end
          echi_record[field["name"]] = value
        end
        echi_record.save
      
        #Scan past the end of line record
        @binary_file.read(1)
        @log.debug '<====================STOP RECORD ' + @record_cnt.to_s + ' ====================>'
        @record_cnt += 1
      end
      @binary_file.close
    end
    
    #Move the file to the processed directory
    FileUtils.mv(echi_file, @processeddirectory)
    
    if $config["echi_process_log"] == "Y"
      #Finish logging the details on the file
      echi_log.records = @record_cnt
      echi_log.processed_at = Time.now
      echi_log.save
    end
    
    return @record_cnt
  end
  
  def connect_ftpsession
    #Open ftp connection
    begin
      if $config["echi_connect_type"] == 'ftp'
        ftp_session = Net::FTP.new($config["echi_host"])
        ftp_session.login $config["echi_username"], $config["echi_password"]
        @log.info "Successfully connected to the ECHI FTP server"
      else
        #Stub for possible SSH support in the future
        #session = Net::SSH.start(config["echi_host"], config["echi_port"], config["echi_username"], config["echi_password"])
        @log.fatal "SSH currently not supported, please use FTP for accessing the ECHI server"
        exit
      end
    rescue => err
      @log.fatal "Could not connect with the FTP server - " + err
      send_email_alert "FTP"
      return -1
    end
    return ftp_session
  end
  
  #Connect to the ftp server and fetch the files each time
  def fetch_ftp_files
   attempts = 0
   ftp_session = -1
   while ftp_session == -1 do
     ftp_session = connect_ftpsession
     if ftp_session == -1
       sleep 5
     end
     attempts += 1
     if $config["echi_ftp_retry"] == attempts
       ftp_session = 0
     end
   end
   if ftp_session != 0
     begin
       if $config["echi_ftp_directory"] != nil
         ftp_session.chdir($config["echi_ftp_directory"])
       end
       files = ftp_session.list('chr*')
       
       #Also fetch the agname.dat file if it is configured to be processed
       if $config["echi_update_agent_data"] == "Y"
         files = files + ftp_session.list("agname.dat")
       end
       
       file_cnt = 0
       files.each do | file |
         file_data = file.split(' ')
         
         local_filename = $workingdir + '/../files/to_process/' + file_data[8]
         ftp_session.getbinaryfile(file_data[8], local_filename)
         if $config["echi_ftp_delete"] == 'Y'
           begin
             ftp_session.delete(remote_filename)
           rescue => err
             @log.fatal err
           end
         end
         file_cnt += 1
       end
       ftp_session.close
    rescue => err
      @log.fatal "Could not fetch from ftp server - " + err
    end
   end
   return 
  end

  def process_ascii filename
    echi_file = $workingdir + "/../files/to_process/" + filename
  
    if $config["echi_process_log"] == "Y"
      #Log the file
      echi_log = EchiLog.new
      echi_log.filename = filename
      #echi_log.filenumber = filenumber
      #echi_log.version = fileversion
    end
  
    #Perform a transaction for each file, including the log table
    #in order to commit as one atomic action upon success
    EchiRecord.transaction do
      @record_cnt = 0
      FasterCSV.foreach(echi_file) do |row|
        if row != nil
          @log.debug '<====================START RECORD ' + @record_cnt.to_s + ' ====================>'
          echi_record = EchiRecord.new
          cnt = 0
          @echi_schema["fields"].each do | field |
            if field["type"] == "bool" || field["type"] == "bool_int"
              case row[cnt]
              when "0"
                echi_record[field["name"]] = "N"
              when "1"
                echi_record[field["name"]] = "Y"
              end
              @log.debug field["name"] + ' == ' + row[cnt]
            else
              echi_record[field["name"]] = row[cnt]
              if row[cnt] != nil
                @log.debug field["name"] + ' == ' + row[cnt]
              end
            end
            cnt += 1
          end
          echi_record.save
          @log.debug '<====================STOP RECORD ' + @record_cnt.to_s + ' ====================>'
          @record_cnt += 1
        end
      end
    end
  
    #Move the file to the processed directory
    FileUtils.mv(echi_file, @processeddirectory)
  
    if $config["echi_process_log"] == "Y"
      #Finish logging the details on the file
      echi_log.records = @record_cnt
      echi_log.processed_at = Time.now
      echi_log.save
    end
  
    return @record_cnt
  end

  def insert_agent_data field
 
    begin
      echi_agent = EchiAgent.new
      echi_agent.group_id = field[0]
      echi_agent.login_id = field[1]
      echi_agent.name = field[2]
      echi_agent.save
    rescue => err
      @log.info "Unable to insert agent record - " + err
    end
 
  end
  
  #Method to insert data into 'echi_agents' based on agname.dat
  def process_agent_data
    agent_file = $workingdir + "/../files/to_process/agname.dat"
        
      if File.exists?(agent_file)
        EchiAgent.transaction do
          @record_cnt = 0
          File.open(agent_file).each do |row|
            if row != nil
              field = row.rstrip.split('|')
              @log.debug '<====================START AGENT RECORD ' + @record_cnt.to_s + ' ====================>'
              agent = EchiAgent.find(:first, :conditions => [ "login_id = ? AND group_id = ?", field[1], field[0]])
              if agent != nil
                if agent.name != field[2]
                  agent.name = field[2]
                  agent.update
                  @record_cnt += 1
                  @log.debug "Updated record - " + field.inspect
                else
                  @log.debug "No update required for - " + field.inspect
                end
              else
                insert_agent_data field
                @record_cnt += 1
                @log.debug "Inserted new record - " + field.inspect
              end
            end
            @log.debug '<====================STOP AGENT RECORD ' + @record_cnt.to_s + ' ====================>'
          end
        end
        @agent_file_processed = Time.now
        #Move the file to the processed directory
        begin
          agname_new_filename = "agname_" + UUID.timestamp_create.to_s + ".dat"
          target_file = @processeddirectory + "/" + agname_new_filename
          FileUtils.mv(agent_file, target_file)
        rescue => err
          @log.info "Issue with agname_*.dat filename - " + err
        end
        if $config["echi_process_log"] == "Y"
          #Log the file
          echi_log = EchiLog.new
          echi_log.filename = agname_new_filename
          #echi_log.filenumber = filenumber
          #echi_log.version = fileversion
          #Finish logging the details on the file
          echi_log.records = @record_cnt
          echi_log.processed_at = Time.now
          echi_log.save
        end
      end
    end

  require $workingdir + '/echi-converter/version.rb'
end