import sqlite3
import os
from time import time, strftime

class Database:

  database_name = "collector.db"
  table_list = ["user", "computer", "system", "disk"]
  CREATE_USER_TABLE = "create table if not exists user " \
                        "(partition text, pid real, process text, " \
                        " cpu_percent real, cpu_time real, " \
                        " cpu_num_threads real,  memory_percent real, " \
                        " memory_rss real, io_rw_counter real, " \
                        " io_cycles_counter real, date text, time text, " \
                        " reported integer NULL DEFAULT 0)"

  CREATE_COMPUTER_TABLE = "create table if not exists computer "\
                          "(cpu_num_core real, cpu_frequency real, cpu_type text," \
                          " memory_size real, memory_type text, partition_list text," \
                          " date text, time text, reported integer NULL DEFAULT 0)"


  CREATE_SYSTEM_TABLE = "create table if not exists system " \
                        "(loadavg real, cpu_percent real, memory_used real, "\
                        " memory_free real, net_in_bytes real, net_in_errors real, "\
                        " net_in_dropped real, net_out_bytes real, net_out_errors real, "\
                        " net_out_dropped real, date text, time text, " \
                        " reported integer NULL DEFAULT 0)"

  CREATE_DISK_PARTITION = "create table if not exists disk "\
                          "(partition text, used text, free text, mountpoint text, " \
                          " date text, time text, reported integer NULL DEFAULT 0)" 


  INSERT_USER_TEMPLATE = "insert into user(" \
            "partition, pid, process, cpu_percent, cpu_time, " \
             "cpu_num_threads, memory_percent," \
             "memory_rss, io_rw_counter, io_cycles_counter, " \
             "date, time) values " \
             "('%s', %s, '%s', %s, %s, %s, %s, %s, %s, %s, '%s', '%s' )" 



  INSERT_COMPUTER_TEMPLATE = "insert into computer("\
            " cpu_num_core, cpu_frequency, cpu_type," \
            "memory_size, memory_type, partition_list," \
            "date, time) values "\
            "(%s, %s, '%s', %s, '%s', '%s', '%s', '%s' )"

  INSERT_DISK_TEMPLATE = "insert into disk("\
            " partition, used, free, mountpoint," \
            " date, time) "\
            "values ('%s', %s,  %s, '%s', '%s', '%s' )"
    
  INSERT_SYSTEM_TEMPLATE = "insert into system("\
            " loadavg, cpu_percent, memory_used, memory_free," \
            " net_in_bytes, net_in_errors, net_in_dropped," \
            " net_out_bytes, net_out_errors, net_out_dropped, " \
            " date, time) values "\
            "( %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, '%s', '%s' )"

  def __init__(self, directory = None):
    assert self.database_name is not None
    self.uri = os.path.join(directory, self.database_name)
    self.connection = None
    self.cursor = None
    self._bootstrap()

  def connect(self):
    self.connection = sqlite3.connect(self.uri)
    self.cursor = self.connection.cursor()

  def commit(self):
    assert self.connection is not None
    self.connection.commit()

  def close(self):
    assert self.connection is not None
    self.cursor.close()
    self.connection.close()

  def _execute(self, sql):
    assert self.connection is not None
    return self.cursor.execute(sql)

  def _bootstrap(self):
    assert self.CREATE_USER_TABLE is not None
    self.connect()
    self._execute(self.CREATE_USER_TABLE)
    self._execute(self.CREATE_COMPUTER_TABLE)
    self._execute(self.CREATE_SYSTEM_TABLE)
    self._execute(self.CREATE_DISK_PARTITION)
    self.commit()
    self.close()

  def _getInsertionDateTuple(self):
    return strftime("%Y-%m-d -- %H:%M:%S").split(" -- ")

  ###################
  # Insertion methods
  ###################
  def insertUserSnapshot(self, partition, pid, process, cpu_percent, cpu_time, 
        cpu_num_threads, memory_percent, memory_rss, io_rw_counter, 
        io_cycles_counter, insertion_date, insertion_time):
    """ Insert user processes snapshots information on a database """
    insertion_sql = self.INSERT_USER_TEMPLATE % \
              ( partition, pid, process, cpu_percent, cpu_time,
                cpu_num_threads, memory_percent,
                memory_rss, io_rw_counter, io_cycles_counter,
                insertion_date, insertion_time)
    self._execute(insertion_sql)
    return insertion_sql

  def insertComputerSnapshot(self, cpu_num_core, cpu_frequency, cpu_type,
         memory_size, memory_type, partition_list, insertion_date, insertion_time):
    """Insert Computer general informations snapshots informations on 
       the database
    """
    insertion_sql = self.INSERT_COMPUTER_TEMPLATE % \
              ( cpu_num_core, cpu_frequency, cpu_type, 
                memory_size, memory_type, 
                partition_list, insertion_date, 
                insertion_time)
    self._execute(insertion_sql)  
    return insertion_sql

  def insertDiskPartitionSnapshot(self, partition, used, free, mountpoint,
                                        insertion_date, insertion_time):
    """ Insert Disk Partitions informations on the database """
    insertion_sql = self.INSERT_DISK_TEMPLATE % \
             ( partition, used, free, mountpoint, 
               insertion_date, insertion_time )
    self._execute(insertion_sql)  
    return insertion_sql
    
  def insertSystemSnapshot(self, loadavg, cpu_percent, memory_used, memory_free,
       net_in_bytes, net_in_errors, net_in_dropped, net_out_bytes, 
       net_out_errors, net_out_dropped, insertion_date, insertion_time):
    """ Include System general Snapshot on the database 
    """
    insertion_sql = self.INSERT_SYSTEM_TEMPLATE % \
             ( loadavg, cpu_percent, memory_used, memory_free,
               net_in_bytes, net_in_errors, net_in_dropped,
               net_out_bytes, net_out_errors, net_out_dropped,
               insertion_date, insertion_time )
    self._execute(insertion_sql)  
    return insertion_sql

  def getDataScopeList(self, ignore_date=None, reported=0):
    """ Get from the present unique dates from the system
        Use a smaller table to sabe time.
    """
    if ignore_date is not None:
      where_clause = " AND date != '%s'" % ignore_date
    else:
      where_clause = ""
    select_sql = "SELECT date, count(time) FROM system "\
                 " WHERE reported = %s %s GROUP BY date" % \
                                    (reported, where_clause)
    return self._execute(select_sql)

  def markDayAsReported(self, date_scope, table_list):
    """ Mark all registers from a certain date as reported """
    update_sql = "UPDATE %s SET reported = 1 " \
                 "WHERE date = '%s' AND reported = 0"
    for table in table_list:
      self._execute(update_sql % (table, date_scope))

  def select(self, table, date=None, columns="*"):
    """ Query database for a full table information """
    if date is not None:
      where_clause = " WHERE date = '%s' " % date
    else:
      where_clause = ""
    select_sql = "SELECT %s FROM %s %s " % (columns, table, where_clause)
    return self._execute(select_sql)


  #####################################################
  # Export Tables as Dict for handle realtime plotting
  #####################################################
  def exportSystemAsDict(self, date):
    """ Export system table as dictionally, formatting the output 
        for present it in a nicer presentation. 
    """  
    collected_entry_dict = {}

    collected_entry_dict["loadavg"] = []
    collected_entry_dict["cpu_percent"] = []
    collected_entry_dict["memory_used"] = []
    collected_entry_dict["memory_free"] = []
    collected_entry_dict["net_in_bytes"] = []
    collected_entry_dict["net_in_errors"] = []
    collected_entry_dict["net_in_dropped"] = []
    collected_entry_dict["net_out_bytes"] = []
    collected_entry_dict["net_out_errors"] = []
    collected_entry_dict["net_out_dropped"] = []

    first_entry = 1
    last_entry_in = 0
    last_entry_out = 0
    entry_list =  self._execute(
        "SELECT loadavg, cpu_percent, memory_used, memory_free," \
               " net_in_bytes, net_in_errors, net_in_dropped," \
               " net_out_bytes, net_out_errors, net_out_dropped, " \
               " date, time FROM system WHERE date = '%s'" % date) 

    for entry in entry_list:

      entry_time = "%s %s" % (entry[10], str(entry[11]))
      if not first_entry:
        _entry_in = entry[4] - last_entry_in
        last_entry_in = entry[4]
        entry_in = _entry_in

        _entry_out = entry[7] - last_entry_out
        last_entry_out = entry[7]
        entry_out = _entry_out
      
      else:
        first_entry = 0
        last_entry_in = entry[4]
        last_entry_out = entry[7]
        continue

      collected_entry_dict["loadavg"].append(
             {'entry': entry[0], 'time': entry_time })
      collected_entry_dict["cpu_percent"].append(
             {'entry': entry[1], 'time': entry_time })
      collected_entry_dict["memory_used"].append(
             {'entry': entry[2]/1024, 'time': entry_time })
      collected_entry_dict["memory_free"].append(
             {'entry': entry[3]/1024, 'time': entry_time })
      collected_entry_dict["net_in_bytes"].append(
             {'entry': entry_in/1024, 'time': entry_time })
      collected_entry_dict["net_in_errors"].append(
             {'entry': entry[5], 'time': entry_time })
      collected_entry_dict["net_in_dropped"].append(
             {'entry': entry[6], 'time': entry_time })
      collected_entry_dict["net_out_bytes"].append(
             {'entry': entry_out/1024, 'time': entry_time })
      collected_entry_dict["net_out_errors"].append(
             {'entry': entry[8], 'time': entry_time })
      collected_entry_dict["net_out_dropped"].append(
             {'entry': entry[9], 'time': entry_time })

    return collected_entry_dict

  def exportDiskAsDict(self, date):
    """ Export a column from a table for a given date.
    """
    collected_entry_dict = {}
    entry_list =  self._execute(
        "SELECT partition, used, free, date, time "\
        "from disk WHERE date = '%s'" % (date))

    for partition, used, free,  __date, __time in entry_list:
      partition_used = "%s-used" % partition
      partition_free = "%s-free" % partition
      if partition_used not in collected_entry_dict:
        collected_entry_dict[partition_used] = []

      if partition_free not in collected_entry_dict:
        collected_entry_dict[partition_free] = []

      collected_entry_dict[partition_used].append(
        {'entry': int(used)/1024, 
         'time': "%s %s" % (__date, str(__time))})

      collected_entry_dict[partition_free].append(
        {'entry': int(free)/1024, 
         'time': "%s %s" % (__date, str(__time))})

    return collected_entry_dict

