#
# 
#  [ md5_all, md5_list, file_name ]
# 
#
import os
import sys
import logging
import sqlite3 as sql
from libs.exceptions import FingerprintIndexWrite
from libs.exceptions import FingerprintIndexOpen
from libs.fingerprint import FingerprintDB

# prefixed with "_" so that it will be listed first and visible
INDEX_FILENAME = '_index_dpfp.db'


class FingerprintIndex:
  """
  Class handling an index of fingerprints for effeciently locating a fingerprint
  """

  #
  def __init__(self):
    self.db_conn = None
    self.cur = None
    return

  #
  def openIndex(self, fp_dir):
    fq_fpidx = fp_dir + os.path.sep + INDEX_FILENAME
    try:
      if (os.path.isfile(fq_fpidx)):
        self.db_conn = sql.connect(fq_fpidx)
        logging.info("DB Open SUCCESSFUL")
      else:
        logging.info("No index file found, creating index now...")
        self.createIndex(fp_dir)
    except:
      raise FingerprintIndexOpen("Error opening/creating an index file")
    finally:
      if self.db_conn:
        self.db_conn.close()
      self.db_conn = None

  #
  def createIndex(self, fp_dir):
    fq_fpidx = fp_dir + os.path.sep + INDEX_FILENAME
    try:
      self.db_conn = sql.connect(fq_fpidx)
      self.db_conn.execute('''
          CREATE TABLE md5_all (
          md5_db TEXT PRIMARY KEY,
          md5_list TEXT,
          fp_list TEXT,
          fp_count INTEGER);
        ''')
      self.db_conn.execute('''
          CREATE TABLE md5_tables (
          md5_table TEXT PRIMARY KEY,
          fp_list TEXT,
          fp_count INTEGER);
        ''')
      logging.info("Successfully created index table")      
      self.__populateIndex(fp_dir) 
      logging.info("Successfully populated the index")
    except Exception as e:
      raise FingerprintIndexWrite("Error creating an index file\n{}".format(e))
    finally:
      if self.db_conn:
        self.db_conn.close()
      self.db_conn = None

  #
  def __populateIndex(self, fp_dir):
    """ read each file, pull md5, add row to database """
    failCount = 0
    finCount = 0
    try:
      self.cur  = self.db_conn.cursor()
      db = FingerprintDB()
      files = os.listdir(fp_dir)
      for file in files:
        try:
          fq_file = fp_dir + os.path.sep + file
          db.importJson(fq_file)
          self.__insertMod_md5_all(db.db_hash, db.table_hashes.values(), file)
          self.__insertMod_md5_tables(db.table_hashes.values(), file)
          finCount = finCount+1
          if ((finCount % 5) == 0):
            self.db_conn.commit()
        except Exception as e:
          logging.error(e)
          failCount = failCount+1
    except:
      pass
    finally:
      self.db_conn.commit()
    logging.info("Completed populating the index. Completed: {}  Failed: {} ".format(str(finCount), str(failCount)))

  #
  def __insertMod_md5_all(self, md5_db, md5_list, filename):
    try:
      # logging.info("INSERT INTO md5_index VALUES(?, ?, ?): {}; {}; {}".format(md5_all, str(md5_list), filename))
      self.db_conn.execute(
        '''
        INSERT INTO md5_all VALUES(?, ?, ?, ?)
        ''', [md5_db, ','.join(md5_list), filename, 1])
    except sql.IntegrityError:
      try:
        (fp_list, fp_count) = self.__selectFileList(md5_db)
        fp_list += ","+filename
        fp_count += 1
        # logging.info("fp_list=={}".format(fp_list))
        self.db_conn.execute(
          '''
          UPDATE md5_all SET fp_list=?, fp_count=? WHERE md5_db=?
          ''', [fp_list, fp_count, md5_db])
      except Exception as e:
        raise FingerprintIndexWrite("Error updating a row\n{}".format(e))
    except Exception as e:
      raise FingerprintIndexWrite("Error inserting a row\n{}".format(e))

  #
  def __insertMod_md5_tables(self, md5_db, filename):
    # insert the md5 of the table schemas
    for md5_table in md5_db:
      try:
        self.db_conn.execute(
          '''
          INSERT INTO md5_tables VALUES(?, ?, ?)
          ''', [md5_table, filename, 1])
      except sql.IntegrityError:
        try:
          (fp_list, fp_count) = self.__selectFileList222(md5_table)
          fp_list += ","+filename
          fp_count += 1          
          self.db_conn.execute(
            '''
            UPDATE md5_tables SET fp_list=?, fp_count=? WHERE md5_table=?
            ''', [fp_list, fp_count, md5_table])
        except Exception as e:
          raise FingerprintIndexWrite("Error updating a row\n{}".format(e))
      except Exception as e:
        raise FingerprintIndexWrite("Error inserting a row\n{}".format(e))

  #
  def __selectFileList(self, md5_db):
    try:
      rows = self.cur.execute(
        '''
        SELECT fp_list, fp_count FROM md5_all WHERE md5_db=?
        ''', [md5_db])
      for row in rows:
        return (row[0], row[1])
    except:
      raise FingerprintIndexWrite("Error selecting fp_list\n{}".format(e))

  #
  def __selectFileList222(self, md5_table):
    try:
      rows = self.cur.execute(
        '''
        SELECT fp_list, fp_count FROM md5_tables WHERE md5_table=?
        ''', [md5_table])
      for row in rows:
        return (row[0], row[1])
    except:
      raise FingerprintIndexWrite("Error selecting fp_list\n{}".format(e))

  #
  def __checkIntegrity(self):
    """ Sanity check the number of files against the index rows """
    pass

  #
  def dirCompare(self, folder):
    pass


  def compareFingerprint(self, fp1, fp2):
    pass