# -*- coding: utf-8 -*-
# vim: set noet ts=4:
#
# scim-python
#
# Copyright (c) 2007-2008 Huang Peng <shawn.p.huang@gmail.com>
#
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330,
# Boston, MA  02111-1307  USA
#
# $Id: $
#
import os
import os.path as path
import time
import sys
import sqlite3 as sqlite
import re
import uuid
import traceback
import PYUtil
import PYDict
import PYParser

(YLEN, Y0, Y1, Y2, Y3, YX, S0, S1, S2, S3, PHRASE, FREQ, USER_FREQ) = range (0, 13)

FLUSH_PERIOD = 60 * 5 # 5 minute

class PYSQLiteDB:
	"""phrase database that contains all phrases and phrases' pinyin"""
	def __init__ (self, name = "py.db", user_db = None, filename = None):
	
		# init last flush time
		self._last_flush_time = None
	
		if filename:
			self.db = sqlite.connect (filename)
			self.parser = PYParser.PinYinParser ()
			return

		name = os.path.join (os.path.dirname (__file__), name)

		# open system phrase database
		self.db = sqlite.connect (name)

		self.parser = PYParser.PinYinParser ()
		# self.db.execute ("PRAGMA locking_mode = EXCLUSIVE;")
		self.db.execute ("PRAGMA synchronous = NORMAL;")
		self.db.execute ("PRAGMA temp_store = MEMORY;")
		
		if user_db != None:
			home_path = os.getenv ("HOME")
			pinyin_path = path.join (home_path, ".scim", "scim-python", "pinyin")
			user_db = path.join (pinyin_path, user_db)
			if not path.isdir (pinyin_path):
				os.makedirs (pinyin_path)

			try:
				desc = get_database_desc (user_db)
				if desc == None or desc["id"] != "0.1":
					new_name = "%s.%d" %(user_db, os.getpid())
					print >> sys.stderr, "Can not support the user db. We will rename it to %s" % new_name
					os.rename (user_db, new_name)
			except:
				pass
		else:
			user_db = ":memory:"
		
		
		# open user phrase database
		try:
			self.db.execute ("ATTACH DATABASE \"%s\" AS user_db;" % user_db)
		except:
			print >> sys.stderr, "The user database was damaged. We will recreate it!"
			os.rename (user_db, "%s.%d" % (user_db, os.getpid ()))
			self.db.execute ("ATTACH DATABASE \"%s\" AS user_db;" % user_db)

		
		# try create all tables in user database
		self.create_tables ("user_db")
		self.create_indexes ("user_db")
		self.generate_userdb_desc ()

		self.select_cache = Cache ()

	def create_tables (self, database = "main"):
		"""create all phrases tables that contain all phrases"""
		
		try:
			self.db.executescript ("PRAGMA default_cache_size = 5000;")
			self.flush (True)
		except:
			pass

		# create pinyin table
		sqlstring = "CREATE TABLE IF NOT EXISTS %s.py_pinyin (pinyin TEXT PREMARY KEY);" % database
		self.db.execute (sqlstring)
		
		# create pinyin table
		sqlstring = "CREATE TABLE IF NOT EXISTS %s.py_shengmu (shengmu TEXT PREMARY KEY);" % database
		self.db.execute (sqlstring)

		# create phrase table
		sqlstring = """CREATE TABLE IF NOT EXISTS %(database)s.py_phrase (
							ylen INTEGER, 
							y0 INTEGER, y1 INTEGER, y2 INTEGER, y3 INTEGER, yx TEXT,
							s0 INTEGER, s1 INTEGER, s2 INTEGER, s3 INTEGER,
							phrase TEXT,
							freq INTEGER, user_freq INTEGER);"""
		
		self.db.executescript (sqlstring % { "database":database })
		self.flush (True)

	def generate_userdb_desc (self):
		try:
			sqlstring = "CREATE TABLE user_db.desc (name PRIMARY KEY, value);"
			self.db.executescript (sqlstring)
			sqlstring = "INSERT INTO user_db.desc  VALUES (?, ?);"
			self.db.execute (sqlstring, ("version", "0.1"))
			self.db.execute (sqlstring, ("id", str (uuid.uuid4 ())))
			sqlstring = "INSERT INTO user_db.desc  VALUES (?, DATETIME(\"now\", \"localtime\"));"
			self.db.execute (sqlstring, ("create-time", ))
			self.flush (True)
		except:
			print "desc table has been created."

	def create_indexes (self, database = "main"):
		# create indexes
		sqlstring = """
				CREATE INDEX IF NOT EXISTS %(database)s.py_phrase_index_1 ON
					py_phrase (y0, y1, y2, y3);
				CREATE INDEX IF NOT EXISTS %(database)s.py_phrase_index_2 ON
					py_phrase (ylen, y0, y1, y2, y3);
				CREATE INDEX IF NOT EXISTS %(database)s.py_phrase_index_3 ON
					py_phrase (ylen, s0, s1, s2, s3);
				CREATE INDEX IF NOT EXISTS %(database)s.py_phrase_index_4 ON
					py_phrase (s0, s1, s2, s2, s3);
				CREATE INDEX IF NOT EXISTS %(database)s.py_phrase_index_5 ON
					py_phrase (phrase);
				"""
		self.db.executescript (sqlstring % { "database" : database })
		self.flush (True)

	def optimize_database (self):
		sqlstring = """
				CREATE TABLE tmp AS SELECT * FROM py_phrase;
				DELETE FROM py_phrase;
				INSERT INTO py_phrase SELECT * FROM tmp ORDER BY ylen, y0, y1, y2, y3, yx, phrase;
				DROP TABLE tmp;
				"""
		self.db.executescript (sqlstring)
		self.db.executescript ("VACUUM;")

	def init_pinyin_table (self):
		"""create table pinyin that contains all pinyin"""
		sqlstring = "INSERT INTO py_pinyin (pinyin) VALUES (?)"
		for py in PYDict.PINYIN_DICT.keys ():
			self.db.execute (sqlstring, (unicode (py),))
		self.flush (True)
	
	def init_shengmu_table (self):
		"""create table shengmu that contains all shengmu of pinyin"""
		sqlstring = "INSERT INTO py_shengmu (shengmu) VALUES (?)"
		for shengmu in PYDict.SHENGMU_DICT.keys ():
			self.db.execute (sqlstring, (unicode (shengmu),))
		self.flush (True)

	def add_phrases (self, phrases, database = "main"):
		""" add phrases to database, phrases is a iterable object
		Like: [(phrase, pinyin, freq), (phrase, pinyin, freq), ...]
		"""
		sqlstring = """INSERT INTO %s.py_phrase (ylen, y0, y1, y2, y3, yx, s0, s1, s2, s3, phrase, freq, user_freq)
			VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"""
		line = 1
		for  phrase, pinyin, freq in phrases:
			try:
				py = self.parser.parse (pinyin)
				if len (py) != len (phrase):
					error_message = u"%s %s: Can not parse pinyin." % (phrase, pinyin)
					raise Exception (error_message.encode ("utf8"))
				record = [None, None, None, None, None, None, None, None, None, None, None, None, None]
				record [YLEN] = len (py)
				i = 0
				for p in py[:4]:
					record[Y0 + i] = p.get_pinyin_id ()
					record[S0 + i] = p.get_sheng_mu_id ()
					i += 1
				if len (py) > 4:
					record[YX] = "'".join (map (str, py[4:]))
				record[PHRASE] = phrase
				record[FREQ] = freq
				record[USER_FREQ] = None
				self.db.execute (sqlstring % database, record)
			except Exception, e:
				print line, ":", phrase.encode ("utf-8"), pinyin, freq
				import traceback
				traceback.print_exc ()
				# print e
			line += 1
			
		self.flush (True)

	def get_pinyin_table (self):
		"""get pinyin table"""
		try:
			return self._pinyin_table
		except:
			pass

		sql = "SELECT phrase, y0, s0 FROM py_phrase WHERE ylen = 1"
		
		pinyin_table = {}
		result = self.db.execute (sql % i)
		for phrase, y0, s0 in result:
			if phrase not in pinyin_table:
				pinyin_table [phrase] = []
			pinyin_table [phrase].append ((y0, s0))
		self._pinyin_table = pinyin_table
		
		return pinyin_table

	def select_words_by_pinyin_list (self, pys, mohu = False):
		"""select words from database by list that contains PYUtil.PinYinWord objects"""
		
		pinyin_string = u"'".join (map (str, pys))
		result = self.select_cache [pinyin_string]
		if result != None:
			return result
		
		tables_union = """( SELECT * FROM main.py_phrase WHERE %(conditions)s UNION ALL
		SELECT * FROM user_db.py_phrase WHERE %(conditions)s )"""
		
		if mohu:
			sql_conditions = ["+ylen = %d" % len (pys) ]
		else:
			sql_conditions = ["ylen = %d" % len (pys) ]
			

		i = 0
		if mohu == False:
			for py in pys[:4]:
				if py.is_valid_pinyin ():
					sql_conditions.append ("y%d = %d" % (i, py.get_pinyin_id ()))
				else:
					sql_conditions.append ("s%d = %d" % (i, py.get_sheng_mu_id ()))
				i += 1
		else:
			for py in pys[:4]:
				if py.is_valid_pinyin ():
					shengmu = py.get_shengmu ()
					yunmu = py.get_pinyin ()[len (shengmu):]
					if shengmu in PYDict.MOHU_SHENGMU:
						shengmu_list = PYDict.MOHU_SHENGMU[shengmu]
					else:
						shengmu_list = [shengmu]

					if yunmu in PYDict.MOHU_YUNMU:
						yunmu_list = PYDict.MOHU_YUNMU[yunmu]
					else:
						yunmu_list = [yunmu]
						
					pinyin_ids = []
					for s in shengmu_list:
						for y in yunmu_list:
							pinyin = s + y
							if pinyin in PYDict.PINYIN_DICT:
								pinyin_ids.append (str (PYDict.PINYIN_DICT[pinyin]))
					if len (pinyin_ids) > 1:
						sql_conditions.append ("y%d in (%s)" % (i, ",".join (pinyin_ids)))
					else:
						sql_conditions.append ("y%d == %s" % (i, pinyin_ids[0]))
						
				else:
					shengmu = py.get_shengmu ()
					if shengmu in PYDict.MOHU_SHENGMU:
						shengmu_ids = []
						for s in PYDict.MOHU_SHENGMU[shengmu]:
							shengmu_ids.append (str (PYDict.SHENGMU_DICT[s]))
						sql_conditions.append ("s%d in (%s)" % (i, ",".join (shengmu_ids)))
					else:
						sql_conditions.append ("s%d = %d" % (i, py.get_sheng_mu_id ()))
				i += 1
		
		if pys[4:]:
			pp = lambda (x): x.get_pattern (mohu)
			pattern = "'".join (map (pp, pys[4:]))
			sql_conditions.append ("yx LIKE \"" + pattern + "\"")
		

		tables_union = tables_union % { "conditions" : " AND ".join (sql_conditions) }
		sql_prefix = "SELECT * FROM " + tables_union

		sql_string = sql_prefix + " GROUP BY phrase ORDER BY user_freq DESC, freq DESC;"

		result = list (self.db.execute (sql_string).fetchall ())
		
		self.select_cache [pinyin_string] = result

		return result
	
	def select_words_by_pinyin_string (self, string, mohu = False):
		"""select words from the database by pinyin string"""

		pys = self.parser.parse (string)
		result = self.select_words_by_pinyin_list (pys, mohu)
		return result

	def commit_phrases (self, records):
		"""this function adjusts frequence of phrase in user database."""

		for record in records:
			if record [USER_FREQ] != None:
				sql = "UPDATE user_db.py_phrase SET user_freq = user_freq + 1 WHERE ylen = ? AND y0 = ? AND phrase = ?;"
				self.db.execute (sql, (record[YLEN], record[Y0], record[PHRASE]))
			else:
				sql = """INSERT INTO user_db.py_phrase (ylen, y0, y1, y2, y3, yx, s0, s1, s2, s3, phrase, freq, user_freq)
					VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 1);"""
				self.db.execute (sql, record[:12])
		self.flush ()
		self.select_cache.clear ()

	def commit_phrase (self, record):
		self.commit_phrases ([record])

	def commit_char (self, char, pinyin_id, shengmu_id):
		sql = "SELECT * FROM main.py_phrase WHERE ylen = 1 AND y0 = ? AND phrase = ?"
		records = self.db.execute (sql, (pinyin_id, char)).fetchall ()
		self.commit_phrases (records)

	def new_phrase (self, phrases, freq = None, user_freq = 1):
		"""this function create a new phrase from a phrase list and put it into user database."""
		pinyin_ids = []
		shengmu_ids = []
		phrase = u""
		phrase_length = 0
		for p in phrases:
			if phrase_length + p[YLEN] > 8:
				break
			phrase += p[PHRASE]
			phrase_length += p[YLEN]
			if p[YLEN] > 4:
				ys = p[YX].split ("'")
			for i in range (0, p[YLEN]):
				if i < 4:
					pinyin_ids.append (p[Y0 + i])
					shengmu_ids.append (p[S0 + i])
				else:
					w = PYUtil.PinYinWord (ys[i - 4])
					pinyin_ids.append (w.get_pinyin_id ())
					shengmu_ids.append (w.get_sheng_mu_id ())
		
		sql = """INSERT INTO user_db.py_phrase
			(ylen, y0, y1, y2, y3, yx, s0, s1, s2, s3, phrase, freq, user_freq) 
			VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"""

		values = [phrase_length, None, None, None, None, None, None, None, None, None, phrase, freq, user_freq]

		if phrase_length <=4:
			values[1: 1 + phrase_length] = pinyin_ids [:phrase_length]
			values[6: 6 + phrase_length] = shengmu_ids [:phrase_length]
		else:
			values[1: 5] = pinyin_ids [:4]
			values[6: 10] = shengmu_ids [:4]
			get_pinyin = lambda id: PYDict.ID_PINYIN_DICT[id]
			values[5] = "'".join (map (get_pinyin, pinyin_ids[4:]))

		self.db.execute (sql, values)

		self.flush ()
		self.select_cache.clear ()

	def remove_phrase (self, record):
		"Remove phrase from user database"

		sql = "DELETE FROM user_db.py_phrase WHERE ylen = ? AND y0 = ? AND phrase = ?"

		self.db.execute (sql, (record[YLEN], record[Y0], record[PHRASE]))
		
		self.flush ()
		self.select_cache.clear ()

	def flush (self, force = False):
		if self._last_flush_time == None:
			self._last_flush_time = time.time ()
		if force or time.time() - self._last_flush_time >= FLUSH_PERIOD:
			self.db.commit ()
			self._last_flush_time = time.time ()

	
class Cache:
	"""cache object for cache history queries"""

	class Slot:
		"""Slot item of cache object"""
		def __init__ (self):
			self.time = -1
			self.value = None
			self.index = None
	
	def __init__ (self, max_slot = 1024):
		self._max_slot = max_slot
		self.clear ()

	def clear (self):
		self._slots = []
		self._dict = {}
		self._time = 0

	def __delitem__ (self, index):
		if not self._dict.has_key (index):
			return None
		del self._dict [index]

	def __getitem__ (self, index):
		"""return a vale associate with the giving index. It cache does not has this index,
		it will retrun None."""
		if not self._dict.has_key (index):
			return None
		
		slot = self._dict [index]
		self._time += 1
		slot.time = self._time
		return slot.value

	def __setitem__ (self, index, value):
		if self._dict.has_key (index):
			slot = self._dict[index]
		else:
			slot = self.get_slot ()
		self._time += 1
		slot.value = value
		slot.time = self._time
		slot.index = index
		self._dict[index] = slot

	def get_slot (self):
		"""get_slot will return a empty slot. If there is not any empty slot, 
		it will find the oldest slot and return it."""
		if len (self._slots) < self._max_slot:
			slot = Cache.Slot ()
			self._slots.append (slot)
		else:
			self._slots.sort (lambda x,y : x.time - y.time)		
			slot = self._slots[0]
			del self._dict[slot.index]
		return slot

def get_database_desc (db_file):
	if not path.exists (db_file):
		raise Exception ("%s does not exist!" % dbname)
	try:
		desc = {}
		db = sqlite.connect (db_file)
		for row in db.executescript ("SELECT * FROM desc;"):
			desc [row[0]] = row[1]
		return desc
	except:
		return None

def test_select_words ():
	import time

	db = PYSQLiteDB ()
	while True:
		l = raw_input ().strip ()
		if not l:
			break
		t = time.time ()
		res = db.select_words_by_pinyin_string (l)
		
		t = time.time () - t
		
		i = 0
		for p in res:
			print "%s = %s %s " % (i, str (p), p[PHRASE].encode ("utf8"))
			i += 1
		print "OK t =", t, " count =", len (res)
		while True:
			try:
				commit = int (raw_input ("commit = ").strip ())
				db.commit_phrase (res[commit])
			except KeyboardInterrupt, e:
				print "Exit"
				sys.exit (0)
			except:
				print "Input is invalidate"
				continue
			break

	

def test_case (string):
	db = PYSQLiteDB ()
	parser = PYParser.PinYinParser ()
	pys = parser.parse (string)

	result = u""

	while len (result) != len (pys):
		pps = pys[len (result):]
		for x in range (len (pps), 0, -1):
			candidates = db.select_words_by_pinyin_list (pps[:x])
			if candidates:
				result += candidates[0][PHRASE]
				break
	print "'".join (map (str, pys))
	print result

def test ():
	test_case ("gaodangfangdichankaifashangdedongtianjiuyaolaile")
	test_case ("huanyingshiyongwokaifadezhinengpinyinshurufa")
	test_case ("beijingshirenminzhengfujuedingzaitongzhouqujianlizhengfuxingzhengjidi")
	test_case ("woguojuminshoumingqiwangtigaodaoqishisansui")
	test_case ("wgjmshmqwtgdqshss")
	test_case ("xjinyhuiyouyongme")
	
if __name__ == "__main__":
	import timeit
	t = timeit.Timer ("PYSQLiteDB.test ()","import PYSQLiteDB")
	print t.repeat (3,1)