import os
import sys
import tempfile
import shutil
import subprocess
import time
import hashlib
import struct

import utils
from conf import conf
from conf import sf
import exceptions
import database

def __buildtempcnf__(variable_count, files, strlines):
	""" Builds temporally file for cnf formulas
	  variable_count - number of variables in formulas
	  files          - list of files with formulas
	  strlines       - list of string lines with formulas"""
	lines = set()
	# Copy strlines
	for ln in strlines:
		lines.add(ln)
	# Files
	for file in files:
		with open(file, 'r') as f:
			for ln in f:
				lines.add(ln.rstrip())

	first_line = "p cnf " + str(variable_count) + " " + str(len(lines))

	wfile = tempfile.NamedTemporaryFile(delete=False)
	wfile.write(bytes(first_line + '\n', 'UTF-8'))
	for ln in lines:
		wfile.write(bytes(ln + ' 0\n', 'UTF-8'))
	wfile.close()
	return wfile.name

def __exec_sat__(file, args, conf_num):
	"""Executes SAT solver and returns configuration."""
	picosat_cmd = [sf(conf.picosat), file]
	picosat_cmd += conf.picosat_args
	picosat_cmd += args
	stdout = utils.callsubprocess('picosat', picosat_cmd, conf.picosat_output,
			True, allow_all_exit_codes = True)

	rtn = []
	solut = []
	for line in stdout:
		if line[0] == 's':
			try:
				solut.remove(0)
				rtn.append(solut)
			except ValueError:
				pass
			solut = []
			if not line.rstrip() == 's SATISFIABLE':
				raise exceptions.NoSolution()
		elif line[0] == 'v':
			for sl in line[2:].split():
				solut.append(int(sl))
	try:
		solut.remove(0)
		rtn.append(solut)
	except ValueError:
		pass
	# Ensure smap existence
	utils.build_symbol_map()
	# Translate to dict
	con = list()
	for rt in rtn:
		cond = dict()
		for r in rt:
			if r < 0:
				val = False
				r *= -1
			else:
				val = True
			if r > int(conf_num):
				break;
			if 'NONAMEGEN' in utils.smap[r]: # ignore generated names
				continue
			cond[utils.smap[r]] = val
		con.append(cond)
	return con

def __txt_config__(con):
	config = []
	for key, val in con.items():
		txt = 'CONFIG_' + key + '='
		if val:
			txt += 'y'
		else:
			txt += 'n'
		config.append(txt)
	return config

def __write_temp_config_file__(con):
	wfile = tempfile.NamedTemporaryFile(delete=False)
	txt = __txt_config__(con)
	for ln in txt:
		wfile.write(bytes(ln + '\n', sys.getdefaultencoding()))
	wfile.close()
	return wfile.name

def __load_config_text__(txt):
	rtn = dict()
	for ln in txt:
		if not ln:
			continue
		if ln[0] == '#' or not '=' in ln:
			continue
		indx = ln.index('=')
		if (ln[indx + 1] == 'y'):
			rtn[ln[7:indx]] = True
		else:
			rtn[ln[7:indx]] = False
	return rtn


def __load_config_file__(file):
	f = open(file, 'r')
	rtn = __load_config_text__(f)
	f.close()
	return rtn

def __calchash__(con):
	dt = database.database()
	csort = dt.get_configsort()

	cstr = ""
	for c in csort:
		try:
			if con[c]:
				cstr += c
		except KeyError:
			pass

	# Add missing
	for key, val in con.items():
		try:
			csort.index(key)
		except ValueError:
			indx = len(csort)
			csort.append(key)
			dt.add_configsort(key)
			if val:
				cstr += key

	hsh = hashlib.md5(bytes(cstr, 'UTF-8'))
	return hsh.hexdigest()


def __calchash_file__(file):
	"""Calculates hash from configuration file"""
	con = __load_config_file__(file)
	return __calchash__(con)

def __register_conf__(con, conf_num, generator):
	dtb = database.database()
	# Solution to configuration
	txtconfig = __txt_config__(con)
	hsh = __calchash__(con)
	cconf = dtb.get_configration(hsh)
	for cc in cconf:
		print('hash: ' + hsh)
		if compare_text(cc.config, txtconfig):
			print("I: Generated existing configuration.")
			return False
		else:
			print("W: Generated configuration with collision hash.")
			# TODO this might have to be tweaked
			raise Exception()
	dtb.add_configuration(hsh, txtconfig, generator)
	return True

def __generate_single__(var_num, conf_num):
	measure_list = set()
	if not os.path.isfile(sf(conf.single_generated_file)):
		with open(sf(conf.measure_file), 'r') as fi:
			for ln in fi:
				measure_list.add(int(ln))
	else:
		with open(sf(conf.single_generated_file), 'r') as f:
			for ln in f:
				measure_list.add(int(ln))
	if not measure_list:
		return False
	tfile = __buildtempcnf__(var_num, (sf(conf.rules_file),
		sf(conf.fixed_file)), [str(measure_list.pop())])
	with open(sf(conf.single_generated_file), 'w') as fo:
		for ln in measure_list:
			fo.write(str(ln) + '\n')
	try:
		confs = __exec_sat__(tfile, ['-i', '0'], conf_num)
		for con in confs:
			if not __register_conf__(con, conf_num, 'single-sat'):
				return __generate_single__(var_num, conf_num)
	except exceptions.NoSolution:
		return __generate_single__(var_num, conf_num)
	finally:
		os.remove(tfile)
	return True

def __generate_random__(var_num, conf_num):
	tfile = __buildtempcnf__(var_num, (sf(conf.rules_file), sf(conf.fixed_file)), set())
	try:
		while True:
			seed = struct.unpack('<L', os.urandom(4))[0]
			confs = __exec_sat__(tfile, ['-i', '3', '-s', str(seed)], conf_num)
			for con in confs:
				if __register_conf__(con, conf_num, 'random-sat'):
					return True
	finally:
		os.remove(tfile)

def generate():
	"""Collect boolean equations from files rules and required
	And get solution with picosat
	"""
	# Check if rules_file exist. If it was generated.
	if not os.path.isfile(sf(conf.rules_file)):
		raise exceptions.MissingFile(conf.rules_file,"Run parse_kconfig.")
	if not os.path.isfile(sf(conf.fixed_file)):
		raise exceptions.MissingFile(conf.required_file,"Run allconfig and initialization process.")

	# Load variable count
	with open(sf(conf.variable_count_file)) as f:
		var_num = f.readline().rstrip()
		conf_num = f.readline().rstrip()

	if __generate_single__(var_num, conf_num):
		return
	elif __generate_random__(var_num, conf_num):
		return

	raise exceptions.NoNewConfiguration()

def compare(conf1, conf2):
	"""Compared two configuration"""
	# This is not exactly best comparison method
	for key, val in conf1.items():
		try:
			if conf2[key] != val:
				return False
		except ValueError:
			return False
	for key, val in conf2.items():
		try:
			if conf1[key] != val:
				return False
		except ValueError:
			return False
	return True

def compare_text(text1, text2):
	conf1 = __load_config_text__(text1)
	conf2 = __load_config_text__(text2)
	return compare(conf1, conf2)

def compare_file(file1, file2):
	conf1 = __load_config_file__(file1)
	conf2 = __load_config_file__(file2)
	return compare(conf1, conf2)