from twisted.internet import reactor, defer
import time
from datetime import datetime
import Queue
import signal
import Cache

import lib.settings as settings

import lib.logger
log = lib.logger.get_logger('DBInterface')

class DBInterface():
    def __init__(self):
        self.dbi = self.connectDB()

    def init_main(self):
        self.dbi.check_tables()
 
        self.q = Queue.Queue()
        self.queueclock = None

        self.cache = Cache.Cache()

        self.nextStatsUpdate = 0

        self.scheduleImport()
        
        self.next_force_import_time = time.time() + settings.DB_LOADER_FORCE_TIME
    
        signal.signal(signal.SIGINT, self.signal_handler)

    def signal_handler(self, signal, frame):
        log.warning("SIGINT Detected, shutting down")
        self.do_import(self.dbi, True)
        reactor.stop()

    def set_bitcoinrpc(self, bitcoinrpc):
        self.bitcoinrpc = bitcoinrpc

    def connectDB(self):
        if settings.DATABASE_DRIVER == "sqlite":
            log.debug('DB_Sqlite INIT')
            import DB_Sqlite
            return DB_Sqlite.DB_Sqlite()
        elif settings.DATABASE_DRIVER == "mysql":
             if settings.VARIABLE_DIFF:
                log.debug("DB_Mysql_Vardiff INIT")
                import DB_Mysql_Vardiff
                return DB_Mysql_Vardiff.DB_Mysql_Vardiff()
             else:  
                log.debug('DB_Mysql INIT')
                import DB_Mysql
                return DB_Mysql.DB_Mysql()
        elif settings.DATABASE_DRIVER == "postgresql":
            log.debug('DB_Postgresql INIT')
            import DB_Postgresql
            return DB_Postgresql.DB_Postgresql()
        elif settings.DATABASE_DRIVER == "none":
            log.debug('DB_None INIT')
            import DB_None
            return DB_None.DB_None()
        else:
            log.error('Invalid DATABASE_DRIVER -- using NONE')
            log.debug('DB_None INIT')
            import DB_None
            return DB_None.DB_None()
	    

    def scheduleImport(self):
        # This schedule's the Import
        if settings.DATABASE_DRIVER == "sqlite":
        	use_thread = False
	else:   use_thread = True
        
        if use_thread:
            self.queueclock = reactor.callLater(settings.DB_LOADER_CHECKTIME , self.run_import_thread)
        else:
            self.queueclock = reactor.callLater(settings.DB_LOADER_CHECKTIME , self.run_import)
    
    def run_import_thread(self):
        log.debug("run_import_thread current size: %d", self.q.qsize())
        
        if self.q.qsize() >= settings.DB_LOADER_REC_MIN or time.time() >= self.next_force_import_time:  # Don't incur thread overhead if we're not going to run
            reactor.callInThread(self.import_thread)
                
        self.scheduleImport()

    def run_import(self):
        log.debug("DBInterface.run_import called")
        
        self.do_import(self.dbi, False)
        
        self.scheduleImport()

    def import_thread(self):
        # Here we are in the thread.
        dbi = self.connectDB()        
        self.do_import(dbi, False)
        
        dbi.close()

    def _update_pool_info(self, data):
        self.dbi.update_pool_info({ 'blocks' : data['blocks'], 'balance' : data['balance'],
            'connections' : data['connections'], 'difficulty' : data['difficulty'] })

    def do_import(self, dbi, force):
        log.debug("DBInterface.do_import called. force: %s, queue size: %s", 'yes' if force == True else 'no', self.q.qsize())
        
        # Flush the whole queue on force
        forcesize = 0
        if force == True:
            forcesize = self.q.qsize()

        # Only run if we have data
        while self.q.empty() == False and (force == True or self.q.qsize() >= settings.DB_LOADER_REC_MIN or time.time() >= self.next_force_import_time or forcesize > 0):
            self.next_force_import_time = time.time() + settings.DB_LOADER_FORCE_TIME
            
            force = False
            # Put together the data we want to import
            sqldata = []
            datacnt = 0
            
            while self.q.empty() == False and datacnt < settings.DB_LOADER_REC_MAX:
                datacnt += 1
                data = self.q.get()
                sqldata.append(data)
                self.q.task_done()

            forcesize -= datacnt
                
            # try to do the import, if we fail, log the error and put the data back in the queue
            try:
                log.info("Inserting %s Share Records", datacnt)
                dbi.import_shares(sqldata)
            except Exception as e:
                log.error("Insert Share Records Failed: %s", e.args[0])
                for k, v in enumerate(sqldata):
                    self.q.put(v)
                break  # Allows us to sleep a little

    def queue_share(self, data):
        self.q.put(data)

    def found_block(self, data):
        try:
            log.info("Updating Found Block Share Record")
            self.do_import(self.dbi, True)  # We can't Update if the record is not there.
            self.dbi.found_block(data)
        except Exception as e:
            log.error("Update Found Block Share Record Failed: %s", e.args[0])

    def check_password(self, username, password):
        if username == "":
            log.info("Rejected worker for blank username")
            return False
        
        # Force username and password to be strings
        username = str(username)
        password = str(password)
        if not settings.USERS_CHECK_PASSWORD and self.user_exists(username): 
            return True
        elif self.cache.get(username) == password:
            return True
        elif self.dbi.check_password(username, password):
            self.cache.set(username, password)
            return True
        elif settings.USERS_AUTOADD == True:
            self.insert_user(username, password)
            self.cache.set(username, password)
            return True
        
        log.info("Authentication for %s failed" % username)
        return False
    
    def list_users(self):
        return self.dbi.list_users()
    
    def get_user(self, id):
        return self.dbi.get_user(id)

    def user_exists(self, username):
    	if self.cache.get(username) is not None:
             return True
        user = self.dbi.get_user(username)
        return user is not None 

    def insert_user(self, username, password):        
        return self.dbi.insert_user(username, password)

    def delete_user(self, username):
    	self.mc.delete(username)
        self.usercache = {}
        return self.dbi.delete_user(username)
        
    def update_user(self, username, password):
        self.mc.delete(username)
        self.mc.set(username, password)
        return self.dbi.update_user(username, password)

    def update_worker_diff(self, username, diff):
        return self.dbi.update_worker_diff(username, diff)

    def get_pool_stats(self):
        return self.dbi.get_pool_stats()
    
    def get_workers_stats(self):
        return self.dbi.get_workers_stats()

    def clear_worker_diff(self):
        return self.dbi.clear_worker_diff()