#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
SAT: a jabber client
Copyright (C) 2009, 2010, 2011  Jérôme Poisson (goffi@goffi.org)

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""


from logging import debug, info, warning, error
from twisted.enterprise import adbapi
from twisted.internet import defer
import os.path

class SqliteStorage():
    """This class manage storage with Sqlite database"""


    def __init__(self, db_filename):
        """Connect to the given database
        @param db_filename: full path to the Sqlite database"""
        self.initialized = defer.Deferred() #triggered when memory is fully initialised and ready
        init_defers = [] #list of deferred we have to wait to before initialisation is complete
        self.profiles={} #we keep cache for the profiles (key: profile name, value: profile id)

        info(_("Connecting database"))
        new_base = not os.path.exists(db_filename) #do we have to create the database ?
        self.dbpool = adbapi.ConnectionPool("sqlite3", db_filename, check_same_thread=False)
        init_defers.append(self.dbpool.runOperation("PRAGMA foreign_keys = ON").addErrback(lambda x: error(_("Can't activate foreign keys"))))
        if new_base:
            info(_("The database is new, creating the tables"))
            database_creation = [
            "CREATE TABLE profiles (id INTEGER PRIMARY KEY ASC, name TEXT, UNIQUE (name))",
            "CREATE TABLE historic (id INTEGER PRIMARY KEY ASC, profile_id INTEGER, source TEXT, dest TEXT, source_res TEXT, dest_res TEXT, timestamp DATETIME, message TEXT, FOREIGN KEY(profile_id) REFERENCES profiles(id))",
            "CREATE TABLE param_gen (category TEXT, name TEXT, value TEXT, PRIMARY KEY (category,name))",
            "CREATE TABLE param_ind (category TEXT, name TEXT, profile_id INTEGER, value TEXT, PRIMARY KEY (category,name,profile_id), FOREIGN KEY(profile_id) REFERENCES profiles(id))"]
            for op in database_creation:
                d = self.dbpool.runOperation(op)
                d.addErrback(lambda x: error(_("Error while creating tables in database [QUERY: %s]") % op ))
                init_defers.append(d)

        def fillProfileCache(ignore):
            d = self.dbpool.runQuery("SELECT name,id FROM profiles").addCallback(self._profilesCache)
            d.chainDeferred(self.initialized)
            
        defer.DeferredList(init_defers).addCallback(fillProfileCache)

    #Profiles
    def _profilesCache(self, profiles_result):
        """Fill the profiles cache
        @param profiles_result: result of the sql profiles query"""
        for profile in profiles_result:
            name, id = profile
            self.profiles[name] = id 
   
    def getProfilesList(self):
        """"Return list of all registered profiles"""
        return self.profiles.keys()

    def hasProfile(self, profile_name):
        """return True if profile_name exists
        @param profile_name: name of the profile to check"""
        return self.profiles.has_key(profile_name)
    
    def createProfile(self, name):
        """Create a new profile
        @param name: name of the profile
        @return: deferred triggered once profile is actually created"""
        def getProfileId(ignore):
            return self.dbpool.runQuery("SELECT (id) FROM profiles WHERE name = ?", (name,))
       
        def profile_created(profile_id):
            _id = profile_id[0][0]
            self.profiles[name] = _id #we synchronise the cache
        
        d = self.dbpool.runQuery("INSERT INTO profiles(name) VALUES (?)", (name,))
        d.addCallback(getProfileId)
        d.addCallback(profile_created)
        d.addErrback(lambda ignore: error(_("Can't create profile %(name)s" % {"name":name})))
        return d

    #Params
    def loadGenParams(self, params_gen):
        """Load general parameters
        @param params_gen: dictionary to fill
        @return: deferred"""
        def fillParams(result):
            for param in result:
                category,name,value = param
                params_gen[(category, name)] = value
        debug(_("loading general parameters from database")) 
        return self.dbpool.runQuery("SELECT category,name,value FROM param_gen").addCallback(fillParams)

    def loadIndParams(self, params_ind, profile):
        """Load general parameters
        @param params_ind: dictionary to fill
        @param profile: a profile which *must* exist
        @return: deferred"""
        def fillParams(result):
            for param in result:
                category,name,value = param
                params_ind[profile][(category, name)] = value
        debug(_("loading individual parameters from database")) 
        d = self.dbpool.runQuery("SELECT category,name,value FROM param_gen WHERE profile_id=?", self.profiles[profile])
        d.addCallback(fillParams)
        return d

    def getIndParam(self, category, name, profile):
        """Ask database for the value of one specific individual parameter
        @param category: category of the parameter
        @param name: name of the parameter
        @param profile: %(doc_profile)s
        @return: deferred"""
        d = self.dbpool.runQuery("SELECT value FROM param_ind WHERE category=? AND name=? AND profile_id=?", (category,name,self.profiles[profile]))
        d.addCallback(self.__getFirstResult)
        return d


    def setGenParam(self, category, name, value):
        """Save the general parameters in database
        @param category: category of the parameter
        @param name: name of the parameter
        @param value: value to set
        @return: deferred"""
        d = self.dbpool.runQuery("REPLACE INTO param_gen(category,name,value) VALUES (?,?,?)", (category, name, value))
        d.addErrback(lambda ignore: error(_("Can't set general parameter (%(category)s/%(name)s) in database" % {"category":category, "name":name})))
        return d

    def setIndParam(self, category, name, value, profile):
        """Save the general parameters in database
        @param category: category of the parameter
        @param name: name of the parameter
        @param value: value to set
        @param profile: a profile which *must* exist
        @return: deferred"""
        d = self.dbpool.runQuery("REPLACE INTO param_ind(category,name,profile_id,value) VALUES (?,?,?,?)", (category, name, self.profiles[profile], value))
        d.addErrback(lambda ignore: error(_("Can't set individual parameter (%(category)s/%(name)s) for [%(profile)s] in database" % {"category":category, "name":name, "profile":profile})))
        return d

    ##Helper methods##

    def __getFirstResult(self, result):
        """Return the first result of a database query
        Useful when we are looking for one specific value"""
        return "" if not result else result[0][0]