#!/usr/bin/env python3
#########################
#
# timeTrack.py
# by 4nima
# v.2.1.2
#
#########################
# simple time tracking with database 
#########################

import datetime
import sqlite3
import json
import os
import logging

# Main class
class TimeTrack:
    def __init__(self, DATABASE='timetrack.db', CONFIG='timetrack.conf'):
        self.DATABASE   = DATABASE
        self.CONFIG     = CONFIG
        self.USERID     = 0
        self.USERNAME   = ''
        self.OLDEVENT   = 2
        self.LOGFILE    = 'timetrack.log'
        self.DBCON     =  sqlite3.connect(self.DATABASE, detect_types=sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES)
        logging.basicConfig(
            filename=self.LOGFILE,
            level=logging.DEBUG, 
            format='%(asctime)s - %(process)d-%(levelname)s: %(message)s',
            datefmt='%Y-%m-%d %H:%M:%S'
        )
        self.db_setup()
        self.load_config()

    def __del__(self):
        self.DBCON.close()
    
    ## Prepartation
    #==============
    ### Check OS and clear screen
    def clear_screen(self):
        if os.name == 'posix':
            logging.debug('Unix/Linux system detected')
            _ = os.system('clear')
        else:
            logging.debug('Winwos System detected')
            _ = os.system('cls')

    ### Loads or creates a config file
    def load_config(self):
        if os.path.isfile(self.CONFIG):
            logging.info('Config file was found')
            try:
                with open(self.CONFIG) as config_data:
                    data = json.load(config_data)
            except ValueError:
                logging.error('Config file has no valid JSON syntax')
                print('TimeTrack wird beendet: Fehler in der JSON-Konfig ({})'.format(self.CONFIG))
                quit()
            else:
                logging.info('Config file was loaded successfully')
                self.USERID = data['user']
                self.OLDEVENT = data['oldevent']
                logging.debug('UserID {} was used'.format(data['user']))
                self.set_user()

        else:
            logging.warning('Config file not found')
            config = {
                'default' : 'interactive',
                'user' : 1,
                'oldevent' : 2
            }
            with open(self.CONFIG, "w") as outfile:
                json.dump(config, outfile, indent=4, sort_keys=True)
                logging.info('Config file created successfully')

            #> wenn man keine datei erstellen darf/kann, fällt das skript in einen loop ?
            self.load_config()
            
    ### Creates a database if none is found
    def db_setup(self):
        if os.path.isfile(self.DATABASE):
            logging.info('Database file was found')
        else:
            logging.info('Database file was not found, will create ')
        
        sql = []
        sql.append("""
            CREATE TABLE IF NOT EXISTS time_entries (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                starttime TIMESTAMP NOT NULL,
                endtime TIMESTAMP NOT NULL,
                breaktime1 TIMESTAMP,
                user_id INTEGER NOT NULL,
                activity TEXT,
                reference TEXT,
                category_id INTEGER,
                client_id INTEGER,
                lock BOOLEAN
            )
        """)

        sql.append("""
            CREATE TABLE IF NOT EXISTS active_events (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                starttime TIMESTAMP NOT NULL,
                breaktime TIMESTAMP,
                user_id INT NOT NULL
            )
        """)

        sql.append("""
            CREATE TABLE IF NOT EXISTS users (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                name TEXT NOT NULL,
                worktime INT,
                worktime_span INT
            )
        """)

        sql.append("""
            CREATE TABLE IF NOT EXISTS clients (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                name TEXT NOT NULL
            )
        """)

        sql.append("""
            CREATE TABLE IF NOT EXISTS categories (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                name TEXT NOT NULL
            )
        """)

        logging.debug('Create initial database tables')
        try:
            with self.DBCON as con:
                for SQL in sql:
                    con.execute(SQL)
        except sqlite3.Error as err:
            logging.error('Table could not be created')
            logging.debug(sql)
            logging.error('SQLError: {}'.format(err))
            print('TimeTrack wird beendet: Fehler bei Datanbank Setup')
            quit()
        else:
            logging.debug('Table was created successfully or already exists')

    ### Get an active event based on a user or event ID
    def get_active_event(self, USERID='', EVENTID=''):
        if USERID:
            logging.debug('Search events based on userid: {}'.format(USERID))
            sql = "SELECT * FROM active_events WHERE user_id = ?"
            searchdata = [USERID]
        elif EVENTID:
            logging.debug('Search event based on eventid: {}'.format(EVENTID))
            sql = "SELECT * FROM active_events WHERE id = ?"
            searchdata = [EVENTID]
        else:
            sql = "SELECT * FROM active_events"
            searchdata = False
            
        try:
            with sqlite3.connect(self.DATABASE, detect_types=sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES) as con:
                cur = con.cursor()
                if searchdata:
                    logging.debug('Search event')
                    cur.execute(sql, searchdata)
                else:
                    logging.debug('Get all Events')
                    cur.execute(sql)
                eventdata = cur.fetchall()
        except sqlite3.Error as err:
            logging.debug(sql)
            logging.error('SQLError: {}'.format(err))
            print('Fehler beim auslesen der aktiven Events')
        else:
            logging.debug('Events could be read out successfully')
        
        con.close()
        if eventdata == []:
            logging.debug('No active events found')
            return 0
        else:
            logging.debug('{} events found'.format(len(eventdata)))
            return eventdata[0]

    ### Get time entries based on various criteria
    def get_time_entry(self, USERID='', TIMEID='', CATEGORYID='', CLIENTID='', REFERENCE='', STARTTIME='', ENDTIME='', DAY=''):
        if USERID:
            logging.debug('Search time entries based on userid: {}'.format(USERID))
            sql = "SELECT * FROM time_entries WHERE user_id = ?"
            searchdata = [USERID]
        elif TIMEID:
            logging.debug('Search time entrys based on timeid: {}'.format(TIMEID))
            sql = "SELECT * FROM time_entries WHERE id = ?"
            searchdata = [TIMEID]
        elif CATEGORYID:
            logging.debug('Search time entrys based on categoryid: {}'.format(CATEGORYID))
            sql = "SELECT * FROM time_entries WHERE category_id = ?"
            searchdata = [CATEGORYID]
        elif CLIENTID:
            logging.debug('Search time entrys based on clientid: {}'.format(CLIENTID))
            sql = "SELECT * FROM time_entries WHERE client_id = ?"
            searchdata = [CLIENTID]
        elif REFERENCE:
            logging.debug('Search time entrys based on reference: {}'.format(REFERENCE))
            sql = "SELECT * FROM time_entries WHERE reference = ?"
            searchdata = [REFERENCE]
        else:
            sql = "SELECT * FROM time_entries"
            searchdata = False
            
        try:
            with sqlite3.connect(self.DATABASE, detect_types=sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES) as con:
                cur = con.cursor()
                if searchdata:
                    logging.debug('Search time entry')
                    cur.execute(sql, searchdata)
                else:
                    logging.debug('Get all time entries')
                    cur.execute(sql)
                timedata = cur.fetchall()
        except sqlite3.Error as err:
            logging.debug(sql)
            logging.error('SQLError: {}'.format(err))
            print('Fehler beim auslesen der Zeiteinträge')
        else:
            logging.debug('Time entries could be read out successfully')

        con.close()

        if DAY:
            logging.debug('Search time entries by date: {}'.format(DAY))
            tmp = []
            for entry in timedata:
                if entry[1].date() == DAY:
                    tmp.append(entry)
            timedata = tmp[:]
        else:
            tmp = []
            if STARTTIME:
                logging.debug('Search time entries by starttime: {}'.format(STARTTIME))
                for entry in timedata:
                    if entry[1] > STARTTIME:
                        tmp.append(entry)
                timedata = tmp[:]
                pass
            tmp = []
            if ENDTIME:
                logging.debug('Search time entrie by endtime: {}'.format(ENDTIME))
                for entry in timedata:
                    if entry[2] < ENDTIME:
                        tmp.append(entry)
                timedata = tmp[:]
        if timedata == []:
            logging.debug('No time entries found')
            return 0
        else:
            logging.debug('{} time entries found'.format(len(timedata)))
            return timedata

    ## user handling
    #===============
    ### Creates a user who does not yet exist
    def create_user(self, USER=''):
        if USER == '':
            username = input('Benutzername eingaben: ')
            logging.debug('Selected username: {}'.format(username))
        else:
            username = USER

        while self.get_users(NAME=username):
            print('Der gewünsche Benutzername ({}) ist schon vergeben'.format(username))
            username = input('Wähle einen anderen Benutzernamen: ')
            logging.debug('Try again: Selected username: {}'.format(username))

        logging.debug('Accepted username: {}'.format(username))

        sql = "INSERT INTO users ( name ) values ( ? )"
        try:
            with self.DBCON as con:
                con.execute(sql, [username])
        except sqlite3.Error as err:
            logging.error('User could not be saved in database')
            logging.debug(sql)
            logging.error('SQLError: {}'.format(err))
        else:
            logging.info('User was saved successfully')

    ### Outputs existing users from the DB
    def get_users(self, UID=0, NAME=''):
        if not UID == 0:
            logging.debug('Get user by ID: {}'.format(UID))
            data = UID
            sql = "SELECT * FROM users WHERE id = ?"
        elif not NAME == '':
            logging.debug('Get user by username: {}'.format(NAME))
            data = NAME
            sql = "SELECT * FROM users WHERE name LIKE ?"
        else:
            logging.debug('Get all users')
            data = ''
            sql = "SELECT * FROM users"
        
        try:
            with self.DBCON as con:
                cur = con.cursor()
                if data:
                    cur.execute(sql, [data])
                else:
                    cur.execute(sql)
                data = cur.fetchall()
        except sqlite3.Error as err:
            logging.error('Could not get user')
            logging.debug(sql)
            logging.error('SQLError: {}'.format(err))
            print('Fehler beim Zugriff auf die Benutzer Datenbank')
            return 1
        else:
            logging.debug('User database read out successfully')

        return data

    ### Defines a user for the session
    def set_user(self):
        data = self.get_users()
        if not data: 
            logging.info("No user was found")
            print("Es wurde kein Benutzer gefunden, bitte legen sie einen neuen an.")
            self.create_user()
        
        data = self.get_users(UID=self.USERID)
        if data == []:
            logging.error('User ID was not found')
        else: 
            self.USERNAME = data[0][1]

    ## Time handling
    #===============
    ### Creates an active event if none exists for the user
    def save_event(self, TIME=datetime.datetime.now()):
        if not self.get_active_event(USERID=self.USERID):
            logging.debug('No active events found for the user: {}'.format(self.USERID))

            sql = "INSERT INTO active_events ( starttime, user_id ) VALUES ( ?, ? )"
            try:
                with self.DBCON as con:
                    con.execute(sql, [TIME, self.USERID])
            except sqlite3.Error as err:
                logging.error('Event could not be created')
                logging.debug(sql)
                logging.error('SQLError: {}'.format(err))
                print('Event konnte nicht gespeichert werden.')
                return False
            else:
                logging.info('Event was created successfully')

            return True

        else:
            logging.warning('Active events found for the user, new event could not be created')
            return False

    ### Deletes an active event based on a user or event ID
    def delete_event(self, ENTRYID='', USERID=''):
        if not ENTRYID == '':
            logging.info('Deletes event based on eventid: {}'.format(ENTRYID))
            sql = "DELETE FROM active_events WHERE id = ?"
            data = ENTRYID
        elif not USERID == '':
            logging.info('Deletes events based on userid: {}'.format(USERID))
            sql = "DELETE FROM active_events WHERE user_id = ?"
            data = USERID
        else:
            logging.warning('No indication of what should be deleted')
            print('Keine angabe was gelöscht werden soll')
            return 0

        try:
            with self.DBCON as con:
                con.execute(sql, [data])
        except sqlite3.Error as err:
            logging.error('Event could not be deleted')
            logging.debug(sql)
            logging.error('SQLError: {}'.format(err))
            print('Fehler beim löschen des Events.')
        else:
            logging.debug('Event was successfully deleted')

    ### Checks for existing time entries and creates a new one if none is available.
    def time_start(self, AUTOFORWARD=True):
        self.clear_screen()
        starttime = datetime.datetime.now()
        logging.debug('New Event process started at {}'.format(starttime))
        if self.save_event(starttime):
            print('Neues Event gestartet um {}'.format(starttime.strftime("%H:%M")))
            if AUTOFORWARD:
                self.time_stop()
        else:
            data = self.get_active_event(USERID=self.USERID)
            print('Es existiert bereits ein aktives Event.')
            if (data[1] + datetime.timedelta(hours=self.OLDEVENT)) <= datetime.datetime.now():
                logging.info('Event exceeds allowed duration')
                print('Zeiteintrag ist zu alt laut den Einstellungen (älter {} Stunden)'.format(self.OLDEVENT))

                if datetime.date.today() == data[1].date():
                    print('Start um: {}'.format(data[1].strftime("%H:%M")))
                else:
                    print('Start am: {}'.format(data[1].strftime("%d.%m.%Y um %H:%M")))
                
                elapsed = datetime.datetime.now() - data[1]
                if elapsed.days:
                    logging.debug('Event older than 1 day ({} days)'.format(elapsed.days))
                    print('Vergangene Zeit: >{} Tage'.format(elapsed.days))
                else:
                    logging.debug('Event younger than 1 day')
                    print('Vergangene Zeit: >{} Stunden'.format(int(elapsed.seconds/3600)))
 
                printtext = [
                    'Wie soll mit dem Event verfahren werden?',
                    '[1] fortsetzen',
                    '[2] löschen',
                    '[0] abbrechen'
                ]
                userinput = self.userchoise(printtext, 3)
                self.clear_screen()

                if userinput == 1:
                    logging.debug('Event should be continued')
                    self.time_stop()
                elif userinput == 2:
                    logging.info('Event should be deleted (eventid: {})'.format(data[0]))
                    self.delete_event(data[0])
                    self.time_start()
            
            else:
                logging.debug('Event continues (eventid{})'.format(data[0]))
                print('Event von {} Uhr geladen'.format(data[1].strftime("%H:%M")))
                self.time_stop()

    ### Stops existing time entries
    def time_stop(self):
        data = self.get_active_event(USERID=self.USERID)
        logging.debug('Event stop progess is started')
        if data:
            self.clear_screen()
            printtext = [
                'Event von {} Uhr beenden?'.format(data[1].strftime("%H:%M")),
                '[1] für beenden',
                '[2] für löschen',
                '[0] für abbrechen'
            ]
            userinput = self.userchoise(printtext, 3)
            self.clear_screen()

            if userinput == 1:
                logging.debug('Event is ended')
                print('Eingabe beenden mittels doppelter Leerzeile.')
                print('Durchgeführte Tätigkeiten:')
                userinput = []
                while True:
                    try:
                        if userinput[-1] == '' and userinput[-2] == '':
                            break
                    except IndexError:
                        pass
                    userinput.append(input())
                
                logging.debug('User input: {}'.format(userinput))
                del userinput[-1]
                del userinput[-1]
                action = ''
                for i in userinput:
                    if not action == '':
                        action += "\n"
                    action += i

                endtime = datetime.datetime.now()
                logging.debug('Event end process start at {}'.format(endtime))

                sql = "INSERT INTO time_entries ( starttime, endtime, user_id, activity ) VALUES ( ?, ?, ?, ? )"
                try:
                    with self.DBCON as con:
                        con.execute(sql, [data[1], endtime, self.USERID, action])
                except sqlite3.Error as err:
                    logging.error('Time entry could not be created')
                    logging.debug(sql)
                    logging.error('SQLError: {}'.format(err))
                    print('Zeiteintrag konnte nicht gespeichert werden.')
                    return False
                else:
                    logging.info('Time entry was created successfully')
                
                self.delete_event(data[0])
                self.clear_screen()
                self.print_time_entry(STARTTIME=data[1], ENDTIME=endtime, ACTIVITY=action)
                print('Zeiteintrag wurde gespeichert.')
                printtext = [
                    'Nächsten Zeiteintrag beginnen ?',
                    '[1] Ja',
                    '[0] Nein'
                ]
                userinput = self.userchoise(printtext)
                self.clear_screen()

                if userinput == 1:
                    self.time_start()

            elif userinput == 2:
                logging.info('Event should be deleted (eventid: {})'.format(data[0]))
                self.delete_event(data[0])

    ## Interactive mode
    #==================
    ### Main menu of the interactive menu
    def start_interactive_mode(self):
        self.clear_screen()
        printtext = [
            '=> Hauptmenü - Angemeldet als {}'.format(self.USERNAME),
            'Was willst du tun?',
            '[1] Zeiterfassung starten',
            '[2] heutiger Report',
            '[3] Benutzerverwaltung',
            '[0] Programm verlassen'
        ]
        userinput = self.userchoise(printtext, 4)

        if userinput == 1:
            logging.debug('Start TimeTrack')
            self.time_start()
        elif userinput == 2:
            logging.info('Print todays report')
            self.report_by_day(DETAIL=True)
            input()
        elif userinput == 3:
            self.interactive_usermanagment()
        elif userinput == 4:
            print('commig soon ...')
            input()
        else:
            exit()
        self.start_interactive_mode()
    
    def interactive_usermanagment(self):
        self.clear_screen()
        printtext = [
            '==> Benutzerverwaltung - Angemeldet als {}'.format(self.USERNAME),
            'Was willst du tun?',
            '[1] Benutzer anlegen',
            '[2] Benutzer wechseln',
            '[3] Benutzer löschen',
            '[0] abbrechen'
        ]
        userinput = self.userchoise(printtext, 4)

        if userinput == 1:
            self.create_user()
        elif userinput == 2:
            pass
        elif userinput == 3:
            pass

    ## Reports
    #=========
    ### One day report, optionally with time entries
    def report_by_day(self, DATE=datetime.date.today(), USER='', DETAIL=''):
        if not USER: 
            USER = self.USERID
        timedata = self.get_time_entry(DAY=DATE, USERID=USER)
        
        STARTTIMES  = []
        ENDTIMES    = []
        DURATIONS   = []

        for entry in timedata:
            STARTTIMES.append(entry[1])
            ENDTIMES.append(entry[2])
            DURATIONS.append(entry[2] - entry[1])

        if timedata:
            FIRSTSTARTTIME  = min(STARTTIMES)
            LASTENDTIME     = max(ENDTIMES)
            TRACKEDTIMESPAN = (LASTENDTIME - FIRSTSTARTTIME)
            TRACKEDTIME     = sum(DURATIONS, datetime.timedelta())
            NONTRACKEDTIME  = (TRACKEDTIMESPAN - TRACKEDTIME)
            ENTRIECOUNT     = len(timedata)
            
            self.clear_screen()
            text = "{:40} {}"
            print(text.format("Beginn des ersten Zeiteintrags:", FIRSTSTARTTIME.strftime('%d.%m.%Y %H:%M')))
            print(text.format("Ende des letzen Zeiteintrags:", LASTENDTIME.strftime('%d.%m.%Y %H:%M')))
            print(text.format("Maximal erfassbare Zeit:", self.timedela_to_string(TRACKEDTIMESPAN)))
            print(text.format("Nicht erfasste Zeit:", self.timedela_to_string(NONTRACKEDTIME)))
            print(text.format("Erfasste Zeit:", self.timedela_to_string(TRACKEDTIME)))
            print(text.format("Zeiteinträge:", ENTRIECOUNT))

            printtext = [
                'Zeiteinträge anzeigen?',
                '[1] Ja',
                '[0] Nein'
            ]
            userinput = self.userchoise(printtext)
            if userinput == 1:
                for entry in timedata:
                    self.print_time_entry(entry[1], entry[2], entry[4])

    ## Outputs
    #=========
    ### Shows a time entry
    def print_time_entry(self, STARTTIME='', ENDTIME='', ACTIVITY=''):
        s = (ENDTIME - STARTTIME).seconds
        hours, remainder = divmod(s, 3600)
        minutes, seconds = divmod(remainder, 60)
        
        print(50*"-")
        print('Start: {} Uhr'.format(STARTTIME.strftime('%H:%M')))
        print('Ende: {} Uhr'.format(ENDTIME.strftime('%H:%M')))
        print('Dauer: {:02}:{:02}:{:02}'.format(int(hours), int(minutes), int(seconds)))
        if not ACTIVITY == '':
            print('Aktivität:')
            print(ACTIVITY)
        print(50*"-")

    ## Miscellaneous
    #===============
    ### User selection
    def userchoise(self, TEXT='', MAX=2):
        userinput = -1
        while not -1 < int(userinput) < MAX:
            for text in TEXT:
                print(text)
            userinput = input('Aktion: ')
            logging.debug('User input: {}'.format(userinput))
            try:
                int(userinput)
            except ValueError:
                userinput = -1
            else:
                self.clear_screen()
        return int(userinput)

    ### Conversion to string of Timedelta typ
    def timedela_to_string(self, TIME):
        s = TIME.seconds
        hours, remainder = divmod(s, 3600)
        minutes, seconds = divmod(remainder, 60)
        output = '{:02}:{:02}:{:02}'.format(int(hours), int(minutes), int(seconds))
        return output
  

if __name__ == "__main__":
    test = TimeTrack()
    test.start_interactive_mode()
    test.DBCON.close()