import sqlite3

class Session:

    def __init__(self, db_agent):
        self.user = -1
        self.db_agent = db_agent
        self.resultstring = 'no results yet'

    def set_user(self, db_index):
        self.user = db_index
        return 'User set'

    def get_active_user(self):
        sql_command = f'''
                      SELECT Vorname, Nachname
                      FROM Spieler_in
                      WHERE id = {self.user}
                      '''
        active_user = ''
        try:
            first_name, name = self.db_agent.execute(sql_command).fetchone()
            active_user = f'{first_name} {name}'
        except:
            active_user = 'No active user'
        return active_user

    def invoke_command(self, command, arguments):
        self.resultstring = ''
        if command == 'a':
            self.resultstring += self.set_user(arguments[0])
        elif command == 'n':
            self.create_new_user(arguments[0], arguments[1])
            self.resultstring += f'Created new user {arguments[0]} {arguments[1]}.'
        elif command == 's':
            self.resultstring += self.show_works()
        elif command == 'su':
            self.resultstring += self.show_users()
        elif command == 'q':
            self.resultstring += 'Bye-bye'
        else:
            self.resultstring += 'Could not understand command.'

    def result(self):
        return self.resultstring
    
    def create_new_user(self, first_name, name):
        sql_command = f'''
                      INSERT INTO Spieler_in (Vorname, Nachname)
                      VALUES ("{first_name}", "{name}");
                      '''
        self.db_agent.execute(sql_command)

    def show_users(self):
        sql_command = '''
                      SELECT * FROM Spieler_in;
                      '''
        result_list = self.db_agent.execute(sql_command).fetchall()
        fun_resultstring = ''
        for item in result_list:
            fun_resultstring += f'{item[0]}: {item[1]} {item[2]}\n'
        return fun_resultstring

    def show_works(self):
        sql_command = '''
                      SELECT id
                      FROM Werk
                      '''
        list_of_work_ids = self.db_agent.execute(sql_command).fetchall()
        # GET WORKS OUT!
        return ''


# End session

class Werk_unter_id:
    # con = sqlite3.connect('repertoire.db')
    # reader = con.cursor()

    def __init__(self, werk_id, db_agent):
        self.values = dict()
        self.reader = db_agent
        
        sql_wui = f"""
                  SELECT *
                  FROM Werk
                  WHERE id = {werk_id}
                  """
        werk_list_val = self.reader.execute(sql_wui).fetchone()
        werk_list_att = ('id', 'Komp_id', 'VOE_Jahr', 'Opus', 'Sammlung', 'Haupttonart', 'Titel', 'Satztitel', 'Aliasname', 'Werkverzeichnis', 'Werkverzeichnisnummer')                         
        for tup in zip(werk_list_att, werk_list_val):
            self.values[tup[0]] = tup[1]

        sql_comp = f"""
                   SELECT Vorname, Name
                   FROM Komponist_in
                   WHERE id = {self.values['Komp_id']}
                   """
        werk_comp = self.reader.execute(sql_comp).fetchone()
        self.values['Vorname'] = werk_comp[0]
        self.values['Name'] = werk_comp[1]

        sql_suw = f"""
                  SELECT *
                  FROM Satz
                  WHERE Werk_id = {werk_id}
                  """
        saetze = dict()
        nummern = set()
        suw_liste = self.reader.execute(sql_suw).fetchall()
        # 0 Werk_id, 1 Lfd_Satznummer, 2 Nummer, 3 Bezeichnung, 4 Tonart, 5 Aufnahme
        for satz in suw_liste:
            saetze[satz[1]] = satz[2], satz[3], satz[4]
            if not satz[2] is None:
                nummern.add(satz[2])
        self.values['Sätze'] = saetze
        if len(nummern) == 1:
            self.sätze_unter_nummer = True
            self.values['Nummer'] = nummern.pop()
        else:
            self.sätze_unter_nummer = False

    def sammlung(self):
        sammlung = self.values['Sammlung']
        if not sammlung:
            return 'ohne'
        else:
            return sammlung

    def __str__(self):
        ret_str = ''
        for key, value in self.values.items():
            if not value is None:
                ret_str += f'{key}: {value}\n'
        return ret_str

# End Werk_unter_id

def parse_user_input(user_in):
    split_user_in = user_in.split()
    command = split_user_in[0]
    if command in ('a', 'n', 'q', 's', 'su'):
        arguments = split_user_in[1:]
        return (command, arguments)
    else:
        return (None, None)

def command_line_loop(session):
    user_in = ''
    while not user_in == 'q':
        user_in = input(f'Piano-Repertoire: {session.get_active_user()} >>> ')
        command, arguments = parse_user_input(user_in)
        session.invoke_command(command, arguments)
        # print(f'command: {command}, arguments: {arguments}')
        print(session.result())

def main():
    con = sqlite3.connect('repertoire.db')
    db_agent = con.cursor()
    session = Session(db_agent)
    command_line_loop(session)
    con.commit()
    print('changes committed.')
    con.close()
    print('db-connection closed. Bye-bye!')


if __name__ == '__main__':
    main()