fixes bug: setting user who is not present in pianist-table is no longer allowed

README.md

@@ -25,9 +25,10 @@ At the moment, an alpha version is undertaken, with these features:
 - Show mastered movements for activated user (`sm`)
 - display, if work or movement is mastered from active user when viewing works and movements
 - Works are shown sorted by composer and opus/work_directory-number (`s`, `smo`) or by composer and collection (`sm`)
-- (planned) Remove work or movement from being mastered for active user
-- (planned) Remove user
-- (planned) Fix known bugs
+- Remove work or movement from being mastered for active user (`r number_of_work` or `r number_of_work number_of_movement`)
+- Remove user (`delete_my_user_record_including_all_mastered_works`)
+- Fixed bug: double marking crashes the program
+- Fixed bug: check for user before setting
 
 _(planned) Release piano_repertoire_cli V 0.0.1 alpha (learn about versioning before)_
 
@@ -44,4 +45,5 @@ _(planned) Port funtionality to a kivy-GUI_
 
 ## Known Bugs
 
-- Marking a piece as mastered the second time, the database won’t insert the entry and the program will crash
+- Trying to mark works as mastered that are not present crashes the program
+- Providing alphabetic chars where numbers are expected crashes the program

rep_cli.py

@@ -9,9 +9,11 @@ class Session:
         self.resultstring = 'no results yet'
         self.commands = {'a': (self.set_user, 'Set an active user\n   Usage: a number_of_user'),
                          'c': (self.show_composers, 'Shows composers'),
+                         'delete_my_user_record_including_all_mastered_works': (self.delete_user, 'DangerZone: deletes user and all marks of mastered works'),
                          'h': (self.show_help, 'Displays this help document'),
                          'm': (self.mark_work_as_mastered, 'Marks work or movement as mastered for the active user\n   Usage: m number_of_work, m number_of_work number_of_movement'),
                          'n': (self.create_new_user, 'Creates new user\n   Usage: n firstname name'),
+                         'r': (self.remove_work_as_mastered, 'Unmarks work or movement as mastered for the active user\n   Usage: r number_of_work, r number_of_work number_of_movement'),
                          's': (self.show_works, 'Show the works stored in the database\n   Usage: s, s number_of_composer'),
                          'sm': (self.show_mastered, 'Show mastered movements for activated user'),
                          'smo': (self.show_mastered_opus, 'Show mastered movements for activated user, sorted by opus.'),
@@ -21,9 +23,19 @@ class Session:
                         }
 
     def set_user(self, arguments):
+        resultstring = ''
         db_index = arguments[0]
-        self.user = db_index
-        return 'User set'
+        sql_command = f'''
+                      SELECT *
+                      FROM pianist
+                      WHERE id = {db_index}
+                      '''
+        if self.db_agent.execute(sql_command).fetchone():
+            self.user = db_index
+            resultstring += 'User set'
+        else:
+            resultstring += 'No such user' 
+        return resultstring
 
     def get_active_user(self):
         sql_command = f'''
@@ -80,6 +92,21 @@ class Session:
         self.db_agent.execute(sql_command)
         return f'Created new user {first_name} {name}.'
 
+    def delete_user(self, _):
+        resultstring = ''
+        if self.user == -1:
+            resultstring += 'Please activate user'
+        else:
+            user_name = self.get_active_user()
+            sql_command = f'''
+                          DELETE FROM pianist
+                          WHERE id = {self.user}
+                          '''
+            self.db_agent.execute(sql_command)
+            resultstring += f'Deleted user {user_name}'
+        return resultstring
+
+
     def show_composers(self, _):
         sql_command = '''
                       SELECT id, first_name, name
@@ -193,25 +220,69 @@ class Session:
         return fun_resultstring
 
     def mark_work_as_mastered(self, arguments):
-        work_id = arguments[0]
-        resultstring = 'adding:\n'
-        work = work_under_id(work_id, self.db_agent)
-        if len(arguments) > 1: # in case there is a movement number given
-            mov_number = int(arguments[1])
-            sql_command = f'''
-                          INSERT INTO is_able_to_play (work_id, mov_id, pianist_id)
-                          VALUES ({work_id}, {mov_number}, {self.user})
-                          '''
-            self.db_agent.execute(sql_command)
-            resultstring += f'{work.pretty_mov(mov_number)}\n'
-        else: # mark all movements of the work as mastered
-            for mov_number in work.values['movements'].keys():
-                sql_command = f'''
-                              INSERT INTO is_able_to_play (work_id, mov_id, pianist_id)
-                              VALUES ({work_id}, {mov_number}, {self.user})
-                              '''
-                self.db_agent.execute(sql_command)
-                resultstring += f'{work.pretty_mov(mov_number)}\n'
+        if self.user == -1:
+            resultstring = 'Please activate user'
+        else:
+            work_id = arguments[0]
+            resultstring = 'adding:\n'
+            work = work_under_id(work_id, self.db_agent)
+            if len(arguments) > 1: # in case there is a movement number given
+                mov_number = int(arguments[1])
+                if self.movement_is_mastered(work_id, mov_number):
+                    resultstring += f'Already marked as mastered: {work.pretty_mov(mov_number)}\n'
+                else:
+                    sql_command = f'''
+                                  INSERT INTO is_able_to_play (work_id, mov_id, pianist_id)
+                                  VALUES ({work_id}, {mov_number}, {self.user})
+                                  '''
+                    self.db_agent.execute(sql_command)
+                    resultstring += f'{work.pretty_mov(mov_number)}\n'
+            else: # mark all movements of the work as mastered
+                for mov_number in work.values['movements'].keys():
+                    if self.movement_is_mastered(work_id, mov_number):
+                        resultstring += f'Already marked as mastered: {work.pretty_mov(mov_number)}\n'
+                    else:
+                        sql_command = f'''
+                                      INSERT INTO is_able_to_play (work_id, mov_id, pianist_id)
+                                      VALUES ({work_id}, {mov_number}, {self.user})
+                                      '''
+                        self.db_agent.execute(sql_command)
+                        resultstring += f'{work.pretty_mov(mov_number)}\n'
+        return resultstring
+
+    def remove_work_as_mastered(self, arguments):
+        if self.user == -1:
+            resultstring = 'Please activate user'
+        else:
+            work_id = arguments[0]
+            resultstring = 'removing:\n'
+            work = work_under_id(work_id, self.db_agent)
+            if len(arguments) > 1: # in case there is a movment number given
+                mov_number = int(arguments[1])
+                if self.movement_is_mastered(work_id, mov_number):
+                    sql_command = f'''
+                                  DELETE FROM is_able_to_play
+                                  WHERE work_id = {work_id}
+                                    AND mov_id = {mov_number}
+                                    AND pianist_id = {self.user}
+                                  '''
+                    self.db_agent.execute(sql_command)
+                    resultstring += f'{work.pretty_mov(mov_number)}\n'
+                else:
+                    resultstring += f'Movement was not marked as mastered: {work.pretty_mov(mov_number)}\n'
+            else:
+                for mov_number in work.values['movements'].keys():
+                    if self.movement_is_mastered(work_id, mov_number):
+                        sql_command = f'''
+                                  DELETE FROM is_able_to_play
+                                  WHERE work_id = {work_id}
+                                    AND mov_id = {mov_number}
+                                    AND pianist_id = {self.user}
+                                  '''
+                        self.db_agent.execute(sql_command)
+                        resultstring += f'{work.pretty_mov(mov_number)}\n'
+                    else:
+                        resultstring += f'Movement was not marked as mastered: {work.pretty_mov(mov_number)}\n'
         return resultstring
 
     def quit(self, _):
@@ -367,6 +438,8 @@ def command_line_loop(session):
 def main():
     con = sqlite3.connect('repertoire.db')
     db_agent = con.cursor()
+    sql_command = 'PRAGMA foreign_keys = ON'
+    db_agent.execute(sql_command)
     session = Session(db_agent)
     command_line_loop(session)
     con.commit()

repertoire.sql

@@ -52,7 +52,7 @@ CREATE TABLE is_able_to_play(
     recording VARCHAR(255),
     PRIMARY KEY(work_id, mov_id, pianist_id),
     FOREIGN KEY(work_id, mov_id) REFERENCES movement(work_id, mov_number),
-    FOREIGN KEY(pianist_id) REFERENCES pianist(id)
+    FOREIGN KEY(pianist_id) REFERENCES pianist(id) ON DELETE CASCADE
 );
 
 CREATE TABLE plays_in(
@@ -63,5 +63,5 @@ CREATE TABLE plays_in(
     PRIMARY KEY(concert_id, pianist_id, work_id, mov_id),
     FOREIGN KEY(concert_id) REFERENCES concert(id),
     FOREIGN KEY(work_id, mov_id) REFERENCES movement(work_id, mov_number),
-    FOREIGN KEY(pianist_id) REFERENCES pianist(id)
+    FOREIGN KEY(pianist_id) REFERENCES pianist(id) ON DELETE CASCADE
 );