add list-changes command

2 files changed, 137 insertions, 0 deletions

diff --git a/geldschieberbot.py b/geldschieberbot.py
index a2c5186..6f55696 100644
--- a/geldschieberbot.py
+++ b/geldschieberbot.py
@@ -191,6 +191,7 @@ cars pay car-name amount - pay a bill for the specified car
 tanken amount [person] [car] [info] - calculate fuel costs, service charge and add them to the person's and car's balance respectively
 
 fuck - rewind last change
+list-changes [n] [first] - list the last n changes starting at first
 
 weekly name cmd -  repeat cmd each week
 monthly name cmd - repeat cmd each month
@@ -626,6 +627,63 @@ cmds["fuck"] = fuck
 cmds["rewind"] = fuck
 cmds["undo"] = fuck
 
+def list_changes(sender, args, msg):
+    if not sender in num2name:
+        return None, "you must register first"
+
+    sender_name = num2name[sender]
+
+    changes_to_list = 5
+    if len(args) >= 2:
+        try:
+            changes_to_list = int(args[1])
+        except ValueError:
+            return None, 'the amount of changes to list must be a number'
+
+
+    nchanges = len(changes[sender_name])
+    if nchanges == 0:
+        return "Nothing to list", None
+
+    first_to_list = nchanges - changes_to_list
+    if first_to_list < 0:
+        first_to_list = 0
+
+    if len(args) == 3:
+        try:
+            first_to_list = int(args[2]) - 1
+        except ValueError:
+            return None, 'the first change to list must be a number'
+
+        if first_to_list > nchanges:
+            return None, 'the first change to list is bigger than there are changes'
+
+    msg = ""
+    for i, change in enumerate(changes[sender_name]):
+        if i < first_to_list:
+            continue
+
+        if i >= first_to_list + changes_to_list:
+            # i is used to track how many changes we listed
+            # This change will not be listed so decrement i before extiting the loop.
+            i -= 1
+            break
+
+        msg += f'Change {i + 1}:\n'
+        msg += f'{" ".join(change[0])}\n'
+        for sender, recipient, amount in change[1:]:
+            msg += "{} {} {} {}\n".format(sender,
+                                          ("->" if amount < 0 else "<-"),
+                                          to_euro(abs(amount)),
+                                          recipient)
+
+    # prepend message header because we want to know how much changes we actually listed
+    msg = f'Changes from {sender_name} {first_to_list + 1}-{i + 1}\n' + msg
+
+    return msg, None
+
+cmds["list-changes"] = list_changes
+
 def schedule(sender, args, msg):
     if not sender in num2name:
         return None, "you must register first"
diff --git a/test.py b/test.py
index 56f6949..b26fc89 100755
--- a/test.py
+++ b/test.py
@@ -708,6 +708,85 @@ New Balance: bob -> 5.00 charlie
 
 
 #TODO: tanken, transfer, cars pay
+class TestListChangesCmd(unittest.TestCase):
+
+    def setUp(self):
+        reset_state("test/state.json_3users")
+
+    def test_list_changes_unregistered(self):
+        res = run_bot(self, "+4971576357", "!list-changes")
+        self.assertEqual(res.stdout, 'ERROR: you must register first')
+
+    def test_list_changes_single_change(self):
+        run_bot(self, num[alice], f"!schieb {bob} 10")
+        res = run_bot(self, num[alice], "!list-changes")
+        msg = \
+"""Changes from alice 1-1
+Change 1:
+!schieb bob 10
+alice <- 10.00 bob
+"""
+        self.assertEqual(res.stdout, msg)
+
+    def test_list_changes_single_change_invalid_amount(self):
+        run_bot(self, num[alice], f"!schieb {bob} 10")
+        res = run_bot(self, num[alice], "!list-changes foo")
+        msg = \
+"""ERROR: the amount of changes to list must be a number"""
+        self.assertEqual(res.stdout, msg)
+
+    def test_list_changes_single_change_invalid_offset(self):
+        run_bot(self, num[alice], f"!schieb {bob} 10")
+        res = run_bot(self, num[alice], "!list-changes 1 foo")
+        msg = \
+"""ERROR: the first change to list must be a number"""
+        self.assertEqual(res.stdout, msg)
+
+        res = run_bot(self, num[alice], "!list-changes 1 20")
+        msg = \
+"""ERROR: the first change to list is bigger than there are changes"""
+        self.assertEqual(res.stdout, msg)
+
+    def test_list_changes_two_changes(self):
+        run_bot(self, num[alice], f"!schieb {bob} 10")
+        run_bot(self, num[alice], f"!zieh {charlie} 5")
+        res = run_bot(self, num[alice], "!list-changes")
+        msg = \
+"""Changes from alice 1-2
+Change 1:
+!schieb bob 10
+alice <- 10.00 bob
+Change 2:
+!zieh charlie 5
+alice -> 5.00 charlie
+"""
+        self.assertEqual(res.stdout, msg)
+
+    def test_list_changes_one_of_two(self):
+        run_bot(self, num[alice], f"!schieb {bob} 10")
+        run_bot(self, num[alice], f"!zieh {charlie} 5")
+        res = run_bot(self, num[alice], "!list-changes 1")
+        msg = \
+"""Changes from alice 2-2
+Change 2:
+!zieh charlie 5
+alice -> 5.00 charlie
+"""
+        self.assertEqual(res.stdout, msg)
+
+    def test_list_changes_only_second(self):
+        run_bot(self, num[alice], f"!schieb {bob} 10")
+        run_bot(self, num[alice], f"!zieh {charlie} 5")
+        run_bot(self, num[alice], f"!split 9 {bob} {charlie}")
+        res = run_bot(self, num[alice], "!list-changes 1 2")
+        msg = \
+"""Changes from alice 2-2
+Change 2:
+!zieh charlie 5
+alice -> 5.00 charlie
+"""
+        self.assertEqual(res.stdout, msg)
+
 class TestFuckCmd(unittest.TestCase):
 
     def setUp(self):