Revert auto-assigned ids back to letters; only detected ids are numeric

Auto-assignment (no real id known: a manual add, or an accepted
proposal with no confident marker-id read) must stay visually
distinct from a genuinely detected id, or a made-up number could
collide with or be mistaken for a real one. Reverts the previous
commit's switch to numeric auto-assignment (_next_free_numeric_id) --
that was wrong, caught by the user immediately. _next_free_id
(letters, rolling over to "AA"/"AB"/... past 26) is back as the
fallback, still scoped per type (that part of the previous change was
correct and stays). Plain numbers are reserved for an id
_accept_proposal is actually confident was read off the marker itself
(Proposal.detected_id), passed straight through and never touching
auto-assignment.

Also fixes detected_id's own collision pre-check in _accept_proposal,
which wasn't scoped per type either -- same bug as the Change ID
popover fix, just in a second place: a detected id could get
needlessly discarded because an unrelated type already used that
number, not because of a real collision.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

TODO.md

@@ -207,23 +207,41 @@ Status legend: [x] fixed+tested, [~] partially addressed, [ ] open/needs input
         (`tests/test_app_accept_proposal.py`).
       - Auto-assignment itself (`Board.add_target`/`add_ally` with no
         `id_`/no usable detection) changed from one shared letter
-        sequence per group (targets, or allies) to its own 1/2/3...
+        sequence per group (targets, or allies) to its own sequence per
-        sequence per TYPE within each group -- Tank#1/Infantry#1 rather
+        TYPE within each group -- Tank#A/Infantry#A rather than
-        than Tank#A/Infantry#B, matching the game's own numbering (and
+        Tank#A/Infantry#B. This directly reverses an earlier deliberate
-        what `detected_id` looks like when it IS read). This directly
+        fix in this same file (see the "Allies and enemies seem to share
-        reverses an earlier deliberate fix in this same file (see the
+        indices" entry above, which moved FROM per-type TO
-        "Allies and enemies seem to share indices" entry above, which
+        shared-per-group) -- that fix is still correct for what it fixed
-        moved FROM per-type TO shared-per-group) -- that fix is still
+        (targets-vs-allies must stay separate namespaces), just not for
-        correct for what it fixed (targets-vs-allies must stay separate
+        per-type-vs-shared, which the user has now clarified the other
-        namespaces), just not for per-type-vs-shared, which the user has
+        way. Tests in `test_models.py` updated to match (renamed
-        now clarified the other way. `_next_free_id` (the letter
-        sequence, with its own StopIteration-safe rollover to "AA" past
-        26) is gone, replaced by `_next_free_numeric_id` -- a plain
-        counter can't run out the way a fixed alphabet could, so there's
-        no equivalent rollover concern to carry forward. Tests in
-        `test_models.py` updated to match (renamed
         `test_auto_id_is_shared_across_types...` ->
         `test_auto_id_is_per_type...`, since it now asserts the opposite).
+
+        First pass at this ALSO switched auto-assignment from letters to
+        plain numbers (1/2/3...), reasoning that it should match what
+        `detected_id` looks like when read successfully. Wrong -- caught
+        by the user immediately: auto-assignment (no real id known, a
+        manual add or an accept with no confident read) and a genuinely
+        detected id need to stay visually distinct, or a made-up
+        auto-assigned number could collide with, or be mistaken for, a
+        real one. Reverted back to `_next_free_id` (letters, rolling
+        over to "AA"/"AB"/... past 26 rather than raising
+        `StopIteration`) as the auto-assignment fallback, scoped per
+        type same as above; plain numbers are reserved for an id
+        `_accept_proposal` is actually confident was read off the
+        marker itself (`Proposal.detected_id`), passed straight through
+        as `id_` and never touching auto-assignment at all.
+      - `_accept_proposal` now actually USES `detected_id` (it was only
+        being logged before, never applied) -- an accepted proposal's
+        entity id prefers the detected number over auto-assignment,
+        falling back on a collision (scoped per type, same bug fixed
+        in two places: this collision pre-check, and the "Change ID"
+        popover's own check, which still enforced the OLD shared-per-
+        group rule after the auto-assignment change above and rejected
+        valid renames across types). 4 new regression tests
+        (`tests/test_app_accept_proposal.py`).
       - `detected_id` is now shown, not just logged: the proposal
         popover's heading (", id #8") and the pending-proposal's own
         on-map label (`? #8 G8 5:4`) both show it while there's still a

src/fenigma/app.py

@@ -760,7 +760,8 @@ class MainWindow(Adw.ApplicationWindow):
         # than losing this one accept's traceability to the game's own
         # number.
         id_ = proposal.detected_id
-        existing = {a.id for a in self.board.allies} if is_ally else {t.id for t in self.board.targets}
+        group = self.board.allies if is_ally else self.board.targets
+        existing = {o.id for o in group if o.type == type_}  # per-type, same as Board.add_target/add_ally
         if id_ in existing:
             id_ = None
         if is_ally:

src/fenigma/models.py

@@ -18,6 +18,7 @@ Coord) to work out everything else. This module just defines the shape.
 
 from __future__ import annotations
 
+import itertools
 import string
 from dataclasses import dataclass, field
 from enum import Enum
@@ -502,28 +503,37 @@ class ScoutFlight:
         return f"ScoutFlight#{self.id}"
 
 
-def _next_free_numeric_id(used: set[str]) -> str:
+def _next_free_id(used: set[str]) -> str:
-    """Next unused id in a plain 1, 2, 3... sequence -- matches the small
+    """Next unused id in a short, human-friendly LETTER sequence: single
-    integer ids the game itself shows per unit (see
+    uppercase letters (A..Z) first, then two-letter combinations
-    map_vision.read_marker_id and app.py's _accept_proposal, which
+    (AA..ZZ, spreadsheet-column style) once those run out, and so on.
-    prefers that detected id over this auto-assignment whenever it has
+    Scoped per TYPE, not per group: add_target()/add_ally() only look at
-    one), scoped per TYPE, not per group: add_target()/add_ally() only
+    existing entities of the SAME type when building `used`, so a Tank
-    look at existing entities of the SAME type when building `used`, so
+    and an Infantry added back to back both start at 'A' (Tank#A,
-    a Tank and an Infantry added back to back both start at '1', each
+    Infantry#A), each type keeping its own independent sequence.
-    type keeping its own independent count (Infantry #1/#2/#3,
-    Mechanized #1/#2/#3, ..., same as the game's own numbering) rather
-    than sharing one sequence across every type in the group.
 
-    Older versions of this used a letter sequence (A, B, C..., rolling
+    Deliberately letters, not numbers: a manually-added entity (map
-    over to AA/AB/... past 26) shared across a whole group instead of
+    right-click "Add target", or an accepted screenshot proposal with no
-    per type -- switched away from per-type once before (see TODO.md)
+    confident id read) has no real game id to report, so it gets an
-    because sharing made it too easy to run past 26 letters. That's not
+    obviously-not-a-real-id placeholder instead -- app.py's
-    a concern here: a plain counter never runs out, there's no fixed
+    _accept_proposal reserves plain numbers for an id it's actually
-    alphabet to exhaust regardless of how it's scoped."""
+    confident was read off the marker itself (map_vision.read_marker_id
-    n = 1
+    via Proposal.detected_id), passed straight through as this
-    while str(n) in used:
+    function's caller's `id_` and never touching this auto-assignment at
-        n += 1
+    all. Letters can't collide with a real (numeric) detected id either,
-    return str(n)
+    on top of just reading honestly as 'made up'.
+
+    Can't run out the way `next(c for c in string.ascii_uppercase if c
+    not in used)` used to (a real regression, see TODO.md): rolls over to
+    two-letter ids ('AA', 'AB', ...) past 26 instead of raising
+    StopIteration."""
+    length = 1
+    while True:
+        for combo in itertools.product(string.ascii_uppercase, repeat=length):
+            candidate = "".join(combo)
+            if candidate not in used:
+                return candidate
+        length += 1
 
 
 SAVE_FORMAT_VERSION = 3
@@ -596,15 +606,18 @@ class Board:
         location: Location | Coord | None = None,
         id_: str | None = None,
     ) -> Target:
-        # Own 1/2/3... sequence per TYPE, not one shared across every
+        # Own A/B/C... sequence per TYPE, not one shared across every
         # target regardless of type -- a Tank and an Infantry auto-
-        # assigned back to back both start at '1' (Tank#1, Infantry#1),
+        # assigned back to back both start at 'A' (Tank#A, Infantry#A).
-        # matching how the game itself numbers units. targets-vs-allies
+        # targets-vs-allies is still its own separate id namespace (see
-        # is still its own separate id namespace (see add_ally); type
+        # add_ally); type now subdivides it further too. Letters, not
-        # now subdivides it further too. See _next_free_numeric_id.
+        # numbers, when auto-assigning here specifically: see
+        # _next_free_id's own docstring for why (a real detected id, when
+        # there is one, is passed in as `id_` and never reaches this
+        # auto-assignment at all).
         if not id_:
             used = {t.id for t in self.targets if t.type == type_}
-            id_ = _next_free_numeric_id(used)
+            id_ = _next_free_id(used)
         t = Target(type=type_, id=id_, location=_as_location(location))
         self.targets.append(t)
         return t
@@ -619,14 +632,14 @@ class Board:
         location: Location | Coord | None = None,
         id_: str | None = None,
     ) -> Ally:
-        # A separate id namespace from add_target()'s: an ally Tank#1
+        # A separate id namespace from add_target()'s: an ally Tank#A
-        # and a hostile Target Tank#1 are unrelated, so auto-assignment
+        # and a hostile Target Tank#A are unrelated, so auto-assignment
         # here only looks at other allies, never self.targets. Own
-        # 1/2/3... sequence per TYPE too, same as add_target -- see its
+        # A/B/C... sequence per TYPE too, same as add_target -- see its
-        # own comment and _next_free_numeric_id.
+        # own comment and _next_free_id.
         if not id_:
             used = {a.id for a in self.allies if a.type == type_}
-            id_ = _next_free_numeric_id(used)
+            id_ = _next_free_id(used)
         a = Ally(type=type_, id=id_, location=_as_location(location))
         self.allies.append(a)
         return a

tests/test_app_accept_proposal.py

@@ -1,11 +1,11 @@
 """_accept_proposal: an accepted proposal's entity id should prefer the
 marker's own detected "#<N>" id (map_vision.read_marker_id, via
-Proposal.detected_id) over an auto-assigned number, so ids on the board
+Proposal.detected_id) over an auto-assigned letter, so ids on the board
-match what's actually on screen -- falling back to auto-assign only when
+match what's actually on screen -- falling back to auto-assign (a
-there's no detection, or it collides with an id already used for that
+letter, deliberately not a number, so it can't collide with or be
-type in that group (see _accept_proposal's own docstring, and
+mistaken for a real detected id -- see models.py's _next_free_id) only
-models.py's _next_free_numeric_id for the per-type auto-assignment
+when there's no detection, or it collides with an id already used for
-these fall back to).
+that type in that group (see _accept_proposal's own docstring).
 
 Needs a real Adw/Gtk init (MainWindow.__new__ skips __init__, so no
 window/widgets are actually built, but Adw.init() is still required for
@@ -46,7 +46,7 @@ def test_accept_uses_the_detected_id_when_present():
 def test_accept_falls_back_to_auto_id_with_no_detection():
     win = _window()
     win._accept_proposal(_proposal(detected_id=None))
-    assert win.board.targets[0].id == "1"
+    assert win.board.targets[0].id == "A"
 
 
 def test_accept_falls_back_to_auto_id_on_a_detected_id_collision():

tests/test_models.py

@@ -54,58 +54,60 @@ def test_clear_units_keeps_recon_infrastructure():
 def test_ally_and_target_ids_are_independent_namespaces():
     """An ally Tank#1 and a hostile Target Tank#1 are unrelated -- adding
     one must never be influenced by the other's ids, and auto-assignment
-    on each side starts from '1' independently."""
+    on each side starts from 'A' independently. Explicit id_="1" here
+    (as an accepted screenshot proposal's detected_id would pass, see
+    app.py's _accept_proposal) to also check that auto-assignment
+    correctly skips a real numeric id already in use, not just other
+    letters."""
     board = Board()
     t1 = board.add_target(TargetType.TANK, _coord(), id_="1")
     a1 = board.add_ally(TargetType.TANK, _coord(), id_="1")
     assert t1.id == a1.id == "1"
     assert t1 is not a1
 
-    # '1' is already taken (explicitly) for TANK on each side, so the next
-    # auto-assigned Tank on each side must skip it and land on '2'.
     t_auto = board.add_target(TargetType.TANK, _coord())
     a_auto = board.add_ally(TargetType.TANK, _coord())
-    assert t_auto.id == "2"  # first free number among *target* Tanks only
+    assert t_auto.id == "A"  # first free letter among *target* Tanks only
-    assert a_auto.id == "2"  # first free number among *ally* Tanks only, unaffected by the target above
+    assert a_auto.id == "A"  # first free letter among *ally* Tanks only, unaffected by the target above
 
 
 def test_auto_id_is_per_type_within_targets_and_within_allies():
-    """Each TYPE gets its own independent 1/2/3... sequence within a group
+    """Each TYPE gets its own independent A/B/C... sequence within a group
     (all targets, or all allies) -- a Tank and an Infantry auto-assigned
-    back to back both start at '1' (Tank#1, Infantry#1), matching how the
+    back to back both start at 'A' (Tank#A, Infantry#A), rather than
-    game itself numbers units, rather than sharing one sequence across
+    sharing one sequence across every type in the group."""
-    every type in the group."""
     board = Board()
     tank = board.add_target(TargetType.TANK, _coord())
     infantry = board.add_target(TargetType.INFANTRY, _coord())
-    assert tank.id == "1"
+    assert tank.id == "A"
-    assert infantry.id == "1"  # own sequence, not '2' just because a Tank came first
+    assert infantry.id == "A"  # own sequence, not 'B' just because a Tank came first
 
     second_tank = board.add_target(TargetType.TANK, _coord())
-    assert second_tank.id == "2"  # but a SECOND Tank does advance the Tank sequence
+    assert second_tank.id == "B"  # but a SECOND Tank does advance the Tank sequence
 
     ally_tank = board.add_ally(TargetType.TANK, _coord())
     ally_infantry = board.add_ally(TargetType.INFANTRY, _coord())
-    assert ally_tank.id == "1"
+    assert ally_tank.id == "A"
-    assert ally_infantry.id == "1"
+    assert ally_infantry.id == "A"
 
 
-def test_auto_id_keeps_counting_past_26_entities_of_one_type():
+def test_auto_id_survives_past_26_entities_of_one_type():
-    """The id sequence is a plain integer counter now (see
+    """A real crash: `next(c for c in string.ascii_uppercase if c not in
-    _next_free_numeric_id), not the old letter sequence that could raise
+    used)` raises StopIteration the instant all 26 letters are taken --
-    StopIteration past 26 (see TODO.md/git history) -- nothing special
+    reachable after accepting/adding 26+ of the same type into one group
-    should happen crossing 26, it just keeps counting."""
+    in a single session. Must roll over to two-letter ids ('AA', 'AB',
+    ...) instead of raising."""
     board = Board()
     for _ in range(26):
         board.add_target(TargetType.TANK, _coord())
     twenty_seventh = board.add_target(TargetType.TANK, _coord())
-    assert twenty_seventh.id == "27"
+    assert twenty_seventh.id == "AA"
 
     board2 = Board()
     for _ in range(26):
         board2.add_ally(TargetType.TANK, _coord())
     twenty_seventh_ally = board2.add_ally(TargetType.TANK, _coord())
-    assert twenty_seventh_ally.id == "27"
+    assert twenty_seventh_ally.id == "AA"
 
 
 def test_find_by_name_prefers_target_over_same_named_ally():