# ScoreKeeper — Score-Tracking & "High-Score Table" Domain Analysis > **Scope of this document:** the domain logic that tracks player scores and (intended) the > high-score table. Written for a new team member who must understand the scoring system > *without opening the source*. Every claim below is traced to a file/line so it can be > re-verified. > > **Bottom line up front (read this first):** ScoreKeeper currently tracks **live scores > only, in memory, for the running server session**. It has **no persistence** and **no > high-score table**. The high-score table is *described as a planned feature* in the > README and is where the `/score-archive` command is *intended* to land scores, but > **that code path is an unimplemented stub today.** There is no sorting, no tie-breaking, > no entry cap, no decay, and no scoring formula/weighting anywhere in the codebase. > This is a greenfield/early-stage domain — the write-up documents the *real* state and > flags the gap, because documenting features that don't exist as if they did would mislead > the next engineer. --- ## 0. How to read the rest of this doc against the task's four questions The task asks for (1) the score-entry data model + persistence format, (2) how scores are recorded, (3) the high-score-table algorithm, and (4) scoring formulas/weighting. For each question the answer is: **the mechanism that exists vs. the mechanism the project intends**, so readers never conflate the two. | # | Question | Short answer | |---|----------|--------------| | 1 | Score-entry data model & persistence | Live score = `UUID -> int` in a `HashMap`. **No persistence** (load/save are `TODO` stubs). | | 2 | How scores are recorded | **Manual, event-free:** the *administrator* runs a command. No game events, no timers. | | 3 | High-score-table algorithm | **Not implemented.** No sort/tie-break/cap/decay. Only an aspirational `/score-archive`. | | 4 | Scoring formulas / weighting | **None.** Scores are plain integer accumulators; no weighting, no decay, no bonuses. | --- ## 1. The score-entry data model & persistence *(task Q1)* ### 1.1 What a "score entry" actually is (current reality) The entire live-score domain is **one field** in the plugin's entry-point class: - **File:** `src/main/java/com/majinnaibu/minecraft/plugins/scorekeeper/ScoreKeeperPlugin.java:38` - **Declaration:** `private final HashMap _playerScores = new HashMap();` That is the whole model: | Aspect | Value | |--------|-------| | Record shape | A single `Integer` (the score), keyed by a player's `UUID`. | | Key type | `java.util.UUID` — the player's `UniqueId`, *not* the name string. | | Value type | `int` (Java `Integer`), autoboxed into the map. | | Container | one `java.util.HashMap` on the plugin instance. | | Uniqueness | one entry per `UUID`. A player can have exactly one live score at a time. | | Default for a new player | `0` — see §3.1 ("first-time player" edge case). | There is **no `Score`/`ScoreEntry`/`PlayerStats` value class**, no timestamp, no name stored alongside the score (name is looked up from the live server only — see §2.3), and no secondary index. ### 1.2 Persistence format: **none exists** Persistence is *intended* but *not built*. Three concrete stubs prove this: 1. **On disable (server stop):** `ScoreKeeperPlugin.java:46-49` `onDisable()` logs *"Unable to save scores to file. This feature is not implemented yet."* — the map is **discarded** on shutdown; nothing is written. 2. **On enable (server start):** `ScoreKeeperPlugin.java:59-60` `onEnable()` logs *"Unable to load scores from file. This feature is not implemented yet."* — the map always starts **empty** `{}` every server start. 3. **Archive:** `ScoreKeeperPlugin.java:72-74` `archiveScore(Player)` logs *"Unable to archive score for ."* and returns — the "save to high-score table" action is a no-op. So there is **no SQLite, no JSON, no YAML, no flat file, no config.yml**. The only file on disk that concerns scores is `plugin.yml` (the command manifest — it lists the commands but stores no scores). A grep of the whole tree for `sql / json / yaml / saveResource / YamlConfiguration / File / Files. / Gson / Jackson` finds **zero hits** other than the TODO/log strings. **Persistence format today = "in RAM only, lost on server restart."** > Implication for a new engineer: any "who's the top player" question answered *across > restarts* is impossible today. Scores reset to the map being empty on every server boot. --- ## 2. How scores are recorded *(task Q2)* ### 2.1 The recording model is **manual and command-driven — no events, no timers** Scores move only when an administrator (or console/RCON) **types a command**. There is: - **No** `implements Listener`, no `@EventHandler`, no `registerEvents(...)`, no `getServer().getPluginManager().registerEvents(...)`. - **No** scheduler: no `getScheduler()`, no `runTask`, no `Timer`. - **No** automatic hook to game events (e.g. a player killing a mob or reaching a goal awards points automatically — *nothing like that exists*). A grep for `EventListener|@EventHandler|Listener|Scheduler|runTask` across `src/` returns **zero**. So "scoring" happens **on demand**, by a person, via one of the four mutating commands: | Command | Effect on the map | Source | |---------|-------------------|--------| | `/score-add [player] ` | `score += amount` | `ScoreKeeperPlugin.addScore` `:67-70` | | `/score-subtract [player] ` | `score -= amount` | `ScoreKeeperPlugin.subtractScore` `:88-91` | | `/score-reset [player]` | `score = 0` | `ScoreKeeperPlugin.resetScore` `:80-82` | | `/score-archive [player]` | **intended** to snapshot to a high-score table and reset to 0; **actually a no-op** | `ScoreKeeperPlugin.archiveScore` `:72-74` | `/score-get [player]` is read-only (returns the score, §2.4). ### 2.2 The add/subtract primitives (the only real "write" path) Both funnel through one private setter: ``` addScore(player, n) -> old = getPlayerScore(player); setPlayerScore(player, old + n) :67-70 subtractScore(player,n)-> old = getPlayerScore(player); setPlayerScore(player, old - n) :88-91 setScore(player, s) -> setPlayerScore(player, s) :84-86 resetScore(player) -> setPlayerScore(player, 0) :80-82 setPlayerScore(p, v) -> _playerScores.put(p.getUniqueId(), v) :108-110 ``` Notes a new engineer must internalize: - **Read-modify-write.** `addScore`/`subtractScore` read the current value, compute, write back in two map operations. (There is no concurrency control — see §5 risks.) - **`int` math.** Values are Java `int`; a score can go **negative** (there is no floor at 0 — `/score-subtract 50` on a 10-score yields `-40`), and can overflow `int` only after `~2.1e9` points, which is not a practical concern. - **No validation of the direction.** The only validation is *syntactic*: the amount must parse as an integer (see §2.3). ### 2.3 Command surface (who/what is allowed to record a score) Every command executor lives in `src/main/java/.../scorekeeper/commands/` and shares one shape: parse args, resolve the target player, call the `ScoreKeeperPlugin` method, return `true` (consumed). Two behavioral details matter: - **Self-target default:** if a *player* runs a command and omits the name, they target *themselves*: `targetPlayer = (Player) sender`. (e.g. `ScoreGetCommand.java:44`, `ScoreAddCommand.java:48`, `ScoreResetCommand.java:47-49`.) - **RCON/console path:** if the sender is **not** a player (console/RCON), a player name is **required** — omitting it prints usage instead of acting (`ScoreGetCommand.java:46-48`, `ScoreAddCommand.java:45-47`, `ScoreResetCommand.java:44-46`). - **Name resolution:** `getServer().getPlayerExact(name)` — **exact, case-sensitive** lookup by the *currently online* name (`ScoreGetCommand.java:50`, `ScoreAddCommand.java:57`, `ScoreResetCommand.java:50`). A name that is not online yields `null` → "Can't find a player with that name". Note the *map key is a UUID*, but *lookup by name only works while that player is online* — you cannot change an offline player's score by name today. - **No permission nodes anywhere.** `plugin.yml` declares no `permission:`/`permissions:` and the code checks none. The README's note ("the commands aside from get are intended for admins … Permissions support is coming") is **intent, not enforcement** — a vanilla player can run `/score-add` today. ### 2.4 Reading a score (`/score-get`) `ScoreGetCommand.java:38-84` → `ScoreKeeperPlugin.getScore(player)` → `getPlayerScore(player)` (`ScoreKeeperPlugin.java:76-78, 100-106`). It returns the live integer (0 for a known-but- unwritten player, which also *materializes* a 0 entry, see §3.1). Output formatting ("Your score is N" vs. "PLAYER's score is N") depends only on whether the sender is the target or not — it carries no ranking or table. --- ## 3. The high-score-table algorithm *(task Q3)* ### 3.1 What exists: **nothing. It is aspirational.** There is **no high-score table, no ranking structure, no sort, no tie-break rule, no max entry count, and no decay/rotation** anywhere in the codebase. The task's premise ("the high-score table") reflects the **product intent** in the README, not the **code**. Concretely: - The README (`README.md:11`) says `/score-archive` *"Saves the player's score to a 'High Scores' table and resets their current score to 0."* - The manifest (`plugin.yml:18-20`) declares `/score-archive` with that very description. - But the command is a stub: `ScoreArchiveCommand.java:37-39` (`onCommand` body) replies *"archive command unimplemented"*, and the underlying `archiveScore` (`ScoreKeeperPlugin.java:72-74`) only logs and returns — it neither writes a table nor resets anything. Therefore the "algorithm" is: **no-op.** A new engineer asked to "implement the high-score table" is starting from zero; the design questions in §3.2 are **open**, not answered by code. ### 3.2 Open design questions the table must settle (no code today decides these) Since no implementation exists, these are *decisions to be made*, recorded here so the implementation task doesn't reinvent the debate: - **Storage/persistence format.** The load/save TODOs (`:47`, `:59`) say "to file"; `plugin.yml`/Bukkit convention favors YAML (`YamlConfiguration`), but JSON/SQLite are all viable. **Unchosen.** Persisting to `data/` via `getDataFolder()` is the idiomatic Bukkit path. - **What an entry is.** Today a live score is just `{uuid -> int}`. A high-score entry likely needs **player name + score + (timestamp?) + (date earned?)**. Name is *not* currently stored with the score, so a durable table must capture the name at archive time (a UUID-only entry can't render a leaderboard without the name being resolvable). - **Sorting / ordering.** Almost certainly **descending by score**. - **Tie-breaking.** Undefined. Candidate rules: by *score only*; by *earliest* archived first (stable, time-ordered); by *name* (alphabetical); or "first to reach that score." - **Max entries / cap.** Undefined. A leaderboard needs a cap (e.g. top 10 / top 30); today there is no cap because there is no table. - **Decay / rotation / time window.** None, and none described in docs — so the safe default is **"scores are permanent, no decay."** - **Reset semantics on archive.** README promises archive *resets to 0* *and* records. `ScoreArchiveCommand` must decide: does archiving also reset? Does it allow multi-entries (a player appearing more than once) or one row per player? All open. ### 3.3 Full lifecycle of a score: creation → (intended) display on the high-score table This is the acceptance-criterion walk-through. Each stage is marked **[REAL]** (in code now) or **[GAP]** (intended, not built). 1. **Player joins / acts** — a score *doesn't* exist yet. First interaction with the map is lazy (see stage 4a). **[REAL]** 2. **Admin records a score** — `admin: /score-add Alice 10`. Parsed in `ScoreAddCommand`, routed to `addScore`. The first time this runs for Alice, `getPlayerScore` **creates** her entry at 0 and returns it; then `10` is written. **[REAL]** 3. **Score accumulates** — later `/score-add Alice 5` → 15; `/score-subtract Alice 2` → 13; `/score-reset Alice` → 0. All in the in-memory map, live only. **[REAL]** 4. **Read** — `/score-get Alice` → "Alice's score is 13". No ranking shown. **[REAL]** 5. **Server restart** — `onDisable` *cannot* save (stub), `onEnable` *cannot* load (stub); the map is **lost**. Alice's 13 is gone; every score starts empty again. **[REAL] — this is the current data-loss reality.** 6. **Intended: archive to the high-score table** — `admin: /score-archive Alice` should freeze Alice's 13 into a durable, sorted leaderboard and reset her live score to 0, so it survives restarts. **[GAP]** — currently returns "archive command unimplemented". 7. **Intended: display on the high-score table** — a command (not yet built) renders the capped, sorted list. **[GAP]** — no such command, no structure to render. **Edge cases (explicitly, per the acceptance criteria):** - **First-time player / first write.** A player has no map entry until `getPlayerScore` is called, which **inserts `0` on first access** (`ScoreKeeperPlugin.java:100-106`). So a first `/score-add X 10` yields **10, not** `10 - 0` ambiguity, and a first `/score-subtract X 3` yields **−3** (no minimum-0 clamp). A first `/score-get X` returns **0** and *materializes* the entry at 0. This `get-or-create-0` behavior is the de-facto "first-time player" rule. **[REAL]** - **Ties.** **Undefined** because no table exists. When the table is built, decide a tie-break (§3.2). No code today can observe or sort ties — `HashMap` gives no order. **[GAP]** - **Table full.** **Undefined** because no cap exists. When a cap is introduced, decide what happens to the displaced entry: drop it, or "rotate" it into overflow. No code today enforces a maximum. **[GAP]** - **Offline / unknown name.** `getPlayerExact(name)` returns `null` for anyone not currently online or any misspelling → the command prints "Can't find a player with that name" and changes nothing. You **cannot** archive or reset an *offline* player by name today; by-UUID writes (if a future table stores names+UUIDs) would fix that. **[REAL]** - **Negative / large scores.** No clamp; negatives allowed, `int` overflow only near ~2.1 billion. **[REAL]** - **Double-spawn / relogin.** Keyed by `UUID`, **not name**, so a name change or two players sharing a name can't collide on the *live* map; but a *name* is never stored, so a future table that only persists the UUID can later fail to render a name. --- ## 4. Scoring formulas & weighting *(task Q4)* **None.** There is: - No formula, no multiplier, no combo/bonus/streak logic. - No weighting between action types. - No time-based decay or "points per game" normalization. Scores are **pure integer accumulators**: `score = Σ(adds) − Σ(subtracts)` over the session, resettable to 0 by `/score-reset` (intended: on `/score-archive`). The only "arithmetic" in the code is the `+`/`−` in `addScore`/`subtractScore` and the `0` floor written by `resetScore`. `int` semantics apply (wrapping overflow; no checked arithmetic). Any formula/weighting is a **future-design** decision, not encoded today. --- ## 5. Data-flow diagram (text) ``` ADMINISTRATOR / CONSOLE / RCON (no game events, no scheduler, no auto-scoring) │ types a command ▼ ┌─────────────────────────────┐ │ command executors │ commands/Score*Command.java │ parse args + resolve player│ getPlayerExact(name) ── must be ONLINE (name→UUID) │ (self-target if player) │ no permission checks └──────────────┬──────────────┘ │ calls ▼ ┌───────────────────────────────────────────────┐ │ ScoreKeeperPlugin (entry point; plugin.yml main)│ │ │ │ addScore / subtractScore / resetScore / setScore │ read-modify-write on... │ getScore (read) archiveScore (STUB)│ └──────────────┬───────────────────────┬──────────┘ │ read-modify-write │ (intended: snapshot→table, reset 0) ▼ ▼ live map: HashMap ╳ NOT IMPLEMENTED "score entry = one int per UUID" high-score table: default 0, no clamp, in RAM only ─ no structure, no sort, │ ─ no persistence, ├─ READ: /score-get → "N" ─ no cap/decay │ └─ LIFECYCLE: onEnable : load from file → TODO (stays {} ; lost on restart) onDisable : save to file → TODO (map discarded at shutdown) PERSISTENCE: none │ SCORE FORMULA: none │ EVENTS/TIMERS: none │ PERMISSIONS: none │ HIGH-SCORE TABLE: aspirational stub only ``` --- ## 6. Quick reference — "where to look first" | I want to understand… | Go to | |-----------------------|-------| | The entire live data model | `ScoreKeeperPlugin.java:38` (one `HashMap`) | | How a score changes | `addScore`/`subtractScore`/`resetScore`/`setScore` `:67-91` | | How a score is read | `getScore` `:76-78` → `getPlayerScore` `:100-106` (note get-or-create-0) | | The "high-score table" | **Doesn't exist** — see `archiveScore` stub `:72-74`; design open in §3.2 | | Persistence (save/load) | `onDisable` `:46-49`, `onEnable` `:59-60` — both `TODO`, not built | | Command behaviors | `commands/Score*Command.java` (self-target default; RCON requires a name; exact online-name lookup) | | What's declared/intended but not wired | `plugin.yml:18-20` (`/score-archive`), `README.md:11`, `README.md` notes | | Build/runtime target | `build.gradle` (paper-api 1.21.7, Java 21), `plugin.yml` (`api-version: 1.21`) | --- ## 7. Risks a new engineer should know (correctness gaps in the *current* live domain) These are real, not future-work — flagging because the doc's job is to prevent a new developer from assuming the system is more mature than it is: 1. **Data loss on restart.** No save/load (`:47`, `:59`). Every server boot wipes all scores. Any "leaderboard across sessions" is broken by design. 2. **No permissions.** Anyplayer can self-add points. README says this is by intent ("coming after I get archive to work") but it is not enforced. 3. **Race condition on add/subtract.** `read → compute → write` is not atomic and the `HashMap` is not thread-safe; concurrent command executions could lose an update. (Low likelihood today since commands are serial on one thread, but it's a latent bug for any async/event-driven scoring that gets added.) 4. **No minimum-0 / no validation of amount sign.** Subtracts produce negatives freely. 5. **Name lookups are online-only & exact.** Can't target offline players by name; case-sensitive; "Alice" ≠ "alice". 6. **No high-score table.** The flagship advertised feature (`/score-archive` → "High Scores" table) is a no-op; a new engineer must not expect ranking/persistence to work. --- ## 8. Summary for the synthesizer (`Project.md` § "domain model & scoring logic") Distilled, code-grounded, and honest: - **Model:** one `int` per player `UUID`, held in `ScoreKeeperPlugin._playerScores` (`HashMap`), default `0`. - **Recording:** manual, admin-driven commands; **no events/timers**; no permission guard. - **Persistence:** **none** — load/save are `TODO`; scores are lost on restart. - **High-score table:** **does not exist** — `/score-archive` is a stub; sorting/tie-break/ cap/decay are **undecided design items** (listed in §3.2). - **Formula/weighting:** **none** — plain `int` accumulation. - **Lifecycle:** create-on-first-access (0) → add/subtract/reset (live only) → read via `/score-get` → *intended* archive+reset + table display **not built** → lost on restart. - **Edge cases:** first-time/first-write ⇒ 0-or-delta, no floor; ties/table-full ⇒ undefined (no table yet); offline/unknown name ⇒ "can't find", unchanged. Everything below the "high-score table" line of the README is **future work**, and the write-up's job is to make that boundary explicit so the next team member isn't misled.