| | 1 | = Use-case model = |
| | 2 | |
| | 3 | == Actors / Roles == |
| | 4 | |
| | 5 | '''Visitor''' – Anyone using EduBerza without an account, who can look at public market |
| | 6 | information, create an account, and log in. |
| | 7 | |
| | 8 | '''Trader''' – A registered, logged-in user who deposits virtual funds, places market buy and |
| | 9 | sell orders, follows the value of their portfolio, and keeps a watchlist of assets they want to |
| | 10 | monitor. |
| | 11 | |
| | 12 | '''Market Simulator''' – An external automated system (the bot in `bots/`) that writes simulated |
| | 13 | trades and candles into the database so prices move without a connection to a real exchange. |
| | 14 | |
| | 15 | == Use-Cases == |
| | 16 | |
| | 17 | === Visitor === |
| | 18 | |
| | 19 | * [wiki:UseCase0001 UC0001] – '''Register new account''' – Visitor creates an account with a |
| | 20 | unique username and e-mail; the password is stored as a SHA-256 hash. |
| | 21 | * [wiki:UseCase0002 UC0002] – '''Log in''' – Visitor authenticates with username and password so |
| | 22 | the system treats every following action as a Trader. |
| | 23 | |
| | 24 | === Trader === |
| | 25 | |
| | 26 | * [wiki:UseCase0003 UC0003] – '''Deposit virtual funds''' – Trader tops up their virtual cash |
| | 27 | balance; the user row and the ledger are written in one transaction. |
| | 28 | * [wiki:UseCase0004 UC0004] – '''Place market BUY order''' – Trader buys a crypto asset at the |
| | 29 | current market price, which debits cash and upserts the holding at a running weighted-average |
| | 30 | price. |
| | 31 | * [wiki:UseCase0005 UC0005] – '''Place market SELL order''' – Trader sells part or all of a |
| | 32 | holding at the current market price, which credits cash and preserves the cost basis. |
| | 33 | * [wiki:UseCase0006 UC0006] – '''View portfolio and transaction history''' – Trader inspects |
| | 34 | current holdings, unrealised P/L, cash balances and the most recent ledger entries. |
| | 35 | * [wiki:UseCase0007 UC0007] – '''Manage watchlist''' – Trader lists, adds and removes crypto |
| | 36 | assets on a personal watchlist, where adding an asset already on the list is a no-op. |
| | 37 | |
| | 38 | === Market Simulator === |
| | 39 | |
| | 40 | The Market Simulator initiates no use case of its own. It participates in |
| | 41 | [wiki:UseCase0004 UC0004] and [wiki:UseCase0005 UC0005] indirectly, by keeping |
| | 42 | `project.market_trades` populated so that `project.v_latest_prices` returns a current price for |
| | 43 | every active market. |
| | 44 | |
| | 45 | == Use-case model diagram == |
| | 46 | |
| | 47 | {{{#!comment |
| | 48 | The diagram is optional for P3. Attach the exported image to this wiki page as |
| | 49 | use_case_diagram.png and then replace this comment with: |
| | 50 | |
| | 51 | [[Image(use_case_diagram.png)]] |
| | 52 | }}} |
| | 53 | |
| | 54 | == Detailed Use-Cases == |
| | 55 | |
| | 56 | The following use-cases are documented in detail, with SQL tested against the P2 database: |
| | 57 | |
| | 58 | * [wiki:UseCase0001 UseCase0001] – Visitor registers a new account |
| | 59 | * [wiki:UseCase0002 UseCase0002] – Visitor logs in |
| | 60 | * [wiki:UseCase0003 UseCase0003] – Trader deposits virtual funds |
| | 61 | * [wiki:UseCase0004 UseCase0004] – Trader places a market BUY order |
| | 62 | * [wiki:UseCase0005 UseCase0005] – Trader places a market SELL order |
| | 63 | * [wiki:UseCase0006 UseCase0006] – Trader views portfolio and transaction history |
| | 64 | * [wiki:UseCase0007 UseCase0007] – Trader manages a watchlist |
| | 65 | |
| | 66 | == Realization details on selection of the most important use cases == |
| | 67 | |
| | 68 | This is a solo project, so '''at least 3 use cases''' are required. '''7 use cases''' are |
| | 69 | documented, for a safety margin. All seven are implemented in the P4 prototype; see `server/` |
| | 70 | for the Go source and [wiki:PrototypeImplementation] for the documented runs. |
| | 71 | |
| | 72 | ||=Use case=||=Importance=||=Why it was selected=|| |
| | 73 | ||[wiki:UseCase0001 UC0001 – Register]||High||Nothing else works without it; demonstrates `INSERT` with a uniqueness check.|| |
| | 74 | ||[wiki:UseCase0002 UC0002 – Log in]||High||Authenticates every Trader action; demonstrates `SELECT` with parameter binding.|| |
| | 75 | ||[wiki:UseCase0003 UC0003 – Deposit]||High||Shows a multi-row transaction: `UPDATE users` plus `INSERT INTO transactions`.|| |
| | 76 | ||[wiki:UseCase0004 UC0004 – Buy]||Very high||Core of the exchange: `INSERT orders`, `UPDATE users`, upsert `holdings`, ledger entry, market trade.|| |
| | 77 | ||[wiki:UseCase0005 UC0005 – Sell]||Very high||Dual of Buy; demonstrates row-level `FOR UPDATE` locking and cost-basis bookkeeping.|| |
| | 78 | ||[wiki:UseCase0006 UC0006 – Portfolio]||High||Demonstrates joins over `holdings`, `markets` and `crypto`, and the `v_portfolio` view.|| |
| | 79 | ||[wiki:UseCase0007 UC0007 – Watchlist]||Medium||Demonstrates N–M relation handling and `ON CONFLICT` upsert semantics.|| |
