Added better currency and exchange information.

src/main/java/nl/andrewl/coyotecredit/model/Account.java

@@ -5,6 +5,9 @@ import lombok.Getter;
 import lombok.NoArgsConstructor;
 
 import javax.persistence.*;
+import java.math.BigDecimal;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 
 /**
@@ -31,5 +34,11 @@ public class Account {
 	@OneToMany(mappedBy = "account", fetch = FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true)
 	private Set<Balance> balances;
 
-
+	public Map<Currency, BigDecimal> getMappedBalances() {
+		Map<Currency, BigDecimal> b = new HashMap<>();
+		for (var bal : getBalances()) {
+			b.put(bal.getCurrency(), bal.getAmount());
+		}
+		return b;
+	}
 }

src/main/java/nl/andrewl/coyotecredit/model/Balance.java

@@ -19,6 +19,6 @@ public class Balance {
 	@ManyToOne(optional = false, fetch = FetchType.EAGER)
 	private Currency currency;
 
-	@Column(nullable = false, precision = 24, scale = 4)
+	@Column(nullable = false, precision = 24, scale = 10)
 	private BigDecimal amount;
 }

src/main/java/nl/andrewl/coyotecredit/model/Currency.java

@@ -3,6 +3,7 @@ package nl.andrewl.coyotecredit.model;
 import lombok.Getter;
 
 import javax.persistence.*;
+import java.util.Objects;
 
 /**
  * Represents a type of currency. This can be an actual fiat currency, or
@@ -10,6 +11,7 @@ import javax.persistence.*;
  * exchange.
  */
 @Entity
+@Table(uniqueConstraints = @UniqueConstraint(columnNames = {"identifier", "type"}))
 @Getter
 public class Currency {
 	@Id
@@ -19,9 +21,28 @@ public class Currency {
 	@Column(nullable = false)
 	private String identifier;
 
+	@Enumerated(EnumType.STRING)
+	private CurrencyType type;
+
 	@Column(nullable = false)
 	private String name;
 
 	@Column
 	private String description;
+
+	@Column(nullable = false)
+	private float minDenomination = 0.01f;
+
+	@Override
+	public boolean equals(Object other) {
+		if (!(other instanceof Currency c)) return false;
+		if (c.getId() != null && this.getId() != null) return this.getId().equals(c.getId());
+		return this.identifier.equals(c.getIdentifier()) &&
+				this.type.equals(c.getType());
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(this.identifier, this.type);
+	}
 }

src/main/java/nl/andrewl/coyotecredit/model/CurrencyType.java

@@ -0,0 +1,7 @@
+package nl.andrewl.coyotecredit.model;
+
+public enum CurrencyType {
+	FIAT,
+	CRYPTO,
+	STOCK
+}

src/main/java/nl/andrewl/coyotecredit/model/Exchange.java

@@ -3,6 +3,7 @@ package nl.andrewl.coyotecredit.model;
 import lombok.Getter;
 
 import javax.persistence.*;
+import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -21,11 +22,15 @@ public class Exchange {
 	@Column(nullable = false)
 	private String name;
 
-	@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
-	@JoinTable(
-			name = "exchange_supported_currency",
-			joinColumns = @JoinColumn(name = "currency_id"),
-			inverseJoinColumns = @JoinColumn(name = "exchange_id")
-	)
-	private Set<Currency> supportedCurrencies;
+	@OneToMany(mappedBy = "exchange")
+	private Set<ExchangePair> currencyPairs;
+
+	public Set<Currency> getSupportedCurrencies() {
+		Set<Currency> currencies = new HashSet<>();
+		for (var pair : getCurrencyPairs()) {
+			currencies.add(pair.getFromCurrency());
+			currencies.add(pair.getToCurrency());
+		}
+		return currencies;
+	}
 }

src/main/java/nl/andrewl/coyotecredit/model/ExchangePair.java

@@ -0,0 +1,30 @@
+package nl.andrewl.coyotecredit.model;
+
+import lombok.Getter;
+
+import javax.persistence.*;
+import java.math.BigDecimal;
+
+/**
+ * Represents a pair of currencies that can be exchanged at a set exchange rate.
+ */
+@Entity
+@Table(uniqueConstraints = @UniqueConstraint(columnNames = {"from_currency_id", "to_currency_id", "exchange_id"}))
+@Getter
+public class ExchangePair {
+	@Id
+	@GeneratedValue(strategy = GenerationType.IDENTITY)
+	private Long id;
+
+	@ManyToOne(optional = false)
+	private Exchange exchange;
+
+	@ManyToOne(optional = false)
+	private Currency fromCurrency;
+
+	@ManyToOne(optional = false)
+	private Currency toCurrency;
+
+	@Column(nullable = false, precision = 24, scale = 10)
+	private BigDecimal exchangeRate = new BigDecimal("1.0");
+}

src/main/java/nl/andrewl/coyotecredit/service/AccountService.java

@@ -1,5 +1,6 @@
 package nl.andrewl.coyotecredit.service;
 
+import lombok.AllArgsConstructor;
 import lombok.RequiredArgsConstructor;
 import nl.andrewl.coyotecredit.dao.AccountRepository;
 import nl.andrewl.coyotecredit.model.Account;
@@ -9,6 +10,7 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.server.ResponseStatusException;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Service
@@ -29,13 +31,36 @@ public class AccountService {
 				.toList();
 	}
 
+	public static class FullAccountData {
+		public long id;
+		public String number;
+		public String exchangeName;
+		public List<BalanceData> balances;
+	}
+
+	@AllArgsConstructor
+	public static class BalanceData {
+		public String currencyIdentifier;
+		public String amount;
+	}
+
 	@Transactional(readOnly = true)
-	public AccountData getAccountData(User user, long accountId) {
+	public FullAccountData getAccountData(User user, long accountId) {
 		Account account = accountRepository.findById(accountId)
 				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+
 		if (!account.getUser().getId().equals(user.getId())) {
 			throw new ResponseStatusException(HttpStatus.NOT_FOUND);
 		}
-		return new AccountData(account.getId(), account.getNumber(), account.getExchange().getName());
+		FullAccountData d = new FullAccountData();
+		d.id = account.getId();
+		d.number = account.getNumber();
+		d.exchangeName = account.getExchange().getName();
+		List<BalanceData> balanceData = new ArrayList<>();
+		for (var bal : account.getBalances()) {
+			balanceData.add(new BalanceData(bal.getCurrency().getIdentifier(), bal.getAmount().toPlainString()));
+		}
+		d.balances = balanceData;
+		return d;
 	}
 }

src/main/resources/templates/account.html

@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html
+        lang="en"
+        xmlns:th="http://www.thymeleaf.org"
+>
+<head>
+    <title>CC - Account</title>
+</head>
+
+<body>
+    <h1>Account <span th:text="${account.number}"></span></h1>
+
+    <h3>Balance</h3>
+    <ul>
+        <li th:each="balance : ${account.balances}">
+            <span th:text="${balance.currencyIdentifier}"></span> - <span th:text="${balance.amount}"></span>
+        </li>
+    </ul>
+</body>