Rename "Database" to "Vault"

We decided on calling the state file the "vault" a while back. This patch makes
the naming consistent across the codebase. I left "DatabaseImporter" classes
alone, because I'm not sure what a better name for those would be.

app/src/main/java/com/beemdevelopment/aegis/vault/VaultEntry.java

@@ -0,0 +1,167 @@
+package com.beemdevelopment.aegis.vault;
+
+import com.beemdevelopment.aegis.encoding.Base64;
+import com.beemdevelopment.aegis.encoding.Base64Exception;
+import com.beemdevelopment.aegis.otp.GoogleAuthInfo;
+import com.beemdevelopment.aegis.otp.OtpInfo;
+import com.beemdevelopment.aegis.otp.OtpInfoException;
+import com.beemdevelopment.aegis.otp.TotpInfo;
+import com.beemdevelopment.aegis.util.UUIDMap;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.Arrays;
+import java.util.Objects;
+import java.util.UUID;
+
+public class VaultEntry extends UUIDMap.Value {
+    private String _name = "";
+    private String _issuer = "";
+    private String _group;
+    private OtpInfo _info;
+    private byte[] _icon;
+
+    private VaultEntry(UUID uuid, OtpInfo info) {
+        super(uuid);
+        _info = info;
+    }
+
+    public VaultEntry(OtpInfo info) {
+        super();
+        _info = info;
+    }
+
+    public VaultEntry(OtpInfo info, String name, String issuer) {
+        this(info);
+        setName(name);
+        setIssuer(issuer);
+    }
+
+    public VaultEntry(GoogleAuthInfo info) {
+        this(info.getOtpInfo(), info.getAccountName(), info.getIssuer());
+    }
+
+    public JSONObject toJson() {
+        JSONObject obj = new JSONObject();
+
+        try {
+            obj.put("type", _info.getType());
+            obj.put("uuid", getUUID().toString());
+            obj.put("name", _name);
+            obj.put("issuer", _issuer);
+            obj.put("group", _group);
+            obj.put("icon", _icon == null ? JSONObject.NULL : Base64.encode(_icon));
+            obj.put("info", _info.toJson());
+        } catch (JSONException e) {
+            throw new RuntimeException(e);
+        }
+
+        return obj;
+    }
+
+    public static VaultEntry fromJson(JSONObject obj) throws JSONException, OtpInfoException, Base64Exception {
+        // if there is no uuid, generate a new one
+        UUID uuid;
+        if (!obj.has("uuid")) {
+            uuid = UUID.randomUUID();
+        } else {
+            uuid = UUID.fromString(obj.getString("uuid"));
+        }
+
+        OtpInfo info = OtpInfo.fromJson(obj.getString("type"), obj.getJSONObject("info"));
+        VaultEntry entry = new VaultEntry(uuid, info);
+        entry.setName(obj.getString("name"));
+        entry.setIssuer(obj.getString("issuer"));
+        entry.setGroup(obj.optString("group", null));
+
+        Object icon = obj.get("icon");
+        if (icon != JSONObject.NULL) {
+            entry.setIcon(Base64.decode((String) icon));
+        }
+
+        return entry;
+    }
+
+    public String getName() {
+        return _name;
+    }
+
+    public String getIssuer() {
+        return _issuer;
+    }
+
+    public String getGroup() {
+        return _group;
+    }
+
+    public byte[] getIcon() {
+        return _icon;
+    }
+
+    public OtpInfo getInfo() {
+        return _info;
+    }
+
+    public void setName(String name) {
+        _name = name;
+    }
+
+    public void setIssuer(String issuer) {
+        _issuer = issuer;
+    }
+
+    public void setGroup(String group) {
+        _group = group;
+    }
+
+    public void setInfo(OtpInfo info) {
+        _info = info;
+    }
+
+    public void setIcon(byte[] icon) {
+        _icon = icon;
+    }
+
+    public boolean hasIcon() {
+        return _icon != null;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof VaultEntry)) {
+            return false;
+        }
+
+        VaultEntry entry = (VaultEntry) o;
+        return super.equals(entry) && equivalates(entry);
+    }
+
+    /**
+     * Reports whether this entry is equivalent to the given entry. The UUIDs of these
+     * entries are ignored during the comparison, so they are not necessarily the same
+     * instance.
+     */
+    public boolean equivalates(VaultEntry entry) {
+        return getName().equals(entry.getName())
+                && getIssuer().equals(entry.getIssuer())
+                && Objects.equals(getGroup(), entry.getGroup())
+                && getInfo().equals(entry.getInfo())
+                && Arrays.equals(getIcon(), entry.getIcon());
+    }
+
+    /**
+     * Reports whether this entry has its values set to the defaults.
+     */
+    public boolean isDefault() {
+        return equivalates(getDefault());
+    }
+
+    public static VaultEntry getDefault() {
+        try {
+            return new VaultEntry(new TotpInfo(null));
+        } catch (OtpInfoException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}