impl welcomer feature

src/main/java/cc/fascinated/bat/features/welcomer/WelcomerPlaceholders.java

@@ -0,0 +1,82 @@
+package cc.fascinated.bat.features.welcomer;
+
+import cc.fascinated.bat.model.BatGuild;
+import cc.fascinated.bat.model.BatUser;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+import java.util.Date;
+
+/**
+ * @author Fascinated (fascinated7)
+ */
+@AllArgsConstructor
+@Getter
+public enum WelcomerPlaceholders {
+    USER_MENTION("{user_mention}", BatUser.class) {
+        @Override
+        public String replacePlaceholder(Object object) {
+            return ((BatUser) object).getDiscordUser().getAsMention();
+        }
+    },
+    USER_NAME("{user_name}", BatUser.class) {
+        @Override
+        public String replacePlaceholder(Object object) {
+            return ((BatUser) object).getName();
+        }
+    },
+    GUILD_NAME("{guild_name}", BatGuild.class) {
+        @Override
+        public String replacePlaceholder(Object object) {
+            return ((BatGuild) object).getName();
+        }
+    },
+    JOIN_DATE("{join_date}", null) {
+        @Override
+        public String replacePlaceholder(Object object) {
+            return "<t:%s>".formatted(new Date().toInstant().getEpochSecond());
+        }
+    };
+
+    /**
+     * The placeholder string that will get replaced
+     */
+    private final String placeholder;
+
+    /**
+     * The class that the placeholder is associated with
+     */
+    private final Class<?> clazz;
+
+    /**
+     * Replaces the placeholder with the string based on the overridden method
+     *
+     * @param object The object to replace the placeholder with
+     * @return The string with the placeholder replaced
+     */
+    public String replacePlaceholder(Object object) {
+        if (clazz != null && !clazz.isInstance(object)) {
+            throw new IllegalArgumentException("Object is not an instance of " + clazz.getName());
+        }
+        return null;
+    }
+
+    /**
+     * Replaces all placeholders in a message with the objects provided
+     *
+     * @param message The message to replace the placeholders in
+     * @param objects The objects to replace the placeholders with
+     * @return The message with the placeholders replaced
+     */
+    public static String replaceAllPlaceholders(String message, Object... objects) {
+        for (WelcomerPlaceholders placeholder : values()) {
+            for (Object object : objects) {
+                if (placeholder.getClazz() != null && !placeholder.getClazz().isInstance(object)) {
+                    continue;
+                }
+                message = message.replace(placeholder.getPlaceholder(), placeholder.replacePlaceholder(object));
+            }
+        }
+        return message;
+    }
+}