add password strength error parser

Author: lbalmaceda

src/main/java/com/auth0/exception/APIException.java

@@ -74,7 +74,13 @@ private static String obtainExceptionMessage(Map<String, Object> values) {
             return (String) values.get("error_description");
         }
         if (values.containsKey("description")) {
-            return (String) values.get("description");
+            Object description = values.get("description");
+            if(description instanceof String) {
+                return (String) description;
+            } else{
+                PasswordStrengthErrorParser policy = new PasswordStrengthErrorParser((Map<String, Object>) description);
+                return policy.getDescription();
+            }
         }
         if (values.containsKey("message")) {
             return (String) values.get("message");

src/main/java/com/auth0/exception/PasswordStrengthErrorParser.java

@@ -0,0 +1,96 @@
+package com.auth0.exception;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+@SuppressWarnings("unchecked")
+class PasswordStrengthErrorParser {
+    private static final String RULE_TYPE_LENGTH_AT_LEAST = "lengthAtLeast";
+    private static final String RULE_TYPE_CONTAINS_AT_LEAST = "containsAtLeast";
+    private static final String RULE_TYPE_SHOULD_CONTAIN = "shouldContain";
+    private static final String RULE_TYPE_IDENTICAL_CHARS = "identicalChars";
+
+    private static final String KEY_RULES = "rules";
+    private static final String KEY_CODE = "code";
+    private static final String KEY_VERIFIED = "verified";
+    private static final String KEY_FORMAT = "format";
+    private static final String KEY_ITEMS = "items";
+    private static final String KEY_MESSAGE = "message";
+
+    private String description;
+
+    PasswordStrengthErrorParser(Map<String, Object> descriptionMap) {
+        List<Map<String, Object>> rules = (List<Map<String, Object>>) descriptionMap.get(KEY_RULES);
+        parseRules(rules);
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    private void parseRules(List<Map<String, Object>> rules) {
+        List<String> items = new ArrayList<>();
+        for (Map<String, Object> rule : rules) {
+            boolean isVerified = (boolean) rule.get(KEY_VERIFIED);
+            if (isVerified) {
+                continue;
+            }
+            String code = (String) rule.get(KEY_CODE);
+            switch (code) {
+                case RULE_TYPE_LENGTH_AT_LEAST:
+                    items.add(asLengthAtLeast(rule));
+                    break;
+                case RULE_TYPE_IDENTICAL_CHARS:
+                    items.add(asIdenticalChars(rule));
+                    break;
+                case RULE_TYPE_CONTAINS_AT_LEAST:
+                case RULE_TYPE_SHOULD_CONTAIN:
+                    items.add(asContainsCharset(rule));
+                    break;
+            }
+        }
+
+        this.description = joinStrings("; ", items);
+    }
+
+    private String asLengthAtLeast(Map<String, Object> rule) {
+        List<Number> length = (List<Number>) rule.get(KEY_FORMAT);
+        String message = (String) rule.get(KEY_MESSAGE);
+        return String.format(message, length.get(0).intValue());
+    }
+
+    private String asContainsCharset(Map<String, Object> rule) {
+        List<Map<String, Object>> itemsList = (List<Map<String, Object>>) rule.get(KEY_ITEMS);
+        List<String> items = new ArrayList<>();
+        for (Map<String, Object> i : itemsList) {
+            items.add((String) i.get(KEY_MESSAGE));
+        }
+        String requiredItems = joinStrings(", ", items);
+        String message = (String) rule.get(KEY_MESSAGE);
+
+        if (rule.containsKey(KEY_FORMAT)) {
+            List<Number> quantity = (List<Number>) rule.get(KEY_FORMAT);
+            message = String.format(message, quantity.get(0).intValue(), quantity.get(1).intValue());
+        }
+
+        return String.format("%s %s", message, requiredItems);
+    }
+
+    private String asIdenticalChars(Map<String, Object> rule) {
+        List<Object> example = (List<Object>) rule.get(KEY_FORMAT);
+        Number count = (Number) example.get(0);
+        String message = (String) rule.get(KEY_MESSAGE);
+        return String.format(message, count.intValue(), example.get(1));
+    }
+
+    private String joinStrings(String delimiter, List<String> items) {
+        StringBuilder sb = new StringBuilder();
+        int i;
+        for (i = 0; i < items.size() - 1; i++) {
+            sb.append(items.get(i)).append(delimiter);
+        }
+        sb.append(items.get(i));
+        return sb.toString();
+    }
+}