Rewrote the escaping logic - hopefully better readable

Signed-off-by: Jurrie Overgoor <[email protected]>

jkube-kit/common/src/main/java/org/eclipse/jkube/kit/common/util/TemplateUtil.java

@@ -13,17 +13,32 @@
  */
 package org.eclipse.jkube.kit.common.util;
 
+import java.lang.invoke.MethodHandles;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class TemplateUtil {
-  private static final String HELM_DIRECTIVE_REGEX = "\\{\\{.*\\}\\}";
+  private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+
+  private static final String HELM_END_TAG = "}}";
+  private static final String HELM_START_TAG = "{{";
+
+  private static final String YAML_HELM_ESCAPE_KEY = "escapedHelm";
+  private static final String YAML_LIST_TAG = "-";
+  private static final String YAML_KEY_VALUE_SEPARATOR = ": ";
 
   private TemplateUtil() {
   }
 
   /**
-   * This function will replace all Helm directives with a valid Yaml line containing the base64 encoded Helm directive.
+   * This function will replace all single line Helm directives with a valid Yaml line containing the base64 encoded Helm
+   * directive.
+   * Helm directives that are values (so not a full line) will be left alone.
    *
    * Helm lines that are by themselves will be converted like so:
    * <br/>
@@ -32,17 +47,17 @@ private TemplateUtil() {
    * <pre>
    * {{- $myDate := .Value.date }}
    * {{ include "something" . }}
+   * myKey: "Regular line"
    * someKey: {{ a bit of Helm }}
-   * someOtherKey: {{ another bit of Helm }}
    * </pre>
    *
    * Output:
    *
    * <pre>
-   * escapedHelm0: BASE64STRINGOFCHARACTERS=
-   * escapedHelm1: ANOTHERBASE64STRING=
-   * someKey: escapedHelmValueBASE64STRING==
-   * someOtherKey: escapedHelmValueBASE64STRING
+   * escapedHelm0: e3stICA6PSAuVmFsdWUuZGF0ZSB9fQ==
+   * escapedHelm1: e3sgaW5jbHVkZSBzb21ldGhpbmcgLiB9fQ==
+   * myKey: "Regular line"
+   * someKey: {{ a bit of Helm }}
    * </pre>
    *
    * The <strong>escapedHelm</strong> and <strong>escapedHelmValue</strong> flags are needed for unescaping.
@@ -52,7 +67,58 @@ private TemplateUtil() {
    * @see #unescapeYamlTemplate(String)
    */
   public static String escapeYamlTemplate(final String yaml) {
-    return escapeYamlTemplateLines(escapeYamlTemplateValues(yaml));
+    final AtomicLong helmEscapeIndex = new AtomicLong();
+    return iterateOverLines(yaml,
+        (line, lineEnding, lineNumber) -> escapeYamlLine(line, lineNumber, helmEscapeIndex) + lineEnding);
+  }
+
+  private static String escapeYamlLine(final String line, final long lineNumber, final AtomicLong helmEscapeIndex) {
+    if (line.trim().startsWith(HELM_START_TAG)) {
+      // Line starts with optional indenting and then '{{', so replace whole line
+      checkHelmStartAndEndTags(line, lineNumber);
+
+      final int startOfHelm = line.indexOf(HELM_START_TAG);
+      final String indentation = line.substring(0, startOfHelm);
+      final String base64EncodedLine = Base64Util.encodeToString(line.substring(startOfHelm));
+      final long currentHelmEscapeIndex = helmEscapeIndex.getAndIncrement();
+      return indentation + YAML_HELM_ESCAPE_KEY + currentHelmEscapeIndex + YAML_KEY_VALUE_SEPARATOR + base64EncodedLine;
+    } else if (line.trim().startsWith(YAML_LIST_TAG)) {
+      // Line starts with optional indenting and then '-'. Strip the '-', parse again, readd the '-'.
+      final int startOfRestOfLine = line.indexOf(YAML_LIST_TAG) + YAML_LIST_TAG.length();
+      final String prefix = line.substring(0, startOfRestOfLine);
+      final String restOfLine = line.substring(startOfRestOfLine);
+      return prefix + escapeYamlLine(restOfLine, lineNumber, helmEscapeIndex);
+    } else if (line.contains(YAML_KEY_VALUE_SEPARATOR)) {
+      // Line is a "key: value" line. Strip the key, parse again, readd the key.
+      final int startOfRestOfLine = line.indexOf(YAML_KEY_VALUE_SEPARATOR) + YAML_KEY_VALUE_SEPARATOR.length();
+      final String key = line.substring(0, startOfRestOfLine);
+      final String value = line.substring(startOfRestOfLine);
+
+      if (value.trim().startsWith(HELM_START_TAG)) {
+        checkHelmStartAndEndTags(value, lineNumber);
+
+        final String base64EncodedLine = Base64Util.encodeToString(value);
+        return key + YAML_HELM_ESCAPE_KEY + base64EncodedLine;
+      } else {
+        // Value was a regular value
+        return line;
+      }
+    } else {
+      // Line was a regular line
+      return line;
+    }
+  }
+
+  private static void checkHelmStartAndEndTags(final String line, final long lineNumber) {
+    final int startCount = StringUtils.countMatches(line, HELM_START_TAG);
+    final int endCount = StringUtils.countMatches(line, HELM_END_TAG);
+    if (startCount != endCount) {
+      LOG.warn("Found {} Helm start tag{} ('{}') but {} end tag{} ('{}') on line {}. "
+          + "Expected this to be equal! Note that multi-line Helm directives are not supported.",
+          startCount, startCount == 1 ? "" : "s", HELM_START_TAG,
+              endCount, endCount == 1 ? "" : "s", HELM_END_TAG,
+                  lineNumber);
+    }
   }
 
   /**
@@ -64,101 +130,63 @@ public static String escapeYamlTemplate(final String yaml) {
    * @return the Yaml that was originally provided to {@link #escapeYamlTemplate(String)}
    * @see #escapeYamlTemplate(String)
    */
-  public static String unescapeYamlTemplate(final String template) {
-    return unescapeYamlTemplateLines(unescapeYamlTemplateValues(template));
+  public static String unescapeYamlTemplate(final String yaml) {
+    return iterateOverLines(yaml, (line, lineEnding, lineNumber) -> unescapeYamlLine(line) + lineEnding);
   }
 
-  /**
-   * This function is responsible for escaping the Helm directives that are stand-alone.
-   * For example:
-   *
-   * <pre>
-   * {{ include "something" . }}
-   * </pre>
-   *
-   * @see #unescapeYamlTemplateLines(String)
-   */
-  private static String escapeYamlTemplateLines(String template) {
-    long escapedHelmIndex = 0;
-    final Pattern compile = Pattern.compile("^( *-? *)(" + HELM_DIRECTIVE_REGEX + ".*)$", Pattern.MULTILINE);
-    Matcher matcher = compile.matcher(template);
-    while (matcher.find()) {
-      final String indentation = matcher.group(1);
-      final String base64Line = Base64Util.encodeToString(matcher.group(2));
-      template = matcher.replaceFirst(indentation + "escapedHelm" + escapedHelmIndex + ": " + base64Line);
-      matcher = compile.matcher(template);
-      escapedHelmIndex++;
+  private static String unescapeYamlLine(final String line) {
+    if (line.trim().startsWith(YAML_HELM_ESCAPE_KEY)) {
+      // Line starts with optional indenting and then 'escapedHelm', so replace whole line
+      final int endOfIndentation = line.indexOf(YAML_HELM_ESCAPE_KEY);
+      final int startOfBase64Helm = line.indexOf(YAML_KEY_VALUE_SEPARATOR) + YAML_KEY_VALUE_SEPARATOR.length();
+      final String indentation = line.substring(0, endOfIndentation);
+      final String base64DecodedLine = Base64Util.decodeToString(line.substring(startOfBase64Helm));
+      return indentation + base64DecodedLine;
+    } else if (line.trim().startsWith(YAML_LIST_TAG)) {
+      // Line starts with optional indenting and then '-'. Strip the '-', parse again, readd the '-'.
+      final int startOfRestOfLine = line.indexOf(YAML_LIST_TAG) + YAML_LIST_TAG.length();
+      final String prefix = line.substring(0, startOfRestOfLine);
+      final String restOfLine = line.substring(startOfRestOfLine);
+      return prefix + unescapeYamlLine(restOfLine);
+    } else if (line.contains(YAML_KEY_VALUE_SEPARATOR)) {
+      // Line is a "key: value" line. Strip the key, parse again, readd the key.
+      final int startOfRestOfLine = line.indexOf(YAML_KEY_VALUE_SEPARATOR) + YAML_KEY_VALUE_SEPARATOR.length();
+      final String key = line.substring(0, startOfRestOfLine);
+      final String value = line.substring(startOfRestOfLine);
+      if (value.trim().startsWith(YAML_HELM_ESCAPE_KEY)) {
+        final String base64DecodedLine = Base64Util.decodeToString(value.substring(YAML_HELM_ESCAPE_KEY.length()));
+        return key + base64DecodedLine;
+      } else {
+        // Value was a regular value
+        return line;
+      }
+    } else {
+      // Line was a regular line
+      return line;
     }
-    return template;
   }
 
-  /**
-   * This function is responsible for reinstating the stand-alone Helm directives.
-   * For example:
-   *
-   * <pre>
-   * BASE64STRINGOFCHARACTERS=
-   * </pre>
-   *
-   * It is the opposite of {@link #escapeYamlTemplateLines(String)}.
-   *
-   * @see #escapeYamlTemplateLines(String)
-   */
-  private static String unescapeYamlTemplateLines(String template) {
-    final Pattern compile = Pattern.compile("^( *-? *)escapedHelm[\\d]+: \"?(.*?)\"?$", Pattern.MULTILINE);
-    Matcher matcher = compile.matcher(template);
-    while (matcher.find()) {
-      final String indentation = matcher.group(1);
-      final String helmLine = Base64Util.decodeToString(matcher.group(2));
-      template = matcher.replaceFirst(indentation + helmLine.replace("$", "\\$"));
-      matcher = compile.matcher(template);
-    }
-    return template;
-  }
+  private static String iterateOverLines(final String yaml, final IterateOverLinesCallback iterator) {
+    final Matcher matcher = Pattern.compile("(.*)(\\R|$)").matcher(yaml);
+    final StringBuilder result = new StringBuilder();
+    int index = 0;
+    long lineNumber = 0;
+    while (matcher.find(index) && matcher.start() != matcher.end()) {
+      final String line = matcher.group(1);
+      final String lineEnding = matcher.group(2);
 
-  /**
-   * This function is responsible for escaping the Helm directives that are Yaml values.
-   * For example:
-   *
-   * <pre>
-   * someKey: {{ a bit of Helm }}
-   * </pre>
-   *
-   * @see #unescapeYamlTemplateValues(String)
-   */
-  private static String escapeYamlTemplateValues(String template) {
-    final Pattern compile = Pattern.compile("^( *[^ ]+ *): *(" + HELM_DIRECTIVE_REGEX + ".*)$", Pattern.MULTILINE);
-    Matcher matcher = compile.matcher(template);
-    while (matcher.find()) {
-      final String indentation = matcher.group(1);
-      final String base64Value = Base64Util.encodeToString(matcher.group(2));
-      template = matcher.replaceFirst(indentation + ": escapedHelmValue" + base64Value);
-      matcher = compile.matcher(template);
+      final String escapedYamlLine = iterator.onLine(line, lineEnding, lineNumber);
+      lineNumber++;
+
+      result.append(escapedYamlLine);
+
+      index = matcher.end();
     }
-    return template;
+    return result.toString();
   }
 
-  /**
-   * This function is responsible for reinstating the Helm directives that were Yaml values.
-   * For example:
-   *
-   * <pre>
-   * someKey: escapedHelmValueBASE64STRING==
-   * </pre>
-   *
-   * It is the opposite of {@link #escapeYamlTemplateValues(String)}.
-   *
-   * @see #escapeYamlTemplateValues(String)
-   */
-  private static String unescapeYamlTemplateValues(String template) {
-    final Pattern compile = Pattern.compile("^( *[^ ]+ *): *\"?escapedHelmValue(.*?)\"?$", Pattern.MULTILINE);
-    Matcher matcher = compile.matcher(template);
-    while (matcher.find()) {
-      final String indentation = matcher.group(1);
-      final String helmValue = Base64Util.decodeToString(matcher.group(2));
-      template = matcher.replaceFirst(indentation + ": " + helmValue.replace("$", "\\$"));
-      matcher = compile.matcher(template);
-    }
-    return template;
+  @FunctionalInterface
+  private interface IterateOverLinesCallback {
+    String onLine(String input, String lineEnding, long lineNumber);
   }
 }