feat: add log masking feature

code/src/main/kotlin/com/expediagroup/sdk/core/common/Feature.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2024 Expedia, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.expediagroup.sdk.core.common
+
+/**
+ * Interface representing a feature that can be enabled.
+ * Implementations of this interface should provide the logic for enabling the feature.
+ */
+internal interface Feature {
+    /**
+     * Enables the feature.
+     * This method should contain the logic required to activate or enable the feature.
+     */
+    fun enable()
+}

code/src/main/kotlin/com/expediagroup/sdk/core/logging/masking/AbstractLogMaskingFeature.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2024 Expedia, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.expediagroup.sdk.core.logging.masking
+
+import com.expediagroup.sdk.core.common.Feature
+
+/**
+ * Interface representing the configuration for masking.
+ */
+internal abstract class AbstractLogMaskingFeature: Feature {
+    /**
+     * A set of globally masked fields.
+     *
+     * @return A set of strings representing the global masked fields.
+     */
+    open val globalMaskedFields: Set<String>
+        get() = emptySet()
+
+    /**
+     * A set of path-specific masked fields.
+     *
+     * @return A set of lists of strings representing the path masked fields.
+     */
+    open val pathMaskedFields: Set<List<String>>
+        get() = emptySet()
+
+    override fun enable() {
+        mask.addPatternIfNotExists(
+            *MaskingPatternBuilder().apply {
+                globalFields(*globalMaskedFields.toTypedArray())
+                pathFields(*pathMaskedFields.toTypedArray())
+            }.build().toTypedArray()
+        )
+    }
+}

code/src/main/kotlin/com/expediagroup/sdk/core/logging/masking/LogMasker.kt

@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2024 Expedia, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.expediagroup.sdk.core.logging.masking
+
+import com.ebay.ejmask.api.MaskingPattern
+
+/**
+ * Interface for pattern-based masking.
+ */
+internal interface PatternBasedMask : (String) -> String {
+    /**
+     * Adds masking patterns if they do not already exist.
+     *
+     * @param maskingPatterns Vararg of MaskingPattern to be added.
+     * @return True if patterns were added, false if they already existed.
+     */
+    fun addPatternIfNotExists(vararg maskingPatterns: MaskingPattern): Boolean
+
+    /**
+     * Retrieves the list of current masking patterns.
+     *
+     * @return A list of MaskingPattern.
+     */
+    fun patterns(): List<MaskingPattern>
+
+    /**
+     * Clears all existing masking patterns.
+     */
+    fun clear()
+}
+
+/**
+ * Object implementing the PatternBasedMask interface.
+ */
+internal val mask = object : PatternBasedMask {
+    val patterns: MutableList<MaskingPattern> = mutableListOf()
+
+    /**
+     * Applies all masking patterns to the input string.
+     *
+     * @param input The input string to be masked.
+     * @return The masked string.
+     */
+    override fun invoke(input: String): String {
+        var masked = input
+
+        patterns.forEach { pattern: MaskingPattern ->
+            masked = pattern.replaceAll(masked)
+        }
+
+        return masked
+    }
+
+    /**
+     * Retrieves the list of current masking patterns.
+     *
+     * @return A list of MaskingPattern.
+     */
+    override fun patterns() =
+        this.patterns.toList()
+
+    /**
+     * Clears all existing masking patterns.
+     */
+    override fun clear() {
+        patterns.clear()
+    }
+
+    /**
+     * Adds masking patterns if they do not already exist.
+     *
+     * @param maskingPatterns Vararg of MaskingPattern to be added.
+     * @return True if patterns were added, false if they already existed.
+     */
+    override fun addPatternIfNotExists(vararg maskingPatterns: MaskingPattern): Boolean {
+        var addedPattern = false
+
+        maskingPatterns.forEach newPatterns@{ pattern ->
+            patterns.forEach existingPatterns@{
+                val patternExists = (it.pattern.pattern() == pattern.pattern.pattern())
+                    .and(it.replacement == pattern.replacement)
+
+                if (patternExists) {
+                    return@newPatterns
+                }
+            }
+
+            patterns.add(pattern).also { addedPattern = true }
+        }
+
+        return addedPattern
+    }
+}