feat: add log masking feature

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

@@ -0,0 +1,5 @@
+package com.expediagroup.sdk.core.common
+
+internal interface Feature {
+    fun enable()
+}

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

@@ -0,0 +1,91 @@
+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
+    }
+}

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

@@ -0,0 +1,33 @@
+package com.expediagroup.sdk.core.logging.masking
+
+import com.expediagroup.sdk.core.common.Feature
+
+/**
+ * Interface representing the configuration for masking.
+ */
+internal abstract class LogMaskingFeature: 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/MaskingPatternBuilder.kt

@@ -0,0 +1,79 @@
+package com.expediagroup.sdk.core.logging.masking
+
+import com.ebay.ejmask.api.MaskingPattern
+
+/**
+ * Builder class for creating masking patterns.
+ */
+internal class MaskingPatternBuilder {
+    private var globalFields: Set<String> = setOf()
+    private var pathFields: Set<List<String>> = setOf()
+
+    /**
+     * Adds global fields to be masked.
+     *
+     * @param name Vararg of field names to be masked globally.
+     * @return The current instance of MaskingPatternBuilder.
+     */
+    fun globalFields(vararg name: String): MaskingPatternBuilder = apply {
+        globalFields += name.toSortedSet()
+    }
+
+    /**
+     * Adds path-specific fields to be masked.
+     *
+     * @param paths Vararg of lists of field names to be masked by path.
+     * @return The current instance of MaskingPatternBuilder.
+     */
+    fun pathFields(vararg paths: List<String>) = apply {
+        pathFields += paths.map { it.takeLast(2) }
+    }
+
+    /**
+     * Builds the list of MaskingPattern based on the added global and path fields.
+     *
+     * @return A list of MaskingPattern.
+     */
+    fun build(): List<MaskingPattern> = buildList {
+        /**
+         * Builds masking patterns for global fields.
+         *
+         * @return A list of MaskingPattern for global fields.
+         */
+        fun buildGlobalFieldsMaskingPattern(): List<MaskingPattern> =
+            if (globalFields.isEmpty()) {
+                emptyList()
+            } else {
+                val patternGenerator = CustomJsonFullValuePatternBuilder()
+                listOf(
+                    MaskingPattern(
+                        0,
+                        patternGenerator.buildPattern(0, *globalFields.toTypedArray()),
+                        patternGenerator.buildReplacement(0, *globalFields.toTypedArray())
+                    )
+                )
+            }
+
+        /**
+         * Builds masking patterns for path-specific fields.
+         *
+         * @return A list of MaskingPattern for path-specific fields.
+         */
+        fun buildPathFieldsMaskingPattern(): List<MaskingPattern> = buildList {
+            pathFields.forEachIndexed { index, path ->
+                CustomJsonRelativeFieldPatternBuilder().also { patternGenerator ->
+                    add(
+                        MaskingPattern(
+                            index + 1,
+                            patternGenerator.buildPattern(1, *path.toTypedArray()),
+                            patternGenerator.buildReplacement(1, *path.toTypedArray())
+                        )
+                    )
+                }
+            }
+        }
+
+        addAll(buildGlobalFieldsMaskingPattern())
+        addAll(buildPathFieldsMaskingPattern())
+    }
+}

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

@@ -0,0 +1,46 @@
+package com.expediagroup.sdk.core.logging.masking
+
+import com.ebay.ejmask.extenstion.builder.json.JsonFullValuePatternBuilder
+import com.ebay.ejmask.extenstion.builder.json.JsonRelativeFieldPatternBuilder
+import com.expediagroup.sdk.core.logging.common.Constant.OMITTED
+
+
+/**
+ * Custom implementation of JsonFieldPatternBuilder for building JSON field patterns.
+ */
+internal class CustomJsonFullValuePatternBuilder : JsonFullValuePatternBuilder() {
+
+    companion object {
+        @JvmStatic
+        val REPLACEMENT_TEMPLATE = "\"$1$2$OMITTED\""
+    }
+
+    /**
+     * Builds the replacement string for the given field names.
+     * Ignores the visibleCharacters parameter.
+     *
+     * @param visibleCharacters Number of visible characters. Value is ignored.
+     * @param fieldNames Vararg of field names.
+     * @return The replacement string.
+     */
+    override fun buildReplacement(visibleCharacters: Int, vararg fieldNames: String?): String =
+        REPLACEMENT_TEMPLATE
+}
+
+internal class CustomJsonRelativeFieldPatternBuilder : JsonRelativeFieldPatternBuilder() {
+    companion object {
+        @JvmStatic
+        val REPLACEMENT_TEMPLATE = "$1$OMITTED$3"
+    }
+
+    /**
+     * Builds the replacement string for the given field names.
+     * Ignores the visibleCharacters parameter.
+     *
+     * @param visibleCharacters Number of visible characters. Value is ignored.
+     * @param fieldNames Vararg of field names.
+     * @return The replacement string.
+     */
+    override fun buildReplacement(visibleCharacters: Int, vararg fieldNames: String?): String =
+        REPLACEMENT_TEMPLATE
+}