Add gravatarImageUrlToGravatarImageUrl to utils + minor improvements

gravatar/src/main/java/com/gravatar/DefaultAvatarImage.kt

@@ -1,11 +1,12 @@
 package com.gravatar
 
 enum class DefaultAvatarImage(val style: String) {
-    MYSTERY_MAN("mm"),
+    MYSTERY_PERSON("mp"),
     STATUS_404("404"),
     IDENTICON("identicon"),
     MONSTER("monsterid"),
     WAVATAR("wavatar"),
     RETRO("retro"),
     BLANK("blank"),
+    ROBOHASH("robohash"),
 }

gravatar/src/main/java/com/gravatar/GravatarConstants.kt

@@ -5,7 +5,13 @@ object GravatarConstants {
     const val GRAVATAR_IMAGE_BASE_URL = "https://www.gravatar.com/"
     const val GRAVATAR_IMAGE_HOST = "www.gravatar.com"
     const val GRAVATAR_IMAGE_PATH = "avatar"
+    const val GRAVATAR_IMAGE_RAW_HOST = "gravatar.com"
 
     // Gravatar API
     const val GRAVATAR_API_BASE_URL = "https://api.gravatar.com/v1/"
+
+    // Minimum and maximum size of the avatar
+    const val MINIMUM_AVATAR_SIZE = 1
+    const val MAXIMUM_AVATAR_SIZE = 2048
+    val AVATAR_SIZE_RANGE = MINIMUM_AVATAR_SIZE..MAXIMUM_AVATAR_SIZE
 }

gravatar/src/main/java/com/gravatar/GravatarUtils.kt

@@ -1,14 +1,31 @@
 package com.gravatar
 
 import android.net.Uri
+import com.gravatar.GravatarConstants.AVATAR_SIZE_RANGE
 import com.gravatar.GravatarConstants.GRAVATAR_IMAGE_HOST
 import com.gravatar.GravatarConstants.GRAVATAR_IMAGE_PATH
+import com.gravatar.GravatarConstants.GRAVATAR_IMAGE_RAW_HOST
 import java.security.MessageDigest
 
 private fun ByteArray.toHex(): String {
     return joinToString("") { "%02x".format(it) }
 }
 
+private fun Uri.Builder.appendGravatarQueryParameters(
+    size: Int? = null,
+    defaultAvatarImage: DefaultAvatarImage? = null,
+    rating: ImageRating? = null,
+    forceDefaultAvatarImage: Boolean? = null,
+): Uri.Builder {
+    size?.let { require(it in AVATAR_SIZE_RANGE) { "Size parameter must be in range $AVATAR_SIZE_RANGE" } }
+    return this.apply {
+        defaultAvatarImage?.let { appendQueryParameter("d", it.style) } // eg. default monster, "d=monsterid"
+        size?.let { appendQueryParameter("s", it.toString()) } // eg. size 42, "s=42"
+        rating?.let { appendQueryParameter("r", it.rating) } // eg. rated pg, "r=pg"
+        forceDefaultAvatarImage?.let { appendQueryParameter("f", "y") } // eg. force yes, "f=y"
+    }
+}
+
 fun String.sha256Hash(): String {
     return MessageDigest.getInstance("SHA-256").digest(this.toByteArray()).toHex()
 }
@@ -19,20 +36,62 @@ fun emailAddressToGravatarHash(email: String): String {
 
 fun emailAddressToGravatarUrl(
     email: String,
-    defaultAvatarImage: DefaultAvatarImage? = null,
     size: Int? = null,
+    defaultAvatarImage: DefaultAvatarImage? = null,
+    rating: ImageRating? = null,
+    forceDefaultAvatarImage: Boolean? = null,
 ): String {
-    return emailAddressToGravatarUri(email, defaultAvatarImage, size).toString()
+    return emailAddressToGravatarUri(email, size, defaultAvatarImage, rating, forceDefaultAvatarImage).toString()
 }
 
-fun emailAddressToGravatarUri(email: String, defaultAvatarImage: DefaultAvatarImage? = null, size: Int? = null): Uri {
+fun emailAddressToGravatarUri(
+    email: String,
+    size: Int? = null,
+    defaultAvatarImage: DefaultAvatarImage? = null,
+    rating: ImageRating? = null,
+    forceDefaultAvatarImage: Boolean? = null,
+): Uri {
     return Uri.Builder()
         .scheme("https")
         .authority(GRAVATAR_IMAGE_HOST)
         .appendPath(GRAVATAR_IMAGE_PATH)
         .appendPath(emailAddressToGravatarHash(email))
-        .apply {
-            defaultAvatarImage?.let { appendQueryParameter("d", it.style) }
-            size?.let { appendQueryParameter("size", it.toString()) }
-        }.build()
+        .appendGravatarQueryParameters(size, defaultAvatarImage, rating, forceDefaultAvatarImage)
+        .build()
+}
+
+fun rewriteGravatarImageUrlQueryParams(
+    url: String,
+    size: Int? = null,
+    defaultAvatarImage: DefaultAvatarImage? = null,
+    rating: ImageRating? = null,
+    forceDefaultAvatarImage: Boolean? = null,
+): String {
+    return rewriteGravatarImageUriQueryParams(url, size, defaultAvatarImage, rating, forceDefaultAvatarImage).toString()
+}
+
+/**
+ * Rewrite gravatar URL to use different options. Keep only the path and hash.
+ *
+ * @param url Gravatar URL
+ * @param size Size of the avatar, must be between 1 and 2048. Optional: default to 80
+ * @param defaultAvatarImage Default avatar image. Optional: default to gravatar logo
+ * @param rating Image rating. Optional: default to General, suitable for display on all websites with any audience
+ * @param forceDefaultAvatarImage Force default avatar image. Optional: default to false
+ */
+fun rewriteGravatarImageUriQueryParams(
+    url: String,
+    size: Int? = null,
+    defaultAvatarImage: DefaultAvatarImage? = null,
+    rating: ImageRating? = null,
+    forceDefaultAvatarImage: Boolean? = null,
+): Uri {
+    val uri = Uri.parse(url)
+    require(uri.host?.contains(GRAVATAR_IMAGE_RAW_HOST, true) ?: false) { "Not a gravatar URL: ${uri.host}" }
+    return Uri.Builder()
+        .scheme(uri.scheme)
+        .authority(uri.host)
+        .appendEncodedPath(uri.pathSegments.joinToString("/"))
+        .appendGravatarQueryParameters(size, defaultAvatarImage, rating, forceDefaultAvatarImage)
+        .build()
 }

gravatar/src/main/java/com/gravatar/ImageRating.kt

@@ -0,0 +1,8 @@
+package com.gravatar
+
+enum class ImageRating(val rating: String) {
+    General("g"),
+    ParentalGuidance("pg"),
+    Restricted("r"),
+    X("x"),
+}