From 578526d3d8bf8e4a4017465995c37efcf327ddf7 Mon Sep 17 00:00:00 2001
From: Eshu <tjano.xibalba@gmail.com>
Date: Sat, 7 Oct 2023 17:33:53 +0900
Subject: [PATCH] TextCodec.SeqCodec

---
 .../main/scala/zio/http/codec/TextCodec.scala | 18 ++++++-
 .../http/codec/internal/EncoderDecoder.scala  | 47 ++++++++++---------
 2 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/zio-http/src/main/scala/zio/http/codec/TextCodec.scala b/zio-http/src/main/scala/zio/http/codec/TextCodec.scala
index 41d06c0974..5e3968f9ec 100644
--- a/zio-http/src/main/scala/zio/http/codec/TextCodec.scala
+++ b/zio-http/src/main/scala/zio/http/codec/TextCodec.scala
@@ -16,8 +16,9 @@
 
 package zio.http.codec
 
-import java.util.UUID
+import zio.Chunk
 
+import java.util.UUID
 import zio.stacktracer.TracingImplicits.disableAutoTrace
 
 /**
@@ -59,6 +60,8 @@ object TextCodec {
 
   implicit val uuid: TextCodec[UUID] = UUIDCodec
 
+  implicit def seq[A](implicit scalarCodec: TextCodec[A]): TextCodec[Chunk[A]] = SeqCodec(scalarCodec)
+
   final case class Constant(string: String) extends TextCodec[Unit] {
 
     def apply(value: String): Unit = if (value == string) () else throw new MatchError(value)
@@ -190,4 +193,17 @@ object TextCodec {
     override def toString(): String = "TextCodec.uuid"
   }
 
+  case class SeqCodec[A](scalarCodec: TextCodec[A]) extends TextCodec[Chunk[A]] {
+    override def apply(value: String): Chunk[A] = (scalarCodec andThen (Chunk(_)))(value)
+
+    // TODO Find a better naming
+    override def describe: String = s"a sequence of ${scalarCodec.describe}"
+
+    override def encode(value: Chunk[A]): String =
+      throw new NotImplementedError("encode is not implemented for SeqCodec")
+
+    override def isDefinedAt(value: String): Boolean = scalarCodec.isDefinedAt(value)
+
+    override def toString: String = s"TextCodec.seq[${scalarCodec.toString}]"
+  }
 }
diff --git a/zio-http/src/main/scala/zio/http/codec/internal/EncoderDecoder.scala b/zio-http/src/main/scala/zio/http/codec/internal/EncoderDecoder.scala
index 720ec51e4a..4afe5253bb 100644
--- a/zio-http/src/main/scala/zio/http/codec/internal/EncoderDecoder.scala
+++ b/zio-http/src/main/scala/zio/http/codec/internal/EncoderDecoder.scala
@@ -17,15 +17,11 @@
 package zio.http.codec.internal
 
 import zio._
-import zio.stacktracer.TracingImplicits.disableAutoTrace
-
-import zio.stream.ZStream
-
-import zio.schema.Schema
-import zio.schema.codec.{BinaryCodec, Codec}
-
 import zio.http._
 import zio.http.codec._
+import zio.schema.Schema
+import zio.schema.codec.{BinaryCodec, Codec}
+import zio.stream.ZStream
 
 private[codec] trait EncoderDecoder[-AtomTypes, Value] {
   def decode(url: URL, status: Status, method: Method, headers: Headers, body: Body)(implicit
@@ -279,18 +275,21 @@ private[codec] object EncoderDecoder {
       var i       = 0
       val queries = flattened.query
       while (i < queries.length) {
-        val query = queries(i).erase
-
-        val queryParamValue =
-          queryParams
-            .getAllOrElse(query.name, Nil)
-            .collectFirst(query.textCodec)
-
-        queryParamValue match {
-          case Some(value) =>
-            inputs(i) = value
-          case None        =>
-            throw HttpCodecError.MissingQueryParam(query.name)
+        val query = queries(i)
+
+        query.textCodec match {
+          case TextCodec.SeqCodec(scalarCodec) =>
+            queryParams
+              .getAllOrElse(query.name, Nil)
+              .map(value =>
+                if (scalarCodec.isDefinedAt(value)) scalarCodec(value)
+                else throw HttpCodecError.MalformedQueryParam(query.name, query.textCodec),
+              )
+          case scalarCodec                     =>
+            inputs(i) = queryParams
+              .getAllOrElse(query.name, Nil)
+              .collectFirst(scalarCodec)
+              .getOrElse(throw HttpCodecError.MissingQueryParam(query.name))
         }
 
         i = i + 1
@@ -475,12 +474,14 @@ private[codec] object EncoderDecoder {
 
       var i = 0
       while (i < inputs.length) {
-        val query = flattened.query(i).erase
+        val query = flattened.query(i) // .erase
         val input = inputs(i)
 
-        val value = query.textCodec.encode(input)
-
-        queryParams = queryParams.add(query.name, value)
+        queryParams = query.textCodec match {
+          case TextCodec.SeqCodec(scalarCodec) =>
+            queryParams.addAll(query.name, input.asInstanceOf[Chunk[?]].map(scalarCodec.erase.encode))
+          case scalarCodec                     => queryParams.add(query.name, scalarCodec.erase.encode(input))
+        }
 
         i = i + 1
       }