/*
 * Copyright (c) 2021 jxnu-liguobin && contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package io.github.dreamylost.macros

import scala.reflect.macros.whitebox

/**
 *
 * @author 梦境迷离
 * @since 2021/7/7
 * @version 1.0
 */
object jsonMacro {

  class JsonProcessor(override val c: whitebox.Context) extends AbstractMacroProcessor(c) {

    import c.universe._

    override def impl(annottees: c.universe.Expr[Any]*): c.universe.Expr[Any] = {
      def jsonFormatter(className: TypeName, fields: List[Tree]): Tree = {
        fields.length match {
          case 0 => c.abort(c.enclosingPosition, "Cannot create json formatter for case class with no fields")
          case _ =>
            c.info(c.enclosingPosition, s"jsonFormatter className: $className, field length: ${fields.length}", force = true)
            q"implicit val jsonAnnotationFormat = play.api.libs.json.Json.format[$className]"
        }
      }

      // The dependent type need aux-pattern in scala2. Now let's get around this.
      def modifiedDeclaration(classDecl: ClassDef, compDeclOpt: Option[ModuleDef] = None): Any = {
        val (className, fields) = classDecl match {
          case q"$mods class $tpname[..$tparams] $ctorMods(...$paramss) extends ..$bases { ..$body }" =>
            if (!mods.asInstanceOf[Modifiers].hasFlag(Flag.CASE)) {
              c.abort(c.enclosingPosition, s"Annotation is only supported on case class. classDef: $classDecl, mods: $mods")
            } else {
              c.info(c.enclosingPosition, s"modifiedDeclaration className: $tpname, paramss: $paramss", force = true)
              (tpname, paramss.asInstanceOf[List[List[Tree]]])
            }
          case _ => c.abort(c.enclosingPosition, s"${ErrorMessage.ONLY_CLASS} classDef: $classDecl")
        }
        c.info(c.enclosingPosition, s"modifiedDeclaration className: $className, fields: $fields", force = true)
        val cName = className.asInstanceOf[TypeName]
        val format = jsonFormatter(cName, fields.flatten)
        val compDecl = modifiedCompanion(compDeclOpt, format, cName)
        c.info(c.enclosingPosition, s"format: $format, compDecl: $compDecl", force = true)
        // Return both the class and companion object declarations
        c.Expr(
          q"""
        $classDecl
        $compDecl
      """)

      }

      val resTree = handleWithImplType(annottees: _*)(modifiedDeclaration)
      printTree(force = true, resTree.tree)

      resTree
    }
  }
}