// ------------------------------------------------------------------------
//   Project atila
//   Active Thing (activething.com) git.activething.com/go
//
//   File name  rpacker_map.go
//   Created by DEV
//   Modified   05/02/2024
//
//   Copyright 2024 activething.com 
// ------------------------------------------------------------------------
// 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 pjson

import (
	"activething.com/go/gogo/packs"
	"reflect"
	"sort"
)

type (

	rMap struct {
		keyFn  rMapEntryFnc
		packFn rPackerFnc
	}
)



func rMapPacker (rtype reflect.Type) rPackerFnc {
	return (*newRMap(rtype)).pack
}


func newRMap(rtype reflect.Type) *rMap {
	return &rMap{
		packFn:  rTypePacker  (rtype.Elem()),
		keyFn  : stringifyRKey(rtype.Key()),
	}
}


func (p *rMap) pack (s *packs.State, v reflect.Value, f packs.Flags) {
	if p.keyFn == nil {
		s.SetError(packs.G.ErrInvalidKey)
		return
	}

	if v.IsNil() {
		s.W(G.nullValue)
		return
	}
	if v.Len() == 0 {
		s.Write2Byte('{','}')
		return
	}

	if s.Level > maxCyclesAfter {
		if fn,ok := s.CheckCycle(v.UnsafePointer()); ok {
			defer fn()
		} else {
			s.SetError(packs.G.ErrRedundantPack)
			return
		}
	}

	mi := v.MapRange()
	ls := make(rMapEntryList,v.Len())

	for i:=0; mi.Next(); i++ {
		ls[i] = rMapEntry{
			v: mi.Value(),
		}
		if er := p.keyFn(&ls[i], mi.Key()); er != nil {
			s.SetError(er)
			return
		}
	}

	sort.Sort(ls)

	s.Open ('{')
	for i:=0; i<len(ls); i++ {
		if i>0 {
			s.WriteByte(',')
		}
		packString(s,ls[i].k,ls[i].f)
		if s.Error != nil {
			return
		}
		s.WriteByte(':')
		p.packFn(s,ls[i].v,0)
		if s.Error != nil {
			return
		}
	}
	s.Close('}')
}