package gameserver

import (
	"fmt"
	pb "gac-hkrpg-go/protocol/proto"
)

// Current schema MOADBALHMFD is SelectedEliteBranchId in layer/sync and
// EliteBranchId in both requests. The reference SelectEncounter and
// BuildEncounterSelectionUpdateSync use a one-based offered-branch index.
func cwSetEncounterSelection(run *pb.MPIMAEMCEFH, index uint32) (*pb.KFNCAIHIHCM, error) {
	stage, _ := cwStage(run)
	if stage == nil {
		return nil, fmt.Errorf("CW Encounter stage missing")
	}
	layer := stage.GetIMPNAHBCADN().GetMPOBBIPMNNJ()
	if layer == nil || len(layer.BPDABHGFBFO) < 2 || index == 0 || uint64(index) > uint64(len(layer.BPDABHGFBFO)) || layer.BPDABHGFBFO[index-1] == nil {
		return nil, fmt.Errorf("CW Encounter branch is not in the active offer")
	}
	layer.MOADBALHMFD = index
	return &pb.KFNCAIHIHCM{MNLCHEJKDHO: &pb.KFNCAIHIHCM_FGODNPLCECH{FGODNPLCECH: &pb.KEPIEGKPFIJ{MOADBALHMFD: index}}}, nil
}

func cwSelectEncounter(run *pb.MPIMAEMCEFH, request *pb.OHAINOHGKCM) (*pb.GridFightSyncUpdateResultScNotify, error) {
	if run.GetFMIGOKIDKJL().GetBAKAKODKECM() == nil || request == nil {
		return nil, fmt.Errorf("CW Encounter selection is not active")
	}
	queue := run.FMIGOKIDKJL.QueuePosition
	if queue == ^uint32(0) {
		return nil, fmt.Errorf("CW pending identifiers exhausted")
	}
	selected, err := cwSetEncounterSelection(run, request.MOADBALHMFD)
	if err != nil {
		return nil, err
	}
	// Reference phase transition: SelectingEncounter -> AwaitingBattleReturn,
	// followed by the ordinary ReturnPreparation action; no battle starts here.
	pending := &pb.CHCHAJIANIM{QueuePosition: queue + 1, FGLIODAJFML: &pb.CHCHAJIANIM_LGNPHHBGKFH{LGNPHHBGKFH: &pb.HJPDALHDJHC{}}}
	run.FMIGOKIDKJL = pending
	return cwNotify(selected, cwFinish(queue), cwUnlock(), &pb.KFNCAIHIHCM{MNLCHEJKDHO: &pb.KFNCAIHIHCM_FMIGOKIDKJL{FMIGOKIDKJL: pending}}), nil
}

func init() {
	cwHandle("GridFightUpdateEliteBranchSelect", func(s *Session, req *pb.GridFightUpdateEliteBranchSelectCsReq, rsp *pb.GridFightUpdateEliteBranchSelectScRsp) error {
		rsp.Retcode = uint32(pb.Retcode_RET_GRID_FIGHT_PARAM_NOT_MATCH)
		catalog, data, err := cwPreparingData(s)
		if err != nil {
			return nil
		}
		selected, err := cwSetEncounterSelection(data.DHFOFLFCLAH, req.MOADBALHMFD)
		if err != nil {
			PacketLog("CW_ENCOUNTER_UPDATE rejected: " + err.Error())
			return nil
		}
		if err = s.saveCurrencyWarsData(data, catalog); err != nil {
			return nil
		}
		if err = cwSend(s, cwNotify(selected)); err != nil {
			return err
		}
		rsp.Retcode = 0
		return nil
	})
}