package gameserver

import (
	"encoding/hex"
	"encoding/json"
	"fmt"
	"strconv"

	"gac-hkrpg-go/internal/common"
)

// These are adventure actor/placement identifiers, not battle wave monsters.
// Their reference binary provenance is retained in the editable resource.
// Applying the overlay never changes an existing session/run or a save file.
func applyPeakSceneOverrides(data *ChallengeDataConfig) {
	var catalog struct {
		SourceKind string `json:"source_kind"`
		BinaryHash string `json:"binary_sha256"`
		Offset     string `json:"source_file_offset"`
		Length     uint32 `json:"decoded_byte_length"`
		Data       struct {
			Groups []struct {
				GroupID uint32 `json:"group_id"`
				Stages  map[string]struct {
					NPC      uint32 `json:"npc_monster_id"`
					Entrance uint32 `json:"map_entrance_id"`
					Group    uint32 `json:"maze_group_id"`
				} `json:"stages"`
			} `json:"challenge_peak_extra_data"`
		} `json:"data"`
	}
	markAll := func(err error) {
		for id, stage := range data.Peak {
			stage.SceneResourceError = err.Error()
			data.Peak[id] = stage
		}
		Log("[PEAK] scene override rejected: " + err.Error())
	}
	raw, err := common.ReadResourceFile("resources/ChallengePeakSceneOverrides.json")
	if err != nil {
		markAll(err)
		return
	}
	if err := json.Unmarshal(raw, &catalog); err != nil {
		markAll(err)
		return
	}
	digest, err := hex.DecodeString(catalog.BinaryHash)
	_, offsetErr := strconv.ParseUint(catalog.Offset, 0, 64)
	if err != nil || len(digest) != 32 || offsetErr != nil || catalog.Length == 0 || catalog.SourceKind != "reference-server-embedded-data" {
		markAll(fmt.Errorf("Peak scene override provenance is incomplete"))
		return
	}
	res, err := common.GameRes()
	if err != nil {
		markAll(err)
		return
	}
	seen := make(map[string]bool)
	for _, group := range catalog.Data.Groups {
		for id, row := range group.Stages {
			stage, exists := data.Peak[id]
			if !exists || seen[id] || group.GroupID == 0 || stage.GroupID != group.GroupID {
				markAll(fmt.Errorf("Peak scene override has unknown, duplicate or mismatched stage %s", id))
				return
			}
			seen[id] = true
			stage.SceneResourceError = ""
			if row.NPC == 0 || row.Entrance == 0 || row.Group == 0 {
				stage.SceneResourceError = "Peak scene override has an empty actor/placement identifier"
			} else if scenes := res.LevelOutputConfigs[row.Entrance]; len(scenes) == 0 {
				stage.SceneResourceError = fmt.Sprintf("Peak entrance %d has no resource scene", row.Entrance)
			} else {
				_, scene, _ := firstSceneOfEntry(res, row.Entrance)
				placement, ok := scene.Scenes[row.Group]
				if !ok || len(placement.Monsters) == 0 {
					stage.SceneResourceError = fmt.Sprintf("Peak entrance %d group %d has no resource monster placement", row.Entrance, row.Group)
				}
			}
			stage.Entrance, stage.Group, stage.MonsterID = row.Entrance, row.Group, row.NPC
			data.Peak[id] = stage
		}
	}
	for id, stage := range data.Peak {
		if !seen[id] {
			stage.SceneResourceError = "Peak stage is missing from the scene override resource"
			data.Peak[id] = stage
		}
	}
	Log(fmt.Sprintf("[PEAK] scene override loaded stages=%d reference_sha256=%s; Client acceptance unverified", len(seen), catalog.BinaryHash))
}