package common

import (
	"encoding/json"
	"fmt"
)

// nil resets an override. Merge only the edited item keys, so a simultaneous
// game-side gacha grant cannot be erased by an SDK inventory edit.
func PatchMaterialOverrides(updates map[uint32]*uint32) (map[uint32]uint32, error) {
	for id := range updates {
		if id == 0 {
			return nil, fmt.Errorf("invalid material ID")
		}
	}
	persistentWriteMu.Lock()
	defer persistentWriteMu.Unlock()
	unlock, err := lockPersistentFile()
	if err != nil {
		return nil, err
	}
	defer unlock()
	raw, err := readResourceFile("freesr-data.json")
	if err != nil {
		return nil, err
	}
	var root map[string]json.RawMessage
	if err = json.Unmarshal(raw, &root); err != nil || root == nil {
		return nil, fmt.Errorf("invalid FreeSR import")
	}
	materials := map[uint32]uint32{}
	if value, exists := root["materials"]; exists {
		if err = json.Unmarshal(value, &materials); err != nil {
			return nil, err
		}
		if materials == nil {
			materials = map[uint32]uint32{}
		}
	}
	for id, count := range updates {
		if count == nil {
			delete(materials, id)
		} else {
			materials[id] = *count
		}
	}
	root["materials"], err = json.Marshal(materials)
	if err != nil {
		return nil, err
	}
	return materials, writeJSONAtomic("freesr-data.json", root)
}