package inventoryapi

import (
	"context"
	inventory "crossnokaye-interview-assignment/services/inventory/gen/inventory"
	"errors"
	"log"
)

// inventory service example implementation.
// The example methods log the requests and return zero values.
type inventorysrvc struct {
	logger      *log.Logger
	inventories map[int]*[]int //key = characterId, value = array of itemIds
}

// NewInventory returns the inventory service implementation.
func NewInventory(logger *log.Logger) inventory.Service {
	inventoryMap := make(map[int]*[]int)
	return &inventorysrvc{logger, inventoryMap}
}

// AddItem implements addItem.
func (s *inventorysrvc) AddItem(ctx context.Context, p *inventory.InventoryRecord) (err error) {
	s.logger.Print("inventory.addItem")

	itemList := s.inventories[*p.CharacterID]
	if itemList == nil {
		itemList = s.initCharacterInventory(p.CharacterID)
	}
	newItemList := append(*itemList, *p.ItemID)
	s.inventories[*p.CharacterID] = &newItemList

	return
}

// RemoveItem implements removeItem.
func (s *inventorysrvc) RemoveItem(ctx context.Context, p *inventory.InventoryRecord) (err error) {
	s.logger.Print("inventory.removeItem")

	itemList := s.inventories[*p.CharacterID]
	if itemList == nil {
		s.logger.Printf("inventory for character with id %d not found", p.CharacterID)
		return errors.New("item not found")
	}

	idx := indexOf(*p.ItemID, *itemList)
	if idx != -1 {
		newItemList := remove(*itemList, idx)
		s.inventories[*p.CharacterID] = &newItemList
	} else {
		s.logger.Printf("character with id %d does not have item %d in inventory", &p.CharacterID, &p.ItemID)
		return errors.New("item not found for character")
	}

	return
}

func (s *inventorysrvc) ListInventory(ctx context.Context, payload *inventory.ListInventoryPayload) (res []int, err error) {
	res = *s.inventories[*payload.CharacterID]

	return
}

func (s *inventorysrvc) initCharacterInventory(characterId *int) (itemList *[]int) {
	list := make([]int, 0)
	itemList = &list
	s.inventories[*characterId] = &list
	return
}

func indexOf(element int, data []int) int {
	for k, v := range data {
		if element == v {
			return k
		}
	}
	return -1 //not found.
}

func remove(s []int, i int) []int {
	s[i] = s[len(s)-1]
	return s[:len(s)-1]
}