package inventoryapi

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

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

// NewInventory returns the inventory service implementation.
func NewInventory(logger *log.Logger) inventory.Service {
	inventoryMap := make(map[string]*[]string)
	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.CharacterName]
	if itemList == nil {
		itemList = s.initCharacterInventory(p.CharacterName)
	}
	newItemList := append(*itemList, p.ItemName)
	(*s.inventories)[p.CharacterName] = &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.CharacterName]
	if itemList == nil {
		s.logger.Printf("inventory for character with name '%s' not found", p.CharacterName)
		return inventory.MakeNotFound(fmt.Errorf("inventory for character with name '%s' not found", p.CharacterName))
	}

	idx := indexOf(p.ItemName, *itemList)
	if idx != -1 {
		newItemList := remove(*itemList, idx)
		(*s.inventories)[p.CharacterName] = &newItemList
	} else {
		s.logger.Printf("character with name '%s' does not have item '%s' in inventory", p.CharacterName, p.ItemName)
		return inventory.MakeNotFound(fmt.Errorf("character with name '%s' does not have item '%s' in inventory",
			p.CharacterName, p.ItemName))
	}

	return
}

func (s *inventorysrvc) RemoveAll(ctx context.Context, payload *inventory.RemoveAllPayload) (err error) {
	s.logger.Print("inventory.removeAll")

	itemList := (*s.inventories)[*payload.CharacterName]
	if itemList == nil {
		s.logger.Printf("inventory for character with name '%s' not found", payload.CharacterName)
		return inventory.MakeNotFound(fmt.Errorf("inventory for character with name '%s' not found",
			*payload.CharacterName))
	}
	delete(*s.inventories, *payload.CharacterName)
	return
}

func (s *inventorysrvc) ListInventory(ctx context.Context, payload *inventory.ListInventoryPayload) (res []string, err error) {
	s.logger.Print("inventory.listInventory")
	if (*s.inventories)[*payload.CharacterName] == nil {
		s.logger.Printf("inventory for character with name '%s' not found", payload.CharacterName)
		return nil, inventory.MakeNotFound(fmt.Errorf("inventory for character with name '%s' not found",
			*payload.CharacterName))
	}
	res = *((*s.inventories)[*payload.CharacterName])

	return
}

func (s *inventorysrvc) ListCharactersWithItem(ctx context.Context, payload *inventory.ListCharactersWithItemPayload) (res []string, err error) {
	s.logger.Print("inventory.listCharactersWithItem")

	for character := range *(s.inventories) {
		idxOfItem := indexOf(*payload.ItemName, *(*s.inventories)[character])
		if idxOfItem != -1 {
			res = append(res, character)
		}
	}
	return
}

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

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

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