import ApiRequestService from "./apiRequestService";
import {AssociativeArray} from "./data";
import {useRepo} from "pinia-orm";
import UrlBuilder from "~/services/utils/urlBuilder";
import ModelNormalizer from "./serializer/normalizer/modelNormalizer";
import HydraDenormalizer from "./serializer/denormalizer/hydraDenormalizer";
import ApiModel from "~/models/ApiModel";

/**
 * Entity manager: make operations on the models defined with the Pinia-Orm library
 *
 * @see https://pinia-orm.codedredd.de/
 */
class EntityManager  {
    private apiRequestService: ApiRequestService;

    public constructor(apiRequestService: ApiRequestService) {
        this.apiRequestService = apiRequestService
    }

    public getRepository(model: typeof ApiModel) {
        return useRepo(model)
    }

    private static getEntityModel(entity: ApiModel): typeof ApiModel{
        return Object.getPrototypeOf(entity)
    }

    /**
     * Fetch one entity by its id, save it to the store and returns it
     *
     * @param model  Model of the object to fetch
     * @param id   Id of the object to fetch
     * @param forceRefresh  Force a new get request to the api ;
     *                      current object in store will be overwritten if it exists
     */
    public async fetch(model: typeof ApiModel, id: number, forceRefresh: boolean = false) {

        const repository = this.getRepository(model)

        // If the entity is already in the store and forceRefresh is false, return the object in store
        if (!forceRefresh) {
            const item = repository.find(id)
            if (item && typeof item !== 'undefined') {
                return item
            }
        }

        // Else, get the object from the API
        const url = UrlBuilder.concat('api', model.entity, String(id))

        const response = await this.apiRequestService.get(url)

        // deserialize the response
        const entity = await HydraDenormalizer.denormalize(response)
        entity.persisted = true

        entity.initialState = structuredClone(entity)

        // Save data into the store
        repository.save(entity)

        return entity
    }

    public findBy(model: typeof ApiModel, query: AssociativeArray) {
        // TODO: implement
    }

    public fetchAll(model: typeof ApiModel) {
        // TODO: implement
    }

    public async persist(model: typeof ApiModel, entity: ApiModel) {
        const data = ModelNormalizer.normalize(entity)
        let url = UrlBuilder.concat('api', model.entity)
        let response = null

        if (entity.persisted) {
            url = UrlBuilder.concat(url, String(entity.id))
            response = await this.apiRequestService.put(url, data)
        } else {
            response = await this.apiRequestService.post(url, data)
        }

        const fetchedEntity = await HydraDenormalizer.denormalize(response)
        fetchedEntity.persisted = true

        // Save data into the store
        const repository = this.getRepository(model)
        repository.save(fetchedEntity)

        return fetchedEntity
    }

    public async delete(model: typeof ApiModel, id: number) {
        const repository = this.getRepository(model)
        const entity = repository.find(id) as ApiModel

        if (!entity || typeof entity === 'undefined') {
            throw new Error(model + ' ' + id + ' does not exists in store')
        }

        // If object has been persisted to the datasource, send a delete request
        if (entity.persisted) {
            const url = UrlBuilder.concat('api', model.entity, String(id))
            await this.apiRequestService.delete(url)
        }

        // update the store
        repository.destroy(id)
    }

    public new(model: typeof ApiModel) {
        const repository = this.getRepository(model)

        const entity = repository.make()
        entity.persisted = false

        // Save data into the store
        repository.save(entity)

        return entity
    }

    public reset(entity: ApiModel) {
        if (entity.initialState === null) {
            console.log('object has no initial state - abort')
            return
        }

        entity = entity.initialState as ApiModel
        entity.initialState = structuredClone(entity)

        const repository = this.getRepository(this.getEntityModel(entity))
        repository.save(entity)
    }
}

export default EntityManager