/**
 * Entities Store
 */

import { ref, computed, readonly } from 'vue'
import { defineStore } from 'pinia'
import { entityService } from '../services/entityService'
import { EntityObject } from '../models'
import type {
  SourceSelector,
  ListFilter,
  ListSort,
  ListRange,
  DocumentInterface,
  EntityDeleteResponse,
  EntityDeltaResponse,
} from '../types'

export const useEntitiesStore = defineStore('documentsEntitiesStore', () => {
  // State
  const _entities = ref<Record<string, EntityObject>>({})
  const transceiving = ref(false)

  // Getters
  const count = computed(() => Object.keys(_entities.value).length)
  const has = computed(() => count.value > 0)
  const entities = computed(() => Object.values(_entities.value))

  const entitiesByService = computed(() => {
    const groups: Record<string, EntityObject[]> = {}

    Object.values(_entities.value).forEach((entity) => {
      const serviceKey = `${entity.provider}:${entity.service}`
      const serviceEntities = (groups[serviceKey] ??= [])
      serviceEntities.push(entity)
    })

    return groups
  })

  function identifierKey(
    provider: string,
    service: string | number,
    collection: string | number,
    identifier: string | number,
  ): string {
    return `${provider}:${service}:${collection}:${identifier}`
  }

  function entity(
    provider: string,
    service: string | number,
    collection: string | number,
    identifier: string | number,
    retrieve: boolean = false,
  ): EntityObject | null {
    const key = identifierKey(provider, service, collection, identifier)
    if (retrieve === true && !_entities.value[key]) {
      console.debug(`[Documents Manager][Store] - Force fetching entity "${key}"`)
      fetch(provider, service, collection, [identifier])
    }

    return _entities.value[key] || null
  }

  function entitiesForService(provider: string, service: string | number): EntityObject[] {
    const serviceKeyPrefix = `${provider}:${service}:`
    return Object.entries(_entities.value)
      .filter(([key]) => key.startsWith(serviceKeyPrefix))
      .map(([_, entityObj]) => entityObj)
  }

  function entitiesForCollection(provider: string, service: string | number, collection: string | number): EntityObject[] {
    const collectionKeyPrefix = `${provider}:${service}:${collection}:`
    return Object.entries(_entities.value)
      .filter(([key]) => key.startsWith(collectionKeyPrefix))
      .map(([_, entityObj]) => entityObj)
  }

  function clearService(provider: string, service: string | number): void {
    const serviceKeyPrefix = `${provider}:${service}:`
    Object.keys(_entities.value)
      .filter((key) => key.startsWith(serviceKeyPrefix))
      .forEach((key) => {
        delete _entities.value[key]
      })
  }

  function clearCollection(provider: string, service: string | number, collection: string | number): void {
    const collectionKeyPrefix = `${provider}:${service}:${collection}:`
    Object.keys(_entities.value)
      .filter((key) => key.startsWith(collectionKeyPrefix))
      .forEach((key) => {
        delete _entities.value[key]
      })
  }

  function clearAll(): void {
    _entities.value = {}
  }

  // Actions
  async function list(sources?: SourceSelector, filter?: ListFilter, sort?: ListSort, range?: ListRange): Promise<Record<string, EntityObject>> {
    transceiving.value = true
    try {
      const response = await entityService.list({ sources, filter, sort, range })

      const hydrated: Record<string, EntityObject> = {}
      Object.entries(response).forEach(([providerId, providerServices]) => {
        Object.entries(providerServices).forEach(([serviceId, serviceCollections]) => {
          Object.entries(serviceCollections).forEach(([collectionId, collectionEntities]) => {
            Object.entries(collectionEntities).forEach(([entityId, entityObj]) => {
              const key = identifierKey(providerId, serviceId, collectionId, entityId)
              hydrated[key] = entityObj
            })
          })
        })
      })

      _entities.value = { ..._entities.value, ...hydrated }

      console.debug('[Documents Manager][Store] - Successfully retrieved', Object.keys(hydrated).length, 'entities')
      return hydrated
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to retrieve entities:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function fetch(
    provider: string,
    service: string | number,
    collection: string | number,
    identifiers: (string | number)[],
  ): Promise<Record<string, EntityObject>> {
    transceiving.value = true
    try {
      const response = await entityService.fetch({ provider, service, collection, identifiers })

      const hydrated: Record<string, EntityObject> = {}
      Object.entries(response).forEach(([identifier, entityObj]) => {
        const key = identifierKey(provider, service, collection, identifier)
        hydrated[key] = entityObj
        _entities.value[key] = entityObj
      })

      console.debug('[Documents Manager][Store] - Successfully fetched', Object.keys(hydrated).length, 'entities')
      return hydrated
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to fetch entities:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function extant(sources: SourceSelector) {
    transceiving.value = true
    try {
      const response = await entityService.extant({ sources })
      console.debug('[Documents Manager][Store] - Successfully checked entity availability')
      return response
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to check entity availability:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function create(
    provider: string,
    service: string | number,
    collection: string | number,
    properties: DocumentInterface,
    options?: Record<string, unknown>,
  ): Promise<EntityObject> {
    transceiving.value = true
    try {
      const response = await entityService.create({ provider, service, collection, properties, options })
      const key = identifierKey(response.provider, response.service, response.collection, response.identifier)
      _entities.value[key] = response

      console.debug('[Documents Manager][Store] - Successfully created entity:', key)
      return response
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to create entity:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function update(
    provider: string,
    service: string | number,
    collection: string | number,
    identifier: string | number,
    properties: DocumentInterface,
  ): Promise<EntityObject> {
    transceiving.value = true
    try {
      const response = await entityService.update({ provider, service, collection, identifier, properties })
      const key = identifierKey(response.provider, response.service, response.collection, response.identifier)
      _entities.value[key] = response

      console.debug('[Documents Manager][Store] - Successfully updated entity:', key)
      return response
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to update entity:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function remove(
    provider: string,
    service: string | number,
    collection: string | number,
    identifier: string | number,
  ): Promise<EntityDeleteResponse> {
    transceiving.value = true
    try {
      const response = await entityService.delete({ provider, service, collection, identifier })
      if (response.success) {
        const key = identifierKey(provider, service, collection, identifier)
        delete _entities.value[key]
      }

      console.debug('[Documents Manager][Store] - Successfully deleted entity:', `${provider}:${service}:${collection}:${identifier}`)
      return response
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to delete entity:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function delta(sources: SourceSelector): Promise<EntityDeltaResponse> {
    transceiving.value = true
    try {
      const response = await entityService.delta({ sources })

      Object.entries(response).forEach(([provider, providerData]) => {
        if (providerData === false) return

        Object.entries(providerData).forEach(([service, serviceData]) => {
          if (serviceData === false) return

          Object.entries(serviceData).forEach(([collection, collectionData]) => {
            if (collectionData === false) return

            collectionData.deletions.forEach((identifier) => {
              const key = identifierKey(provider, service, collection, identifier)
              delete _entities.value[key]
            })
          })
        })
      })

      console.debug('[Documents Manager][Store] - Successfully processed entity delta')
      return response
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to process entity delta:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function read(
    provider: string,
    service: string | number,
    collection: string | number,
    identifier: string | number,
  ): Promise<string | null> {
    transceiving.value = true
    try {
      const response = await entityService.read({ provider, service, collection, identifier })
      return response.content
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to read entity:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  async function write(
    provider: string,
    service: string | number,
    collection: string | number,
    identifier: string | number,
    content: string,
  ): Promise<number> {
    transceiving.value = true
    try {
      const response = await entityService.write({ provider, service, collection, identifier, content, encoding: 'base64' })
      return response.bytesWritten
    } catch (error: any) {
      console.error('[Documents Manager][Store] - Failed to write entity:', error)
      throw error
    } finally {
      transceiving.value = false
    }
  }

  return {
    transceiving: readonly(transceiving),
    count,
    has,
    entities,
    entitiesByService,
    entity,
    entitiesForService,
    entitiesForCollection,
    clearService,
    clearCollection,
    clearAll,
    list,
    fetch,
    extant,
    create,
    update,
    delete: remove,
    delta,
    read,
    write,
  }
})