import { computed, ref, shallowRef } from 'vue'
import { defineStore } from 'pinia'
import { CollectionObject } from '@PeopleManager/models/collection'
import { EntityObject } from '@PeopleManager/models/entity'
import { IndividualObject } from '@PeopleManager/models/individual'
import { OrganizationObject } from '@PeopleManager/models/organization'
import { GroupObject } from '@PeopleManager/models/group'
import type { ServiceObject } from '@PeopleManager/models/service'
import { useCollectionsStore } from '@PeopleManager/stores/collectionsStore'
import { useEntitiesStore } from '@PeopleManager/stores/entitiesStore'
import { useServicesStore } from '@PeopleManager/stores/servicesStore'
import { useImportStore } from '@PeopleManager/stores/importStore'

export const usePeopleStore = defineStore('peopleStore', () => {
  const servicesStore = useServicesStore()
  const collectionsStore = useCollectionsStore()
  const entitiesStore = useEntitiesStore()
  const importStore = useImportStore()

  // UI state
  const sidebarVisible = ref(true)
  const loading = ref(false)

  // Selection state
  const selectedCollection = shallowRef<CollectionObject | null>(null)
  const selectedEntity = shallowRef<EntityObject | null>(null)

  // Entity editor state
  const entityEditorMode = ref<'edit' | 'view'>('view')

  // Collection editor state
  const showCollectionEditor = ref(false)
  const editingCollection = shallowRef<CollectionObject | null>(null)
  const collectionEditorMode = ref<'create' | 'edit'>('create')

  // Import state
  const showImportDialog = ref(false)

  // Derived state
  const collections = computed(() => collectionsStore.collections)
  const entities = computed(() => entitiesStore.entities)

  // --- Collection actions ---

  function selectCollection(collection: CollectionObject) {
    selectedCollection.value = collection
    selectedEntity.value = null
  }

  function openEditCollection(collection: CollectionObject) {
    editingCollection.value = collection
    collectionEditorMode.value = 'edit'
    showCollectionEditor.value = true
  }

  function openCreateCollection() {
    editingCollection.value = new CollectionObject()
    collectionEditorMode.value = 'create'
    showCollectionEditor.value = true
  }

  async function saveCollection(collection: CollectionObject, service: ServiceObject) {
    if (collectionEditorMode.value === 'create') {
      const created = await collectionsStore.create(
        service.provider,
        service.identifier ?? '',
        collection.properties,
      )
      selectedCollection.value = created
    } else {
      await collectionsStore.update(
        collection.identifier,
        collection.properties,
      )
    }

    showCollectionEditor.value = false
  }

  async function deleteCollection(collection: CollectionObject) {
    await collectionsStore.delete(collection.identifier)

    if (selectedCollection.value?.identifier === collection.identifier) {
      selectedCollection.value = null
      selectedEntity.value = null
    }

    showCollectionEditor.value = false
  }

  // --- Entity actions ---

  function createEntity(type: string) {
    const entity = new EntityObject()

    if (type === 'organization') {
      entity.properties = new OrganizationObject()
    } else if (type === 'group') {
      entity.properties = new GroupObject()
    } else {
      entity.properties = new IndividualObject()
    }

    selectedEntity.value = entity
    entityEditorMode.value = 'edit'
  }

  function selectEntity(entity: EntityObject) {
    selectedEntity.value = entity
    entityEditorMode.value = 'view'
  }

  function startEditingEntity() {
    entityEditorMode.value = 'edit'
  }

  function cancelEditingEntity() {
    entityEditorMode.value = 'view'
  }

  function closeEntityEditor() {
    selectedEntity.value = null
    entityEditorMode.value = 'view'
  }

  async function saveEntity(entity: EntityObject, collection?: CollectionObject | null) {
    const targetCollection = collection instanceof CollectionObject
      ? collection
      : selectedCollection.value

    if (!targetCollection) {
      throw new Error('[People] - No collection selected, cannot save entity')
    }

    if (!entity.identifier) {
      // Create
      entity.properties.created = new Date()
      selectedEntity.value = await entitiesStore.create(
        targetCollection.identifier,
        entity.properties,
      )
    } else {
      // Update
      entity.properties.modified = new Date()
      selectedEntity.value = await entitiesStore.update(
        entity.identifier,
        entity.properties,
      )
    }

    selectedCollection.value = targetCollection
    entityEditorMode.value = 'view'
  }

  async function deleteEntity(entity: EntityObject, collection?: CollectionObject | null) {
    const targetCollection = collection instanceof CollectionObject
      ? collection
      : selectedCollection.value

    if (!targetCollection) {
      throw new Error('[People] - No collection selected, cannot delete entity')
    }

    await entitiesStore.delete([entity.identifier])

    closeEntityEditor()
  }

  // --- Import actions ---

  /**
   * Queue selected VCF files and open the import dialog.
   * Defaults each file's target to the currently selected collection.
   */
  async function openImport(files: File[]) {
    importStore.removeAllFiles()
    importStore.reset()

    for (const file of files) {
      const contents = await file.text()
      const id = importStore.addFile({
        name: file.name,
        contents,
        size: file.size,
        type: file.type,
      })
      if (selectedCollection.value) {
        importStore.setCollectionForFile(id, selectedCollection.value.identifier)
      }
    }

    importStore.stage = 'selecting'
    showImportDialog.value = true
  }

  /**
   * Close the import dialog. When refresh is requested, reload the entity lists for
   * every collection that received contacts, then clear the import queue.
   */
  async function closeImport(refresh: boolean = false) {
    showImportDialog.value = false

    if (refresh) {
      const targets = new Set<CollectionObject['identifier']>()
      for (const id of importStore.order) {
        const target = importStore.sessions[id]?.targetIdentifier
        if (target) targets.add(target)
      }
      for (const target of targets) {
        await entitiesStore.list([target])
      }
    }

    importStore.removeAllFiles()
    importStore.reset()
  }

  // --- Lifecycle ---

  async function initialize() {
    loading.value = true
    try {
      await servicesStore.list()
      await collectionsStore.list()

      if (
        selectedCollection.value
        && !collections.value.find(c => c.identifier === selectedCollection.value?.identifier)
      ) {
        selectedCollection.value = null
      }
    } finally {
      loading.value = false
    }
  }

  return {
    // State
    sidebarVisible,
    loading,
    selectedCollection,
    selectedEntity,
    entityEditorMode,
    showCollectionEditor,
    editingCollection,
    collectionEditorMode,
    showImportDialog,

    // Derived
    collections,
    entities,

    // Collection actions
    selectCollection,
    openEditCollection,
    openCreateCollection,
    saveCollection,
    deleteCollection,

    // Entity actions
    createEntity,
    selectEntity,
    startEditingEntity,
    cancelEditingEntity,
    closeEntityEditor,
    saveEntity,
    deleteEntity,

    // Import actions
    openImport,
    closeImport,

    // Lifecycle
    initialize,
  }
})