import { Ref, toRaw } from 'vue'
import { deepIsRevise } from './diff'

export const storeSecurityPush = <T extends any>(items: T[], pushItem: T) => {
  const index = items.indexOf(pushItem)
  if (!~index) {
    items.push(pushItem)
    return true
  } else {
    return false
  }
} 
export const storeSecurityDelete = <T extends any>(items: T[], pushItem: T) => {
  const index = items.indexOf(pushItem)
  if (~index) {
    items.splice(index, 1)
    return true
  } else {
    return false
  }
} 

export function addStoreItem <T extends {id: any}>(
  items: Ref<T[]>, 
  addAction: (item: T) => Promise<T>,
): (item: T) => Promise<T>
export function addStoreItem <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  addAction: (item: K) => Promise<K>,
  transform: (item: T) => Promise<K> | K
): (item: T) => Promise<K>
export function addStoreItem <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  addAction: (item: K) => Promise<K>,
  transform?: (item: T) => Promise<K> | K
) {
  return async (item: T) => {
    let actionData: K
    if (transform) {
      actionData = await transform(item)
    } else {
      actionData = item as unknown as K
    }
    const newItem = await addAction(actionData)
    const self = items.value.find(findItem => findItem.id === item.id)
    if (self) {
      Object.assign(self, newItem)
    } else {
      storeSecurityPush(items.value, item)
    }
    return newItem
  }
}

export function updateStoreItem <T extends {id: any}>(
  items: Ref<T[]>, 
  updateAction: (item: T, oldItem: T) => Promise<any>,
): (item: T, oldItem: T) => Promise<void>
export function updateStoreItem <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  updateAction: (item: K, oldItem: T) => Promise<any>,
  transform: (item: T) => Promise<K> | K
): (item: T, oldItem: T) => Promise<void>
export function updateStoreItem <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  updateAction: (item: K, oldItem: T) => Promise<any>,
  transform?: (item: T) => Promise<K> | K
) {
  return async (item: T, oldItem: T) => {
    let actionData: K
    if (transform) {
      actionData = await transform(item)
    } else {
      actionData = item as unknown as K
    }
    await updateAction(actionData, oldItem)
    const storeItem = items.value.find(atom => atom.id === item.id)
    if (storeItem) {
      Object.assign(storeItem, item)
    }
  }
}

export function deleteStoreItem <T extends {id: any}>(
  items: Ref<T[]>, 
  deleteAction: (item: T) => Promise<any>,
): (item: T) => Promise<void>
export function deleteStoreItem <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  deleteAction: (item: K) => Promise<any>,
  transform: (item: T) => Promise<K> | K
): (item: T) => Promise<void>
export function deleteStoreItem <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  deleteAction: (item: K) => Promise<any>,
  transform?: (item: T) => Promise<K> | K
) {
  return async (item: T) => {
    let actionData: K
    if (transform) {
      actionData = await transform(item)
    } else {
      actionData = item as unknown as K
    }
    await deleteAction(actionData)
    storeSecurityDelete(items.value, item)
  }
}
export function fetchStoreItems <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  fetchAction: () => Promise<T[]>, 
  callback: (() => void) | null,
): () => Promise<void>
export function fetchStoreItems <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  fetchAction: () => Promise<K[]>, 
  callback: (() => void) | null,
  transform: (items: K[]) => Promise<T[]> | T[],
): () => Promise<void>
export function fetchStoreItems <T extends {id: any}, K extends {id: any} = T>(
  items: Ref<T[]>, 
  fetchAction: () => Promise<K[]>, 
  callback: (() => void) | null,
  transform?: (items: K[]) => Promise<T[]> | T[],
) {
  return async () => {
    const fetchItems = await fetchAction()

    let actionData: T[]
    if (transform) {
      actionData = await transform(fetchItems)
    } else {
      actionData = fetchItems as unknown as T[]
    }
    items.value = actionData
    callback && callback()
  }
}

export const saveStoreItems = <T extends {id: any}>(
  newItems: Ref<T[]>,
  getOldItem: () => T[],
  actions: {
    add?: ReturnType<typeof addStoreItem<T>>,
    update?: ReturnType<typeof updateStoreItem<T>>,
    delete?: ReturnType<typeof deleteStoreItem<T>>,
  }
) => () => {
  const oldItems = getOldItem()
  const {
    deleted,
    updated,
    added
  } = diffStoreItemsChange(newItems.value, oldItems)

  const promiseAll: Promise<any>[] = []
  
  if (actions.delete) {
    for (const delItem of deleted) {
      promiseAll.push(actions.delete(delItem))
    }
  }
  if (actions.update) {
    for (const [newItem, oldItem] of updated) {
      promiseAll.push(actions.update(newItem, oldItem))
    }
  }
  if (actions.add) {
    for (const addItem of added) {
      promiseAll.push(actions.add(addItem))
    }
  }
  return Promise.all(promiseAll)
}

export const diffStoreItemsChange = <T extends Array<{ id: any }>>(newItems: T, oldItems: T) => {
  const addedItems = [] as unknown as T
  const deletedItems = [] as unknown as T
  const updateItems = [] as unknown as [T[number], T[number]][]
  newItems = toRaw(newItems)
  for (const newItem of newItems) {
    const oldItem = oldItems.find(oldItem => newItem.id === oldItem.id)
    if (!oldItem) {
      storeSecurityPush(addedItems, newItem)
    } else if (deepIsRevise(oldItem, newItem)) {
      storeSecurityPush(updateItems, [newItem, oldItem] as any)
    }
  }

  for (const oldItem of oldItems) {
    const newItem = newItems.find(newItem => newItem.id === oldItem.id)
    if (!newItem) {
      storeSecurityPush(deletedItems, oldItem)
    }
  }

  return {
    added: addedItems,
    deleted: deletedItems,
    updated: updateItems
  }
}

export const recoverStoreItems = <T extends Array<{ id: any }>>(items: Ref<T>, getBackupItems: () => T) => () => {
  const backupItems = getBackupItems()
  items.value = backupItems.map(oldItem => {
    const model = items.value.find(item => item.id === oldItem.id)
    console.log("===>", model, oldItem)
    return model ? Object.assign(model, oldItem) : oldItem
  }) as T
}