//
// Copyright © 2020, 2021 Anticrm Platform Contributors.
// Copyright © 2021 Hardcore Engineering Inc.
//
// Licensed under the Eclipse Public License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License. You may
// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//
// See the License for the specific language governing permissions and
// limitations under the License.
//

import core, {
  AttachedDoc,
  Class,
  ClassifierKind,
  Client,
  Collection,
  Doc,
  FindResult,
  Hierarchy,
  Lookup,
  matchQuery,
  Mixin,
  Obj,
  Ref,
  TxOperations
} from '@anticrm/core'
import type { IntlString } from '@anticrm/platform'
import { getResource } from '@anticrm/platform'
import { getAttributePresenterClass, KeyedAttribute } from '@anticrm/presentation'
import { ErrorPresenter, getPlatformColorForText } from '@anticrm/ui'
import type { Action, ActionTarget, BuildModelOptions, ObjectDDParticipant } from '@anticrm/view'
import view, { AttributeModel, BuildModelKey } from '@anticrm/view'
import plugin from './plugin'

/**
 * Define some properties to be used to show component until data is properly loaded.
 */
export interface LoadingProps {
  length: number
}

/**
 * @public
 */
export async function getObjectPresenter (
  client: Client,
  _class: Ref<Class<Obj>>,
  preserveKey: BuildModelKey
): Promise<AttributeModel> {
  const clazz = client.getHierarchy().getClass(_class)
  const presenterMixin = client.getHierarchy().as(clazz, view.mixin.AttributePresenter)
  if (presenterMixin.presenter === undefined) {
    if (clazz.extends !== undefined) {
      return await getObjectPresenter(client, clazz.extends, preserveKey)
    } else {
      throw new Error('object presenter not found for ' + JSON.stringify(preserveKey))
    }
  }
  const presenter = await getResource(presenterMixin.presenter)
  const key = preserveKey.sortingKey ?? preserveKey.key
  const sortingKey =
    clazz.sortingKey !== undefined ? (key.length > 0 ? key + '.' + clazz.sortingKey : clazz.sortingKey) : key
  return {
    key: preserveKey.key,
    _class,
    label: preserveKey.label ?? clazz.label,
    presenter,
    sortingKey
  }
}

async function getAttributePresenter (
  client: Client,
  _class: Ref<Class<Obj>>,
  key: string,
  preserveKey: BuildModelKey
): Promise<AttributeModel> {
  const attribute = client.getHierarchy().getAttribute(_class, key)
  let attrClass = getAttributePresenterClass(attribute)
  const clazz = client.getHierarchy().getClass(attrClass)
  let presenterMixin = client.getHierarchy().as(clazz, view.mixin.AttributePresenter)
  let parent = clazz.extends
  while (presenterMixin.presenter === undefined && parent !== undefined) {
    const pclazz = client.getHierarchy().getClass(parent)
    attrClass = parent
    presenterMixin = client.getHierarchy().as(pclazz, view.mixin.AttributePresenter)
    parent = pclazz.extends
  }
  if (presenterMixin.presenter === undefined) {
    throw new Error('attribute presenter not found for ' + JSON.stringify(preserveKey))
  }
  const resultKey = preserveKey.sortingKey ?? preserveKey.key
  const sortingKey = attribute.type._class === core.class.ArrOf ? resultKey + '.length' : resultKey
  const presenter = await getResource(presenterMixin.presenter)
  return {
    key: preserveKey.key,
    sortingKey,
    _class: attrClass,
    label: preserveKey.label ?? attribute.label,
    presenter,
    icon: presenterMixin.icon,
    attribute
  }
}

async function getPresenter<T extends Doc> (
  client: Client,
  _class: Ref<Class<T>>,
  key: BuildModelKey,
  preserveKey: BuildModelKey,
  lookup?: Lookup<T>
): Promise<AttributeModel> {
  if (key.presenter !== undefined) {
    const { presenter, label, sortingKey } = key
    return {
      key: key.key ?? '',
      sortingKey: sortingKey ?? '',
      _class,
      label: label as IntlString,
      presenter: await getResource(presenter),
      props: key.props
    }
  }
  if (key.key.length === 0) {
    return await getObjectPresenter(client, _class, preserveKey)
  } else {
    if (key.key.startsWith('$lookup')) {
      if (lookup === undefined) {
        throw new Error(`lookup class does not provided for ${key.key}`)
      }
      return await getLookupPresenter(client, _class, key, preserveKey, lookup)
    }
    return await getAttributePresenter(client, _class, key.key, preserveKey)
  }
}

export async function buildModel (options: BuildModelOptions): Promise<AttributeModel[]> {
  console.log('building table model for', options)
  // eslint-disable-next-line array-callback-return
  const model = options.keys
    .map((key) => (typeof key === 'string' ? { key: key } : key))
    .map(async (key) => {
      try {
        return await getPresenter(options.client, options._class, key, key, options.options?.lookup)
      } catch (err: any) {
        if (options.ignoreMissing ?? false) {
          return undefined
        }
        const stringKey = key.label ?? key.key
        console.error('Failed to find presenter for', key, err)
        const errorPresenter: AttributeModel = {
          key: '',
          sortingKey: '',
          presenter: ErrorPresenter,
          label: stringKey as IntlString,
          _class: core.class.TypeString,
          props: { error: err }
        }
        return errorPresenter
      }
    })
  return (await Promise.all(model)).filter((a) => a !== undefined) as AttributeModel[]
}

function filterActions (
  client: Client,
  doc: Doc,
  targets: ActionTarget[],
  derived: Ref<Class<Doc>> = core.class.Doc
): Array<Ref<Action>> {
  const result: Array<Ref<Action>> = []
  const hierarchy = client.getHierarchy()
  const clazz = hierarchy.getClass(doc._class)
  const ignoreActions = hierarchy.as(clazz, view.mixin.IgnoreActions)
  const ignore = ignoreActions?.actions ?? []
  for (const target of targets) {
    if (ignore.includes(target.action)) {
      continue
    }
    if (target.query !== undefined) {
      const r = matchQuery([doc], target.query)
      if (r.length === 0) {
        continue
      }
    }
    if (hierarchy.isDerived(doc._class, target.target) && client.getHierarchy().isDerived(target.target, derived)) {
      result.push(target.action)
    }
  }
  return result
}

/**
 * @public
 *
 * Find all action contributions applicable for specified _class.
 * If derivedFrom is specifie, only actions applicable to derivedFrom class will be used.
 * So if we have contribution for Doc, Space and we ask for SpaceWithStates and derivedFrom=Space,
 * we won't recieve Doc contribution but recieve Space ones.
 */
export async function getActions (
  client: Client,
  doc: Doc,
  derived: Ref<Class<Doc>> = core.class.Doc
): Promise<FindResult<Action>> {
  const targets = await client.findAll(view.class.ActionTarget, {})
  return await client.findAll(view.class.Action, { _id: { $in: filterActions(client, doc, targets, derived) } })
}

export async function deleteObject (client: TxOperations, object: Doc): Promise<void> {
  const hierarchy = client.getHierarchy()
  const promises: Promise<any>[] = []
  if (client.getHierarchy().isDerived(object._class, core.class.AttachedDoc)) {
    const adoc = object as AttachedDoc
    promises.push(client.removeCollection(object._class, object.space, adoc._id, adoc.attachedTo, adoc.attachedToClass, adoc.collection).catch(err => console.error(err)))
  } else {
    promises.push(client.removeDoc(object._class, object.space, object._id).catch(err => console.error(err)))
  }
  promises.push(deleteClassCollections(client, object._class, object))
  const mixins = getMixins(hierarchy, object._class, object)
  for (const mixin of mixins) {
    promises.push(deleteClassCollections(client, mixin, object))
  }

  promises.push(deleteRelatedDocuments(hierarchy, object, client))
  await Promise.all(promises)
}

async function deleteClassCollections (client: TxOperations, _class: Ref<Class<Doc>>, object: Doc): Promise<void> {
  const hierarchy = client.getHierarchy()
  const attributes = hierarchy.getAllAttributes(_class)
  for (const [name, attribute] of attributes) {
    if (hierarchy.isDerived(attribute.type._class, core.class.Collection)) {
      const collection = attribute.type as Collection<AttachedDoc>
      const allAttached = await client.findAll(collection.of, { attachedTo: object._id })
      for (const attached of allAttached) {
        await deleteObject(client, attached).catch(err => console.log('failed to delete', name, err))
      }
    }
  }
}

function getParentClass (hierarchy: Hierarchy, _class: Ref<Class<Doc>>): Ref<Class<Doc>> {
  const baseDomain = hierarchy.getDomain(_class)
  const ancestors = hierarchy.getAncestors(_class)
  let result: Ref<Class<Doc>> = _class
  for (const ancestor of ancestors) {
    try {
      const domain = hierarchy.getClass(ancestor).domain
      if (domain === baseDomain) {
        result = ancestor
      }
    } catch {}
  }
  return result
}

function getMixins (hierarchy: Hierarchy, _class: Ref<Class<Doc>>, object: Doc): Ref<Mixin<Doc>>[] {
  const parentClass = getParentClass(hierarchy, _class)
  const descendants = hierarchy.getDescendants(parentClass)
  return descendants.filter(
    (m) => hierarchy.getClass(m).kind === ClassifierKind.MIXIN && hierarchy.hasMixin(object, m)
  )
}

async function deleteRelatedDocuments (hierarchy: Hierarchy, object: Doc, client: TxOperations): Promise<void> {
  const objectClass = hierarchy.getClass(object._class)
  if (hierarchy.hasMixin(objectClass, view.mixin.ObjectDDParticipant)) {
    const removeParticipand: ObjectDDParticipant = hierarchy.as(objectClass, view.mixin.ObjectDDParticipant)
    const collector = await getResource(removeParticipand.collectDocs)
    const docs = await collector(object, client)
    for (const d of docs) {
      await deleteObject(client, d)
    }
  }
}

export function getMixinStyle (id: Ref<Class<Doc>>, selected: boolean): string {
  const color = getPlatformColorForText(id as string)
  return `
    background: ${color + (selected ? 'ff' : '33')};
    border: 1px solid ${color + (selected ? '0f' : '66')};
  `
}

async function getLookupPresenter<T extends Doc> (client: Client, _class: Ref<Class<T>>, key: BuildModelKey, preserveKey: BuildModelKey, lookup: Lookup<T>): Promise<AttributeModel> {
  const lookupClass = getLookupClass(key.key, lookup, _class)
  const lookupProperty = getLookupProperty(key.key)
  const lookupKey = { ...key, key: lookupProperty[0] }
  const model = await getPresenter(client, lookupClass[0], lookupKey, preserveKey)
  model.label = getLookupLabel(client, lookupClass[1], lookupClass[0], lookupKey, lookupProperty[1])
  return model
}

function getLookupLabel<T extends Doc> (client: Client, _class: Ref<Class<T>>, lookupClass: Ref<Class<Doc>>, key: BuildModelKey, attrib: string): IntlString {
  if (key.label !== undefined) return key.label
  if (key.key === '') {
    try {
      const attribute = client.getHierarchy().getAttribute(_class, attrib)
      return attribute.label
    } catch {}
    const clazz = client.getHierarchy().getClass(lookupClass)
    return clazz.label
  } else {
    const attribute = client.getHierarchy().getAttribute(lookupClass, key.key)
    return attribute.label
  }
}

function getLookupClass<T extends Doc> (key: string, lookup: Lookup<T>, parent: Ref<Class<T>>): [Ref<Class<Doc>>, Ref<Class<Doc>>] {
  const _class = getLookup(key, lookup, parent)
  if (_class === undefined) {
    throw new Error('lookup class does not provided for ' + key)
  }
  return _class
}

function getLookupProperty (key: string): [string, string] {
  const parts = key.split('$lookup')
  const lastPart = parts[parts.length - 1]
  const split = lastPart.split('.').filter((p) => p.length > 0)
  const prev = split.shift() ?? ''
  const result = split.join('.')
  return [result, prev]
}

function getLookup (key: string, lookup: Lookup<any>, parent: Ref<Class<Doc>>): [Ref<Class<Doc>>, Ref<Class<Doc>>] | undefined {
  const parts = key.split('$lookup.').filter((p) => p.length > 0)
  const currentKey = parts[0].split('.').filter((p) => p.length > 0)[0]
  const current = (lookup as any)[currentKey]
  const nestedKey = parts.slice(1).join('$lookup.')
  if (nestedKey.length > 0) {
    if (!Array.isArray(current)) {
      return
    }
    return getLookup(nestedKey, current[1], current[0])
  }
  if (Array.isArray(current)) {
    return [current[0], parent]
  }
  if (current === undefined && lookup._id !== undefined) {
    const reverse = (lookup._id as any)[currentKey]
    return reverse !== undefined ? [reverse, parent] : undefined
  }
  return current !== undefined ? [current, parent] : undefined
}

export function getBooleanLabel (value: boolean | undefined): IntlString {
  if (value === true) return plugin.string.LabelYes
  if (value === false) return plugin.string.LabelNo
  return plugin.string.LabelNA
}
export function getCollectionCounter (hierarchy: Hierarchy, object: Doc, key: KeyedAttribute): number {
  if (hierarchy.isMixin(key.attr.attributeOf)) {
    return (hierarchy.as(object, key.attr.attributeOf) as any)[key.key]
  }
  return (object as any)[key.key] ?? 0
}