//
// Copyright © 2022 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, {
  type ArrOf,
  type Class,
  type Doc,
  type DocIndexState,
  type DocumentQuery,
  type DocumentUpdate,
  extractDocKey,
  type Hierarchy,
  isFullTextAttribute,
  type MeasureContext,
  type Ref,
  type WorkspaceId,
  getFullTextContext,
  type Branding
} from '@hcengineering/core'
import { jsonToText, markupToJSON } from '@hcengineering/text'
import { type DbAdapter } from '../adapter'
import { updateDocWithPresenter } from '../mapper'
import { type FullTextAdapter, type IndexedDoc, type ServerStorage } from '../types'
import { summaryStageId } from './summary'
import {
  contentStageId,
  type DocUpdateHandler,
  fieldStateId,
  type FullTextPipeline,
  type FullTextPipelineStage,
  fullTextPushStageId
} from './types'
import { collectPropagate, collectPropagateClasses, docKey, isCustomAttr } from './utils'
import { Analytics } from '@hcengineering/analytics'

/**
 * @public
 */
export class FullTextPushStage implements FullTextPipelineStage {
  require = [fieldStateId, contentStageId, summaryStageId]
  stageId = fullTextPushStageId

  enabled = true

  updateFields: DocUpdateHandler[] = []

  limit = 10

  dimmVectors: Record<string, number[]> = {}

  field_enabled = '_use'

  stageValue: boolean | string = true

  constructor (
    private readonly dbStorage: ServerStorage,
    readonly fulltextAdapter: FullTextAdapter,
    readonly workspace: WorkspaceId,
    readonly branding: Branding | null
  ) {}

  async initialize (ctx: MeasureContext, storage: DbAdapter, pipeline: FullTextPipeline): Promise<void> {
    // Just do nothing
    try {
      const r = await this.fulltextAdapter.initMapping()
      for (const [k, v] of Object.entries(r)) {
        this.dimmVectors[k] = Array.from(Array(v).keys()).map((it) => 0)
      }
    } catch (err: any) {
      Analytics.handleError(err)
    }
  }

  async update (doc: DocIndexState, update: DocumentUpdate<DocIndexState>): Promise<void> {}

  checkIntegrity (indexedDoc: IndexedDoc): void {
    for (const [k, dimms] of Object.entries(this.dimmVectors)) {
      if (indexedDoc[k] === undefined || indexedDoc[k].length !== dimms.length) {
        indexedDoc[k] = dimms
        indexedDoc[`${k}${this.field_enabled}`] = false
      }
    }
  }

  async search (
    _classes: Ref<Class<Doc>>[],
    search: DocumentQuery<Doc>,
    size?: number,
    from?: number
  ): Promise<{ docs: IndexedDoc[], pass: boolean }> {
    return { docs: [], pass: true }
  }

  async collect (toIndex: DocIndexState[], pipeline: FullTextPipeline, ctx: MeasureContext): Promise<void> {
    const bulk: IndexedDoc[] = []

    const part = [...toIndex]
    while (part.length > 0) {
      const toIndexPart = part.splice(0, 50)

      const childIds = toIndexPart
        .filter((it) => {
          const fctx = getFullTextContext(pipeline.hierarchy, it.objectClass)
          return fctx.childProcessingAllowed ?? true
        })
        .map((it) => it._id)

      const allChildDocs = await ctx.with(
        'find-child',
        {},
        async (ctx) =>
          await this.dbStorage.findAll(ctx, core.class.DocIndexState, {
            attachedTo: childIds.length === 1 ? childIds[0] : { $in: childIds }
          })
      )

      for (const doc of toIndexPart) {
        if (pipeline.cancelling) {
          return
        }
        const elasticDoc = createElasticDoc(doc)
        try {
          await ctx.with('updateDoc2Elastic', {}, async () => {
            updateDoc2Elastic(doc.attributes, elasticDoc, undefined, undefined, pipeline.hierarchy)
          })

          // Include all child attributes
          const childDocs = allChildDocs.filter((it) => it.attachedTo === doc._id)
          if (childDocs.length > 0) {
            for (const c of childDocs) {
              const fctx = getFullTextContext(pipeline.hierarchy, c.objectClass)
              if (fctx.parentPropagate ?? true) {
                await ctx.with('updateDoc2Elastic', {}, async () => {
                  updateDoc2Elastic(c.attributes, elasticDoc, c._id, undefined, pipeline.hierarchy, true)
                })
              }
            }
          }
          let parentDoc: DocIndexState | undefined
          if (doc.attachedToClass != null && doc.attachedTo != null) {
            const propagate: Ref<Class<Doc>>[] = collectPropagate(pipeline, doc.attachedToClass)
            if (propagate.some((it) => pipeline.hierarchy.isDerived(doc.objectClass, it))) {
              // We need to include all parent content into this one.
              ;[parentDoc] = await ctx.with(
                'find-parent',
                {},
                async (ctx) =>
                  await this.dbStorage.findAll(ctx, core.class.DocIndexState, {
                    _id: doc.attachedTo as Ref<DocIndexState>
                  })
              )
              if (parentDoc !== undefined) {
                const ppdoc = parentDoc
                await ctx.with('updateDoc2Elastic', {}, async () => {
                  updateDoc2Elastic(ppdoc.attributes, elasticDoc, ppdoc._id, undefined, pipeline.hierarchy, true)
                })

                const collectClasses = collectPropagateClasses(pipeline, parentDoc.objectClass)
                if (collectClasses.length > 0) {
                  const collections = await this.dbStorage.findAll<DocIndexState>(
                    ctx.newChild('propagate', {}),
                    core.class.DocIndexState,
                    { attachedTo: parentDoc._id, objectClass: { $in: collectClasses } }
                  )
                  for (const c of collections) {
                    await ctx.with('updateDoc2Elastic', {}, async () => {
                      updateDoc2Elastic(c.attributes, elasticDoc, c._id, undefined, pipeline.hierarchy, true)
                    })
                  }
                }
              }
            }
          }
          const [spaceDoc] = await ctx.with(
            'find-space',
            {},
            async (ctx) =>
              await this.dbStorage.findAll(ctx, core.class.DocIndexState, {
                _id: (doc.attributes[docKey('space', { _class: doc.objectClass })] ?? doc.space) as Ref<DocIndexState>
              })
          )

          await updateDocWithPresenter(pipeline.hierarchy, doc, elasticDoc, { parentDoc, spaceDoc }, this.branding)

          this.checkIntegrity(elasticDoc)
          bulk.push(elasticDoc)
        } catch (err: any) {
          Analytics.handleError(err)
          const wasError = (doc as any).error !== undefined

          await pipeline.update(doc._id, false, { [docKey('error')]: JSON.stringify({ message: err.message, err }) })
          if (wasError) {
            continue
          }
          // Print error only first time, and update it in doc index
          console.error(err)
          continue
        }
      }
      // Perform bulk update to elastic
      try {
        await this.fulltextAdapter.updateMany(bulk)
        for (const doc of toIndex) {
          await pipeline.update(doc._id, true, {})
        }
      } catch (err: any) {
        Analytics.handleError(err)
      }
    }
  }

  async remove (docs: DocIndexState[], pipeline: FullTextPipeline): Promise<void> {
    await this.fulltextAdapter.remove(docs.map((it) => it._id))
    // will be handled by field processor
    for (const doc of docs) {
      await pipeline.update(doc._id, true, {})
    }
  }
}

/**
 * @public
 */
export function createElasticDoc (upd: DocIndexState): IndexedDoc {
  const doc = {
    id: upd._id,
    _class: [upd.objectClass, ...(upd.mixins ?? [])],
    modifiedBy: upd.modifiedBy,
    modifiedOn: upd.modifiedOn,
    space: [upd.space],
    attachedTo: upd.attachedTo,
    attachedToClass: upd.attachedToClass
  }
  return doc
}
function updateDoc2Elastic (
  attributes: Record<string, any>,
  doc: IndexedDoc,
  docIdOverride?: Ref<DocIndexState>,
  refAttribute?: string,
  hierarchy?: Hierarchy,
  isChildOrParentDoc?: boolean
): void {
  for (const [k, v] of Object.entries(attributes)) {
    if (v == null) {
      continue
    }
    let { _class, attr, docId, extra, digest } = extractDocKey(k)
    if (attr.length === 0) {
      continue
    }

    let vv: any = v
    if (vv != null && extra.includes('base64')) {
      vv = Buffer.from(v, 'base64').toString()
    }
    try {
      const attribute = hierarchy?.getAttribute(_class ?? doc._class[0], attr)
      if (attribute !== undefined && vv != null) {
        if (
          isFullTextAttribute(attribute) ||
          (isChildOrParentDoc === true &&
            !(
              attribute.type._class === core.class.RefTo ||
              (attribute.type._class === core.class.ArrOf &&
                (attribute.type as ArrOf<any>).of._class === core.class.RefTo)
            ))
        ) {
          let vvv = vv
          if (
            attribute.type._class === core.class.TypeMarkup ||
            attribute.type._class === core.class.TypeCollaborativeMarkup
          ) {
            vvv = jsonToText(markupToJSON(vv))
          }
          if (!(doc.fulltextSummary ?? '').includes(vvv)) {
            doc.fulltextSummary = (doc.fulltextSummary ?? '') + vvv + '\n'
            continue
          }
        }
      }
    } catch (err: any) {
      Analytics.handleError(err)
    }

    docId = docIdOverride ?? docId
    if (docId === undefined) {
      if (typeof vv !== 'object' || isCustomAttr(k)) {
        doc[k] = vv
      }
      continue
    }
    const docIdAttr = docKey(attr, { _class, extra: extra.filter((it) => it !== 'base64'), digest })
    if (vv !== null) {
      // Since we replace array of values, we could ignore null
      doc[docIdAttr] =
        doc[docIdAttr] == null
          ? []
          : typeof doc[docIdAttr] === 'string' || !Array.isArray(doc[docIdAttr])
            ? [doc[docIdAttr]]
            : doc[docIdAttr]
      if (vv !== '') {
        if (typeof vv !== 'object') {
          doc[docIdAttr] = Array.from(new Set([...doc[docIdAttr], vv]))
        }
      }
    }
  }

  const spaceKey = docKey('space', { _class: core.class.Doc })
  if (doc[spaceKey] !== undefined) {
    const existsingSpace = Array.isArray(doc.space) ? doc.space : [doc.space]
    const newSpaces = Array.isArray(doc[spaceKey]) ? doc[spaceKey] : [doc[spaceKey]]
    doc.space = [...existsingSpace, ...newSpaces].filter((it, idx, arr) => arr.indexOf(it) === idx)
  }
}