// Copyright 2023 Lance Developers.
//
// Licensed under the Apache 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
//
//     http://www.apache.org/licenses/LICENSE-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 { type EmbeddingFunction } from '../index'
import type OpenAI from 'openai'

export class OpenAIEmbeddingFunction implements EmbeddingFunction<string> {
  private readonly _openai: OpenAI
  private readonly _modelName: string

  constructor (sourceColumn: string, openAIKey: string, modelName: string = 'text-embedding-ada-002') {
    /**
     * @type {import("openai").default}
     */
    let Openai
    try {
      // eslint-disable-next-line @typescript-eslint/no-var-requires
      Openai = require('openai')
    } catch {
      throw new Error('please install openai@^4.24.1 using npm install openai')
    }

    this.sourceColumn = sourceColumn
    const configuration = {
      apiKey: openAIKey
    }

    this._openai = new Openai(configuration)
    this._modelName = modelName
  }

  async embed (data: string[]): Promise<number[][]> {
    const response = await this._openai.embeddings.create({
      model: this._modelName,
      input: data
    })

    const embeddings: number[][] = []
    for (let i = 0; i < response.data.length; i++) {
      embeddings.push(response.data[i].embedding)
    }
    return embeddings
  }

  sourceColumn: string
}