import { BaseChatModel } from '@langchain/core/language_models/chat_models';
import { Model, ModelList, ProviderMetadata } from '../types';
import BaseModelProvider from './baseProvider';
import { ChatAnthropic } from '@langchain/anthropic';
import { Embeddings } from '@langchain/core/embeddings';
import { UIConfigField } from '@/lib/config/types';
import { getConfiguredModelProviderById } from '@/lib/config/serverRegistry';

interface AnthropicConfig {
  apiKey: string;
}

const providerConfigFields: UIConfigField[] = [
  {
    type: 'password',
    name: 'API Key',
    key: 'apiKey',
    description: 'Your Anthropic API key',
    required: true,
    placeholder: 'Anthropic API Key',
    env: 'ANTHROPIC_API_KEY',
    scope: 'server',
  },
];

class AnthropicProvider extends BaseModelProvider<AnthropicConfig> {
  constructor(id: string, name: string, config: AnthropicConfig) {
    super(id, name, config);
  }

  async getDefaultModels(): Promise<ModelList> {
    const res = await fetch('https://api.anthropic.com/v1/models?limit=999', {
      method: 'GET',
      headers: {
        'x-api-key': this.config.apiKey,
        'anthropic-version': '2023-06-01',
        'Content-type': 'application/json',
      },
    });

    if (!res.ok) {
      throw new Error(`Failed to fetch Anthropic models: ${res.statusText}`);
    }

    const data = (await res.json()).data;

    const models: Model[] = data.map((m: any) => {
      return {
        key: m.id,
        name: m.display_name,
      };
    });

    return {
      embedding: [],
      chat: models,
    };
  }

  async getModelList(): Promise<ModelList> {
    const defaultModels = await this.getDefaultModels();
    const configProvider = getConfiguredModelProviderById(this.id)!;

    return {
      embedding: [],
      chat: [...defaultModels.chat, ...configProvider.chatModels],
    };
  }

  async loadChatModel(key: string): Promise<BaseChatModel> {
    const modelList = await this.getModelList();

    const exists = modelList.chat.find((m) => m.key === key);

    if (!exists) {
      throw new Error(
        'Error Loading Anthropic Chat Model. Invalid Model Selected',
      );
    }

    return new ChatAnthropic({
      apiKey: this.config.apiKey,
      temperature: 0.7,
      model: key,
    });
  }

  async loadEmbeddingModel(key: string): Promise<Embeddings> {
    throw new Error('Anthropic provider does not support embedding models.');
  }

  static parseAndValidate(raw: any): AnthropicConfig {
    if (!raw || typeof raw !== 'object')
      throw new Error('Invalid config provided. Expected object');
    if (!raw.apiKey)
      throw new Error('Invalid config provided. API key must be provided');

    return {
      apiKey: String(raw.apiKey),
    };
  }

  static getProviderConfigFields(): UIConfigField[] {
    return providerConfigFields;
  }

  static getProviderMetadata(): ProviderMetadata {
    return {
      key: 'anthropic',
      name: 'Anthropic',
    };
  }
}

export default AnthropicProvider;