const { Client } = require('@microsoft/microsoft-graph-client');
const { msalConfig } = require('./authConfig');
const AuthProvider = require('./AuthProvider');
require('isomorphic-fetch');

class GraphService {
    constructor() {
        this.authProvider = new AuthProvider(msalConfig);
        this.graphClient = null;
    }

    async initialize() {
        try {
            // Get account
            await this.authProvider.login();
            
            // Get token with OneDrive scopes
            const tokenRequest = {
                scopes: ['Files.Read', 'Files.Read.All', 'Sites.Read.All']
            };
            
            const authResponse = await this.authProvider.getToken(tokenRequest);
            
            // Initialize Graph client
            this.graphClient = Client.init({
                authProvider: (done) => {
                    done(null, authResponse.accessToken);
                }
            });

            return authResponse.accessToken;
        } catch (error) {
            console.error('Error initializing Graph service:', error);
            throw error;
        }
    }

    async listFolderContents(folderPath) {
        if (!this.graphClient) {
            await this.initialize();
        }

        try {
            // Clean up the path
            const cleanPath = folderPath.replace(/^\/+|\/+$/g, '');
            const endpoint = `/me/drive/root:/${cleanPath}:/children`;
            
            // Get items from the folder
            const response = await this.graphClient.api(endpoint)
                .select('id,name,size,file,@microsoft.graph.downloadUrl')
                .get();

            return response.value;
        } catch (error) {
            console.error('Error listing folder contents:', error);
            throw error;
        }
    }
}

module.exports = new GraphService();