/*
 * HTTP Google Drive access.
 */

import { Base } from './base.jsx'
import * as util from '../util.jsx'
import generateUuid from '../../client/uuid.js'

export default class Filesystem extends Base {
  constructor(path, options) {
      super('googledrive', path, options)

      if(options.token) {
          this.token = options.token
      } else {
          throw new Error("[googledrive] bearer auth token required")
      }

      if(options.subfolder) {
          this.subfolder = options.subfolder
          if (this.subfolder[0] != '/') {
              this.subfolder = '/' + this.subfolder
          }
      } else {
          this.subfolder = ''
      }
  }
  
  async stat(relativePath){
    var path = this.getGoogledrivePath(relativePath);
    var id = await this.googlePathToId(path);
    return this.googleAPIFetch(`files?corpus=domain&q=%27`+id+`%27%20in%20parents`)
      .then(r => r.json())
      .then(json => {
    	  console.log(path, json, relativePath);
        var items = json.items.map(item => ({
    	    "type": item.mimeType === 'application/vnd.google-apps.folder' && true ? "directory" : 'file',
		      "name": item.title,
		      "size": 0
    	  }));
    	  return JSON.stringify({
        	"type": "directory",
        	"contents": items
        });
    }).then( content =>
      new Response(content, {
          status: 200,
          headers: {'Allow': 'GET,OPTIONS'}
      })
    )
  }

  async read(urlString) {
      var path = this.getGoogledrivePath(urlString);
      var id = await this.googlePathToId(path);
      let response = await this.googleAPIFetch(`files/`+id)
        .then(r => r.json())
        .then(metaData => {
          var m =metaData.mimeType.match(/application\/vnd.google-apps\.(.*)/)
          if(m) {
        		// Need conversion for Google Document types
      			var type = m[1]
            if (type == "spreadsheet") {
        			return this.googleAPIFetch(`files/`+id + '/export?mimeType=text/csv');
            } else if (type == "drawing") {
              // #TODO svg+xml does not seem to work any more? 
              // we can only display this (easily) when this code moves into the service worker
        			return this.googleAPIFetch(`files/`+id + '/export?mimeType=application/pdf');
            } else {
        			return this.googleAPIFetch(`files/`+id + '/export?mimeType=text/html');     
            } 
      		} else {
      			// download file
      			return this.googleAPIFetch(`files/`+id + '?alt=media');
      		}
      });

      if(response.status < 200 && response.status >= 300) {
          throw new Error(response.statusText)
      }

      let blob = await response.blob()

      return new Response(blob, {
          status: 200
      })
  }

  async write(urlString, fileContent) {
    debugger
      var response;
      var data = await fileContent;
      var path = this.getGoogledrivePath(urlString);
      var id = await this.googlePathToId(path);
      if(!id) {
        var folderPath = path.replace(/\/[^\/]*$/,"");
        var fileName = path.replace(/.*\//,"")
        var folderId = await this.googlePathToId(folderPath);
        if (!folderId) {
          throw new Error(`Folder $(folderPath) does not exit`);
        }
         
        var delim = generateUuid()
        var body = `--${delim}
Content-Type: application/json; charset=UTF-8

{
  title: "${fileName}",
  parents: [
    {kind: "drive#folder", id: "${folderId}"}
  ]
}

--${delim}
Content-Type: text/plain; charset=UTF-8

`+data+`

--${delim}--`
        response = await fetch('https://www.googleapis.com/upload/drive/v2/files?uploadType=multipart', {
          method: 'POST',
        	headers: new Headers({
        		"Content-Type": "multipart/related; boundary=" + delim,
        		Authorization: "Bearer " + this.token,
        		"Content-Length": body.length
        	}),
        	body: body
        })
      } else {
        response = await this.googleAPIUpload(id, data);
      }

      if(response.status < 200 && response.status >= 300) {
          throw new Error(response.statusText)
      }

      return fileContent
  }
  
  getGoogledrivePath(relativePath) {
    return this.subfolder + decodeURIComponent(relativePath)
  }
  
  async googleAPIUpload(id, content, mimeType) {
    var headers = new Headers();
    headers.append('Authorization', 'Bearer ' + this.token)

    if (!mimeType) 
      mimeType = (await (await this.googleAPIFetch('files/' + id )).json()).mimeType;
    
    headers.append('Content-Type', mimeType)

    return fetch('https://www.googleapis.com/upload/drive/v2/files/' + id + '?uploadType=media', {
  		method: 'PUT',
  		headers: headers,
  		body: content
  	})
  }
  
  async googleAPIFetch(string) {
    return  fetch(`https://www.googleapis.com/drive/v2/` + string, {
    		method: 'GET',
    		headers: new Headers({
    			Authorization: "Bearer " + this.token
    		}),
    	})
  }

  
  
  async googlePathToId(path) {
    if(!path) { return undefined; }
    if(path === '/') { return 'root'; }
    
    var parentId ='root';
    path = path.replace(/^\//, '').split('/')
    while(path.length > 0 ) {
      let childName = path.shift();
      if(childName === '') { return parentId; }
      let childItem = await this.googleAPIFetch(`files?corpus=domain&q=%27`+ parentId+`%27%20in%20parents`)
      .then(r => r.json())
      .then(json => {
	      return json.items.find(item => item.title === childName)
	    });
    	if(!childItem) { return undefined; } // file not found
      parentId = childItem.id;
    }
    return parentId;
  }



}