server.py

from http.server import HTTPServer, SimpleHTTPRequestHandler, test
import subprocess
import sys
import os
import json
import cgi
import shutil 
import urllib.request
from pathlib import Path
from urllib.parse import unquote
from pathvalidate import sanitize_filename

class CORSRequestHandler (SimpleHTTPRequestHandler):
    def end_headers (self):
        self.send_header('Access-Control-Allow-Origin', '*')
        self.send_header("Cache-Control", "no-cache, no-store, must-revalidate")
        self.send_header("Pragma", "no-cache")
        self.send_header("Expires", "0")
        SimpleHTTPRequestHandler.end_headers(self)

    def save_file(self, file, filename):
        sanitized_filename = sanitize_filename(filename.replace(" ", "-"))
        outpath = os.path.join("/", "work", "uploaded_corpora", sanitized_filename)

        with open(outpath, 'wb') as fout:
            #shutil.copyfileobj(file, fout, 100000)
            
            fout.write(bytes(file, 'utf8'))
        return outpath
        
    
    def get_command(self, form, saved_file_path, yaml_file_path):

        srclang = form.getvalue('srclang')
        trglang = form.getvalue('trglang')
        if not trglang:
            trglang="None"
        format = form.getvalue('corpus-format')
        langformat = form.getvalue('lang-format')
                
        command = []
        command.append("bash")
        command.append("/work/scripts/runstats.sh")
        command.append(saved_file_path)
        command.append(yaml_file_path)
        command.append(srclang)
        command.append(trglang)
        command.append(format)
        command.append(langformat)
        
        return(command)
    
            
    def do_upload(self):

        form=cgi.FieldStorage(fp=self.rfile, headers=self.headers,environ={'REQUEST_METHOD':'POST'})        
                   
        saved_file_path = self.save_file(form.getvalue('corpus'), form.getvalue('corpusname'))
        yaml_file_path = saved_file_path.replace("/uploaded_corpora/", "/yaml_dir/") + ".yaml"
        
        command = self.get_command(form, saved_file_path, yaml_file_path)
        subprocess.Popen(command)

        self.send_response(302)
        self.send_header('Location', self.path.replace("upload", "uploader.html?fromupload=yes"))
        self.send_header("Redirect-From", "upload")
        self.end_headers()
        return 
        

    def do_getcmd(self):

        form=cgi.FieldStorage(fp=self.rfile, headers=self.headers,environ={'REQUEST_METHOD':'POST'})
        
        saved_file_path = "LOCAL/PATH/TO/CORPUS"
        yaml_file_path = os.path.join("/", "work",  "yaml_dir", sanitize_filename(form.getvalue('corpusname')).replace(" ", "-") + ".yaml")
        
        command = self.get_command(form, saved_file_path, yaml_file_path)
        
        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        self.wfile.write(bytes(json.dumps(" ".join(command), ensure_ascii=False), 'utf-8'))
        return
        

    def do_list(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        # Send the html message
        files = sorted((file for file in Path("yaml_dir").iterdir() if not file.name.startswith(".")), key=os.path.getmtime, reverse=True)
        str_files = [str(file).replace("yaml_dir/", "") for file in files]
        self.wfile.write(bytes(json.dumps(str_files, ensure_ascii=False), 'utf-8'))
        #str(os.listdir("yaml_dir")))  
        return
    


    def do_POST(self):
        if self.path == '/upload':
            self.do_upload()
        elif self.path == '/getcmd':
            self.do_getcmd()


    def do_GET(self):
        #if self.path == '/uploader.html':
            
        if self.path == '/list':
            self.do_list()
        elif  "/file/" in self.path:
            self.send_response(200)
            self.send_header('Content-type', 'application/text')
            self.end_headers()
            with open("."+unquote(self.path).replace("/file/", "/yaml_dir/"), 'rb') as file: 
                self.wfile.write(file.read()) # Read the file and send the contents 
        elif "/download/" in self.path:
            self.send_response(200)
            self.send_header('Content-type', 'application/text')
            self.end_headers()
            with open("."+self.path.replace("/download/", "/yaml_dir/"), 'rb') as file:                 
                self.wfile.write(file.read())
        elif "/opus_langs" in self.path:
            self.send_response(200)
            self.send_header('Content-type', 'application/text')
            self.end_headers()
            resp = urllib.request.urlopen("https://opus.nlpl.eu/opusapi/?languages=True")
            content = resp.read()
            content_text = content.decode("utf-8")
            self.wfile.write(bytes(content_text, 'utf-8'))
            #self.wfile.write(bytes(json.dumps(content_text, ensure_ascii=False), "utf-8"))
        else:
            return SimpleHTTPRequestHandler.do_GET(self)
        


                    
if __name__ == '__main__':
    test(CORSRequestHandler, HTTPServer, port=int(sys.argv[1]) if len(sys.argv) > 1 else 8000)