import json
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from threading import Thread

from extensions.api.util import build_parameters, build_parameters_train, try_start_cloudflared
from modules import shared
from modules.chat import generate_chat_reply
from modules.text_generation import encode, generate_reply
from modules.training import do_train

class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == '/api/v1/model':
            self.send_response(200)
            self.end_headers()
            response = json.dumps({
                'result': shared.model_name
            })

            self.wfile.write(response.encode('utf-8'))
        else:
            self.send_error(404)

    def do_POST(self):
        content_length = int(self.headers['Content-Length'])
        body = json.loads(self.rfile.read(content_length).decode('utf-8'))

        if self.path == '/api/v1/generate':
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.end_headers()

            prompt = body['prompt']
            generate_params = build_parameters(body)
            stopping_strings = generate_params.pop('stopping_strings')
            generate_params['stream'] = False

            generator = generate_reply(
                prompt, generate_params, stopping_strings=stopping_strings, is_chat=False)

            answer = ''
            for a in generator:
                answer = a

            response = json.dumps({
                'results': [{
                    'text': answer
                }]
            })

            self.wfile.write(response.encode('utf-8'))

        elif self.path == '/api/v1/chat':
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.end_headers()

            user_input = body['user_input']
            history = body['history']
            regenerate = body.get('regenerate', False)
            _continue = body.get('_continue', False)

            generate_params = build_parameters(body, chat=True)
            generate_params['stream'] = False

            generator = generate_chat_reply(
                user_input, history, generate_params, regenerate=regenerate, _continue=_continue, loading_message=False)

            answer = history
            for a in generator:
                answer = a

            response = json.dumps({
                'results': [{
                    'history': answer
                }]
            })

            self.wfile.write(response.encode('utf-8'))

        elif self.path == '/api/v1/finetune':
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.end_headers()

            generate_params = build_parameters_train(body)
            while True:
                try:
                    print(next(do_train(**generate_params)))
                except StopIteration:
                    break

        elif self.path == '/api/v1/token-count':
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.end_headers()

            tokens = encode(body['prompt'])[0]
            response = json.dumps({
                'results': [{
                    'tokens': len(tokens)
                }]
            })

            self.wfile.write(response.encode('utf-8'))
        else:
            self.send_error(404)


def _run_server(port: int, share: bool = False):
    address = '0.0.0.0' if shared.args.listen else '127.0.0.1'

    server = ThreadingHTTPServer((address, port), Handler)

    def on_start(public_url: str):
        print(f'Starting non-streaming server at public url {public_url}/api')

    if share:
        try:
            try_start_cloudflared(port, max_attempts=3, on_start=on_start)
        except Exception:
            pass
    else:
        print(
            f'Starting API at http://{address}:{port}/api')

    server.serve_forever()


def start_server(port: int, share: bool = False):
    Thread(target=_run_server, args=[port, share], daemon=True).start()