import time
from typing import Tuple, Union

import flask
from flask import Response, request

from llm_server import opts
from llm_server.cluster.backend import get_a_cluster_backend
from llm_server.cluster.cluster_config import cluster_config
from llm_server.custom_redis import redis
from llm_server.database.database import get_token_ratelimit, log_prompt
from llm_server.helpers import auto_set_base_client_api
from llm_server.llm.oobabooga.ooba_backend import OobaboogaBackend
from llm_server.llm.vllm.vllm_backend import VLLMBackend
from llm_server.routes.auth import parse_token
from llm_server.routes.helpers.http import require_api_key, validate_json
from llm_server.routes.queue import priority_queue


class RequestHandler:
    def __init__(self, incoming_request: flask.Request, selected_model: str = None, incoming_json: Union[dict, str] = None):
        self.request = incoming_request
        self.enable_backend_blind_rrd = request.headers.get('LLM-Blind-RRD', False) == 'true'

        # Routes need to validate it, here we just load it
        if incoming_json:
            self.request_valid_json, self.request_json_body = validate_json(incoming_json)
        else:
            self.request_valid_json, self.request_json_body = validate_json(self.request)
        if not self.request_valid_json:
            raise Exception(f'Not valid JSON. Routes are supposed to reject invalid JSON.')

        self.start_time = time.time()
        self.client_ip = self.get_client_ip()
        self.token = self.get_auth_token()
        self.token_priority, self.token_simultaneous_ip = get_token_ratelimit(self.token)
        self.backend_url = get_a_cluster_backend(selected_model)
        self.cluster_backend_info = cluster_config.get_backend(self.backend_url)
        self.selected_model = self.cluster_backend_info['model']

        if not self.cluster_backend_info.get('mode'):
            print(selected_model, self.backend_url, self.cluster_backend_info)

        self.backend = get_backend_handler(self.cluster_backend_info['mode'], self.backend_url)
        self.parameters = None
        self.used = False

        if not self.token.startswith('SYSTEM__'):
            # "recent_prompters" is only used for stats.
            redis.zadd('recent_prompters', {self.client_ip: time.time()})

    def get_auth_token(self):
        if self.request_json_body.get('X-API-KEY'):
            return self.request_json_body['X-API-KEY']
        elif self.request.headers.get('X-Api-Key'):
            return self.request.headers['X-Api-Key']
        elif self.request.headers.get('Authorization'):
            return parse_token(self.request.headers['Authorization'])

    def get_client_ip(self):
        if self.request.headers.get('Llm-Connecting-Ip'):
            return self.request.headers['Llm-Connecting-Ip']
        if self.request.headers.get('X-Connecting-IP'):
            return self.request.headers.get('X-Connecting-IP')
        elif self.request.headers.get('Cf-Connecting-Ip'):
            return self.request.headers.get('Cf-Connecting-Ip')
        elif self.request.headers.get('X-Forwarded-For'):
            return self.request.headers.get('X-Forwarded-For').split(',')[0]
        else:
            return self.request.remote_addr

    def get_parameters(self):
        if self.request_json_body.get('max_tokens'):
            self.request_json_body['max_new_tokens'] = self.request_json_body.pop('max_tokens')
        parameters, parameters_invalid_msg = self.backend.get_parameters(self.request_json_body)
        return parameters, parameters_invalid_msg

    def validate_request(self, prompt: str = None, do_log: bool = False) -> Tuple[bool, Tuple[Response | None, int]]:
        """
        This needs to be called at the start of the subclass handle_request() method.
        :param prompt:
        :param do_log:
        :return:
        """
        invalid_request_err_msgs = []

        self.parameters, parameters_invalid_msg = self.get_parameters()  # Parameters will be None if invalid.
        if self.parameters and not parameters_invalid_msg:
            # Backends shouldn't check max_new_tokens, but rather things specific to their backend.
            # Let the RequestHandler do the generic checks.
            if self.parameters.get('max_new_tokens', 0) > opts.max_new_tokens:
                invalid_request_err_msgs.append(f'`max_new_tokens` must be less than or equal to {opts.max_new_tokens}')

            if prompt:
                prompt_valid, invalid_prompt_err_msg = self.backend.validate_prompt(prompt)
                if not prompt_valid:
                    invalid_request_err_msgs.append(invalid_prompt_err_msg)

            request_valid, invalid_request_err_msg = self.backend.validate_request(self.parameters, prompt, self.request)
            if not request_valid:
                invalid_request_err_msgs.append(invalid_request_err_msg)
        else:
            invalid_request_err_msgs.append(parameters_invalid_msg)

        if len(invalid_request_err_msgs):
            if len(invalid_request_err_msgs) > 1:
                # Format multiple error messages each on a new line.
                e = [f'\n{x}.' for x in invalid_request_err_msgs]
                combined_error_message = '\n'.join(e)
            else:
                # Otherwise, just grab the first and only one.
                combined_error_message = invalid_request_err_msgs[0] + '.'
            backend_response = self.handle_error(combined_error_message, 'Validation Error')

            if do_log:
                log_prompt(self.client_ip, self.token, self.request_json_body.get('prompt', ''), backend_response[0].data.decode('utf-8'), 0, self.parameters, dict(self.request.headers), 0, self.request.url, self.backend_url, is_error=True)
            return False, backend_response
        return True, (None, 0)

    def generate_response(self, llm_request: dict) -> Tuple[Tuple[bool, flask.Response | None, str | None, float], Tuple[Response, int]]:
        prompt = llm_request['prompt']
        if not self.is_client_ratelimited():
            # Validate again before submission since the backend handler may have changed something.
            # Also, this is the first time we validate the prompt.
            request_valid, invalid_response = self.validate_request(prompt, do_log=True)
            if not request_valid:
                return (False, None, None, 0), invalid_response
            event = priority_queue.put((llm_request, self.client_ip, self.token, self.parameters, self.backend_url), self.token_priority, self.selected_model)
        else:
            event = None

        if not event:
            return (False, None, None, 0), self.handle_ratelimited()

        # TODO: add wait timeout
        success, response, error_msg = event.wait()

        end_time = time.time()
        elapsed_time = end_time - self.start_time

        if response:
            try:
                # Be extra careful when getting attributes from the response object
                response_status_code = response.status_code
            except:
                response_status_code = 0
        else:
            response_status_code = None

        # ===============================================

        # We encountered an error
        if not success or not response or error_msg:
            if not error_msg or error_msg == '':
                error_msg = 'Unknown error.'
            else:
                error_msg = error_msg.strip('.') + '.'
            backend_response = self.handle_error(error_msg)
            log_prompt(ip=self.client_ip,
                       token=self.token,
                       prompt=prompt,
                       response=backend_response[0].data.decode('utf-8'),
                       gen_time=None,
                       parameters=self.parameters,
                       headers=dict(self.request.headers),
                       backend_response_code=response_status_code,
                       request_url=self.request.url,
                       backend_url=self.backend_url,
                       is_error=True)
            return (False, None, None, 0), backend_response

        # ===============================================

        response_valid_json, response_json_body = validate_json(response)
        return_json_err = False

        # The backend didn't send valid JSON
        if not response_valid_json:
            return_json_err = True

        # Make sure the backend didn't crap out.
        results = response_json_body.get('results', [])
        if len(results) and not results[0].get('text'):
            return_json_err = True

        if return_json_err:
            error_msg = 'The backend did not return valid JSON.'
            backend_response = self.handle_error(error_msg)
            log_prompt(self.client_ip, self.token, prompt, backend_response[0].data.decode('utf-8'), elapsed_time, self.parameters, dict(self.request.headers), response_status_code, self.request.url, self.backend_url, is_error=True)
            return (False, None, None, 0), backend_response

        # ===============================================

        self.used = True
        return (success, response, error_msg, elapsed_time), self.backend.handle_response(success, self.request, response_json_body, response_status_code, self.client_ip, self.token, prompt, elapsed_time, self.parameters, dict(self.request.headers))

    def is_client_ratelimited(self) -> bool:
        if self.token_priority == 0:
            return False

        queued_ip_count = int(priority_queue.get_queued_ip_count(self.client_ip))
        x = redis.hget('processing_ips', self.client_ip)
        if x:
            processing_ip = int(x)
        else:
            processing_ip = 0

        if queued_ip_count + processing_ip >= self.token_simultaneous_ip:
            print(f'Rejecting request from {self.client_ip} - {queued_ip_count + processing_ip} already queued/processing.')
            return True
        else:
            return False

    def handle_request(self) -> Tuple[flask.Response, int]:
        # Must include this in your child.
        # if self.used:
        #     raise Exception('Can only use a RequestHandler object once.')
        raise NotImplementedError

    def handle_ratelimited(self, do_log: bool = True) -> Tuple[flask.Response, int]:
        raise NotImplementedError

    def handle_error(self, error_msg: str, error_type: str = 'error') -> Tuple[flask.Response, int]:
        raise NotImplementedError


def get_backend_handler(mode, backend_url: str):
    if mode == 'oobabooga':
        return OobaboogaBackend(backend_url)
    elif mode == 'vllm':
        return VLLMBackend(backend_url)
    else:
        raise Exception


def delete_dict_key(d: dict, k: Union[str, list]):
    if isinstance(k, str):
        if k in d.keys():
            del d[k]
    elif isinstance(k, list):
        for item in k:
            if item in d.keys():
                del d[item]
    else:
        raise ValueError
    return d


def before_request():
    auto_set_base_client_api(request)
    if request.endpoint != 'v1.get_stats':
        response = require_api_key()
        if response is not None:
            return response