import sqlite3
import time
from typing import Tuple, Union

import flask
from flask import Response

from llm_server import opts
from llm_server.database import log_prompt
from llm_server.llm.oobabooga.ooba_backend import OobaboogaBackend
from llm_server.llm.vllm.vllm_backend import VLLMBackend
from llm_server.routes.cache import redis
from llm_server.routes.helpers.client import format_sillytavern_err
from llm_server.routes.helpers.http import validate_json
from llm_server.routes.queue import priority_queue
from llm_server.routes.stats import SemaphoreCheckerThread

DEFAULT_PRIORITY = 9999


class RequestHandler:
    def __init__(self, incoming_request: flask.Request):
        self.request = incoming_request
        _, self.request_json_body = validate_json(self.request)  # routes need to validate it, here we just load it
        self.start_time = time.time()
        self.client_ip = self.get_client_ip()
        self.token = self.request.headers.get('X-Api-Key')
        self.priority = self.get_priority()
        self.backend = get_backend()
        self.parameters = None
        self.used = False
        SemaphoreCheckerThread.recent_prompters[self.client_ip] = time.time()

    def get_client_ip(self):
        if 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_priority(self):
        if self.token:
            conn = sqlite3.connect(opts.database_path)
            cursor = conn.cursor()
            cursor.execute("SELECT priority FROM token_auth WHERE token = ?", (self.token,))
            result = cursor.fetchone()
            conn.close()
            if result:
                return result[0]
        return DEFAULT_PRIORITY

    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) -> Tuple[bool, Tuple[Response | None, int]]:
        self.parameters, parameters_invalid_msg = self.get_parameters()
        request_valid = False
        invalid_request_err_msg = None
        if self.parameters:
            request_valid, invalid_request_err_msg = self.backend.validate_request(self.parameters)

        if not request_valid:
            error_messages = [msg for valid, msg in [(request_valid, invalid_request_err_msg), (not bool(parameters_invalid_msg), parameters_invalid_msg)] if not valid and msg]
            combined_error_message = ', '.join(error_messages)
            backend_response = format_sillytavern_err(f'Validation Error: {combined_error_message}.', 'error')
            log_prompt(self.client_ip, self.token, self.request_json_body.get('prompt', ''), backend_response, 0, self.parameters, dict(self.request.headers), 0, self.request.url, is_error=True)
            return False, self.handle_error(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 the prompt right before submission since the backend handler may have changed something.
            prompt_valid, invalid_prompt_err_msg = self.backend.validate_prompt(prompt)
            if not prompt_valid:
                backend_response = format_sillytavern_err(f'Validation Error: {invalid_prompt_err_msg}.', 'error')
                log_prompt(self.client_ip, self.token, self.request_json_body.get('prompt', ''), backend_response, 0, self.parameters, dict(self.request.headers), 0, self.request.url, is_error=True)
                return (False, None, None, 0), self.handle_error(backend_response)

            event = priority_queue.put((llm_request, self.client_ip, self.token, self.parameters), self.priority)
        else:
            event = None

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

        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 = format_sillytavern_err(error_msg, 'error')
            log_prompt(self.client_ip, self.token, prompt, backend_response, None, self.parameters, dict(self.request.headers), response_status_code, self.request.url, is_error=True)
            return (False, None, None, 0), self.handle_error(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 = format_sillytavern_err(error_msg, 'error')
            log_prompt(self.client_ip, self.token, prompt, backend_response, elapsed_time, self.parameters, dict(self.request.headers), response_status_code, self.request.url, is_error=True)
            return (False, None, None, 0), self.handle_error(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:
        queued_ip_count = redis.get_dict('queued_ip_count').get(self.client_ip, 0) + redis.get_dict('processing_ips').get(self.client_ip, 0)
        if queued_ip_count < opts.simultaneous_requests_per_ip or self.priority == 0:
            return False
        else:
            return True

    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) -> Tuple[flask.Response, int]:
        raise NotImplementedError

    def handle_error(self, msg: str) -> Tuple[flask.Response, int]:
        raise NotImplementedError


def get_backend():
    if opts.mode == 'oobabooga':
        return OobaboogaBackend()
    elif opts.mode == 'vllm':
        return VLLMBackend()
    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