import logging
from copy import deepcopy

from fastapi import APIRouter, BackgroundTasks, Depends
from fastapi.exceptions import HTTPException

from freqtrade.constants import Config
from freqtrade.enums import CandleType
from freqtrade.exceptions import OperationalException
from freqtrade.rpc.api_server.api_schemas import (BackgroundTaskStatus, BgJobStarted,
                                                  ExchangeModePayloadMixin, PairListsPayload,
                                                  PairListsResponse, WhitelistEvaluateResponse)
from freqtrade.rpc.api_server.deps import get_config, get_exchange
from freqtrade.rpc.api_server.webserver_bgwork import ApiBG


logger = logging.getLogger(__name__)

# Private API, protected by authentication and webserver_mode dependency
router = APIRouter()


@router.get('/background/{jobid}', response_model=BackgroundTaskStatus, tags=['webserver'])
def background_job(jobid: str):
    if not (job := ApiBG.jobs.get(jobid)):
        raise HTTPException(status_code=404, detail='Job not found.')

    return {
        'job_id': jobid,
        'job_category': job['category'],
        'status': job['status'],
        'running': job['is_running'],
        'progress': job.get('progress'),
        # 'job_error': job['error'],
    }


@router.get('/pairlists/available',
            response_model=PairListsResponse, tags=['pairlists', 'webserver'])
def list_pairlists(config=Depends(get_config)):
    from freqtrade.resolvers import PairListResolver
    pairlists = PairListResolver.search_all_objects(
        config, False)
    pairlists = sorted(pairlists, key=lambda x: x['name'])

    return {'pairlists': [{
        "name": x['name'],
        "is_pairlist_generator": x['class'].is_pairlist_generator,
        "params": x['class'].available_parameters(),
        "description": x['class'].description(),
         } for x in pairlists
    ]}


def __run_pairlist(job_id: str, config_loc: Config):
    try:

        ApiBG.jobs[job_id]['is_running'] = True
        from freqtrade.plugins.pairlistmanager import PairListManager

        exchange = get_exchange(config_loc)
        pairlists = PairListManager(exchange, config_loc)
        pairlists.refresh_pairlist()
        ApiBG.jobs[job_id]['result'] = {
                'method': pairlists.name_list,
                'length': len(pairlists.whitelist),
                'whitelist': pairlists.whitelist
            }
        ApiBG.jobs[job_id]['status'] = 'success'
    except (OperationalException, Exception) as e:
        logger.exception(e)
        ApiBG.jobs[job_id]['error'] = str(e)
    finally:
        ApiBG.jobs[job_id]['is_running'] = False
        ApiBG.jobs[job_id]['status'] = 'failed'
        ApiBG.pairlist_running = False


@router.post('/pairlists/evaluate', response_model=BgJobStarted, tags=['pairlists', 'webserver'])
def pairlists_evaluate(payload: PairListsPayload, background_tasks: BackgroundTasks,
                       config=Depends(get_config)):
    if ApiBG.pairlist_running:
        raise HTTPException(status_code=400, detail='Pairlist evaluation is already running.')

    config_loc = deepcopy(config)
    config_loc['stake_currency'] = payload.stake_currency
    config_loc['pairlists'] = payload.pairlists
    handleExchangePayload(payload, config_loc)
    # TODO: overwrite blacklist? make it optional and fall back to the one in config?
    # Outcome depends on the UI approach.
    config_loc['exchange']['pair_blacklist'] = payload.blacklist
    # Random job id
    job_id = ApiBG.get_job_id()

    ApiBG.jobs[job_id] = {
        'category': 'pairlist',
        'status': 'pending',
        'progress': None,
        'is_running': False,
        'result': {},
        'error': None,
    }
    background_tasks.add_task(__run_pairlist, job_id, config_loc)
    ApiBG.pairlist_running = True

    return {
        'status': 'Pairlist evaluation started in background.',
        'job_id': job_id,
    }


def handleExchangePayload(payload: ExchangeModePayloadMixin, config_loc: Config):
    """
    Handle exchange and trading mode payload.
    Updates the configuration with the payload values.
    """
    if payload.exchange:
        config_loc['exchange']['name'] = payload.exchange
    if payload.trading_mode:
        config_loc['trading_mode'] = payload.trading_mode
        config_loc['candle_type_def'] = CandleType.get_default(
            config_loc.get('trading_mode', 'spot') or 'spot')
    if payload.margin_mode:
        config_loc['margin_mode'] = payload.margin_mode


@router.get('/pairlists/evaluate/{jobid}', response_model=WhitelistEvaluateResponse,
            tags=['pairlists', 'webserver'])
def pairlists_evaluate_get(jobid: str):
    if not (job := ApiBG.jobs.get(jobid)):
        raise HTTPException(status_code=404, detail='Job not found.')

    if job['is_running']:
        raise HTTPException(status_code=400, detail='Job not finished yet.')

    if error := job['error']:
        return {
            'status': 'failed',
            'error': error,
        }

    return {
        'status': 'success',
        'result': job['result'],
    }