#!/usr/bin/env python3
import os
import re
import sys
from datetime import datetime
from configparser import ConfigParser
from starlette.requests import Request
from starlette.routing import Route, Router
from starlette.responses import PlainTextResponse, JSONResponse
from starlette.exceptions import HTTPException
import uvicorn
import json

from pyheatpump.logger import logger_init
logger = logger_init()

"""
default_config = {
    'heatpump': {
        'serial_port': '/dev/ttyUSB0',
        'baudrate': 19200,
        'mac_address': 'None',
        'ip_address': 'dhcp',
        'read_only': 'False',
        'database': '/var/run/pyheatpump/pyheatpump.sqlite3'
    },
    'supervisor': {
        'scheme': 'http',
        'host': '127.0.0.1',
        'port': 8008,
        'certificate': 'None',
        'get_path': '/',
        'post_path': '/',
        'interval': 10000,
        'auth': 'None',
        'initialization': str(datetime.now()),
        'heatpump_id': 'None',
        'last_update': 0
    },
    'api': {
        'host': '127.0.0.1',
        'port': 80
    }
}
"""

CONFIG_FILES=[
    '/etc/pyheatpump.ini',
    './pyheatpump.ini']

config = ConfigParser()#default_section='heatpump')
#config.read_dict(default_config)
config.read(filenames=CONFIG_FILES)

API_HOST=config.get('api', 'host')
API_PORT=config.get('api', 'port')


def save_config():
    with open(CONFIG_FILES[-1], 'w') as conf_file:
        config.write(conf_file)


def mac_address_init():
    from netifaces import gateways, ifaddresses, AF_INET, AF_LINK

    interface = gateways()['default'][AF_INET][1]
    if len(ifaddresses(interface)) == 0:
        logger.error("Can't find interface %s", interface)
        sys.exit(1)

    if len(ifaddresses(interface)[AF_LINK]) == 0:
        logger.error("Can't find interface %s", interface)
        sys.exit(1)

    addr = ifaddresses(interface)[AF_LINK][0]['addr']
    config.set('heatpump', 'mac_address', addr)
    save_config()
    logger.info(f'Got new mac address {addr}')
    return addr

mac_address_init()

def get_config_dict():
    c = config
    return {
        s: {
            i: j
            for i, j in c.items(s)
        }
        for s in c.sections()
    }


async def get_config(request):
    return JSONResponse(get_config_dict())


async def set_config(request):
    d_body = await request.json()

    for sect in d_body.keys():
        if type(d_body[sect]) is not dict:
            continue
        for item in d_body[sect].keys():
            if not config.has_option(sect, item):
                raise HTTPException(404, f'The option {sect}.{item} does not exists')
            else:
                config.set(sect, item, value=d_body[sect][item])

    save_config()
    return PlainTextResponse('OK')

async def config_route(request, *args, **kwargs):
    config.read(filenames=CONFIG_FILES)
    if request['method'] == 'GET':
        return await get_config(request)
    elif request['method'] == 'POST':
        return await set_config(request)


def get_mac():
    return config.get('heatpump','mac_address')


async def mac_route(request, *args, **kwargs):
    config.read(filenames=CONFIG_FILES)
    if request['method'] == 'GET':
        return PlainTextResponse(get_mac())
    elif request['method'] == 'POST':
        body = await request.body()
        mac_address = body.decode()
        if len(mac_address) == 0:
            mac_address = mac_address_init()

        elif re.match('^([0-9a-f]{2}:?){6}$',
            mac_address, re.I) is not None:

            config.set('heatpump','mac_address',mac_address)
            save_config()
        else:
            logger.error(f'Wrong mac format : {mac_address}')

        return PlainTextResponse(' '.join((
            'Current ->',
            get_mac(),
            ', New -> ', mac_address)))


def get_last_update():
    return config.get('supervisor', 'last_update')


def set_last_update(last_update: int=0):
    config.set('supervisor', 'last_update', str(last_update))
    save_config()
    return get_last_update()


async def last_update_route(request, *args, **kwargs):
    """
    last_update :
        == 0 : since current date - interval
        < 0 : since current_date + last_update - interval
        > 0 : since current_data - last_update - interval (same behaviour as < 0) 
    """
    if type(request) != Request or request['method'] == 'GET':
        return PlainTextResponse(get_last_update())

    elif request['method'] == 'POST':
        body = await request.body()
        last_update = int(body.decode() or 0)
        if last_update == 0:
            last_update = int(datetime.now().strftime('%s'))
            logger.info('Reset last update to current time (%s)', last_update)
        else:
            logger.debug('%s of %s seconds', ("Forward" if last_update < 0 else "Rewind"), last_update)
            last_update = int(datetime.now().strftime('%s')) - last_update


        return PlainTextResponse(str(set_last_update(last_update)))


ROUTES=[
    Route('/', config_route, methods=['GET', 'POST']),
    Route('/mac', mac_route, methods=['GET', 'POST']),
    Route('/last_update', last_update_route, methods=['GET', 'POST'])
]

app = Router(routes=ROUTES)

if __name__ == '__main__':
    uvicorn.run('pyHeatpump:conf.app',
        host='127.0.0.1',
        port=8000)