#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
Collect the occupancy dataset.

See the README file for more information.

Author: G.J.J. van den Burg
License: This file is part of TCPD, see the top-level LICENSE file.
Copyright: 2019, The Alan Turing Institute

"""

import argparse
import clevercsv
import hashlib
import json
import os

from functools import wraps
from urllib.request import urlretrieve

SAMPLE = 16

TXT_URL = "https://web.archive.org/web/20191128145102if_/https://raw.githubusercontent.com/LuisM78/Occupancy-detection-data/master/datatraining.txt"

MD5_TXT = "e656cd731300cb444bd10fcd28071e37"
MD5_JSON = "bc6cd9adaf496fe30bf0e417d2c3b0c6"

NAME_TXT = "datatraining.txt"
NAME_JSON = "occupancy.json"


class ValidationError(Exception):
    def __init__(self, filename):
        message = (
            "Validating the file '%s' failed. \n"
            "Please raise an issue on the GitHub page for this project "
            "if the error persists." % filename
        )
        super().__init__(message)


def check_md5sum(filename, checksum):
    with open(filename, "rb") as fp:
        data = fp.read()
    h = hashlib.md5(data).hexdigest()
    return h == checksum


def validate(checksum):
    """Decorator that validates the target file."""

    def validate_decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            target = kwargs.get("target_path", None)
            if os.path.exists(target) and check_md5sum(target, checksum):
                return
            out = func(*args, **kwargs)
            if not os.path.exists(target):
                raise FileNotFoundError("Target file expected at: %s" % target)
            if not check_md5sum(target, checksum):
                raise ValidationError(target)
            return out

        return wrapper

    return validate_decorator


@validate(MD5_TXT)
def download_txt(target_path=None):
    urlretrieve(TXT_URL, target_path)


@validate(MD5_JSON)
def write_json(txt_path, target_path=None):
    with open(txt_path, "r", newline="", encoding="ascii") as fp:
        reader = clevercsv.reader(
            fp, delimiter=",", quotechar='"', escapechar=""
        )
        rows = list(reader)

    header = rows.pop(0)
    header.insert(0, "id")
    as_dicts = [dict(zip(header, r)) for r in rows]

    var_include = ["Temperature", "Humidity", "Light", "CO2"]

    time = [x["date"] for x in as_dicts]
    time = [time[i] for i in range(0, len(time), SAMPLE)]

    data = {
        "name": "occupancy",
        "longname": "Occupancy",
        "n_obs": len(time),
        "n_dim": len(var_include),
        "time": {
            "type": "string",
            "format": "%Y-%m-%d %H:%M:%S",
            "index": list(range(len(time))),
            "raw": time,
        },
        "series": [],
    }
    for idx, var in enumerate(var_include, start=1):
        lbl = "V%i" % idx
        obs = [float(x[var]) for x in as_dicts]
        obs = [obs[i] for i in range(0, len(obs), SAMPLE)]
        data["series"].append({"label": lbl, "type": "float", "raw": obs})

    with open(target_path, "w") as fp:
        json.dump(data, fp, indent="\t")


def collect(output_dir="."):
    txt_path = os.path.join(output_dir, NAME_TXT)
    json_path = os.path.join(output_dir, NAME_JSON)

    download_txt(target_path=txt_path)
    write_json(txt_path, target_path=json_path)


def clean(output_dir="."):
    txt_path = os.path.join(output_dir, NAME_TXT)
    json_path = os.path.join(output_dir, NAME_JSON)

    if os.path.exists(txt_path):
        os.unlink(txt_path)
    if os.path.exists(json_path):
        os.unlink(json_path)


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-o", "--output-dir", help="output directory to use", default="."
    )
    parser.add_argument(
        "action",
        choices=["collect", "clean"],
        help="Action to perform",
        default="collect",
        nargs="?",
    )
    return parser.parse_args()


def main(output_dir="."):
    args = parse_args()
    if args.action == "collect":
        collect(output_dir=args.output_dir)
    elif args.action == "clean":
        clean(output_dir=args.output_dir)


if __name__ == "__main__":
    main()