# -*- coding: utf-8 -*-
"""
This module provides various functions and constants used by the boobank-utils
tools.
"""
import os
import sys
import time
import json
import errno
from termcolor import colored

DEFAULT_CONF_DIR = '~/.config/boobank-utils'
MAX_AGE = 24 * 60 * 60

UNUSUAL_THRESHOLD = 500.0
WORRYING_THRESHOLD = 100.0
HOLYSHIT_THRESHOLD = 0

CURRENCIES = {
    'EUR': '€',
    'USD': '$',
    'GBP': '£',
    'YEN': '¥'
}
DEFAULT_CURRENCY = 'EUR'

COLORING_NONE = 0
COLORING_SIMPLE = 1
COLORING_THRESHOLD = 2
COLORING_MAX = 3

def format_timestamp_colored(timestamp, max_age):
    """
    Format the given Unix timestamp for puny humans.
    Additionally, the timestamp is colored: red if older than max_age, false
    otherwise. This is useful to show whether cached data are obsolete.
    """
    result = format_timestamp(timestamp)
    color = 'red' if timestamp + max_age < time.time() else 'green'
    return colored(result, color)

def format_timestamp(timestamp):
    """
    Format the given Unix timestamp for puny humans.
    """
    return time.strftime('%A %Y-%m-%d %H:%M:%S %Z', time.localtime(timestamp))

def format_amount(amount, currency=DEFAULT_CURRENCY, coloring=None):
    """
    Format the given amount and currency into an optionally colored string.
    """
    amount_format = '%12.2f ' + CURRENCIES.get(currency, currency)
    result = amount_format % amount

    if coloring < COLORING_SIMPLE or coloring >= COLORING_MAX:
        return result

    amount_color = 'green'
    amount_attr = []
    if coloring == COLORING_SIMPLE:
        if amount < 0:
            amount_color = 'red'
    else:
        # Assume COLORING_THRESHOLD:
        if amount < HOLYSHIT_THRESHOLD:
            amount_color = 'red'
            amount_attr = ['blink']
        elif amount < WORRYING_THRESHOLD:
            amount_color = 'red'
        elif amount < UNUSUAL_THRESHOLD:
            amount_color = 'yellow'
    return colored(result, amount_color, attrs=amount_attr)

def mkdir(path, mode):
    """
    Create a directory along with all missing parents.
    All created directories get assigned the given Unix mode.
    """
    try:
        os.makedirs(path, mode)
    except OSError as exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise

def load_json(json_path):
    """
    Return the contents of a JSON file, given its path.
    """
    if json_path == '-':
        return json.load(sys.stdin)
    else:
        with open(json_path, 'r') as filedesc:
            return json.load(filedesc)