# -*- coding: utf-8 -*-
# This file is part of convertdate.
# http://github.com/fitnr/convertdate
# Licensed under the MIT license:
# http://opensource.org/licenses/MIT
# Copyright (c) 2016, fitnr <fitnr@fakeisthenewreal>
"""
The Mayan calendar was developed in Mesoamerica. It includes two interlocking
cycles: the 260-day _Tzolkin_ cycle and the 365-day _Haab'_ cycle. In the _Tzolkin_ cycle,
each day is numbered 1-13 and has one of 20 day names. The _Haab'_ cycle comprises 18 months
of 20 days, along with five additional days (_Wayebʼ_).

The calendrical system also includes the
`Long Count <https://en.wikipedia.org/wiki/Mesoamerican_Long_Count_calendar>`__,
a modified base-20 counting scheme. Dates in the long count are usually written in the form *7.18.14.8.12*.
"""
import itertools
from math import trunc

from . import gregorian
from .utils import amod

EPOCH = 584282.5
HAAB = [
    "Pop",
    "Wo'",
    "Zip",
    "Sotz'",
    "Sek",
    "Xul",
    "Yaxk'in'",
    "Mol",
    "Ch'en",
    "Yax",
    "Sak'",
    "Keh",
    "Mak",
    "K'ank'in",
    "Muwan'",
    "Pax",
    "K'ayab",
    "Kumk'u",
    "Wayeb'",
]

HAAB_TRANSLATIONS = [
    "Mat",
    "Frog",
    "Red",
    "Bat",
    "Bee",
    "Dog",
    "First Sun",
    "Water",
    "Cave",
    "Green",
    "White",
    "Red",
    "Encloser",
    "Yellow Sun",
    "Screech Owl",
    "Planting Time",
    "Turtle",
    "Ripe Corn",
    "Nameless",
]

TZOLKIN = [
    "Imix'",
    "Ik'",
    "Ak'b'al",
    "K'an",
    "Chikchan",
    "Kimi",
    "Manik'",
    "Lamat",
    "Muluk",
    "Ok",
    "Chuwen",
    "Eb'",
    "B'en",
    "Ix",
    "Men",
    "K'ib'",
    "Kab'an",
    "Etz'nab'",
    "Kawak",
    "Ajaw",
]

TZOLKIN_TRANSLATIONS = [
    "Water",
    "Wind",
    "Darkness",
    "Net",
    "Feathered Serpent",
    "Death",
    "Deer",
    "Seed",
    "Jade",
    "Dog",
    "Thread",
    "Path",
    "Maize",
    "Tiger",
    "Bird",
    "Will",
    "Wisdom",
    "Obsidian Knife",
    "Thunder",
    "Sun",
]


def to_jd(baktun, katun, tun, uinal, kin):
    '''Determine Julian day from Mayan long count'''
    return EPOCH + (baktun * 144000) + (katun * 7200) + (tun * 360) + (uinal * 20) + kin


def from_jd(jd):
    '''Calculate Mayan long count from Julian day'''
    d = jd - EPOCH
    if d < 0:
        raise ValueError("Day out of range")
    baktun = trunc(d / 144000)
    d = d % 144000
    katun = trunc(d / 7200)
    d = d % 7200
    tun = trunc(d / 360)
    d = d % 360
    uinal = trunc(d / 20)
    kin = int((d % 20))

    return (baktun, katun, tun, uinal, kin)


def to_gregorian(baktun, katun, tun, uinal, kin):
    jd = to_jd(baktun, katun, tun, uinal, kin)
    return gregorian.from_jd(jd)


def from_gregorian(year, month, day):
    jd = gregorian.to_jd(year, month, day)
    return from_jd(jd)


def to_haab(jd):
    '''Determine Mayan Haab "month" and day from Julian day'''
    # Number of days since the start of the long count
    lcount = trunc(jd) + 0.5 - EPOCH
    # Long Count begins 348 days after the start of the cycle
    day = (lcount + 348) % 365

    count = day % 20
    month = trunc(day / 20)

    return int(count), HAAB[month]


def to_tzolkin(jd):
    '''Determine Mayan Tzolkin "month" and day from Julian day'''
    lcount = trunc(jd) + 0.5 - EPOCH
    day = amod(lcount + 4, 13)
    name = amod(lcount + 20, 20)
    return int(day), TZOLKIN[int(name) - 1]


def lc_to_haab(baktun, katun, tun, uinal, kin):
    jd = to_jd(baktun, katun, tun, uinal, kin)
    return to_haab(jd)


def lc_to_tzolkin(baktun, katun, tun, uinal, kin):
    jd = to_jd(baktun, katun, tun, uinal, kin)
    return to_tzolkin(jd)


def lc_to_haab_tzolkin(baktun, katun, tun, uinal, kin):
    jd = to_jd(baktun, katun, tun, uinal, kin)
    dates = to_tzolkin(jd) + to_haab(jd)
    return "{0} {1} {2} {3}".format(*dates)


def translate_haab(h):
    return dict(list(zip(HAAB, HAAB_TRANSLATIONS))).get(h)


def translate_tzolkin(tz):
    return dict(list(zip(TZOLKIN, TZOLKIN_TRANSLATIONS))).get(tz)


def _haab_count(day, month):
    '''Return the count of the given haab in the cycle. e.g. 0 Pop == 1, 5 Wayeb' == 365'''
    if day < 0 or day > 19:
        raise IndexError("Invalid day number")

    try:
        i = HAAB.index(month)
    except ValueError as err:
        raise ValueError("'{0}' is not a valid Haab' month".format(month)) from err

    return min(i * 20, 360) + day


def _tzolkin_from_count(count):
    number = amod(count, 13)
    name = TZOLKIN[count % 20 - 1]
    return number, name


def _tzolkin_count(day, name):
    if day < 1 or day > 13:
        raise IndexError("Invalid day number")

    days = set(x + day for x in range(0, 260, 13))

    try:
        n = 1 + TZOLKIN.index(name)
    except ValueError as err:
        raise ValueError("'{0}' is not a valid Tzolk'in day name".format(name)) from err

    names = set(y + n for y in range(0, 260, 20))
    return days.intersection(names).pop()


def tzolkin_generator(number=None, name=None):
    """For a given tzolkin name/number combination, return a generator
    that gives cycle, starting with the input"""

    # By default, it will start at the beginning
    number = number or 13
    name = name or "Ajaw"

    if number > 13:
        raise ValueError("Invalid day number")

    if name not in TZOLKIN:
        raise ValueError("Invalid day name")

    count = _tzolkin_count(number, name)

    ranged = itertools.chain(list(range(count, 260)), list(range(1, count)))

    for i in ranged:
        yield _tzolkin_from_count(i)


def longcount_generator(baktun, katun, tun, uinal, kin):
    '''Generate long counts, starting with input'''
    j = to_jd(baktun, katun, tun, uinal, kin)

    while True:
        yield from_jd(j)
        j = j + 1


def next_haab(month, jd):
    '''For a given haab month and a julian day count, find the next start of that month on or after the JDC'''
    if jd < EPOCH:
        raise IndexError("Input day is before Mayan epoch.")

    hday, hmonth = to_haab(jd)

    if hmonth == month:
        days = 1 - hday

    else:
        count1 = _haab_count(hday, hmonth)
        count2 = _haab_count(1, month)

        # Find number of days between haab of given jd and desired haab
        days = (count2 - count1) % 365

    # add in the number of days and return new jd
    return jd + days


def next_tzolkin(tzolkin, jd):
    '''For a given tzolk'in day, and a julian day count, find the next occurrance of that tzolk'in after the date'''
    if jd < EPOCH:
        raise IndexError("Input day is before Mayan epoch.")

    count1 = _tzolkin_count(*to_tzolkin(jd))
    count2 = _tzolkin_count(*tzolkin)

    add_days = (count2 - count1) % 260
    return jd + add_days


def next_tzolkin_haab(tzolkin, haab, jd):
    '''For a given haab-tzolk'in combination, and a Julian day count, find the next occurrance of the combination after the date'''
    # get H & T of input jd, and their place in the 18,980 day cycle
    haabcount = _haab_count(*to_haab(jd))
    haab_desired_count = _haab_count(*haab)

    # How many days between the input day and the desired day?
    haab_days = (haab_desired_count - haabcount) % 365

    possible_haab = set(h + haab_days for h in range(0, 18980, 365))

    tzcount = _tzolkin_count(*to_tzolkin(jd))
    tz_desired_count = _tzolkin_count(*tzolkin)
    # How many days between the input day and the desired day?
    tzolkin_days = (tz_desired_count - tzcount) % 260

    possible_tz = set(t + tzolkin_days for t in range(0, 18980, 260))

    try:
        return possible_tz.intersection(possible_haab).pop() + jd
    except KeyError:
        raise IndexError("That Haab'-Tzolk'in combination isn't possible")


def month_length(month):
    """Not the actual length of the month, but accounts for the 5 unlucky/nameless days"""
    if month == "Wayeb'":
        return 5
    return 20


def haab_monthcalendar(baktun=None, katun=None, tun=None, uinal=None, kin=None, jdc=None):
    '''For a given long count, return a calender of the current haab month, divided into tzolkin "weeks"'''
    if not jdc:
        jdc = to_jd(baktun, katun, tun, uinal, kin)

    haab_number, haab_month = to_haab(jdc)
    first_j = jdc - haab_number + 1

    tzolkin_start_number, tzolkin_start_name = to_tzolkin(first_j)

    gen_longcount = longcount_generator(*from_jd(first_j))
    gen_tzolkin = tzolkin_generator(tzolkin_start_number, tzolkin_start_name)

    # 13 day long tzolkin 'weeks'
    lpad = tzolkin_start_number - 1
    rpad = 13 - (tzolkin_start_number + 19 % 13)

    monlen = month_length(haab_month)

    days = [None] * lpad + list(range(1, monlen + 1)) + rpad * [None]

    def g(x, generate):
        if x is None:
            return None
        return next(generate)

    return [[(k, g(k, gen_tzolkin), g(k, gen_longcount)) for k in days[i : i + 13]] for i in range(0, len(days), 13)]


def haab_monthcalendar_prospective(haabmonth, jdc):
    '''Give the monthcalendar for the next occurance of given haab month after jdc'''
    return haab_monthcalendar(jdc=next_haab(haabmonth, jdc))
