#!/usr/bin/env python3

"""
Calculate probability of getting at least one of a monster part from one
line in the quest rewards. Also calculates expected value of part
counts (N), and probabilities of getting a certain number of rewards (C).

usage: mhprob.py reward_percent fixed_rewards gaurenteed_rewards \
                 [extend_percent]

reward_percent - chance of getting the monster part in %
fixed_rewards - number of rewards in the reward list with 100% chance and
                are not the item you are looking for. Takes away from
                the total possible draw attempts for what you want.
                Default 1 which is typical for line A in many quests.
gaurenteed_rewards - minimum number of quest rewards in the line,
                     including any fixed rewards. In Tri (see link
                     below) this is 3 for line A and 1 for line B.
                     Defaults to 3.
extend_percent - chance of getting one more reward in the line in %,
                 default 69

You can use http://kiranico.com to get reward percent and fixed rewards
values.

For extend percent, use the default unless you have the Lucky Cat or
Ultra Lucky Cat food skills or Good Luck or Great Luck armor skills:

normal extra reward %: 69
good luck extra reward %: 81
great luck extra %: 90

Can also be used to calculate chance of getting a part from carving,
using extend_percent=0, fixed_rewards=0, and gaurenteed_rewards=3 (or
4 for monsters with 4 carves).

Source:
http://www.gamefaqs.com/wii/943655-monster-hunter-tri/faqs/60448
Not sure if there are differences in 3U or 4U.

Example Plain dangerous in 3U, has 2 fixed rewards in A, one in B, hardhorns
are 5% both A and B:
A: ./mhprop.py 5 2 3 69
B: ./mhprop.py 5 1 1 69
For great luck, replace 69 with 90
"""

import sys

import _pathfix

from mhapi import stats

if __name__ == '__main__':
    # in percent
    reward_percent = int(sys.argv[1])
    if len(sys.argv) > 2:
        fixed_rewards = int(sys.argv[2])
    else:
        fixed_rewards = 1
    if len(sys.argv) > 3:
        guarenteed_rewards = int(sys.argv[3])
    else:
        guarenteed_rewards = 3
    if len(sys.argv) > 4:
        extend_percent = int(sys.argv[4])
    else:
        extend_percent = 69

    min_rewards = guarenteed_rewards - fixed_rewards
    max_rewards = 8 - fixed_rewards

    if min_rewards < 0:
        print("Error: fixed_rewards (%d) must be less than or equal to " \
              "guaranteeed_rewards (%d)" % (fixed_rewards, guarenteed_rewards))
        sys.exit(1)

    total_p = 0.0
    expected_attempts = 0.0
    for reward_count in range(min_rewards, max_rewards + 1):
        p = stats._reward_count_p(reward_count, min_rewards, max_rewards,
                                  extend_percent)
        expected_attempts += p * reward_count
        # probability of getting @reward_count rewards that could be the
        # desired item
        print("P(C = %d) = %0.4f" % (reward_count, p))
        total_p += p
    # expected value for number of rewards that could be the desired item
    print("E(C)     = %0.2f" % expected_attempts)

    # math check, make sure all possibilities add up to 1, allowing for
    # some floating point precision loss.
    assert abs(total_p - 1.0) < .00001, "total = %f" % total_p

    p_at_least_one = stats.quest_reward_p(reward_percent, min_rewards,
                                          max_rewards, extend_percent)
    expected = expected_attempts * reward_percent / 100.0

    print("P(N > 0) = %0.2f%%" % p_at_least_one)
    print("E(N)     = %0.4f" % expected)