<?php

/*
Parametry:
 - rodzaj turnieju (4 => teamy, 2 => pary, 1 => ind)
 - l. uczestników
 - suma WK
 - ranga turnieju (0 => K, 1 => Ok, 2 => R, 3 => O, 4 => O*, 5 => O**, 6 => O***, 7 => O****) (opcjonalny, jeśli podano ręczne minPKL i wagę)
 - l. rozdań => 40? (opcjonalny, jeśli podano ręczne minPKL i wagę)
 - ręczne minPKL za pierwsze (opcjonalny)
 - ręczna waga (opcjonalny)
 - ręczny współczynnik zawodniczy (opcjonalny)
 - ręczne progi (opcjonalne)
 
 {
     "type": 2,
     "contestants": 20,
     "title_sum": 230,
     "tournament_rank": 3,
     "over39_boards": 0,
     "manual": {
         "min_points": 50,
         "tournament_weight": 50,
         "players_coefficient": 0.1,
         "points_cutoffs": [[0.1, 0.9], [0.5, 0.0]]
     }
 }

*/

class ParametersException extends Exception {};

function safe_ceil($value, $precision = 1e-6) {
    $ceilValue = ceil($value);
    return (abs($value - $ceilValue) < (1-$precision)) ? $ceilValue : round($value);
}

function recursive_ksort(&$array, $flags = SORT_REGULAR) {
    if (!is_array($array)) return false;
    ksort($array, $flags);
    foreach ($array as &$arr) {
        recursive_ksort($arr, $flags);
    }
    return true;
}

function ensure_parameters($parameters, $params) {
    foreach ($params as $param) {
        if (!isset($parameters[$param])) {
            throw new ParametersException('Missing parameter: ' . $param);
        }
        if (!is_numeric($parameters[$param])) {
            throw new ParametersException('Parameter: ' . $param . ' is not a numeric value (' . $parameters[$param] . ')');
        }
    }
}

function check_values($parameters, $params) {
    foreach ($params as $param => $test) {
        if (!$test($parameters[$param])) {
            throw new ParametersException('Parameter: ' . $param . ' has incorrect value (' . $parameters[$param] . ')');
        }
    }
}

function check_parameters($parameters) {
    ensure_parameters($parameters, array('type', 'contestants', 'title_sum'));
    check_values($parameters, array(
        'type' => function($r) { return ctype_digit($r) && intval($r) > 0; },
        'contestants' => function($r) { return ctype_digit($r) && intval($r) > 0; },
        'title_sum' => function($r) { return floatval($r) >= 0; }
    ));
    if (isset($parameters['players'])) {
        check_values($parameters, array(
            'players' => function($r) { return ctype_digit($r) && intval($r) > 0; }
        ));        
    }
    if (!isset($parameters['manual']) || !isset($parameters['manual']['min_points']) || !isset($parameters['manual']['tournament_weight'])) {
        ensure_parameters($parameters, array('tournament_rank', 'over39_boards'));
        check_values($parameters, array(
            'tournament_rank' => function($r) { return ctype_digit($r) && intval($r) >= 0 && intval($r) <= 7; },
            'over39_boards' => function($r) { return ctype_digit($r) && intval($r) >= 0 && intval($r) <= 1; }
        ));
    } else {
        check_values($parameters['manual'], array(
            'min_points' => function($r) { return ctype_digit($r) && intval($r) >= 0; },
            'tournament_weight' => function($r) { return ctype_digit($r) && intval($r) > 0; }
        ));
    }
    if (isset($parameters['manual']) && isset($parameters['manual']['players_coefficient'])) {
        check_values($parameters['manual'], array(
            'players_coefficient' => function($r) { return floatval($r) >= 0; }
        ));
    }
}

function parse_parameters($parameters) {
    $return = array();
    $return['type'] = intval($parameters['type']);
    if ($return['type'] == 3 || $return['type'] > 4) {
        throw new ParametersException('Parameter: type has incorrect value (' . $return['type'] . ')');
    }
    $return['contestants'] = intval($parameters['contestants']);
    $return['players'] = isset($parameters['players']) ? intval($parameters['players']) : intval($parameters['contestants']) * $return['type'];
    $return['title_sum'] = floatval($parameters['title_sum']);
    $weights = array(
        array(1, 2, 4, 5, 7, 10, 15, 25),
        array(2, 3, 5, 7, 10, 15, 25, 40)
    );
    $return['tournament_weight'] = (isset($parameters['manual']) && isset($parameters['manual']['tournament_weight'])) ? intval($parameters['manual']['tournament_weight']) : $weights[intval($parameters['over39_boards'])][intval($parameters['tournament_rank'])];
    $min_points = array(
        array(0, 0, 0, 0, 50, 75, 150, 200),
        array(0, 0, 0, 0, 70, 100, 200, 300)
    );
    $return['min_points'] = (isset($parameters['manual']) && isset($parameters['manual']['min_points'])) ? intval($parameters['manual']['min_points']) : $min_points[intval($parameters['over39_boards'])][intval($parameters['tournament_rank'])];
    $return['players_coefficient'] = (isset($parameters['manual']) && isset($parameters['manual']['players_coefficient'])) ? intval($parameters['manual']['players_coefficient']) : 0.05;
    $return['points_cutoffs'] = (isset($parameters['manual']) && isset($parameters['manual']['points_cutoffs']) && is_array($parameters['manual']['points_cutoffs'])) ? $parameters['manual']['points_cutoffs'] : array(
        array(0.0, 1.0),
        array(0.02, 0.9),
        array(0.2, 0.2),
        array(0.5, 0.0)
    );
    recursive_ksort($return['points_cutoffs']);
    if ($return['points_cutoffs'][0][0] != 0.0) {
        array_unshift($return['points_cutoffs'], array(0.0, 1.0));
    }
    if ($return['points_cutoffs'][count($return['points_cutoffs'])-1][1] != 0.0) {
        array_push($return['points_cutoffs'], array(1.0, 0.0));
    }
    return $return;
}

function get_position_percentage_from_position($position, $contestants) {
    return ($position - 1) / $contestants;
}

function get_percentage_from_position($position, $contestants, $cutoffs) {
    $position_percentage = get_position_percentage_from_position($position, $contestants);
    for ($prev = 0; $prev < count($cutoffs) - 1; $prev++) {
        $next = $prev + 1;
        if (($cutoffs[$prev][0] <= $position_percentage) && ($cutoffs[$next][0] >= $position_percentage)) {
            $result = ($position_percentage - $cutoffs[$prev][0]) * ($cutoffs[$prev][1] - $cutoffs[$next][1]) / ($cutoffs[$prev][0] - $cutoffs[$next][0]) + $cutoffs[$prev][1];
            return $result;
        }
    }
    return 0.0;
}

function calculate_points($parameters) {
    $max_points = safe_ceil(max(
        $parameters['min_points'],
        (1 + 0.25 * ($parameters['type'] > 2)) * (max(0.15, $parameters['title_sum'] / $parameters['players']) * $parameters['tournament_weight'] + $parameters['players_coefficient'] * $parameters['contestants'] * $parameters['type'])
    ));
    $min_points = 1;
    $result = array("sum" => 0);
    for ($place = 1; $place <= $parameters['contestants']; $place++) {
        $percentage = get_percentage_from_position($place, $parameters['contestants'], $parameters['points_cutoffs']);
        $points = safe_ceil(floatval($max_points) * $percentage);
        $result[$place] = max($min_points, intval($points));
        $result['sum'] += $parameters['type'] * $result[$place];
    }
    return $result;
}

function run($parameters) {
    try {
        check_parameters($parameters);
        $parameters = parse_parameters($parameters);
        $result = calculate_points($parameters);
        return $result;
    }
    catch (ParametersException $e) {
        http_response_code(400);
        die($e->getMessage());
    }
    catch (Exception $e) {
        http_response_code(500);
        die($e->getMessage());
    }
}

/*if ($_SERVER['REQUEST_METHOD'] != 'POST') {
    http_response_code(405);
    die('API only accepts POST requests');
} else {*/
    print(json_encode(run($_REQUEST)));
//}

?>