1 files changed, 189 insertions, 0 deletions
diff --git a/api.php b/api.php
new file mode 100644
index 0000000..e164bbd
--- /dev/null
+++ b/api.php
@@ -0,0 +1,189 @@
+<?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)));
+//}
+
+?>