chore(web): add upgrader for #21

web/app/upgrade/21_problem_difficulty/upgrade.php

@@ -0,0 +1,43 @@
+<?php
+
+return function ($type) {
+	if ($type == 'up') {
+		DB::init();
+
+		$problems = DB::selectAll("select * from problems");
+
+		foreach ($problems as $info) {
+			$problem = new UOJProblem($info);
+
+			$difficulty = -1;
+			$extra_config = $problem->getExtraConfig();
+
+			if (isset($extra_config['difficulty'])) {
+				$old_difficulty = (float)$extra_config['difficulty'];
+
+				$difficulty = (int)(3.0 * $old_difficulty + 5) * 100;
+				$difficulty = (function ($search, $arr) {
+					$closest = null;
+					foreach ($arr as $item) {
+						if ($closest === null || abs($search - $closest) > abs($item - $search)) {
+							$closest = $item;
+						}
+					}
+					return $closest;
+				})($difficulty, UOJProblem::$difficulty);
+			}
+
+			DB::update([
+				"update problems",
+				"set", [
+					"difficulty" => $difficulty,
+				],
+				"where", [
+					"id" => $problem->info['id'],
+				]
+			]);
+
+			echo "Problem: {$problem->info['id']} ({$difficulty})\n";
+		}
+	}
+};