Refactor time splitter, support computing of dates for time entries

src/NodaCountingTimeIndicator.php

@@ -0,0 +1,74 @@
+<?PHP
+/**
+ * Represents a time indicator (CE / BCE).
+ *
+ * @author Joshua Ramon Enslin <joshua@museum-digital.de>
+ */
+declare(strict_types = 1);
+
+/**
+ * Represents a time indicator (CE / BCE).
+ */
+enum NodaCountingTimeIndicator implements JsonSerializable {
+
+    case ce;
+    case bce;
+
+    /**
+     * Returns a value of this type based on a string.
+     *
+     * @param string $input Input to get a value from.
+     *
+     * @return NodaCountingTimeIndicator
+     */
+    public static function fromString(string $input):NodaCountingTimeIndicator {
+
+        return match($input) {
+            '+' => self::ce,
+            '-' => self::bce,
+            'ce' => self::ce,
+            'bce' => self::bce,
+            default => throw new MDpageParameterNotFromListException("Unknown counting time indicator (bc / bce)"),
+        };
+
+    }
+
+    /**
+     * Returns a canonical string representation.
+     *
+     * @return string
+     */
+    public function toString():string {
+
+        return match($this) {
+            self::ce  => '+',
+            self::bce => '-',
+        };
+
+    }
+
+    /**
+     * Returns a canonical string representation.
+     *
+     * @return string
+     */
+    public function toGerman():string {
+
+        return match($this) {
+            self::ce  => ' n. Chr.',
+            self::bce => ' v. Chr.',
+        };
+
+    }
+
+    /**
+     * Provides the option to serialize as a string during json_encode().
+     *
+     * @return string
+     */
+    public function jsonSerialize():string {
+
+        return $this->toString();
+
+    }
+}