From c689f37afc40ac4b2c9e495f081387c2ba4f417a Mon Sep 17 00:00:00 2001
From: Sky Johnson <skylearj@gmail.com>
Date: Fri, 20 Dec 2024 22:57:42 -0600
Subject: [PATCH] Create EXP, point and stat functions

---
 src/math.php | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 src/math.php

diff --git a/src/math.php b/src/math.php
new file mode 100644
index 0000000..9605656
--- /dev/null
+++ b/src/math.php
@@ -0,0 +1,98 @@
+<?php
+
+namespace Math;
+
+/*
+	Internal math functions, such as to calculate EXP, HP, stats, etc.
+*/
+
+/**
+ * Calculates the ***total*** EXP required at a particular level in order to level up.
+ */
+function calculate_exp(int $level, int $growthRate): int
+{
+    if ($level < 1) throw new \InvalidArgumentException("Level must be 1 or greater");
+
+    // Growth rates:
+    // 0 = Erratic
+    // 1 = Fast
+    // 2 = Medium Fast
+    // 3 = Medium Slow
+    // 4 = Slow
+    // 5 = Fluctuating
+
+    if ($growthRate < 0 || $growthRate > 5) throw new \InvalidArgumentException("Growth rate must be between 0 and 5");
+
+    return match($growthRate) {
+        0 => calculate_erratic_exp($level),
+        1 => (4 * pow($level, 3)) / 5,
+        2 => pow($level, 3),
+        3 => ((6 * pow($level, 3)) / 5) - (15 * pow($level, 2)) + (100 * $level) - 140,
+        4 => (5 * pow($level, 3)) / 4,
+        5 => calculate_fluctuating_exp($level),
+    };
+}
+
+/**
+ * Calculate the ***total*** EXP for a given level in the Erratic formula.
+ */
+function calculate_erratic_exp(int $level): int
+{
+    if ($level <= 50) {
+        return (pow($level, 3) * (100 - $level)) / 50;
+    } elseif ($level <= 68) {
+        return (pow($level, 3) * (150 - $level)) / 100;
+    } elseif ($level <= 98) {
+        return (pow($level, 3) * ((1911 - (10 * $level)) / 3)) / 500;
+    } else {
+        return (pow($level, 3) * (160 - $level)) / 100;
+    }
+}
+
+/**
+ * Calculate the ***total*** EXP for a given level in the Fluctuating formula.
+ */
+function calculate_fluctuating_exp(int $level): int
+{
+    if ($level <= 15) {
+        return pow($level, 3) * ((((($level + 1) / 3) + 24) / 50));
+    } elseif ($level <= 36) {
+        return pow($level, 3) * (($level + 14) / 50);
+    } else {
+        return pow($level, 3) * ((($level / 2) + 32) / 50);
+    }
+}
+
+/**
+ * Calculate a points total from a base. Modes: 1 (weak), 2 (normal), 3 (strong)
+ */
+function calculate_points(int $base_points, int $level, int $mode = 2): int
+{
+    if ($level < 1) throw new \InvalidArgumentException("Level must be 1 or greater");
+
+    $growth_multiplier = match($mode) {
+        1 => 0.75,
+        2 => 1.0,
+        3 => 1.5,
+        default => throw new \InvalidArgumentException("Invalid mode. Use 1 (weak), 2 (normal), or 3 (strong)")
+    };
+
+    return floor((2 * $base_points * $level * $growth_multiplier) / 100) + $level + 10;
+}
+
+/**
+ * Calculate a stat total from a base. Modes: 1 (weak), 2 (normal), 3 (strong)
+ */
+function calculate_stat(int $base_stat, int $level, int $mode = 2): int
+{
+    if ($level < 1) throw new \InvalidArgumentException("Level must be 1 or greater");
+
+    $growth_multiplier = match($mode) {
+        1 => 0.75,
+        2 => 1.0,
+        3 => 1.5,
+        default => throw new \InvalidArgumentException("Invalid mode. Use 1 (weak), 2 (normal), or 3 (strong)")
+    };
+
+    return floor((2 * $base_stat * $level * $growth_multiplier) / 100) + 5;
+}