1 files changed, 213 insertions, 0 deletions
diff --git a/library/Icingadb/Util/ThresholdRange.php b/library/Icingadb/Util/ThresholdRange.php
new file mode 100644
index 0000000..675697a
--- /dev/null
+++ b/library/Icingadb/Util/ThresholdRange.php
@@ -0,0 +1,213 @@
+<?php
+
+/* Icinga DB Web | (c) 2021 Icinga GmbH | GPLv2 */
+
+namespace Icinga\Module\Icingadb\Util;
+
+/**
+ * The warning/critical threshold of a measured value
+ */
+class ThresholdRange
+{
+    /**
+     * The smallest value inside the range (null stands for -∞)
+     *
+     * @var float|null
+     */
+    protected $min;
+
+    /**
+     * The biggest value inside the range (null stands for ∞)
+     *
+     * @var float|null
+     */
+    protected $max;
+
+    /**
+     * Whether to invert the result of contains()
+     *
+     * @var bool
+     */
+    protected $inverted = false;
+
+    /**
+     * The unmodified range as passed to fromString()
+     *
+     * @var string
+     */
+    protected $raw;
+
+    /**
+     * Whether the threshold range is valid
+     *
+     * @var bool
+     */
+    protected $isValid = true;
+
+    /**
+     * Create a new instance based on a threshold range conforming to <https://nagios-plugins.org/doc/guidelines.html>
+     *
+     * @param   string  $rawRange
+     *
+     * @return  ThresholdRange
+     */
+    public static function fromString(string $rawRange): self
+    {
+        $range = new static();
+        $range->raw = $rawRange;
+
+        if ($rawRange == '') {
+            return $range;
+        }
+
+        $rawRange = ltrim($rawRange);
+        if (substr($rawRange, 0, 1) === '@') {
+            $range->setInverted();
+            $rawRange = substr($rawRange, 1);
+        }
+
+        if (strpos($rawRange, ':') === false) {
+            $min = 0.0;
+            $max = trim($rawRange);
+            if (! is_numeric($max)) {
+                $range->isValid = false;
+                return $range;
+            }
+
+            $max = floatval(trim($rawRange));
+        } else {
+            list($min, $max) = explode(':', $rawRange, 2);
+            $min = trim($min);
+            $max = trim($max);
+
+            switch ($min) {
+                case '':
+                    $min = 0.0;
+                    break;
+                case '~':
+                    $min = null;
+                    break;
+                default:
+                    if (! is_numeric($min)) {
+                        $range->isValid = false;
+                        return $range;
+                    }
+
+                    $min = floatval($min);
+            }
+
+            if (! empty($max) && ! is_numeric($max)) {
+                $range->isValid = false;
+                return $range;
+            }
+
+            $max = empty($max) ? null : floatval($max);
+        }
+
+        return $range->setMin($min)
+            ->setMax($max);
+    }
+
+    /**
+     * Set the smallest value inside the range (null stands for -∞)
+     *
+     * @param   float|null  $min
+     *
+     * @return  $this
+     */
+    public function setMin(?float $min): self
+    {
+        $this->min = $min;
+        return $this;
+    }
+
+    /**
+     * Get the smallest value inside the range (null stands for -∞)
+     *
+     * @return  float|null
+     */
+    public function getMin()
+    {
+        return $this->min;
+    }
+
+    /**
+     * Set the biggest value inside the range (null stands for ∞)
+     *
+     * @param   float|null  $max
+     *
+     * @return  $this
+     */
+    public function setMax(?float $max): self
+    {
+        $this->max = $max;
+        return $this;
+    }
+
+    /**
+     * Get the biggest value inside the range (null stands for ∞)
+     *
+     * @return  float|null
+     */
+    public function getMax()
+    {
+        return $this->max;
+    }
+
+    /**
+     * Set whether to invert the result of contains()
+     *
+     * @param   bool    $inverted
+     *
+     * @return  $this
+     */
+    public function setInverted(bool $inverted = true): self
+    {
+        $this->inverted = $inverted;
+        return $this;
+    }
+
+    /**
+     * Get whether to invert the result of contains()
+     *
+     * @return  bool
+     */
+    public function isInverted(): bool
+    {
+        return $this->inverted;
+    }
+
+    /**
+     * Return whether $value is inside $this
+     *
+     * @param   float   $value
+     *
+     * @return  bool
+     */
+    public function contains(float $value): bool
+    {
+        return (bool) ($this->inverted ^ (
+            ($this->min === null || $this->min <= $value) && ($this->max === null || $this->max >= $value)
+        ));
+    }
+
+    /**
+     * Return whether the threshold range is valid
+     *
+     * @return bool
+     */
+    public function isValid()
+    {
+        return $this->isValid;
+    }
+
+    /**
+     * Return the textual representation of $this, suitable for fromString()
+     *
+     * @return  string
+     */
+    public function __toString()
+    {
+        return (string) $this->raw;
+    }
+}