ready

src/FuzzySearch.php

@@ -2,4 +2,29 @@
 
 namespace Designbycode\FuzzySearch;
 
-class FuzzySearch {}
+class FuzzySearch {
+
+    private $texts;
+    private $levenshteinDistance;
+
+    public function __construct(array $texts) {
+        $this->texts = $texts;
+        $this->levenshteinDistance = new LevenshteinDistance();
+    }
+
+    public function search($query, $maxDistance = 2): array
+    {
+        $query = strtolower($query); // Convert query to lowercase
+        $results = array();
+        foreach ($this->texts as $text) {
+            $textLowercase = strtolower($text); // Convert text to lowercase
+            $distance = $this->levenshteinDistance->calculate($query, $textLowercase);
+            if ($distance <= $maxDistance) {
+                $results[] = $text; // Store original text (with original case)
+            }
+        }
+        return $results;
+    }
+
+
+}

src/LevenshteinDistance.php

@@ -0,0 +1,50 @@
+<?php
+
+	namespace Designbycode\FuzzySearch;
+
+    class LevenshteinDistance {
+        /**
+         * Calculate the Levenshtein distance between two strings.
+         *
+         * The Levenshtein distance is a measure of the minimum number of single-character edits
+         * (insertions, deletions or substitutions) required to change one word into the other.
+         *
+         * @param string $str1 The first string.
+         * @param string $str2 The second string.
+         * @return int The Levenshtein distance between the two strings.
+         */
+        public static function calculate(string $str1, string $str2): int
+        {
+            // Create a 2D array to store the distances between substrings of $str1 and $str2
+            $distanceMatrix = array();
+
+            // Initialize the first row and column of the matrix
+            $str1Length = strlen($str1);
+            $str2Length = strlen($str2);
+            for ($i = 0; $i <= $str1Length; $i++) {
+                $distanceMatrix[$i][0] = $i; // Distance from empty string to $str1 substrings
+            }
+            for ($j = 0; $j <= $str2Length; $j++) {
+                $distanceMatrix[0][$j] = $j; // Distance from empty string to $str2 substrings
+            }
+
+            // Iterate through the characters of $str1 and $str2
+            for ($i = 1; $i <= $str1Length; $i++) {
+                for ($j = 1; $j <= $str2Length; $j++) {
+                    // Calculate the cost of substitution (0 if characters match, 1 if they don't)
+                    $substitutionCost = ($str1[$i - 1] == $str2[$j - 1]) ? 0 : 1;
+
+                    // Calculate the minimum distance between the current substrings
+                    $insertionDistance = $distanceMatrix[$i - 1][$j] + 1; // Insert a character into $str1
+                    $deletionDistance = $distanceMatrix[$i][$j - 1] + 1; // Delete a character from $str1
+                    $substitutionDistance = $distanceMatrix[$i - 1][$j - 1] + $substitutionCost; // Substitute a character in $str1
+
+                    // Choose the minimum distance
+                    $distanceMatrix[$i][$j] = min($insertionDistance, $deletionDistance, $substitutionDistance);
+                }
+            }
+
+            // Return the Levenshtein distance between the entire strings
+            return $distanceMatrix[$str1Length][$str2Length];
+        }
+    }

tests/FuzzySearchTest.php

@@ -0,0 +1,31 @@
+<?php
+
+    use Designbycode\FuzzySearch\FuzzySearch;
+
+    test('search returns similar matches', function () {
+        $index = ['apple', 'banana', 'orange', 'grape', 'pear'];
+        $fuzzySearch = new FuzzySearch($index);
+        $results = $fuzzySearch->search('aple');
+        expect($results)->toEqual(['apple']);
+    });
+
+    test('search returns no results for non-existent query', function () {
+        $index = ['apple', 'banana', 'orange', 'grape', 'pear'];
+        $fuzzySearch = new FuzzySearch($index);
+        $results = $fuzzySearch->search('xyz');
+        expect($results)->toEqual([]);
+    });
+
+    test('search returns exact match', function () {
+        $index = ['apple', 'banana', 'orange', 'grape', 'pear'];
+        $fuzzySearch = new FuzzySearch($index);
+        $results = $fuzzySearch->search('apple');
+        expect($results)->toEqual(['apple']);
+    });
+
+    test('search is case-insensitive', function () {
+        $index = ['Apple', 'banana', 'orange', 'grape', 'pear'];
+        $fuzzySearch = new FuzzySearch($index);
+        $results = $fuzzySearch->search('aPpLe');
+        expect($results)->toEqual(['Apple']);
+    });