Initial SQLite development (#1)

Reviewed-on: #1

src/Parameters.php

@@ -0,0 +1,81 @@
+<?php declare(strict_types=1);
+
+namespace BitBadger\PDODocument;
+
+/**
+ * Functions to create parameters for queries
+ */
+class Parameters
+{
+    /**
+     * Create an ID parameter (name ":id", key will be treated as a string)
+     *
+     * @param mixed $key The key representing the ID of the document
+     * @return array|string[] An associative array with an "@id" parameter/value pair
+     */
+    public static function id(mixed $key): array
+    {
+        return [':id' => is_int($key) || is_string($key) ? $key : "$key"];
+    }
+
+    /**
+     * Create a parameter with a JSON value
+     *
+     * @param string $name The name of the JSON parameter
+     * @param object|array $document The value that should be passed as a JSON string
+     * @return array An associative array with the named parameter/value pair
+     */
+    public static function json(string $name, object|array $document): array
+    {
+        return [$name => json_encode($document, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES)];
+    }
+
+    /**
+     * Fill in parameter names for any fields missing one
+     *
+     * @param array|Field[] $fields The fields for the query
+     * @return array|Field[] The fields, all with non-blank parameter names
+     */
+    public static function nameFields(array $fields): array
+    {
+        for ($idx = 0; $idx < sizeof($fields); $idx++) {
+            if ($fields[$idx]->paramName == '') $fields[$idx]->paramName = ":field$idx";
+        }
+        return $fields;
+    }
+
+    /**
+     * Add field parameters to the given set of parameters
+     *
+     * @param array|Field[] $fields The fields being compared in the query
+     * @param array $parameters An associative array of parameters to which the fields should be added
+     * @return array An associative array of parameter names and values with the fields added
+     */
+    public static function addFields(array $fields, array $parameters): array
+    {
+        return array_reduce($fields, fn($carry, $item) => $item->appendParameter($carry), $parameters);
+    }
+
+    /**
+     * Create JSON field name parameters for the given field names to the given parameter
+     *
+     * @param string $paramName The name of the parameter for the field names
+     * @param array|string[] $fieldNames The names of the fields for the parameter
+     * @return array An associative array of parameter/value pairs for the field names
+     * @throws DocumentException If the database mode has not been set
+     */
+    public static function fieldNames(string $paramName, array $fieldNames): array
+    {
+        switch (Configuration::$mode) {
+            case Mode::PgSQL:
+                return [$paramName => "ARRAY['" . implode("','", $fieldNames) . "']"];
+            case Mode::SQLite:
+                $it = [];
+                $idx = 0;
+                foreach ($fieldNames as $field) $it[$paramName . $idx++] = "$.$field";
+                return $it;
+            default:
+                throw new DocumentException('Database mode not set; cannot generate field name parameters');
+        }
+    }
+}