From bc582c35356823240dd3633dfbdce70b01279c01 Mon Sep 17 00:00:00 2001
From: BurnyLlama <burnyllama@protonmail.com>
Date: Mon, 1 Nov 2021 19:08:57 +0100
Subject: [PATCH] Added a general search function...

---
 libs/database/searcher.js | 62 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 libs/database/searcher.js

diff --git a/libs/database/searcher.js b/libs/database/searcher.js
new file mode 100644
index 0000000..79abac8
--- /dev/null
+++ b/libs/database/searcher.js
@@ -0,0 +1,62 @@
+import { sqlite } from './init.js'
+
+const entriesPerPage = process.env.ENTRIES_PER_PAGE ?? 50
+
+/**
+ * This is a 'general' search function for the sqlite database...
+ * 
+ * @param {string} table The table to search in.
+ * @param {string} matchField If not 'undefined' or 'null' match 'matchQuery' in this field.
+ * @param {string} matchQuery The value to search for in 'matchField'.
+ * @param {string} orderBy The field of which to order by, if 'null' or 'undefined' it is whatever sqlite sees as default.
+ * @param {boolean} descending If true: sort in ascending order instead of ascending order.
+ * @param {string} method If set to "all" it will give all results instead of only one.
+ * @param {number} page The function paginates; this sets the page to look for.
+ * 
+ * @returns {Promise} Returns a promise which wither resolves with the data or rejects with an error.
+ * 
+ * @author BurnyLlama
+ */
+export default function searcher(table, matchField=undefined, matchQuery=undefined, orderBy=undefined, descending=false, method="get", page=1) {
+    return new Promise(
+        (resolve, reject) => {
+            const pageCount = 
+                method === "get" ? 0 :
+                    parseInt(sqlite
+                        .prepare(`
+                            SELECT count(*) FROM $table
+                            ${!matchField ?? "WHERE $matchField = $matchQuery"}
+                        `)
+                        .get({
+                            table,
+                            matchField, matchQuery
+                        })
+                    )
+
+            if (method === "all" && page > pageCount)
+                reject(`Page number too high! Page count: ${pageCount}`)
+
+            const result = sqlite
+                .prepare(`
+                    SELECT * FROM $table
+                    ${!matchField ?? "WHERE $matchField = $matchQuery"}
+                    ${!orderBy ?? `"ORDER BY $orderBy" ${descending === true ? "DESC" : "ASC"}`}
+                    ${method === "all" ? `LIMIT ${entriesPerPage * (page - 1)}, ${entriesPerPage}` : ""}
+                `)
+                [method === "all" ? "all" : "get"]({
+                    table,
+                    matchField, matchQuery,
+                    orderBy
+                })
+
+            // This check should work?
+            if ((typeof result === "object" && !result[0]) || (!result))
+                reject("No search results found!")
+
+            resolve({
+                result,
+                pageCount
+            })
+        }
+    )
+}
\ No newline at end of file