1 files changed, 49 insertions, 0 deletions
diff --git a/lib/rule_generator.js b/lib/rule_generator.js
new file mode 100644
index 0000000..5db5240
--- /dev/null
+++ b/lib/rule_generator.js
@@ -0,0 +1,49 @@
+const { readdir } = require('fs/promises');
+const { join, resolve } = require('path');
+
+const internals = {
+
+  dates: [
+    'today',
+    'tomorrow',
+    'next friday',
+    'next wednesday',
+    'last thursday',
+    'last tuesday',
+    'the next day divisible by 7',
+    'this afternoon',
+    'next fiscal quarter',
+  ],
+
+  rules: null,
+  currentIndex: 0,
+
+  kRulesDirectory: resolve(process.cwd(), 'rules'),
+
+  async readRules() {
+
+    const ruleFiles = await readdir(internals.kRulesDirectory);
+    const rules = ruleFiles
+      .filter((file) => file.match(/.js$/))
+      .map((file) => require(join(internals.kRulesDirectory, file)));
+
+    internals.rules = rules.sort(() => Math.random() - 0.5)
+  }
+}
+
+module.exports = {
+  async generate() {
+
+    if (!internals.rules) {
+      await internals.readRules();
+    }
+
+    const rule = internals.rules[internals.currentIndex];
+    const time = internals.dates[Math.floor(Math.random() * internals.dates.length)];
+    internals.currentIndex = (internals.currentIndex + 1) % internals.rules.length
+    return {
+      rule: rule(),
+      time
+    }
+  }
+}