feat: setup diesel & schema, course with metrics/audit tables

diesel.toml

@@ -0,0 +1,9 @@
+# For documentation on how to configure this file,
+# see https://diesel.rs/guides/configuring-diesel-cli
+
+[print_schema]
+file = "src/data/schema.rs"
+custom_type_derives = ["diesel::query_builder::QueryId", "Clone"]
+
+[migrations_directory]
+dir = "migrations"

migrations/00000000000000_diesel_initial_setup/down.sql

@@ -0,0 +1,6 @@
+-- This file was automatically created by Diesel to setup helper functions
+-- and other internal bookkeeping. This file is safe to edit, any future
+-- changes will be added to existing projects as new migrations.
+
+DROP FUNCTION IF EXISTS diesel_manage_updated_at(_tbl regclass);
+DROP FUNCTION IF EXISTS diesel_set_updated_at();

migrations/00000000000000_diesel_initial_setup/up.sql

@@ -0,0 +1,36 @@
+-- This file was automatically created by Diesel to setup helper functions
+-- and other internal bookkeeping. This file is safe to edit, any future
+-- changes will be added to existing projects as new migrations.
+
+
+
+
+-- Sets up a trigger for the given table to automatically set a column called
+-- `updated_at` whenever the row is modified (unless `updated_at` was included
+-- in the modified columns)
+--
+-- # Example
+--
+-- ```sql
+-- CREATE TABLE users (id SERIAL PRIMARY KEY, updated_at TIMESTAMP NOT NULL DEFAULT NOW());
+--
+-- SELECT diesel_manage_updated_at('users');
+-- ```
+CREATE OR REPLACE FUNCTION diesel_manage_updated_at(_tbl regclass) RETURNS VOID AS $$
+BEGIN
+    EXECUTE format('CREATE TRIGGER set_updated_at BEFORE UPDATE ON %s
+                    FOR EACH ROW EXECUTE PROCEDURE diesel_set_updated_at()', _tbl);
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION diesel_set_updated_at() RETURNS trigger AS $$
+BEGIN
+    IF (
+        NEW IS DISTINCT FROM OLD AND
+        NEW.updated_at IS NOT DISTINCT FROM OLD.updated_at
+    ) THEN
+        NEW.updated_at := current_timestamp;
+    END IF;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;

migrations/2025-08-27-231618_setup/down.sql

@@ -0,0 +1,4 @@
+-- This file should undo anything in `up.sql`
+DROP TABLE IF EXISTS "courses";
+DROP TABLE IF EXISTS "course_metrics";
+DROP TABLE IF EXISTS "course_audits";

migrations/2025-08-27-231618_setup/up.sql

@@ -0,0 +1,35 @@
+-- Your SQL goes here
+CREATE TABLE "courses"(
+	"id" INT4 NOT NULL PRIMARY KEY,
+	"crn" VARCHAR NOT NULL,
+	"subject" VARCHAR NOT NULL,
+	"course_number" VARCHAR NOT NULL,
+	"title" VARCHAR NOT NULL,
+	"term_code" VARCHAR NOT NULL,
+	"enrollment" INT4 NOT NULL,
+	"max_enrollment" INT4 NOT NULL,
+	"wait_count" INT4 NOT NULL,
+	"wait_capacity" INT4 NOT NULL,
+	"last_scraped_at" TIMESTAMPTZ NOT NULL
+);
+
+CREATE TABLE "course_metrics"(
+	"id" INT4 NOT NULL PRIMARY KEY,
+	"course_id" INT4 NOT NULL,
+	"timestamp" TIMESTAMPTZ NOT NULL,
+	"enrollment" INT4 NOT NULL,
+	"wait_count" INT4 NOT NULL,
+	"seats_available" INT4 NOT NULL,
+	FOREIGN KEY ("course_id") REFERENCES "courses"("id")
+);
+
+CREATE TABLE "course_audits"(
+	"id" INT4 NOT NULL PRIMARY KEY,
+	"course_id" INT4 NOT NULL,
+	"timestamp" TIMESTAMPTZ NOT NULL,
+	"field_changed" VARCHAR NOT NULL,
+	"old_value" TEXT NOT NULL,
+	"new_value" TEXT NOT NULL,
+	FOREIGN KEY ("course_id") REFERENCES "courses"("id")
+);
+

src/data/mod.rs

@@ -0,0 +1,4 @@
+//! Database models and schema.
+
+pub mod models;
+pub mod schema;

src/data/models.rs

@@ -0,0 +1,80 @@
+//! Diesel models for the database schema.
+
+use crate::data::schema::{course_audits, course_metrics, courses};
+use chrono::{DateTime, Utc};
+use diesel::{Insertable, Queryable, Selectable};
+
+#[derive(Queryable, Selectable)]
+#[diesel(table_name = courses)]
+pub struct Course {
+    pub id: i32,
+    pub crn: String,
+    pub subject: String,
+    pub course_number: String,
+    pub title: String,
+    pub term_code: String,
+    pub enrollment: i32,
+    pub max_enrollment: i32,
+    pub wait_count: i32,
+    pub wait_capacity: i32,
+    pub last_scraped_at: DateTime<Utc>,
+}
+
+#[derive(Insertable)]
+#[diesel(table_name = courses)]
+pub struct NewCourse<'a> {
+    pub crn: &'a str,
+    pub subject: &'a str,
+    pub course_number: &'a str,
+    pub title: &'a str,
+    pub term_code: &'a str,
+    pub enrollment: i32,
+    pub max_enrollment: i32,
+    pub wait_count: i32,
+    pub wait_capacity: i32,
+    pub last_scraped_at: DateTime<Utc>,
+}
+
+#[derive(Queryable, Selectable)]
+#[diesel(table_name = course_metrics)]
+#[diesel(belongs_to(Course))]
+pub struct CourseMetric {
+    pub id: i32,
+    pub course_id: i32,
+    pub timestamp: DateTime<Utc>,
+    pub enrollment: i32,
+    pub wait_count: i32,
+    pub seats_available: i32,
+}
+
+#[derive(Insertable)]
+#[diesel(table_name = course_metrics)]
+pub struct NewCourseMetric {
+    pub course_id: i32,
+    pub timestamp: DateTime<Utc>,
+    pub enrollment: i32,
+    pub wait_count: i32,
+    pub seats_available: i32,
+}
+
+#[derive(Queryable, Selectable)]
+#[diesel(table_name = course_audits)]
+#[diesel(belongs_to(Course))]
+pub struct CourseAudit {
+    pub id: i32,
+    pub course_id: i32,
+    pub timestamp: DateTime<Utc>,
+    pub field_changed: String,
+    pub old_value: String,
+    pub new_value: String,
+}
+
+#[derive(Insertable)]
+#[diesel(table_name = course_audits)]
+pub struct NewCourseAudit<'a> {
+    pub course_id: i32,
+    pub timestamp: DateTime<Utc>,
+    pub field_changed: &'a str,
+    pub old_value: &'a str,
+    pub new_value: &'a str,
+}

src/data/schema.rs

@@ -0,0 +1,42 @@
+diesel::table! {
+    courses (id) {
+        id -> Int4,
+        crn -> Varchar,
+        subject -> Varchar,
+        course_number -> Varchar,
+        title -> Varchar,
+        term_code -> Varchar,
+        enrollment -> Int4,
+        max_enrollment -> Int4,
+        wait_count -> Int4,
+        wait_capacity -> Int4,
+        last_scraped_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    course_metrics (id) {
+        id -> Int4,
+        course_id -> Int4,
+        timestamp -> Timestamptz,
+        enrollment -> Int4,
+        wait_count -> Int4,
+        seats_available -> Int4,
+    }
+}
+
+diesel::table! {
+    course_audits (id) {
+        id -> Int4,
+        course_id -> Int4,
+        timestamp -> Timestamptz,
+        field_changed -> Varchar,
+        old_value -> Text,
+        new_value -> Text,
+    }
+}
+
+diesel::joinable!(course_metrics -> courses (course_id));
+diesel::joinable!(course_audits -> courses (course_id));
+
+diesel::allow_tables_to_appear_in_same_query!(courses, course_metrics, course_audits,);

src/lib.rs

@@ -1,6 +1,7 @@
 pub mod app_state;
 pub mod banner;
 pub mod bot;
+pub mod data;
 pub mod error;
 pub mod services;
 pub mod web;

src/main.rs

@@ -18,6 +18,7 @@ mod app_state;
 mod banner;
 mod bot;
 mod config;
+mod data;
 mod error;
 mod services;
 mod web;