feat: add contact page with form handling and validation

- Implemented a contact page with a form for user inquiries.
- Added validation for form fields using Zod schema.
- Integrated PostgreSQL database for storing contact messages.
- Created necessary API endpoints for form submission.
- Added admin authentication and session management.
- Developed CGU, cookies policy, privacy policy, and legal mentions pages.
- Set up Docker configuration for PostgreSQL and application services.
- Enhanced UI with responsive design and accessibility features.

lib/db.ts

@@ -0,0 +1,175 @@
+import { Pool } from "pg";
+
+let pool: Pool | null = null;
+let schemaReady: Promise<void> | null = null;
+
+function getDatabaseUrl() {
+  const url = process.env.DATABASE_URL;
+  if (!url) {
+    throw new Error("DATABASE_URL is not configured.");
+  }
+  return url;
+}
+
+function getPool() {
+  if (!pool) {
+    pool = new Pool({
+      connectionString: getDatabaseUrl(),
+    });
+  }
+  return pool;
+}
+
+async function ensureSchema() {
+  if (!schemaReady) {
+    schemaReady = (async () => {
+      const client = await getPool().connect();
+      try {
+        await client.query(`
+          CREATE TABLE IF NOT EXISTS contact_messages (
+            id BIGSERIAL PRIMARY KEY,
+            name TEXT NOT NULL,
+            email TEXT NOT NULL,
+            project TEXT NOT NULL,
+            request_type TEXT NOT NULL,
+            message TEXT NOT NULL,
+            source_url TEXT,
+            created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+            replied_at TIMESTAMPTZ,
+            admin_reply TEXT,
+            status TEXT NOT NULL DEFAULT 'pending' CHECK (status IN ('pending', 'replied'))
+          );
+        `);
+
+        await client.query(`
+          ALTER TABLE contact_messages
+          ADD COLUMN IF NOT EXISTS status TEXT NOT NULL DEFAULT 'pending'
+          CHECK (status IN ('pending', 'replied'));
+        `);
+
+        await client.query(`
+          UPDATE contact_messages
+          SET status = CASE WHEN replied_at IS NULL THEN 'pending' ELSE 'replied' END
+          WHERE status IS DISTINCT FROM CASE WHEN replied_at IS NULL THEN 'pending' ELSE 'replied' END;
+        `);
+      } finally {
+        client.release();
+      }
+    })();
+  }
+
+  await schemaReady;
+}
+
+export type ContactMessageRow = {
+  id: number;
+  name: string;
+  email: string;
+  project: string;
+  request_type: string;
+  message: string;
+  source_url: string | null;
+  created_at: string;
+  replied_at: string | null;
+  admin_reply: string | null;
+  status: "pending" | "replied";
+};
+
+export async function createMessage(input: {
+  name: string;
+  email: string;
+  project: string;
+  requestType: string;
+  message: string;
+  sourceUrl?: string | null;
+}) {
+  await ensureSchema();
+  const result = await getPool().query<ContactMessageRow>(
+    `
+      INSERT INTO contact_messages (name, email, project, request_type, message, source_url)
+      VALUES ($1, $2, $3, $4, $5, $6)
+      RETURNING *
+    `,
+    [input.name, input.email, input.project, input.requestType, input.message, input.sourceUrl ?? null],
+  );
+
+  return result.rows[0];
+}
+
+export async function listMessages() {
+  await ensureSchema();
+  const result = await getPool().query<ContactMessageRow>(
+    `
+      SELECT *
+      FROM contact_messages
+      ORDER BY created_at DESC
+    `,
+  );
+
+  return result.rows;
+}
+
+export async function getMessageById(id: number) {
+  await ensureSchema();
+  const result = await getPool().query<ContactMessageRow>(
+    `
+      SELECT *
+      FROM contact_messages
+      WHERE id = $1
+      LIMIT 1
+    `,
+    [id],
+  );
+
+  return result.rows[0] ?? null;
+}
+
+export async function markMessageReply(id: number, reply: string) {
+  await ensureSchema();
+  const result = await getPool().query<ContactMessageRow>(
+    `
+      UPDATE contact_messages
+      SET admin_reply = $2,
+          replied_at = NOW(),
+          status = 'replied'
+      WHERE id = $1
+      RETURNING *
+    `,
+    [id, reply],
+  );
+
+  return result.rows[0] ?? null;
+}
+
+export async function setMessageStatus(id: number, status: "pending" | "replied") {
+  await ensureSchema();
+
+  const result = await getPool().query<ContactMessageRow>(
+    `
+      UPDATE contact_messages
+      SET status = $2,
+          replied_at = CASE WHEN $2 = 'replied' THEN COALESCE(replied_at, NOW()) ELSE NULL END,
+          admin_reply = CASE WHEN $2 = 'pending' THEN admin_reply ELSE admin_reply END
+      WHERE id = $1
+      RETURNING *
+    `,
+    [id, status],
+  );
+
+  return result.rows[0] ?? null;
+}
+
+export async function deleteMessage(id: number) {
+  await ensureSchema();
+
+  const result = await getPool().query<{ id: number }>(
+    `
+      DELETE FROM contact_messages
+      WHERE id = $1
+      RETURNING id
+    `,
+    [id],
+  );
+
+  return Boolean(result.rows[0]);
+}