From 68884daf1158f4347c431ce9375c24e6e1bfa8d8 Mon Sep 17 00:00:00 2001
From: Arthur Belleville <arthur.belleville@datadoghq.com>
Date: Sat, 16 May 2026 10:07:12 +0200
Subject: [PATCH] feat(12-01): add discussion schema and queries

---
 backend/internal/db/queries/discussion.sql | 47 ++++++++++++++++++++++
 backend/migrations/0009_discussion.sql     | 42 +++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 backend/internal/db/queries/discussion.sql
 create mode 100644 backend/migrations/0009_discussion.sql

diff --git a/backend/internal/db/queries/discussion.sql b/backend/internal/db/queries/discussion.sql
new file mode 100644
index 0000000..f58a3ad
--- /dev/null
+++ b/backend/internal/db/queries/discussion.sql
@@ -0,0 +1,47 @@
+-- name: ListDiscussionMessagesByTablo :many
+SELECT discussion_messages.id,
+       discussion_messages.tablo_id,
+       discussion_messages.author_user_id,
+       users.email AS author_email,
+       discussion_messages.body,
+       discussion_messages.created_at,
+       discussion_messages.updated_at,
+       discussion_messages.edited_at,
+       discussion_messages.edited_by_user_id,
+       discussion_messages.deleted_at,
+       discussion_messages.deleted_by_user_id
+FROM discussion_messages
+JOIN users ON users.id = discussion_messages.author_user_id
+WHERE discussion_messages.tablo_id = $1
+ORDER BY discussion_messages.created_at, discussion_messages.id;
+
+-- name: CreateDiscussionMessage :one
+INSERT INTO discussion_messages (tablo_id, author_user_id, body)
+VALUES ($1, $2, $3)
+RETURNING id, tablo_id, author_user_id, body, created_at, updated_at, edited_at, edited_by_user_id, deleted_at, deleted_by_user_id;
+
+-- name: GetDiscussionMessageWithAuthor :one
+SELECT discussion_messages.id,
+       discussion_messages.tablo_id,
+       discussion_messages.author_user_id,
+       users.email AS author_email,
+       discussion_messages.body,
+       discussion_messages.created_at,
+       discussion_messages.updated_at,
+       discussion_messages.edited_at,
+       discussion_messages.edited_by_user_id,
+       discussion_messages.deleted_at,
+       discussion_messages.deleted_by_user_id
+FROM discussion_messages
+JOIN users ON users.id = discussion_messages.author_user_id
+WHERE discussion_messages.id = $1
+  AND discussion_messages.tablo_id = $2;
+
+-- name: UpsertDiscussionReadState :one
+INSERT INTO discussion_read_states (tablo_id, user_id, last_read_message_id, last_read_at)
+VALUES ($1, $2, $3, now())
+ON CONFLICT (tablo_id, user_id)
+DO UPDATE SET last_read_message_id = EXCLUDED.last_read_message_id,
+              last_read_at = now(),
+              updated_at = now()
+RETURNING tablo_id, user_id, last_read_message_id, last_read_at, created_at, updated_at;
diff --git a/backend/migrations/0009_discussion.sql b/backend/migrations/0009_discussion.sql
new file mode 100644
index 0000000..a3cc647
--- /dev/null
+++ b/backend/migrations/0009_discussion.sql
@@ -0,0 +1,42 @@
+-- migrations/0009_discussion.sql
+-- Phase 12: Native Tablo Chat
+
+-- +goose Up
+
+CREATE TABLE discussion_messages (
+    id                 uuid        PRIMARY KEY DEFAULT gen_random_uuid(),
+    tablo_id           uuid        NOT NULL REFERENCES tablos(id) ON DELETE CASCADE,
+    author_user_id     uuid        NOT NULL REFERENCES users(id) ON DELETE RESTRICT,
+    body               text        NOT NULL,
+    created_at         timestamptz NOT NULL DEFAULT now(),
+    updated_at         timestamptz NOT NULL DEFAULT now(),
+    edited_at          timestamptz,
+    edited_by_user_id  uuid        REFERENCES users(id) ON DELETE SET NULL,
+    deleted_at         timestamptz,
+    deleted_by_user_id uuid        REFERENCES users(id) ON DELETE SET NULL,
+    CONSTRAINT discussion_messages_body_not_blank CHECK (length(trim(body)) > 0),
+    CONSTRAINT discussion_messages_body_max_length CHECK (char_length(body) <= 10000)
+);
+
+CREATE INDEX discussion_messages_tablo_created_idx ON discussion_messages(tablo_id, created_at, id);
+CREATE INDEX discussion_messages_author_idx ON discussion_messages(author_user_id);
+
+CREATE TABLE discussion_read_states (
+    tablo_id             uuid        NOT NULL REFERENCES tablos(id) ON DELETE CASCADE,
+    user_id              uuid        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    last_read_message_id uuid        REFERENCES discussion_messages(id) ON DELETE SET NULL,
+    last_read_at         timestamptz NOT NULL DEFAULT now(),
+    created_at           timestamptz NOT NULL DEFAULT now(),
+    updated_at           timestamptz NOT NULL DEFAULT now(),
+    PRIMARY KEY (tablo_id, user_id)
+);
+
+CREATE INDEX discussion_read_states_user_idx ON discussion_read_states(user_id, tablo_id);
+
+-- +goose Down
+
+DROP INDEX IF EXISTS discussion_read_states_user_idx;
+DROP TABLE IF EXISTS discussion_read_states;
+DROP INDEX IF EXISTS discussion_messages_author_idx;
+DROP INDEX IF EXISTS discussion_messages_tablo_created_idx;
+DROP TABLE IF EXISTS discussion_messages;