-- app_roles_tracksolid_db.sql — dedicated NON-SUPERUSER login roles for the apps
-- that currently connect to tracksolid_db as the `postgres` SUPERUSER.
-- ─────────────────────────────────────────────────────────────────────────────
-- WHY: six stack services connect to this Postgres server as the postgres superuser
-- (webhook_receiver, ingest_worker, worker, the prod dashboard_api backend on
-- tracksolid_db; gateway + cron on fleet_platform — see the sibling file). That is
-- both a least-privilege problem AND the root of the "too many connections" error:
-- superuser sessions ignore per-role connection caps and can exhaust the 100-slot
-- ceiling (incl. the superuser-reserved slots). Dedicated roles let us pin a hard
-- CONNECTION LIMIT and timeouts per app.
--
-- WHAT THIS DOES (run as the postgres SUPERUSER, on tracksolid_db):
--   * creates capability GROUP roles (NOLOGIN) for read vs. read-write,
--   * creates one LOGIN role per app, NOSUPERUSER, with a CONNECTION LIMIT and
--     bounded GUCs, as a member of the group it needs,
--   * grants the groups SELECT / DML on the operational schemas.
--
-- WHAT IT DOES *NOT* DO: change object ownership. All objects here are owned by
-- `postgres`, so a non-superuser role can write ROWS but cannot ALTER/DROP existing
-- tables (i.e. run migrations). If an app runs DDL at deploy, see step 3 in
-- MIGRATE_APPS_OFF_SUPERUSER.md (reassign the app schemas to `tracksolid_owner` and
-- add the app role to it). Roles here INHERIT, so membership grants apply directly.
--
-- Idempotent. Passwords are supplied as psql vars (never stored in the repo):
--   docker exec -i <timescale_db> psql -U postgres -d tracksolid_db -v ON_ERROR_STOP=1 \
--     -v webhook_pw="$(cat ~/.webhook_app.pw)" \
--     -v ingest_pw="$(cat ~/.ingest_app.pw)" \
--     -v worker_pw="$(cat ~/.worker_app.pw)" \
--     -v dash_pw="$(cat ~/.dashboard_app.pw)" \
--     < scripts/app_roles_tracksolid_db.sql

\set ON_ERROR_STOP on

-- ── 1. Capability groups (NOLOGIN; apps inherit privileges via membership) ──────
DO $$
BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='ts_app_read')  THEN CREATE ROLE ts_app_read  NOLOGIN; END IF;
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='ts_app_write') THEN CREATE ROLE ts_app_write NOLOGIN; END IF;
END $$;

-- Read surface: telemetry + curated reporting layer.
GRANT USAGE ON SCHEMA tracksolid, reporting TO ts_app_read;
GRANT SELECT ON ALL TABLES IN SCHEMA tracksolid, reporting TO ts_app_read;
GRANT SELECT ON reporting.v_trips TO ts_app_read;                 -- matview (not in ALL TABLES)
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA reporting TO ts_app_read;
ALTER DEFAULT PRIVILEGES FOR ROLE postgres IN SCHEMA tracksolid, reporting GRANT SELECT ON TABLES TO ts_app_read;

-- Write surface for ingestion: row DML on telemetry (NOT DDL — see header).
GRANT ts_app_read TO ts_app_write;                                 -- write implies read
GRANT INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA tracksolid TO ts_app_write;
GRANT USAGE, SELECT, UPDATE ON ALL SEQUENCES IN SCHEMA tracksolid TO ts_app_write;
ALTER DEFAULT PRIVILEGES FOR ROLE postgres IN SCHEMA tracksolid
  GRANT INSERT, UPDATE, DELETE ON TABLES TO ts_app_write;
ALTER DEFAULT PRIVILEGES FOR ROLE postgres IN SCHEMA tracksolid
  GRANT USAGE, SELECT, UPDATE ON SEQUENCES TO ts_app_write;

-- ── 2. Per-app LOGIN roles ──────────────────────────────────────────────────────
-- CONNECTION LIMIT is the hard budget cap (sum across all roles must stay < 100).
-- GUCs are belt-and-braces and tunable per app.

-- webhook_receiver — ingests Tracksolid webhooks (writes telemetry; may run migrations).
DO $$ BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='webhook_app') THEN
    CREATE ROLE webhook_app LOGIN INHERIT NOSUPERUSER NOCREATEDB NOCREATEROLE;
  END IF; END $$;
ALTER ROLE webhook_app WITH LOGIN PASSWORD :'webhook_pw' CONNECTION LIMIT 10;
GRANT CONNECT ON DATABASE tracksolid_db TO webhook_app;
GRANT ts_app_write TO webhook_app;
ALTER ROLE webhook_app SET statement_timeout = '120s';                     -- bulk inserts
ALTER ROLE webhook_app SET idle_in_transaction_session_timeout = '120s';
ALTER ROLE webhook_app SET idle_session_timeout = '10min';
ALTER ROLE webhook_app SET lock_timeout = '5s';

-- ingest_worker — background ingestion/normalisation (writes telemetry).
DO $$ BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='ingest_app') THEN
    CREATE ROLE ingest_app LOGIN INHERIT NOSUPERUSER NOCREATEDB NOCREATEROLE;
  END IF; END $$;
ALTER ROLE ingest_app WITH LOGIN PASSWORD :'ingest_pw' CONNECTION LIMIT 10;
GRANT CONNECT ON DATABASE tracksolid_db TO ingest_app;
GRANT ts_app_write TO ingest_app;
ALTER ROLE ingest_app SET statement_timeout = '120s';
ALTER ROLE ingest_app SET idle_in_transaction_session_timeout = '120s';
ALTER ROLE ingest_app SET idle_session_timeout = '10min';
ALTER ROLE ingest_app SET lock_timeout = '5s';
-- If ingestion REFRESHes reporting.v_trips, add it to the existing refresher role:
--   GRANT reporting_refresher TO ingest_app;   -- (uncomment after confirming)

-- worker — fleet_platform worker that also reads tracksolid_db. Assumed READ-ONLY
-- here; widen to ts_app_write only if it actually writes telemetry.
DO $$ BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='worker_app') THEN
    CREATE ROLE worker_app LOGIN INHERIT NOSUPERUSER NOCREATEDB NOCREATEROLE;
  END IF; END $$;
ALTER ROLE worker_app WITH LOGIN PASSWORD :'worker_pw' CONNECTION LIMIT 5;
GRANT CONNECT ON DATABASE tracksolid_db TO worker_app;
GRANT ts_app_read TO worker_app;
ALTER ROLE worker_app SET statement_timeout = '60s';
ALTER ROLE worker_app SET idle_in_transaction_session_timeout = '60s';
ALTER ROLE worker_app SET idle_session_timeout = '10min';
ALTER ROLE worker_app SET lock_timeout = '5s';

-- dashboard_api (PROD backend, currently postgres). If it only reads, prefer the
-- existing dashboard_ro. This role is for a backend that ALSO writes app state;
-- start read-only and widen per discovery.
DO $$ BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='dashboard_app') THEN
    CREATE ROLE dashboard_app LOGIN INHERIT NOSUPERUSER NOCREATEDB NOCREATEROLE;
  END IF; END $$;
ALTER ROLE dashboard_app WITH LOGIN PASSWORD :'dash_pw' CONNECTION LIMIT 8;
GRANT CONNECT ON DATABASE tracksolid_db TO dashboard_app;
GRANT ts_app_read TO dashboard_app;
ALTER ROLE dashboard_app SET statement_timeout = '30s';
ALTER ROLE dashboard_app SET idle_in_transaction_session_timeout = '60s';
ALTER ROLE dashboard_app SET idle_session_timeout = '5min';
ALTER ROLE dashboard_app SET lock_timeout = '5s';

-- ── 3. Verify ───────────────────────────────────────────────────────────────────
-- \du+   -- inspect roles, CONNECTION LIMIT, and memberships