-- Append-only task alert events plus a monotonic current-state projection.

BEGIN;

CREATE SCHEMA IF NOT EXISTS workbench;

CREATE TABLE IF NOT EXISTS workbench.alert_events (
    project_id uuid NOT NULL,
    producer_id text NOT NULL CHECK (length(producer_id) > 0),
    event_id uuid NOT NULL,
    alert_id text NOT NULL CHECK (length(alert_id) > 0),
    event_type text NOT NULL CHECK (event_type IN ('raised','acknowledged','resolved')),
    occurred_at timestamptz NOT NULL,
    ingested_at timestamptz NOT NULL DEFAULT now(),
    document jsonb NOT NULL,
    PRIMARY KEY (project_id,producer_id,event_id),
    CHECK ((jsonb_typeof(document)='object'
        AND document->>'producer_id'=producer_id
        AND document->>'event_id'=event_id::text
        AND document->>'alert_id'=alert_id
        AND document->>'event_type'=event_type
        AND (document->>'occurred_at')::timestamptz=occurred_at) IS TRUE)
);

CREATE INDEX IF NOT EXISTS alert_events_alert_idx
    ON workbench.alert_events(project_id,alert_id,occurred_at,event_id);

CREATE TABLE IF NOT EXISTS workbench.alerts (
    project_id uuid NOT NULL,
    alert_id text NOT NULL CHECK (length(alert_id) > 0),
    revision bigint NOT NULL CHECK (revision >= 1),
    status text NOT NULL CHECK (status IN ('active','acknowledged','resolved')),
    occurred_at timestamptz NOT NULL,
    updated_at timestamptz NOT NULL,
    document jsonb NOT NULL,
    PRIMARY KEY (project_id,alert_id),
    CHECK ((jsonb_typeof(document)='object'
        AND document->>'alert_id'=alert_id
        AND document->>'status'=status
        AND (document->>'occurred_at')::timestamptz=occurred_at) IS TRUE)
);

CREATE INDEX IF NOT EXISTS alerts_active_recent_idx
    ON workbench.alerts(project_id,occurred_at DESC,alert_id)
    WHERE status='active';

REVOKE ALL ON ALL TABLES IN SCHEMA workbench FROM PUBLIC;

COMMIT;