-- Super-Admin account migration (organized-ideas.md §2's "lost access to
-- the old Google account" tier — the self-service link/unlink path in
-- ProfileModal only covers the case where you still control the old
-- account). Discussed at length before building: identity verification is
-- fundamentally a human problem no function can solve, so this is deliberately
-- narrow — it moves *ownership of app data*, never credentials — and it's
-- built to make good practice easy rather than to enforce it outright:
--   * Required, freeform verification-notes field — the function refuses to
--     run without one, but what counts as adequate verification is a human
--     judgment call this schema doesn't try to make for anyone.
--   * A permanent audit row per migration: who performed it, the two
--     accounts (by id and by username snapshot, so the log stays readable
--     even if an account is later deleted), what moved, and why it was
--     believed safe.
--   * Never touches auth.users, passwords, or email — only ownership
--     columns already used to scope RLS elsewhere in this schema.
--   * Never deletes the old account — it's left exactly as it was (still
--     banned/deleted only by the existing, separate, reversible tools) with
--     just a marker recording where its data went.

-- ----------------------------------------------------------------------
-- profiles.migrated_to_user_id — set once an account's data has been moved
-- elsewhere, both to show that state in Manage Users and to stop the same
-- already-emptied account from being migrated a second time by mistake.
-- ----------------------------------------------------------------------

alter table public.profiles add column migrated_to_user_id uuid references public.profiles (id) on delete set null;

-- ----------------------------------------------------------------------
-- account_migrations — permanent audit log. Written only by
-- migrate_account_ownership() below (a security definer function), so
-- there's deliberately no insert/update/delete policy for the authenticated
-- role at all — only a select policy, for Super Admins to review the log.
-- ----------------------------------------------------------------------

create table public.account_migrations (
  id uuid primary key default gen_random_uuid(),
  from_user_id uuid references public.profiles (id) on delete set null,
  to_user_id uuid references public.profiles (id) on delete set null,
  -- Snapshotted at migration time so the log stays legible even after one
  -- of the accounts is later deleted (the FKs above go null, these don't).
  from_username text not null,
  to_username text not null,
  performed_by uuid references public.profiles (id) on delete set null,
  verification_notes text not null,
  diagram_count integer not null,
  private_entity_count integer not null,
  submission_count integer not null,
  created_at timestamptz not null default now()
);

alter table public.account_migrations enable row level security;

create policy "account_migrations_select" on public.account_migrations for select
  using (public.is_super_admin());

-- ----------------------------------------------------------------------
-- Read-only impact preview — shown before a Super Admin commits, same
-- "see the blast radius first" idea as catalog_entity_usage_impact.
-- ----------------------------------------------------------------------

create or replace function public.account_migration_preview(p_from_user_id uuid, p_to_user_id uuid)
returns table(diagram_count integer, private_entity_count integer, submission_count integer)
language plpgsql
stable
security definer
set search_path = public
as $$
begin
  if not public.is_super_admin() then
    raise exception 'insufficient_privilege' using errcode = '42501';
  end if;

  return query
    select
      (select count(*)::int from public.diagrams where owner_id = p_from_user_id),
      (
        (select count(*)::int from public.device_templates where owner_id = p_from_user_id and not is_public) +
        (select count(*)::int from public.device_categories where owner_id = p_from_user_id and not is_public) +
        (select count(*)::int from public.manufacturers where owner_id = p_from_user_id and not is_public) +
        (select count(*)::int from public.port_types where owner_id = p_from_user_id and not is_public) +
        (select count(*)::int from public.cable_types where owner_id = p_from_user_id and not is_public)
      ),
      (select count(*)::int from public.catalog_submissions where submitter_id = p_from_user_id);
end;
$$;

-- ----------------------------------------------------------------------
-- The actual migration. Runs as security definer, which means it bypasses
-- RLS entirely — including diagram_collaborators_insert/_update's "not your
-- own diagram's owner" check added in 20260914000000_prevent_self_collaborator.sql.
-- That check exists to stop a self-collaborator row from ever being
-- created; bypassing it here means this function has to uphold that same
-- invariant by hand (the explicit dedupe deletes below), not rely on RLS
-- to catch a mistake the way client code could.
-- ----------------------------------------------------------------------

create or replace function public.migrate_account_ownership(p_from_user_id uuid, p_to_user_id uuid, p_verification_notes text)
returns table(diagram_count integer, private_entity_count integer, submission_count integer)
language plpgsql
security definer
set search_path = public
as $$
declare
  v_diagram_count int;
  v_template_count int;
  v_category_count int;
  v_manufacturer_count int;
  v_port_type_count int;
  v_cable_type_count int;
  v_submission_count int;
  v_from_username text;
  v_to_username text;
  v_already_migrated uuid;
begin
  if not public.is_super_admin() then
    raise exception 'insufficient_privilege' using errcode = '42501';
  end if;

  if p_from_user_id = p_to_user_id then
    raise exception 'Cannot migrate an account into itself.' using errcode = '22023';
  end if;

  if trim(coalesce(p_verification_notes, '')) = '' then
    raise exception 'Verification notes are required.' using errcode = '22023';
  end if;

  select username, migrated_to_user_id into v_from_username, v_already_migrated
    from public.profiles where id = p_from_user_id;
  select username into v_to_username from public.profiles where id = p_to_user_id;

  if v_from_username is null or v_to_username is null then
    raise exception 'Both accounts must exist.' using errcode = '22023';
  end if;
  if v_already_migrated is not null then
    raise exception 'This account has already been migrated.' using errcode = '22023';
  end if;

  -- Diagrams the old account owns outright become the new account's — but
  -- first drop a now-redundant self-collaborator row if the new account
  -- happened to already be a collaborator on one of them (it's about to
  -- become the owner, which already implies full access).
  delete from public.diagram_collaborators dc
    using public.diagrams d
    where dc.diagram_id = d.id and d.owner_id = p_from_user_id and dc.user_id = p_to_user_id;

  update public.diagrams set owner_id = p_to_user_id where owner_id = p_from_user_id;
  get diagnostics v_diagram_count = row_count;

  -- Collaborator invitations the old account held on *other* people's
  -- diagrams move the same way — dropping the old account's row instead of
  -- moving it wherever the new account is already a collaborator there too.
  delete from public.diagram_collaborators dc1
    where dc1.user_id = p_from_user_id
      and exists (
        select 1 from public.diagram_collaborators dc2
        where dc2.diagram_id = dc1.diagram_id and dc2.user_id = p_to_user_id
      );
  update public.diagram_collaborators set user_id = p_to_user_id where user_id = p_from_user_id;

  -- Private catalog entries only — a public entry isn't "owned" in any
  -- sense that matters to move, and moving it would touch shared state well
  -- outside what this tool is meant to reach.
  update public.device_templates set owner_id = p_to_user_id where owner_id = p_from_user_id and not is_public;
  get diagnostics v_template_count = row_count;
  update public.device_categories set owner_id = p_to_user_id where owner_id = p_from_user_id and not is_public;
  get diagnostics v_category_count = row_count;
  update public.manufacturers set owner_id = p_to_user_id where owner_id = p_from_user_id and not is_public;
  get diagnostics v_manufacturer_count = row_count;
  update public.port_types set owner_id = p_to_user_id where owner_id = p_from_user_id and not is_public;
  get diagnostics v_port_type_count = row_count;
  update public.cable_types set owner_id = p_to_user_id where owner_id = p_from_user_id and not is_public;
  get diagnostics v_cable_type_count = row_count;

  -- Pending/past submissions move too, so "My Submissions" stays continuous
  -- for whoever's now the same person under a new account.
  update public.catalog_submissions set submitter_id = p_to_user_id where submitter_id = p_from_user_id;
  get diagnostics v_submission_count = row_count;

  -- Deliberately untouched: role, can_post_announcements (a fresh account
  -- shouldn't silently inherit elevated capability), username (both
  -- accounts keep their own), and announcement_dismissals (preference-only,
  -- not worth the complexity).

  update public.profiles set migrated_to_user_id = p_to_user_id where id = p_from_user_id;

  insert into public.account_migrations (
    from_user_id, to_user_id, from_username, to_username, performed_by,
    verification_notes, diagram_count, private_entity_count, submission_count
  ) values (
    p_from_user_id, p_to_user_id, v_from_username, v_to_username, auth.uid(),
    p_verification_notes,
    v_diagram_count,
    v_template_count + v_category_count + v_manufacturer_count + v_port_type_count + v_cable_type_count,
    v_submission_count
  );

  return query select
    v_diagram_count,
    v_template_count + v_category_count + v_manufacturer_count + v_port_type_count + v_cable_type_count,
    v_submission_count;
end;
$$;

-- Manage Users needs to know which accounts have already been migrated (to
-- show it, and to grey out migrating them again) — extends the same
-- function AdminUsersModal already calls, rather than a separate round trip.
drop function public.list_users_for_admin();

create function public.list_users_for_admin()
returns table(
  id uuid, username text, email text, role text, can_post_announcements boolean,
  banned_until timestamptz, created_at timestamptz,
  migrated_to_user_id uuid, migrated_to_username text
)
language plpgsql
stable
security definer
set search_path = public
as $$
begin
  if not public.is_super_admin() then
    raise exception 'insufficient_privilege' using errcode = '42501';
  end if;

  return query
    select p.id, p.username, u.email::text, p.role, p.can_post_announcements, u.banned_until, p.created_at,
           p.migrated_to_user_id, mp.username
    from public.profiles p
    join auth.users u on u.id = p.id
    left join public.profiles mp on mp.id = p.migrated_to_user_id
    order by p.created_at desc;
end;
$$;