-- Row-Level Security (RLS) Policies
-- Run this after migrations to enable tenant isolation at the DB level.

-- Helper: current tenant context (set via SET LOCAL in Prisma extension)
-- Usage: SET LOCAL app.current_tenant_id = '<uuid>';

-- ─── Enable RLS ──────────────────────────────────────────

ALTER TABLE users ENABLE ROW LEVEL SECURITY;
ALTER TABLE boards ENABLE ROW LEVEL SECURITY;
ALTER TABLE board_members ENABLE ROW LEVEL SECURITY;
ALTER TABLE columns ENABLE ROW LEVEL SECURITY;
ALTER TABLE cards ENABLE ROW LEVEL SECURITY;
ALTER TABLE card_assignees ENABLE ROW LEVEL SECURITY;
ALTER TABLE tags ENABLE ROW LEVEL SECURITY;
ALTER TABLE card_labels ENABLE ROW LEVEL SECURITY;
ALTER TABLE categories ENABLE ROW LEVEL SECURITY;
ALTER TABLE checklists ENABLE ROW LEVEL SECURITY;
ALTER TABLE checklist_items ENABLE ROW LEVEL SECURITY;
ALTER TABLE comments ENABLE ROW LEVEL SECURITY;
ALTER TABLE attachments ENABLE ROW LEVEL SECURITY;
ALTER TABLE activities ENABLE ROW LEVEL SECURITY;
ALTER TABLE notifications ENABLE ROW LEVEL SECURITY;
ALTER TABLE board_templates ENABLE ROW LEVEL SECURITY;

-- ─── Tenant-scoped tables (direct tenant_id) ────────────

-- Users
DROP POLICY IF EXISTS users_tenant_isolation ON users;
CREATE POLICY users_tenant_isolation ON users
  USING (tenant_id::text = current_setting('app.current_tenant_id', true));

-- Boards
DROP POLICY IF EXISTS boards_tenant_isolation ON boards;
CREATE POLICY boards_tenant_isolation ON boards
  USING (tenant_id::text = current_setting('app.current_tenant_id', true));

-- Tags
DROP POLICY IF EXISTS tags_tenant_isolation ON tags;
CREATE POLICY tags_tenant_isolation ON tags
  USING (tenant_id::text = current_setting('app.current_tenant_id', true));

-- Categories
DROP POLICY IF EXISTS categories_tenant_isolation ON categories;
CREATE POLICY categories_tenant_isolation ON categories
  USING (tenant_id::text = current_setting('app.current_tenant_id', true));

-- Board Templates (null tenant_id = system template, visible to all)
DROP POLICY IF EXISTS board_templates_tenant_isolation ON board_templates;
CREATE POLICY board_templates_tenant_isolation ON board_templates
  USING (
    tenant_id IS NULL
    OR tenant_id::text = current_setting('app.current_tenant_id', true)
  );

-- ─── Board-scoped tables (via join to boards) ───────────

-- Board Members
DROP POLICY IF EXISTS board_members_tenant_isolation ON board_members;
CREATE POLICY board_members_tenant_isolation ON board_members
  USING (
    board_id IN (
      SELECT id FROM boards
      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Columns
DROP POLICY IF EXISTS columns_tenant_isolation ON columns;
CREATE POLICY columns_tenant_isolation ON columns
  USING (
    board_id IN (
      SELECT id FROM boards
      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Activities
DROP POLICY IF EXISTS activities_tenant_isolation ON activities;
CREATE POLICY activities_tenant_isolation ON activities
  USING (
    board_id IN (
      SELECT id FROM boards
      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- ─── Card-scoped tables (via join to columns -> boards) ─

-- Cards
DROP POLICY IF EXISTS cards_tenant_isolation ON cards;
CREATE POLICY cards_tenant_isolation ON cards
  USING (
    column_id IN (
      SELECT c.id FROM columns c
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Card Assignees
DROP POLICY IF EXISTS card_assignees_tenant_isolation ON card_assignees;
CREATE POLICY card_assignees_tenant_isolation ON card_assignees
  USING (
    card_id IN (
      SELECT ca.id FROM cards ca
      JOIN columns c ON ca.column_id = c.id
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Card Labels
DROP POLICY IF EXISTS card_labels_tenant_isolation ON card_labels;
CREATE POLICY card_labels_tenant_isolation ON card_labels
  USING (
    card_id IN (
      SELECT ca.id FROM cards ca
      JOIN columns c ON ca.column_id = c.id
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Checklists
DROP POLICY IF EXISTS checklists_tenant_isolation ON checklists;
CREATE POLICY checklists_tenant_isolation ON checklists
  USING (
    card_id IN (
      SELECT ca.id FROM cards ca
      JOIN columns c ON ca.column_id = c.id
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Checklist Items
DROP POLICY IF EXISTS checklist_items_tenant_isolation ON checklist_items;
CREATE POLICY checklist_items_tenant_isolation ON checklist_items
  USING (
    checklist_id IN (
      SELECT ch.id FROM checklists ch
      JOIN cards ca ON ch.card_id = ca.id
      JOIN columns c ON ca.column_id = c.id
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Comments
DROP POLICY IF EXISTS comments_tenant_isolation ON comments;
CREATE POLICY comments_tenant_isolation ON comments
  USING (
    card_id IN (
      SELECT ca.id FROM cards ca
      JOIN columns c ON ca.column_id = c.id
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Attachments
DROP POLICY IF EXISTS attachments_tenant_isolation ON attachments;
CREATE POLICY attachments_tenant_isolation ON attachments
  USING (
    card_id IN (
      SELECT ca.id FROM cards ca
      JOIN columns c ON ca.column_id = c.id
      JOIN boards b ON c.board_id = b.id
      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- ─── User-scoped tables ─────────────────────────────────

-- Notifications
DROP POLICY IF EXISTS notifications_tenant_isolation ON notifications;
CREATE POLICY notifications_tenant_isolation ON notifications
  USING (
    user_id IN (
      SELECT id FROM users
      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
    )
  );

-- Sessions (no RLS - cross-tenant by design for session validation)
-- Sessions are validated in application code with tenant check