CRM_ENVR/database/migrations/021_performance_indexes.sql

-- ============================================================================
-- Performance & Missing Indexes
-- ============================================================================

-- scheduled_events: index on created_at for list ordering
CREATE INDEX IF NOT EXISTS idx_scheduled_events_created_at ON scheduled_events(created_at DESC);

-- scheduled_events: composite index for common user+status queries
CREATE INDEX IF NOT EXISTS idx_scheduled_events_user_status ON scheduled_events(user_id, status);

-- messages: index on sender_id for delete-by-sender queries
CREATE INDEX IF NOT EXISTS idx_messages_sender ON messages(sender_id);

-- messages: composite for conversation listing
CREATE INDEX IF NOT EXISTS idx_messages_conversation_sender ON messages(conversation_id, sender_id);

-- notifications: composite unread badge query
CREATE INDEX IF NOT EXISTS idx_notifications_user_read ON notifications(user_id, is_read, created_at DESC);

-- ai_conversations: composite user+created query
CREATE INDEX IF NOT EXISTS idx_ai_conversations_user_created ON ai_conversations(user_id, created_at DESC);

-- login_attempts: TTL cleanup
CREATE INDEX IF NOT EXISTS idx_login_attempts_cleanup ON login_attempts(attempted_at) WHERE was_successful = false;

-- facebook_scrape_logs: composite account+created index (replaces separate one)
DROP INDEX IF EXISTS idx_fb_scrape_logs_account;
CREATE INDEX IF NOT EXISTS idx_fb_scrape_logs_account_created ON facebook_scrape_logs(account_id, created_at DESC);

-- lead_conversions: composite lead+customer (replaces two separate indexes)
CREATE INDEX IF NOT EXISTS idx_lead_conversions_lead_customer ON lead_conversions(lead_id, customer_id);

-- ============================================================================
-- Cache current_user_hierarchy_level as session variable for RLS performance
-- ============================================================================

CREATE OR REPLACE FUNCTION set_session_user_context(p_user_id UUID)
RETURNS VOID AS $$
DECLARE
    level INT;
BEGIN
    SELECT MIN(r.hierarchy_level) INTO level
    FROM user_roles ur
    JOIN roles r ON r.id = ur.role_id
    WHERE ur.user_id = p_user_id;

    PERFORM set_config('app.current_user_id', p_user_id::TEXT, true);
    PERFORM set_config('app.current_user_hierarchy_level', COALESCE(level::TEXT, ''), true);
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- Update current_user_hierarchy_level() to use the cached session variable
CREATE OR REPLACE FUNCTION current_user_hierarchy_level()
RETURNS INT AS $$
DECLARE
    level_text TEXT;
BEGIN
    BEGIN
        level_text := NULLIF(current_setting('app.current_user_hierarchy_level', true), '');
        IF level_text IS NOT NULL THEN
            RETURN level_text::INT;
        END IF;
    EXCEPTION WHEN OTHERS THEN
        NULL;
    END;

    RETURN NULL;
END;
$$ LANGUAGE plpgsql STABLE;