namespace Tiku.Infrastructure.Persistence;

internal static class PostgreSqlSaasCatalogConstraintSql
{
    public const string CreateOfferingVersionImmutabilityGuards = """
        create or replace function tiku_guard_saas_offering_version_immutable()
        returns trigger
        language plpgsql
        as $$
        begin
            if tg_op = 'DELETE' then
                if old.status in ('published', 'retired') then
                    raise exception 'published or retired SaaS offering versions cannot be deleted'
                        using errcode = '23514',
                              constraint = 'ck_saas_offering_versions_published_immutable';
                end if;

                return old;
            end if;

            if old.status not in ('published', 'retired') then
                return new;
            end if;

            if old.status = 'published'
               and new.status = 'retired'
               and new.retired_at is not null
               and new.id is not distinct from old.id
               and new.offering_id is not distinct from old.offering_id
               and new.version is not distinct from old.version
               and new.billing_cycle is not distinct from old.billing_cycle
               and new.original_amount_cents is not distinct from old.original_amount_cents
               and new.amount_cents is not distinct from old.amount_cents
               and new.currency is not distinct from old.currency
               and new.effective_at is not distinct from old.effective_at
               and new.published_at is not distinct from old.published_at
               and new.metadata is not distinct from old.metadata
               and new.created_at is not distinct from old.created_at then
                return new;
            end if;

            raise exception 'published or retired SaaS offering versions are immutable'
                using errcode = '23514',
                      constraint = 'ck_saas_offering_versions_published_immutable';
        end;
        $$;

        do $guard$
        begin
            if to_regclass('saas_offering_versions') is not null then
                execute 'create trigger trg_saas_offering_versions_published_immutable
                         before update or delete on saas_offering_versions
                         for each row execute function tiku_guard_saas_offering_version_immutable()';
            end if;
        end
        $guard$;
        """;

    public const string CreateOfferingVersionChildrenImmutabilityGuards = """
        create or replace function tiku_guard_saas_offering_version_child_immutable()
        returns trigger
        language plpgsql
        as $$
        declare
            version_status text;
        begin
            if tg_op = 'DELETE' then
                select status into version_status
                from saas_offering_versions
                where id = old.offering_version_id;

                if version_status is distinct from 'draft' then
                    raise exception 'published or retired SaaS offering version children are immutable'
                        using errcode = '23514',
                              constraint = 'ck_saas_offering_versions_published_immutable';
                end if;

                return old;
            end if;

            if tg_op = 'UPDATE' and old.offering_version_id <> new.offering_version_id then
                select status into version_status
                from saas_offering_versions
                where id = old.offering_version_id;

                if version_status is distinct from 'draft' then
                    raise exception 'published or retired SaaS offering version children are immutable'
                        using errcode = '23514',
                              constraint = 'ck_saas_offering_versions_published_immutable';
                end if;
            end if;

            select status into version_status
            from saas_offering_versions
            where id = new.offering_version_id;

            if version_status is distinct from 'draft' then
                raise exception 'published or retired SaaS offering version children are immutable'
                    using errcode = '23514',
                          constraint = 'ck_saas_offering_versions_published_immutable';
            end if;

            return new;
        end;
        $$;

        do $guard$
        begin
            if to_regclass('saas_offering_version_features') is not null then
                execute 'create trigger trg_saas_offering_version_features_published_immutable
                         before insert or update or delete on saas_offering_version_features
                         for each row execute function tiku_guard_saas_offering_version_child_immutable()';
            end if;

            if to_regclass('saas_offering_version_limits') is not null then
                execute 'create trigger trg_saas_offering_version_limits_published_immutable
                         before insert or update or delete on saas_offering_version_limits
                         for each row execute function tiku_guard_saas_offering_version_child_immutable()';
            end if;
        end
        $guard$;
        """;

    public const string CreateSubscriptionOfferingTypeGuards = """
        create or replace function tiku_guard_saas_subscription_offering_type()
        returns trigger
        language plpgsql
        as $$
        declare
            offering_type text;
            source_version_id uuid;
        begin
            if tg_table_name = 'tenant_saas_subscriptions' then
                select o.type into offering_type
                from saas_offering_versions v
                join saas_offerings o on o.id = v.offering_id
                where v.id = new.base_offering_version_id;

                if offering_type is distinct from 'base_plan' then
                    raise exception 'subscription base offering version must belong to a base plan'
                        using errcode = '23514', constraint = 'ck_tenant_saas_subscription_base_plan';
                end if;

                if new.scheduled_base_offering_version_id is not null then
                    select o.type into offering_type
                    from saas_offering_versions v
                    join saas_offerings o on o.id = v.offering_id
                    where v.id = new.scheduled_base_offering_version_id;
                    if offering_type is distinct from 'base_plan' then
                        raise exception 'scheduled subscription offering version must belong to a base plan'
                            using errcode = '23514', constraint = 'ck_tenant_saas_subscription_base_plan';
                    end if;
                end if;
                return new;
            end if;

            select o.type into offering_type
            from saas_offering_versions v
            join saas_offerings o on o.id = v.offering_id
            where v.id = new.offering_version_id;
            if offering_type is distinct from new.item_type::text then
                raise exception 'subscription item type must match its offering type'
                    using errcode = '23514', constraint = 'ck_tenant_saas_subscription_item_offering_type';
            end if;

            if new.source_order_item_id is not null then
                select offering_version_id into source_version_id
                from platform_billing_order_items
                where tenant_id = new.tenant_id and id = new.source_order_item_id;
                if source_version_id is distinct from new.offering_version_id then
                    raise exception 'subscription item must match its order item snapshot'
                        using errcode = '23514', constraint = 'ck_tenant_saas_subscription_item_order_snapshot';
                end if;
            end if;
            return new;
        end;
        $$;

        do $guard$
        begin
            if to_regclass('tenant_saas_subscriptions') is not null then
                execute 'create trigger trg_tenant_saas_subscriptions_base_plan
                         before insert or update on tenant_saas_subscriptions
                         for each row execute function tiku_guard_saas_subscription_offering_type()';
            end if;
            if to_regclass('tenant_saas_subscription_items') is not null then
                execute 'create trigger trg_tenant_saas_subscription_items_offering_type
                         before insert or update on tenant_saas_subscription_items
                         for each row execute function tiku_guard_saas_subscription_offering_type()';
            end if;
        end
        $guard$;
        """;

    public const string DropOfferingVersionImmutabilityGuards = """
        do $guard$
        begin
            if to_regclass('saas_offering_version_features') is not null then
                execute 'drop trigger if exists trg_saas_offering_version_features_published_immutable on saas_offering_version_features';
            end if;

            if to_regclass('saas_offering_version_limits') is not null then
                execute 'drop trigger if exists trg_saas_offering_version_limits_published_immutable on saas_offering_version_limits';
            end if;

            if to_regclass('saas_offering_versions') is not null then
                execute 'drop trigger if exists trg_saas_offering_versions_published_immutable on saas_offering_versions';
            end if;

            if to_regclass('tenant_saas_subscription_items') is not null then
                execute 'drop trigger if exists trg_tenant_saas_subscription_items_offering_type on tenant_saas_subscription_items';
            end if;

            if to_regclass('tenant_saas_subscriptions') is not null then
                execute 'drop trigger if exists trg_tenant_saas_subscriptions_base_plan on tenant_saas_subscriptions';
            end if;
        end
        $guard$;

        drop function if exists tiku_guard_saas_offering_version_child_immutable();
        drop function if exists tiku_guard_saas_offering_version_immutable();
        drop function if exists tiku_guard_saas_subscription_offering_type();
        """;
}