using Microsoft.EntityFrameworkCore.Migrations;

#nullable disable

namespace HrynCo.NotificationService.DAL.EF.Migrations;

public partial class LinkEmailChannelsToServices : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        // EF runs this whole migration in one transaction. Lock the source rows so a
        // concurrent rename or channel write cannot invalidate the verified mapping.
        migrationBuilder.Sql("""
            LOCK TABLE services IN SHARE ROW EXCLUSIVE MODE;
            LOCK TABLE email_channels IN ACCESS EXCLUSIVE MODE;
            DO $$
            BEGIN
                IF EXISTS (
                    SELECT 1 FROM email_channels c
                    WHERE (SELECT count(*) FROM services s
                        WHERE s.name = c.service_name
                           OR (c.service_name = 'StoreMate-Prod' AND s.name = 'Invemory-Prod')) <> 1
                ) THEN
                    RAISE EXCEPTION 'Email channel migration stopped: every legacy service name must have exactly one existing service (including the approved StoreMate-Prod -> Invemory-Prod alias). Resolve missing or ambiguous names before retrying.';
                END IF;
            END $$;
            ALTER TABLE email_channels ADD COLUMN service_id uuid;
            UPDATE email_channels c SET service_id = s.id
            FROM services s
            WHERE s.name = c.service_name
               OR (c.service_name = 'StoreMate-Prod' AND s.name = 'Invemory-Prod');
            ALTER TABLE email_channels ALTER COLUMN service_id SET NOT NULL;
            """);
        migrationBuilder.DropIndex("IX_email_channels_service_name_priority", "email_channels");
        migrationBuilder.DropColumn("service_name", "email_channels");
        migrationBuilder.CreateIndex("IX_email_channels_service_id_priority", "email_channels", new[] { "service_id", "priority" });
        migrationBuilder.AddForeignKey("FK_email_channels_services_service_id", "email_channels", "service_id",
            "services", principalColumn: "id", onDelete: ReferentialAction.Restrict);
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        // Restore current service names; historical names are intentionally not retained.
        migrationBuilder.Sql("""
            ALTER TABLE email_channels ADD COLUMN service_name character varying(100);
            UPDATE email_channels c SET service_name = s.name FROM services s WHERE s.id = c.service_id;
            ALTER TABLE email_channels ALTER COLUMN service_name SET NOT NULL;
            """);
        migrationBuilder.DropForeignKey("FK_email_channels_services_service_id", "email_channels");
        migrationBuilder.DropIndex("IX_email_channels_service_id_priority", "email_channels");
        migrationBuilder.DropColumn("service_id", "email_channels");
        migrationBuilder.CreateIndex("IX_email_channels_service_name_priority", "email_channels", new[] { "service_name", "priority" });
    }
}