using Microsoft.EntityFrameworkCore.Migrations;

#nullable disable

namespace backend.Migrations
{
    /// <inheritdoc />
    public partial class UpdateTrackingCodeLength : Migration
    {
        /// <inheritdoc />
        protected override void Up(MigrationBuilder migrationBuilder)
        {
            // First, update existing tracking codes to 4-digit numeric values
            // Using a hash-based approach to generate unique 4-digit codes from existing ones
            migrationBuilder.Sql(@"
                DECLARE @Id int, @RowNum int, @NewCode nvarchar(4)
                DECLARE code_cursor CURSOR FOR
                    SELECT Id, ROW_NUMBER() OVER (ORDER BY Id) AS RowNum
                    FROM Users
                OPEN code_cursor
                FETCH NEXT FROM code_cursor INTO @Id, @RowNum
                WHILE @@FETCH_STATUS = 0
                BEGIN
                    SET @NewCode = RIGHT('0000' + CAST((@RowNum + 1000) AS nvarchar(4)), 4)
                    UPDATE Users SET TrackingCode = @NewCode WHERE Id = @Id
                    FETCH NEXT FROM code_cursor INTO @Id, @RowNum
                END
                CLOSE code_cursor
                DEALLOCATE code_cursor
            ");

            migrationBuilder.AlterColumn<string>(
                name: "TrackingCode",
                table: "Users",
                type: "nvarchar(4)",
                maxLength: 4,
                nullable: false,
                oldClrType: typeof(string),
                oldType: "nvarchar(8)",
                oldMaxLength: 8);
        }

        /// <inheritdoc />
        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AlterColumn<string>(
                name: "TrackingCode",
                table: "Users",
                type: "nvarchar(8)",
                maxLength: 8,
                nullable: false,
                oldClrType: typeof(string),
                oldType: "nvarchar(4)",
                oldMaxLength: 4);
        }
    }
}