const NUM_DATA_POINTS = 400;

export function getData() {
  const data: Array<{ year: number; spending: number; tonnes: number }> = [];
  for (let i = 0; i < NUM_DATA_POINTS; i++) {
    data.push({
      year: new Date().getFullYear() - NUM_DATA_POINTS + i,
      spending:
        i === 0 ? random() * 100 : data[i - 1].spending + random() * 10 - 5,
      tonnes: 0,
    });
  }

  // Add tonnes separately to ensure the same randomisation is used for spending as other examples
  for (let i = 0; i < NUM_DATA_POINTS; i++) {
    data[i] = {
      ...data[i],
      tonnes:
        i === 0 ? random() * 1000 : data[i - 1].tonnes + random() * 10 - 5,
    };
  }

  return data;
}

let seed = 1234;
function random() {
  seed = (seed * 16807) % 2147483647;
  return (seed - 1) / 2147483646;
}