import { TickMethod } from '../types';
import { d3Ticks } from './d3-ticks';
import { pows, logs } from '../utils';

export const d3Log: TickMethod = (a, b, n, base = 10) => {
  const shouldReflect = a < 0;
  const pow = pows(base, shouldReflect);
  const log = logs(base, shouldReflect);

  const r = b < a;
  const min = r ? b : a;
  const max = r ? a : b;
  let i = log(min);
  let j = log(max);
  let ticks = [];

  // 如果 base 是整数
  if (!(base % 1) && j - i < n) {
    i = Math.floor(i);
    j = Math.ceil(j);
    if (shouldReflect) {
      for (; i <= j; i += 1) {
        const p = pow(i);
        for (let k = base - 1; k >= 1; k -= 1) {
          const t = p * k;
          if (t > max) break;
          if (t >= min) ticks.push(t);
        }
      }
    } else {
      for (; i <= j; i += 1) {
        const p = pow(i);
        for (let k = 1; k < base; k += 1) {
          const t = p * k;
          if (t > max) break;
          if (t >= min) ticks.push(t);
        }
      }
    }
    if (ticks.length * 2 < n) ticks = d3Ticks(min, max, n);
  } else {
    const count = n === -1 ? j - i : Math.min(j - i, n);
    ticks = d3Ticks(i, j, count).map(pow);
  }

  return r ? ticks.reverse() : ticks;
};