package badtudexo 

import (
	"errors"
	"fmt"
)

// Given a list of base, percent and the result and a tolerance return a list
// of indices where outside this tolerance pct. For instance, given a base of
// [100, 50, 200], percents of [ 10, 10, 10 ], and a tolerance either way of
// 1%, return all in result which are not between 9% and 11% of the
// corresponding index of base: if res were [10, 2, 19], return [1], as the 
// 2nd (1st w/ zero-indexing) elem is the only one outside the allowed pcts.
func EqPct(base, pct, res []float64, tol float64) ([]int, error) {
	var ret []int
	var allgood bool = true
	if len(base) != len(pct) {
		return nil, errors.New("len(base) != len(pct)")
	}

	if len(pct) != len(res) {
		return nil, errors.New("len(pct) != len(res)")
	}

	for i := 0; i < len(pct); i++ {
		min := base[i] * ((pct[i] - tol) / 100)
		max := base[i] * ((pct[i] + tol) / 100)

		if res[i] < min || res[i] > max {
			// fmt.Printf("Min [%v] < Res [%v] > Max [%v]\n", min, res[i], max)
			allgood = false
			ret = append(ret, i)
		}
	}

	if allgood {
		// fmt.Println("EqPct: all good!")
	}

	return ret, nil
}