Function ruleCoverage

internal/sheetsvalidation/copy.go:653–736

(
	segments []copySegment,
	startRow, endRow, startCol, endCol int64,
)

}

func ruleCoverage(
	segments []copySegment,
	startRow, endRow, startCol, endCol int64,
) (*sheets.BooleanCondition, string, bool) {
	if endRow <= startRow || endCol <= startCol {
		return nil, "", false
	}
	type interval struct {
		start int64
		end   int64
		key   string
		rule  *sheets.DataValidationRule
	}
	expectedKey := ""
	haveExpectedKey := false
	var expectedCondition *sheets.BooleanCondition

	for col := startCol; col < endCol; col++ {
		intervals := make([]interval, 0)

		for _, segment := range segments {
			if col < segment.StartCol || col >= segment.EndCol {
				continue
			}
			overlapStart := max(startRow, segment.StartRow)

			overlapEnd := min(endRow, segment.EndRow)
			if overlapEnd > overlapStart {
				intervals = append(intervals, interval{
					start: overlapStart,
					end:   overlapEnd,
					key:   segment.RuleKey,
					rule:  segment.Rule,
				})
			}
		}

		sort.Slice(intervals, func(i, j int) bool { return intervals[i].start < intervals[j].start })
		cursor := startRow
		ruleKey := ""
		haveRuleKey := false
		var condition *sheets.BooleanCondition

		for _, item := range intervals {
			if item.start > cursor {
				return nil, "", false
			}

			if item.end <= cursor {
				continue
			}

			if !haveRuleKey {
				ruleKey = item.key
				haveRuleKey = true

				if item.rule != nil {
					condition = item.rule.Condition