package storage

import (
	"strings"
	"unicode"
)

// SearchWords splits what a user typed into a search box into the words
// an index can match: runs of letters and digits, lower-cased, everything
// else a separator.
//
// Both engines' query languages have operators — FTS5's quotes, AND, NEAR
// and column filters, tsquery's & | ! and parentheses — and a search box is
// not the place to expose them: a user searching for "C++ & Go" means the
// words, not a malformed query. Reducing the term to words and building the
// query from those is what makes any input safe to pass on.
func SearchWords(term string) []string {
	fields := strings.FieldsFunc(term, func(r rune) bool {
		return !unicode.IsLetter(r) && !unicode.IsDigit(r)
	})
	out := fields[:0]
	for _, f := range fields {
		out = append(out, strings.ToLower(f))
	}
	return out
}