package sourcepolicy

import (
	"regexp"

	spb "github.com/moby/buildkit/sourcepolicy/pb"
	"github.com/pkg/errors"
)

func match(src *selectorCache, ref string, attrs map[string]string) (bool, error) {
	for _, c := range src.Constraints {
		if c == nil {
			return false, errors.Errorf("invalid nil constraint for %v", src)
		}
		switch c.Condition {
		case spb.AttrMatch_EQUAL:
			if attrs[c.Key] != c.Value {
				return false, nil
			}
		case spb.AttrMatch_NOTEQUAL:
			if attrs[c.Key] == c.Value {
				return false, nil
			}
		case spb.AttrMatch_MATCHES:
			// TODO: Cache the compiled regex
			matches, err := regexp.MatchString(c.Value, attrs[c.Key])
			if err != nil {
				return false, errors.Errorf("invalid regex %q: %v", c.Value, err)
			}
			if !matches {
				return false, nil
			}
		default:
			return false, errors.Errorf("unknown attr condition: %s", c.Condition)
		}
	}

	if src.Identifier == ref {
		return true, nil
	}

	switch src.MatchType {
	case spb.MatchType_EXACT:
		return false, nil
	case spb.MatchType_REGEX:
		re, err := src.regex()
		if err != nil {
			return false, err
		}
		return re.MatchString(ref), nil
	case spb.MatchType_WILDCARD:
		w, err := src.wildcard()
		if err != nil {
			return false, err
		}
		return w.Match(ref) != nil, nil
	default:
		return false, errors.Errorf("unknown match type: %s", src.MatchType)
	}
}