package strmatcher

import (
	"regexp"
)

// Matcher is the interface to determine a string matches a pattern.
type Matcher interface {
	// Match returns true if the given string matches a predefined pattern.
	Match(string) bool
	String() string
}

// Type is the type of the matcher.
type Type byte

const (
	// Full is the type of matcher that the input string must exactly equal to the pattern.
	Full Type = iota
	// Substr is the type of matcher that the input string must contain the pattern as a sub-string.
	Substr
	// Domain is the type of matcher that the input string must be a sub-domain or itself of the pattern.
	Domain
	// Regex is the type of matcher that the input string must matches the regular-expression pattern.
	Regex
)

// New creates a new Matcher based on the given pattern.
func (t Type) New(pattern string) (Matcher, error) {
	// 1. regex matching is case-sensitive
	switch t {
	case Full:
		return fullMatcher(pattern), nil
	case Substr:
		return substrMatcher(pattern), nil
	case Domain:
		return domainMatcher(pattern), nil
	case Regex:
		r, err := regexp.Compile(pattern)
		if err != nil {
			return nil, err
		}
		return &regexMatcher{
			pattern: r,
		}, nil
	default:
		panic("Unknown type")
	}
}

// IndexMatcher is the interface for matching with a group of matchers.
type IndexMatcher interface {
	// Match returns the index of a matcher that matches the input. It returns empty array if no such matcher exists.
	Match(input string) []uint32
}

type matcherEntry struct {
	m  Matcher
	id uint32
}