package mnt

import (
	"github.com/go-errors/errors"

	"gensokyo.cafe/xmnt/msg"
)

type Mounter interface {
	Mount() error
	Unmount() error
}

type (
	MounterFunc func(*Preset) (Mounter, error)
	MatcherFunc func(string) ([]*Preset, error)
)

var mounters = map[string]MounterFunc{}

func RegisterMounter(typeName string, fn MounterFunc) {
	mounters[typeName] = fn
}

func MounterFromPreset(preset *Preset) (Mounter, error) {
	if fn, ok := mounters[preset.Type]; !ok {
		return nil, errors.Errorf("unknown type %q", preset.Type)
	} else {
		return fn(preset)
	}
}

var matchers []MatcherFunc

func RegisterMatcher(fn MatcherFunc) {
	matchers = append(matchers, fn)
}

func MatchAll(s string) ([]*Preset, error) {
	// Match against presets. If matched, return the preset (should be only one).
	if matches, err := match(s); err != nil {
		msg.Errorf("Failed to find match in presets: %v", err)
	} else if len(matches) > 0 {
		return matches[:1], nil
	}

	// Run other matchers. Might produce multiple matches.
	var ret []*Preset
	rCh := make(chan []*Preset, 1)

	for _, fn := range matchers {
		go func(fn MatcherFunc) {
			matches, err := fn(s)
			if err != nil {
				msg.Errorf("%v", err)
				rCh <- nil
			} else {
				rCh <- matches
			}
		}(fn)
	}
	for range matchers {
		matches := <-rCh
		ret = append(ret, matches...)
	}

	return ret, nil
}