package importer

import (
	"context"
	"fmt"
	"github.com/abelith/spellbook/internal/models"
	"io"
	"sync"
)

type Importer interface {
	Import(ctx context.Context, r io.Reader) (<-chan models.Spell, <-chan error, error)
}

var (
	importers = make(map[string]Importer)
	mu        sync.Mutex
)

func Register(name string, imp Importer) {
	mu.Lock()
	defer mu.Unlock()

	if imp == nil {
		panic("importer: Importer cannot be nil")
	}
	if _, ok := importers[name]; ok {
		panic("importer: Register called twice for " + name)
	}
	importers[name] = imp
}

func Import(ctx context.Context, name string, r io.Reader) (<-chan models.Spell, <-chan error, error) {
	mu.Lock()
	imp, ok := importers[name]
	mu.Unlock()

	if !ok {
		return nil, nil, fmt.Errorf("importer %s not found", name)
	}

	return imp.Import(ctx, r)
}