package loader

import (
	"context"
	"errors"
	"strings"

	"git.aiterp.net/rpdata/api/model/channel"
	"github.com/graph-gophers/dataloader"
)

// Channel gets a character by key
func (loader *Loader) Channel(key, value string) (channel.Channel, error) {
	if !strings.HasPrefix(key, "Channel.") {
		key = "Channel." + key
	}

	if loader.loaders[key] == nil {
		return channel.Channel{}, errors.New("unsupported key")
	}

	loader.loadPrimed(key)

	thunk := loader.loaders[key].Load(loader.ctx, dataloader.StringKey(value))
	res, err := thunk()
	if err != nil {
		return channel.Channel{}, err
	}

	channel, ok := res.(channel.Channel)
	if !ok {
		return channel, errors.New("incorrect type")
	}

	return channel, nil
}

// PrimeChannels primes channels for loading along with the first one.
func (loader *Loader) PrimeChannels(key string, values ...string) {
	if !strings.HasPrefix(key, "Channel.") {
		key = "Channel." + key
	}

	loader.prime(key, values)
}

func channelNameBatch(ctx context.Context, keys dataloader.Keys) []*dataloader.Result {
	var results []*dataloader.Result
	names := keys.Keys()

	channels, err := channel.ListNames(names...)
	if err != nil {
		for range names {
			results = append(results, &dataloader.Result{Data: channel.Channel{}, Error: err})
		}

		return results
	}

	for _, name := range names {
		found := false
		for i := range channels {
			if channels[i].Name == name {
				results = append(results, &dataloader.Result{Data: channels[i]})

				found = true
				break
			}
		}

		if !found {
			results = append(results, &dataloader.Result{Data: channel.Channel{}, Error: err})
		}
	}

	return results
}