package loader

import (
	"context"
	"errors"
	"strings"

	"git.aiterp.net/rpdata/api/models"
	"git.aiterp.net/rpdata/api/models/characters"
	"github.com/graph-gophers/dataloader"
)

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

	loader.loadPrimed(key)

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

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

	char, ok := res.(models.Character)
	if !ok {
		return models.Character{}, errors.New("incorrect type")
	}

	return char, nil
}

// Characters gets characters by key
func (loader *Loader) Characters(key string, values ...string) ([]models.Character, error) {
	if !strings.HasPrefix(key, "Character.") {
		key = "Character." + key
	}

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

	loader.loadPrimed(key)

	thunk := loader.loaders[key].LoadMany(loader.ctx, dataloader.NewKeysFromStrings(values))
	res, errs := thunk()
	for _, err := range errs {
		if err != nil && err != ErrNotFound {
			return nil, err
		}
	}

	chars := make([]models.Character, len(res))

	for i := range res {
		char, ok := res[i].(models.Character)
		if !ok {
			return nil, errors.New("incorrect type")
		}

		chars[i] = char
	}

	return chars, nil
}

// PrimeCharacters adds a set of characters to be loaded if, and only if, characters
// are going to be loaded. This will fill up the cache and speed up subsequent dataloader
// runs.
func (loader *Loader) PrimeCharacters(key string, values ...string) {
	if !strings.HasPrefix(key, "Character.") {
		key = "Character." + key
	}

	loader.prime(key, values)
}

func characterIDBatch(ctx context.Context, keys dataloader.Keys) []*dataloader.Result {
	results := make([]*dataloader.Result, 0, len(keys))
	ids := keys.Keys()

	characters, err := characters.List(&characters.Filter{IDs: ids})
	if err != nil {
		for range ids {
			results = append(results, &dataloader.Result{Error: err})
		}

		return results
	}

	for _, id := range ids {
		found := false

		for _, character := range characters {
			if character.ID == id {
				results = append(results, &dataloader.Result{Data: character})
				found = true
				break
			}
		}

		if !found {
			results = append(results, &dataloader.Result{Data: models.Character{}, Error: ErrNotFound})
		}
	}

	return results
}

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

	characters, err := characters.List(&characters.Filter{Nicks: nicks})
	if err != nil {
		for range nicks {
			results = append(results, &dataloader.Result{Error: err})
		}

		return results
	}

	for _, nick := range nicks {
		found := false
		for i := range characters {
			if characters[i].HasNick(nick) {
				results = append(results, &dataloader.Result{Data: characters[i]})

				found = true
				break
			}
		}

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

	return results
}