package builder

import (
	"fmt"
	"git.dragse.it/anthrove/e621-sdk-go/pkg/e621/builder/basic"
	"git.dragse.it/anthrove/e621-sdk-go/pkg/e621/model"
	"strings"
)

type FavoritesBuilder interface {
	FromUsername(username string) FavoritesBuilder
	FromUserID(userID model.UserID) FavoritesBuilder
	WithTags(tags []string) FavoritesBuilder
	Limit(amount int) FavoritesBuilder
	Execute() ([]model.Post, error)
}

func NewGetFavoritesBuilder(requestContext model.RequestContext) FavoritesBuilder {
	return &getFavorites{
		requestContext: requestContext,
	}
}

type getFavorites struct {
	requestContext model.RequestContext
	user           model.User
	tags           string
	limit          int
	error          error
}

func (g *getFavorites) FromUsername(username string) FavoritesBuilder {
	user := model.User{Name: username}
	g.user = user
	return g
}

func (g *getFavorites) FromUserID(userID model.UserID) FavoritesBuilder {
	user := model.User{ID: userID}
	g.user = user
	return g
}

func (g *getFavorites) WithTags(tagList []string) FavoritesBuilder {
	tags := strings.Join(tagList, ",")
	g.tags = tags
	return g
}

func (g *getFavorites) Limit(amount int) FavoritesBuilder {
	g.limit = amount
	return g
}

func (g getFavorites) Execute() ([]model.Post, error) {
	var err error
	basicFavoritesBuilder := basic.NewGetFavoritesBuilder(g.requestContext)
	var userFavorites []model.Post

	if g.user.ID == 0 && g.user.Name == "" {
		return nil, fmt.Errorf("no UserID or UserName given")
	}

	if g.user.Name != "" {
		g.user, err = basic.NewGetUserBuilder(g.requestContext).SetUsername(g.user.Name).Execute()
		if err != nil {
			return nil, err
		}
	}

	if g.user.ID != 0 {
		basicFavoritesBuilder.SetUserID(g.user.ID)
	}

	if g.limit != 0 {
		basicFavoritesBuilder.SetLimit(g.limit)
	}

	if g.tags == "" {
		userFavorites, err = basicFavoritesBuilder.Execute()
	}

	if g.tags != "" {
		// TODO: implement with tags (channels)
	} else {
		return basicFavoritesBuilder.Execute()
	}

	return userFavorites, err

}

/*
// GetNFavoritesForUser retrieves a specified number of favorites for a user.
func (c *CLient) GetNFavoritesForUser(n int, favoriteBuilder basic.FavoritesBuilder) ([]model.Post, error) {
	// Retrieves a specified number of favorite posts for a user.
	if n < utils.E621_MAX_POST_COUNT {
		favoriteBuilder.SetLimit(n)
	}

	var favorites []model.Post
	var page = 1
	for len(favorites) < n {
		favoriteBuilder.Page(page)
		favoriteBuilder.SetLimit(n - len(favorites))
		newFavorites, err := favoriteBuilder.Execute()
		if err != nil {
			return nil, err
		}
		if len(newFavorites) == 0 {
			break
		}
		favorites = append(favorites, newFavorites...)
		page = page + 1
	}

	return favorites, nil
}

// GetAllFavoritesForUser retrieves all favorites for a user.
func (c *Client) GetAllFavoritesForUser(favoriteBuilder basic.FavoritesBuilder) ([]model.Post, error) {
	// Retrieves all favorite posts for a user.
	return c.GetNFavoritesForUser(math.MaxInt, favoriteBuilder)
}

// GetFavoritesForUserWithTags returns a posts builder for a user's favorites with specific tags.
func (c *Client) GetFavoritesForUserWithTags(username string, tags string) basic.PostsBuilder {
	// Returns a posts builder for a user's favorites with specific tags.
	favoritesBuilder := basic.NewGetPostsBuilder(c.RequestContext).Tags(fmt.Sprintf("fav:%s %s", username, tags))
	return favoritesBuilder
}
*/