package useCases

import (
	"RenewCMS/internal/domain/article"
	"RenewCMS/internal/domain/author"
	"RenewCMS/internal/domain/image"
	"RenewCMS/internal/domain/site"
	"slices"
	"strings"
)

const (
	UsageTypeArticle = "article"
	UsageTypeAuthor  = "author"
	UsageTypeSite    = "site"

	UsageFieldBody               = "body"
	UsageFieldCover              = "cover"
	UsageFieldSocial             = "social"
	UsageFieldAvatar             = "avatar"
	UsageFieldDefaultSocialImage = "default_social_image"
)

type MediaUsage struct {
	Type      string
	ID        uint32
	Title     string
	Published *bool
	Fields    []string
}

type GetMediaUsageUseCase struct {
	imageRepository   image.Repository
	articleRepository article.Repository
	sites             site.Repository
	authors           author.Repository
}

func NewGetMediaUsageUseCase(imageRepository image.Repository, articleRepository article.Repository, sites site.Repository, authors author.Repository) *GetMediaUsageUseCase {
	return &GetMediaUsageUseCase{imageRepository: imageRepository, articleRepository: articleRepository, sites: sites, authors: authors}
}

func (u *GetMediaUsageUseCase) Usage(id uint32) ([]MediaUsage, error) {
	img, err := u.imageRepository.Get(id)
	if err != nil {
		return nil, err
	}
	usages, err := u.articleUsages(img)
	if err != nil {
		return nil, err
	}
	authorUsages, err := u.authorUsages(img)
	if err != nil {
		return nil, err
	}
	siteUsages, err := u.siteUsages(img)
	if err != nil {
		return nil, err
	}
	return slices.Concat(usages, authorUsages, siteUsages), nil
}

func (u *GetMediaUsageUseCase) articleUsages(img image.Image) ([]MediaUsage, error) {
	storedName := image.StoredName(img.Path)
	inBody, err := u.articleRepository.FindByBodyContaining(storedName)
	if err != nil {
		return nil, err
	}
	referencing, err := u.articleRepository.FindByImage(img.ID)
	if err != nil {
		return nil, err
	}
	byID := map[uint32]*MediaUsage{}
	for _, found := range inBody {
		if !strings.Contains(found.Body, storedName) {
			continue
		}
		entry := usageFor(byID, found)
		entry.Fields = append(entry.Fields, UsageFieldBody)
	}
	for _, found := range referencing {
		entry := usageFor(byID, found)
		if found.CoverImageID != nil && *found.CoverImageID == img.ID {
			entry.Fields = append(entry.Fields, UsageFieldCover)
		}
		if found.SocialImageID != nil && *found.SocialImageID == img.ID {
			entry.Fields = append(entry.Fields, UsageFieldSocial)
		}
	}
	usages := make([]MediaUsage, 0, len(byID))
	for _, entry := range byID {
		usages = append(usages, *entry)
	}
	slices.SortFunc(usages, func(a, b MediaUsage) int { return int(a.ID) - int(b.ID) })
	return usages, nil
}

func usageFor(byID map[uint32]*MediaUsage, found article.Article) *MediaUsage {
	if entry, ok := byID[found.ID]; ok {
		return entry
	}
	published := found.IsOnline
	entry := &MediaUsage{Type: UsageTypeArticle, ID: found.ID, Title: found.Title, Published: &published, Fields: []string{}}
	byID[found.ID] = entry
	return entry
}

func (u *GetMediaUsageUseCase) authorUsages(img image.Image) ([]MediaUsage, error) {
	found, err := u.authors.FindByAvatar(img.ID)
	if err != nil {
		return nil, err
	}
	usages := make([]MediaUsage, 0, len(found))
	for _, a := range found {
		usages = append(usages, MediaUsage{Type: UsageTypeAuthor, ID: a.ID, Title: a.Name, Fields: []string{UsageFieldAvatar}})
	}
	return usages, nil
}

func (u *GetMediaUsageUseCase) siteUsages(img image.Image) ([]MediaUsage, error) {
	all, err := u.sites.List()
	if err != nil {
		return nil, err
	}
	usages := []MediaUsage{}
	for _, s := range all {
		if s.DefaultSocialImageID != nil && *s.DefaultSocialImageID == img.ID {
			usages = append(usages, MediaUsage{Type: UsageTypeSite, ID: s.ID, Title: s.Name, Fields: []string{UsageFieldDefaultSocialImage}})
		}
	}
	slices.SortFunc(usages, func(a, b MediaUsage) int { return int(a.ID) - int(b.ID) })
	return usages, nil
}

func articleMentionsImage(a article.Article, img image.Image) bool {
	return strings.Contains(a.Body, image.StoredName(img.Path)) || a.UsesImage(img.ID)
}