package useCases

import (
	"RenewCMS/internal/domain/article"
	"RenewCMS/internal/domain/audit"
	"context"
)

type UpdateArticleUseCase struct {
	articleRepository article.Repository
	bodyRenderer      article.BodyRenderer
	recorder          audit.Recorder
}

func NewUpdateArticleUseCase(articleRepository article.Repository, bodyRenderer article.BodyRenderer, recorder audit.Recorder) *UpdateArticleUseCase {
	return &UpdateArticleUseCase{articleRepository, bodyRenderer, recorder}
}

func (g *UpdateArticleUseCase) UpdateBody(ctx context.Context, id uint32, body string, format article.BodyFormat) (article.Article, error) {
	before, err := g.articleRepository.Get(id)
	if err != nil {
		return article.Article{}, err
	}
	updated, err := g.articleRepository.UpdateBody(id, body)
	if err != nil {
		g.recordFailure(ctx, audit.ActionArticleEdit, before, err)
		return article.Article{}, err
	}
	g.recordChange(ctx, audit.ActionArticleEdit, before, updated)
	return renderArticle(g.bodyRenderer, updated, format)
}

func (g *UpdateArticleUseCase) UpdateIsOnline(ctx context.Context, id uint32, isOnline bool, format article.BodyFormat) (article.Article, error) {
	before, err := g.articleRepository.Get(id)
	if err != nil {
		return article.Article{}, err
	}
	updated, err := g.articleRepository.UpdateIsOnline(id, isOnline)
	if err != nil {
		g.recordFailure(ctx, publishAction(isOnline), before, err)
		return article.Article{}, err
	}
	g.recordChange(ctx, publishAction(isOnline), before, updated)
	return renderArticle(g.bodyRenderer, updated, format)
}

func publishAction(isOnline bool) string {
	if isOnline {
		return audit.ActionArticlePublish
	}
	return audit.ActionArticleUnpublish
}

func (g *UpdateArticleUseCase) recordChange(ctx context.Context, action string, before article.Article, after article.Article) {
	changes := audit.ArticleChanges(before, after)
	if len(changes) == 0 {
		return
	}
	event := audit.NewEvent(action, audit.CategoryArticles)
	event.Target = articleTarget(after)
	event.Changes = changes
	g.recorder.Record(ctx, event)
}

func (g *UpdateArticleUseCase) recordFailure(ctx context.Context, action string, before article.Article, cause error) {
	event := audit.NewEvent(action, audit.CategoryArticles)
	event.Target = articleTarget(before)
	recordFailure(ctx, g.recorder, event, cause)
}