package sitebuilder

import (
	"context"
	"errors"
	"gopkg.in/yaml.v3"
	"lmika.dev/lmika/hugo-cms/models"
	"lmika.dev/lmika/hugo-cms/providers/hugo"
	"log"
	"os"
	"path/filepath"
	"time"
)

func (s *Service) WritePost(site models.Site, post models.Post) models.Job {
	return models.Job{
		Do: func(ctx context.Context) error {
			rbn, err := s.fullRebuildNecessary(ctx, site)
			if err != nil {
				return err
			} else if rbn {
				return s.RebuildSite(site, site).Do(ctx)
			}

			if err := s.writePost(site, post); err != nil {
				return err
			}
			return s.publish(ctx, site)
		},
	}
}

func (s *Service) WriteAllPosts(site models.Site) models.Job {
	return models.Job{
		Do: func(ctx context.Context) error {
			var startId int64
			now := time.Now()
			for {
				posts, err := s.db.ListPublishablePosts(ctx, int64(startId), site.ID, now)
				if err != nil {
					return err
				} else if len(posts) == 0 {
					return nil
				}

				for _, post := range posts {
					if err := s.writePost(site, post); err != nil {
						return err
					}
				}
				startId = posts[len(posts)-1].ID
			}
		},
	}
}

func (s *Service) DeletePost(site models.Site, post models.Post) models.Job {
	return models.Jobs(
		models.Job{
			Do: func(ctx context.Context) error {
				themeMeta, ok := s.themes.Lookup(site.Theme)
				if !ok {
					return errors.New("theme not found")
				}

				postFilename := s.postFilename(site, themeMeta, post)

				if _, err := os.Stat(postFilename); err != nil {
					if errors.Is(err, os.ErrNotExist) {
						return nil
					}
					return err
				}

				if os.Remove(postFilename) != nil {
					return nil
				}
				return nil
			},
		},
		s.Publish(site),
	)
}

func (s *Service) writePost(site models.Site, post models.Post) error {
	themeMeta, ok := s.themes.Lookup(site.Theme)
	if !ok {
		return errors.New("theme not found")
	}

	postFilename := s.postFilename(site, themeMeta, post)

	log.Printf(" .. post %v", postFilename)

	if err := os.MkdirAll(filepath.Dir(postFilename), 0755); err != nil {
		return err
	}

	frontMatter := map[string]string{
		"date": post.PostDate.Format(time.RFC3339),
	}
	if post.Title != "" {
		frontMatter["title"] = post.Title
	} else if themeMeta.PreferTitle {
		frontMatter["title"] = post.PostDate.Format(time.ANSIC)
	}

	fmBytes, err := yaml.Marshal(frontMatter)
	if err != nil {
		return err
	}

	f, err := os.Create(postFilename)
	if err != nil {
		return err
	}
	defer f.Close()

	if _, err := f.WriteString("---\n"); err != nil {
		return err
	}
	if _, err := f.Write(fmBytes); err != nil {
		return err
	}
	if _, err := f.WriteString("---\n"); err != nil {
		return err
	}
	if _, err := f.WriteString(post.Body); err != nil {
		return err
	}

	return nil
}

func (s *Service) postFilename(site models.Site, themeMeta models.ThemeMeta, post models.Post) string {
	return filepath.Join(s.hugo.SiteStagingDir(site, hugo.ContentSiteDir), themeMeta.PostDir, post.CreatedAt.Format("2006-01-02-150405.md"))
}