package sitebuilder

import (
	"context"
	"fmt"
	"lmika.dev/lmika/hugo-cms/models"
	"lmika.dev/pkg/modash/momap"
	"os"
	"time"
)

func (s *Service) WritePage(site models.Site, bundle models.Bundle, page models.Page) models.Job {
	return models.Job{
		Do: func(ctx context.Context) error {
			s.signalSiteBuildingStarted(ctx, site)
			defer s.signalSiteBuildingFinished(ctx, site)

			rbn, err := s.fullRebuildNecessary(ctx, site)
			if err != nil {
				return err
			} else if rbn {
				return s.rebuildSite(ctx, site, site)
			}

			themeMeta, ok := s.themes.Lookup(site.Theme)
			if !ok {
				return fmt.Errorf("theme %s not found in themes", site.Theme)
			}

			bundleInfo, err := s.db.GetSiteBundleInfo(ctx, site.ID)
			if err != nil {
				return err
			}

			if err := s.writePage(pageBuildInfo{
				site:       site,
				themeMeta:  themeMeta,
				bundle:     bundle,
				bundleInfo: bundleInfo,
			}, page); err != nil {
				return err
			}
			return s.publish(ctx, site)
		},
	}
}

func (s *Service) DeletePage(site models.Site, page models.Page) models.Job {
	return models.Job{
		Do: func(ctx context.Context) error {
			s.signalSiteBuildingStarted(ctx, site)
			defer s.signalSiteBuildingFinished(ctx, site)

			bundle, err := s.db.GetBundleWithID(ctx, page.BundleID)
			if err != nil {
				return err
			}
			
			themeMeta, ok := s.themes.Lookup(site.Theme)
			if !ok {
				return fmt.Errorf("theme %s not found in themes", site.Theme)
			}

			bundleInfo, err := s.db.GetSiteBundleInfo(ctx, site.ID)
			if err != nil {
				return err
			}

			postFilename := s.pageFilename(pageBuildInfo{
				site:       site,
				themeMeta:  themeMeta,
				bundle:     bundle,
				bundleInfo: bundleInfo,
			}, page)

			if os.Remove(postFilename) != nil {
				return nil
			}
			// TODO: if dir is empty, delete it

			return s.publish(ctx, site)
		},
	}
}

func (s *Service) writeAllPages(ctx context.Context, site models.Site) error {
	themeMeta, ok := s.themes.Lookup(site.Theme)
	if !ok {
		return fmt.Errorf("theme %s not found in themes", site.Theme)
	}

	bundles, err := s.db.ListBundles(ctx, site.ID)
	if err != nil {
		return err
	}

	bundlesByID := momap.FromSlice(bundles, func(b models.Bundle) (int64, models.Bundle) { return b.ID, b })

	bundleInfo, err := s.db.GetSiteBundleInfo(ctx, site.ID)
	if err != nil {
		return err
	}

	var startId int64
	for {
		pages, err := s.db.ListPublishablePages(ctx, int64(startId), site.ID)
		if err != nil {
			return err
		} else if len(pages) == 0 {
			return nil
		}

		for _, page := range pages {
			if err := s.writePage(pageBuildInfo{
				site:       site,
				themeMeta:  themeMeta,
				bundle:     bundlesByID[page.BundleID],
				bundleInfo: bundleInfo,
			}, page); err != nil {
				return err
			}
		}
		startId = pages[len(pages)-1].ID
	}
}

func (s *Service) writePage(bi pageBuildInfo, page models.Page) error {
	postFilename := s.pageFilename(bi, page)

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

	return s.writeMarkdownFile(postFilename, frontMatter, page.Body)
}

type pageBuildInfo struct {
	site       models.Site
	themeMeta  models.ThemeMeta
	bundle     models.Bundle
	bundleInfo map[int64]models.BundleInfo
}