package classes

import (
	"time"

	"git.golem15.com/golem15/sm-sitemap-plugin/models"
	"git.golem15.com/golem15/summercms/modules/backpack"
	"gorm.io/gorm"
)

// SitemapFile is one file of the sitemap index: its name, the number of
// addresses (pages for an image file, articles for the News file) and the
// newest lastmod of its addresses.
type SitemapFile struct {
	Name    string     `json:"name"`
	Count   int        `json:"count"`
	LastMod *time.Time `json:"lastmod"`
}

// SitemapFiles lists the files the index links, in its order: the
// per-group files, the image files while images_enabled is on, then
// sitemap-news.xml while news_enabled is on and it lists an article.
func SitemapFiles(db *gorm.DB, app *backpack.App, s models.Settings, now time.Time) ([]SitemapFile, error) {
	type fileRow struct {
		Grp     string     `gorm:"column:grp"`
		FileNo  int        `gorm:"column:file_no"`
		N       int        `gorm:"column:n"`
		LastMod *time.Time `gorm:"column:lastmod"`
	}
	var rows []fileRow
	if err := db.Raw(`SELECT grp, file_no, COUNT(*) AS n, MAX(lastmod) AS lastmod FROM golem15_sitemap_urls
WHERE excluded_reason = '' AND file_no IS NOT NULL
GROUP BY grp, file_no ORDER BY grp, file_no`).Scan(&rows).Error; err != nil {
		return nil, err
	}
	if s.ImagesEnabled {
		var images []fileRow
		if err := db.Raw(`SELECT image_file_no AS file_no, COUNT(*) AS n, MAX(lastmod) AS lastmod FROM golem15_sitemap_urls
WHERE excluded_reason = '' AND image_file_no IS NOT NULL AND jsonb_array_length(images) > 0
GROUP BY image_file_no ORDER BY image_file_no`).Scan(&images).Error; err != nil {
			return nil, err
		}
		for i := range images {
			images[i].Grp = ImagesGroup
		}
		rows = append(rows, images...)
	}
	out := make([]SitemapFile, 0, len(rows)+1)
	for _, r := range rows {
		out = append(out, SitemapFile{Name: FileName(r.Grp, r.FileNo), Count: r.N, LastMod: r.LastMod})
	}
	if s.NewsEnabled {
		news, err := NewsEntries(db, app, s, now)
		if err != nil {
			return nil, err
		}
		if len(news) > 0 {
			newest := news[0].Published
			out = append(out, SitemapFile{Name: NewsFile, Count: len(news), LastMod: &newest})
		}
	}
	return out, nil
}

// LeftOut counts the addresses left out of the sitemaps by reason (a
// Filter's or the type switch's; deleted and unpublished rows are holes,
// not left out).
func LeftOut(db *gorm.DB) (map[string]int, error) {
	var rows []struct {
		Reason string `gorm:"column:excluded_reason"`
		N      int    `gorm:"column:n"`
	}
	if err := db.Raw(`SELECT excluded_reason, COUNT(*) AS n FROM golem15_sitemap_urls
WHERE excluded_reason NOT IN ('', ?, ?) GROUP BY excluded_reason`, models.ReasonDeleted, models.ReasonUnpublished).Scan(&rows).Error; err != nil {
		return nil, err
	}
	out := make(map[string]int, len(rows))
	for _, r := range rows {
		out[r.Reason] = r.N
	}
	return out, nil
}