package classes

import (
	"encoding/json"
	"strings"

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

// SiteURLConfigKey is the config key of the site address the sitemaps use
// when the setting is empty.
const SiteURLConfigKey = "golem15.sitemap.site_url"

// LoadSettings reads the settings row; without one the defaults apply.
func LoadSettings(db *gorm.DB) (models.Settings, error) {
	var rows []models.Settings
	if err := db.Where("id = ?", 1).Limit(1).Find(&rows).Error; err != nil {
		return models.Settings{}, err
	}
	if len(rows) == 0 {
		return models.DefaultSettings(), nil
	}
	return rows[0], nil
}

// SiteURL is the absolute site address every <loc> starts with, without a
// trailing slash: the site_url setting, else the config key
// golem15.sitemap.site_url, else app.url (CONTEXT 2026-10-28). A value that
// is not an absolute http(s) URL (models.AllowedFrontendURL) is skipped.
// The request's Host header is never used; "" means no site address is
// configured.
func SiteURL(app *backpack.App, s models.Settings) string {
	candidates := []string{models.Text(s.SiteURL)}
	if app != nil && app.Config != nil {
		candidates = append(candidates, app.Config.String(SiteURLConfigKey), app.Config.String("app.url"))
	}
	for _, c := range candidates {
		c = strings.TrimRight(strings.TrimSpace(c), "/")
		if c != "" && models.AllowedFrontendURL(c) {
			return c
		}
	}
	return ""
}

// Absolute turns a stored address into the absolute URL of a <loc>: a path
// starting with a single / is put on site; an absolute http(s) URL is kept.
// Anything else, or a path without a site address, is "".
func Absolute(site, u string) string {
	switch {
	case strings.HasPrefix(u, "/") && !strings.HasPrefix(u, "//"):
		if site == "" {
			return ""
		}
		return site + u
	case models.AllowedFrontendURL(u):
		return u
	}
	return ""
}

// MergeHTMLPaths merges submitted HTML sitemap addresses (locale to path)
// into the stored ones: a sent locale replaces its address, a blank one
// removes it, the others keep theirs. problem is true when a sent address
// is not a models.ValidHTMLPath; nothing is merged then.
func MergeHTMLPaths(db *gorm.DB, sent map[string]string) (map[string]string, bool) {
	settings, err := LoadSettings(db)
	if err != nil {
		return nil, true
	}
	merged := settings.EffectiveHTMLPaths()
	for locale, path := range sent {
		locale, path = strings.TrimSpace(locale), strings.TrimSpace(path)
		if locale == "" {
			continue
		}
		if path == "" {
			delete(merged, locale)
			continue
		}
		if !models.ValidHTMLPath(path) {
			return nil, true
		}
		merged[locale] = path
	}
	return merged, false
}

// StoreHTMLPaths writes the HTML sitemap addresses to settings row 1.
func StoreHTMLPaths(db *gorm.DB, paths map[string]string) error {
	raw, err := json.Marshal(paths)
	if err != nil {
		return err
	}
	return db.Exec(`UPDATE golem15_sitemap_settings SET html_paths = ?::jsonb WHERE id = 1`, string(raw)).Error
}