package classes

import (
	"context"
	"regexp"
	"strings"
)

// VerificationNamePattern is the form of a verification file name (D-05,
// T-32-21): no slashes, an html, txt or xml extension.
const VerificationNamePattern = `[A-Za-z0-9._-]+\.(html|txt|xml)`

var verificationName = regexp.MustCompile(`^` + VerificationNamePattern + `$`)

// VerificationFile is one stored search-engine verification file.
type VerificationFile struct {
	Name        string
	Body        string
	ContentType string
}

// verificationTypes are the content types per extension.
var verificationTypes = map[string]string{
	".html": "text/html; charset=utf-8",
	".txt":  "text/plain; charset=utf-8",
	".xml":  "application/xml; charset=utf-8",
}

// VerificationFileByName returns the verification file stored in the SEO
// settings under name (D-05, D-103), found false for an unknown or
// malformed name. The frontend serves it at the site root (Phase 33); the
// plugin never registers a root route for it.
func (s *Service) VerificationFileByName(ctx context.Context, name string) (VerificationFile, bool, error) {
	if !verificationName.MatchString(name) {
		return VerificationFile{}, false, nil
	}
	db, err := s.DB(ctx)
	if err != nil {
		return VerificationFile{}, false, err
	}
	settings, err := LoadSettings(db)
	if err != nil {
		return VerificationFile{}, false, err
	}
	for _, f := range settings.Files() {
		if strings.TrimSpace(f.Filename) != name {
			continue
		}
		ext := name[strings.LastIndex(name, "."):]
		return VerificationFile{Name: name, Body: f.Body, ContentType: verificationTypes[strings.ToLower(ext)]}, true, nil
	}
	return VerificationFile{}, false, nil
}