package crawl

import (
	"strings"

	"git.golem15.com/golem15/summercms/modules/pact"
)

// maxSuggestions caps the pages suggested to link to an orphan.
const maxSuggestions = 10

// minPhrase is the shortest phrase a suggestion matches (in bytes).
const minPhrase = 3

// checkOrphans reports orphan_page (D-82): an indexable page a sitemap
// lists that no crawled page links to (the home page is the crawl's
// entry and never an orphan). Its suggestions are the pages whose main
// text mentions the orphan's title or its focus keyphrase; the first
// suggestion's record names the tool that adds the link, else the fix is
// a link in the site's code.
func checkOrphans(res *Result, env *Env) []Finding {
	links := inbound(res)
	var out []Finding
	for _, key := range res.Order {
		p := res.Pages[key]
		if key == HomePath || !p.InSitemap || !env.indexable(res, p) || len(links[key]) > 0 {
			continue
		}
		rec := env.record(key)
		var phrases []string
		add := func(s string) {
			if s = normal(s); len(s) >= minPhrase {
				for _, have := range phrases {
					if have == s {
						return
					}
				}
				phrases = append(phrases, s)
			}
		}
		if rec != nil {
			add(rec.Title)
		}
		if h1 := p.Facts.H1(); len(h1) > 0 {
			add(h1[0])
		}
		add(p.Facts.Title)
		if env.Keyphrases != nil {
			add(env.Keyphrases[key])
		}
		var suggestions []map[string]any
		var first *Record
		for _, other := range res.Order {
			if len(suggestions) >= maxSuggestions {
				break
			}
			op := res.Pages[other]
			if other == key || !op.OK() {
				continue
			}
			text := normal(op.Facts.Text)
			for _, phrase := range phrases {
				if strings.Contains(text, phrase) {
					suggestions = append(suggestions, map[string]any{"url": other, "phrase": phrase})
					if first == nil {
						first = env.record(other)
					}
					break
				}
			}
		}
		f := Finding{Kind: KindOrphanPage, URL: key, Locale: locale(rec), Record: first, Details: map[string]any{"count": len(suggestions), "suggestions": suggestions}}
		if first != nil {
			f.Content = []string{pact.ContentToolEdit}
		}
		out = append(out, f)
	}
	return out
}