package signpost_test

import (
	"context"
	"fmt"
	"strings"

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

// Article is the example's stand-in for a content plugin's record.
type Article struct {
	ID        string
	Slug      string
	Title     string
	Published bool
}

// NewsPlugin is an example content plugin whose record type describes its
// articles to consumers such as sitemaps.
type NewsPlugin struct{ articles []Article }

func (NewsPlugin) ID() string { return "acme.news" }

// MenuItemTypes registers acme-article with a content descriptor: the
// controller that edits articles, their morph type, Describe and Match.
func (p NewsPlugin) MenuItemTypes() []pact.MenuItemType {
	return []pact.MenuItemType{{
		Key:            "acme-article",
		Label:          "acme.news::lang.menuitem.article",
		DefaultPattern: "/news/:slug",
		Placeholders:   []string{":slug", ":id"},
		Resolve:        p.resolve,
		Content: &pact.ContentDescriptor{
			Controller: "acme.news.articles",
			Model:      "acme_news_articles",
			Describe:   p.describe,
			Match:      p.match,
		},
	}}
}

func (p NewsPlugin) resolve(_ context.Context, in pact.MenuItemResolve) (*pact.ResolvedMenuItem, error) {
	return nil, nil
}

// describe answers one article per locale; the URL is built from the
// layered pattern it receives.
func (p NewsPlugin) describe(_ context.Context, in pact.ContentDescribe) (*pact.ContentRecord, error) {
	for _, a := range p.articles {
		if a.ID != in.ID {
			continue
		}
		url := strings.NewReplacer(":slug", a.Slug, ":id", a.ID).Replace(in.Pattern)
		return &pact.ContentRecord{
			ID:        a.ID,
			Published: a.Published,
			Locales:   []pact.ContentLocale{{Locale: "en", URL: url, Title: a.Title}},
		}, nil
	}
	return nil, nil
}

// match reads the path's values with signpost.MatchPattern and checks every
// one against the record: a slug finds the article, and an :id that names
// another article makes the match inexact. Drafts never match.
func (p NewsPlugin) match(_ context.Context, in pact.ContentMatch) (*pact.ContentMatchResult, error) {
	values, ok := signpost.MatchPattern(in.Pattern, in.Path)
	if !ok {
		return nil, nil
	}
	for _, a := range p.articles {
		if a.Slug != values["slug"] || !a.Published {
			continue
		}
		id, hasID := values["id"]
		return &pact.ContentMatchResult{ID: a.ID, Locale: "en", Exact: !hasID || id == a.ID}, nil
	}
	return nil, nil
}

func ExampleRegistry_MatchPath() {
	app := exampleApp() // its menu_items.yaml overrides acme-post of BlogPlugin
	news := NewsPlugin{articles: []Article{{ID: "7", Slug: "launch", Title: "Launch", Published: true}}}
	plugins := []interface{ ID() string }{BlogPlugin{}, news}
	if err := signpost.Activate(app, plugins); err != nil {
		fmt.Println(err)
		return
	}
	reg, _ := app.Lookup[*signpost.Registry]()

	// A record event names the model; the registry finds its type.
	typ, _ := reg.ContentTypeForModel("acme_news_articles")
	rec, _ := reg.Describe(context.Background(), typ.Key, "7", "")
	fmt.Println(typ.Key, rec.Locales[0].URL)

	// A visitor's path maps back to the record.
	key, res, _ := reg.MatchPath(context.Background(), "/news/launch", "")
	fmt.Println(key, res.ID, res.Exact)
	// Output:
	// acme-article /news/launch
	// acme-article 7 true
}