package seo

import (
	"net/http"
	"time"

	apicontrollers "git.golem15.com/golem15/sm-seo-plugin/controllers/api"
	"git.golem15.com/golem15/summercms/modules/pact"
	"git.golem15.com/golem15/summercms/modules/surf"
)

// The throttle buckets of the public endpoints.
const (
	// BucketResolve is the resolve endpoint's bucket.
	BucketResolve = "seo-resolve"
	// BucketNotFound is the 404 report endpoint's bucket.
	BucketNotFound = "seo-notfound"
	// BucketRobots is the /robots.txt bucket.
	BucketRobots = "seo-robots"
)

// Routes mounts GET /robots.txt at the site root and the /_seo/api/v1
// endpoints. None carries backend middleware: crawlers and the frontend
// server call them anonymously (the 404 report with its own token). Every
// /_seo/api/v1 answer carries X-Robots-Tag: noindex.
func (p *Plugin) Routes(r pact.Router) error {
	r.Get("/robots.txt", apicontrollers.Robots(p.Service), "throttle:"+BucketRobots)
	r.Group("/_seo/api/v1", nil, func(g pact.Router) {
		g.Get("/resolve", noindex(apicontrollers.Resolve(p.Service)), "throttle:"+BucketResolve)
		g.Post("/notfound", noindex(apicontrollers.NotFound(p.Service)), "throttle:"+BucketNotFound)
	})
	return nil
}

// noindex adds X-Robots-Tag: noindex to every answer of h.
func noindex(h http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("X-Robots-Tag", "noindex")
		h(w, r)
	}
}

// Buckets registers the per-client-IP buckets behind the configured
// trusted proxies: seo-resolve 600 a minute (the frontend server resolves
// every page it renders), seo-notfound 600 a minute (one report per 404
// page) and seo-robots 120 a minute.
func (p *Plugin) Buckets() map[string]surf.Bucket {
	trusted := surf.TrustedProxies(nil)
	if p.app != nil {
		trusted = surf.TrustedProxies(p.app.Config)
	}
	bucket := func(name string, max int) surf.Bucket {
		return surf.Bucket{
			Name:  name,
			Max:   max,
			Decay: time.Minute,
			Key: func(r *http.Request) string {
				return name + "|" + surf.ClientIP(r, trusted)
			},
		}
	}
	return map[string]surf.Bucket{
		BucketResolve:  bucket(BucketResolve, 600),
		BucketNotFound: bucket(BucketNotFound, 600),
		BucketRobots:   bucket(BucketRobots, 120),
	}
}