package server

import (
	"net/http"
	"net/url"
	"os"
	"strings"
	"time"

	"github.com/go-chi/chi/v5"

	"git.hubris.network/dtoro/artifacto/internal/auth"
)

type unlockData struct {
	Slug  string
	Error string
}

func (s *Server) getArtifact(w http.ResponseWriter, r *http.Request) {
	slug := chi.URLParam(r, "slug")
	art, err := s.store.GetArtifact(slug)
	if err != nil {
		http.NotFound(w, r)
		return
	}
	if art.ExpiresAt != nil && time.Now().After(*art.ExpiresAt) {
		http.NotFound(w, r)
		return
	}
	if art.HasPassword && !s.artifact.Verify(r, slug) {
		s.render(w, "unlock", unlockData{Slug: slug})
		return
	}

	body, err := os.ReadFile(s.store.ArtifactPath(slug))
	if err != nil {
		http.Error(w, "artifact missing on disk", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	w.Write(body)

	// Log view asynchronously. Failures are non-fatal.
	go s.logView(r, slug)
}

func (s *Server) postUnlock(w http.ResponseWriter, r *http.Request) {
	slug := chi.URLParam(r, "slug")
	art, err := s.store.GetArtifact(slug)
	if err != nil || !art.HasPassword {
		http.NotFound(w, r)
		return
	}
	if err := r.ParseForm(); err != nil {
		http.Error(w, "bad form", http.StatusBadRequest)
		return
	}

	vid := s.visitorID(r)
	key := slug + "|" + vid

	if !s.rateLimiter.Allow(key) {
		w.Header().Set("Retry-After", "600")
		http.Error(w, "too many attempts, try again in ~10 minutes", http.StatusTooManyRequests)
		return
	}

	ok := auth.VerifyPassword(art.PasswordHash, r.FormValue("password"))
	_ = s.store.LogUnlockAttempt(slug, vid, ok, time.Now())
	if !ok {
		s.render(w, "unlock", unlockData{Slug: slug, Error: "wrong password"})
		return
	}
	s.artifact.SetCookie(w, slug)
	http.Redirect(w, r, "/p/"+slug, http.StatusSeeOther)
}

func (s *Server) logView(r *http.Request, slug string) {
	now := time.Now()
	vid := s.visitorID(r)
	ref := refererHost(r.Referer())
	_ = s.store.LogView(slug, vid, ref, now)
	_ = s.store.TouchView(slug, now)
}

func refererHost(raw string) string {
	if raw == "" {
		return ""
	}
	u, err := url.Parse(raw)
	if err != nil || u.Host == "" {
		return ""
	}
	return strings.ToLower(u.Host)
}