package frontend

import (
	"encoding/json"
	"log"
	"net/http"
	"os"
	"strings"

	b "streifling.com/jason/cpolis/cmd/backend"
)

func tokenIsVerified(w http.ResponseWriter, r *http.Request) bool {
	idToken := r.Header.Get("Authorization")
	if idToken == "" {
		http.Error(w, "Authorization header missing", http.StatusUnauthorized)
	}

	client, err := b.NewClient()
	if err != nil {
		log.Println(err)
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return false
	}

	_, err = client.Verify(idToken)
	if err != nil {
		log.Println(err)
		http.Error(w, err.Error(), http.StatusUnauthorized)
		return false
	}

	return true
}

func ServePDFList(c *b.Config) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if tokenIsVerified(w, r) {
			files, err := os.ReadDir(c.PDFDir)
			if err != nil {
				log.Println(err)
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			fileNames := make([]string, 0)
			for _, file := range files {
				fileNames = append(fileNames, file.Name())
			}

			w.Header().Set("Content-Type", "application/json")
			if err = json.NewEncoder(w).Encode(fileNames); err != nil {
				log.Println(err)
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
		}
	}
}

func ServePDFs(c *b.Config) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if tokenIsVerified(w, r) {
			pdfIDsString := r.PathValue("ids")
			pdfIDs := strings.Split(pdfIDsString, ",")

			for _, id := range pdfIDs {
				http.ServeFile(w, r, id)
			}
		}
	}
}