package web

import (
	"fmt"
	"net/http"
	"time"

	"github.com/golang-jwt/jwt"
	"github.com/hashicorp/uuid"
)

var (
	tokens = map[string]string{}
)

type TokenRequest struct {
	GrantType   string
	Code        string
	RedirectUri string
}

type TokenResponse struct {
	AccessToken  string
	TokenType    string
	RefreshToken string
	ExpiresIn    int
	IdToken      string
}

func (h *HttpContext) Token(w http.ResponseWriter, r *http.Request) {
	if r.Method == "POST" {
		tr := &TokenRequest{
			GrantType:   r.FormValue("grant_type"),
			Code:        r.FormValue("code"),
			RedirectUri: r.FormValue("redirect_uri"),
		}
		if tr.GrantType == "authorization_code" {
			// Authorization Code Flow https://openid.net/specs/openid-connect-core-1_0.html#CodeFlowAuth
			r := &TokenResponse{
				AccessToken:  tokens[tr.Code],
				TokenType:    "Bearer",
				RefreshToken: "TODO::",
				ExpiresIn:    3600,
				IdToken:      h.createIdToken(r.FormValue("client_id")),
			}

			w.Header().Set("Content-Type", "application/json")
			w.Header().Set("Cache-Control", "no-store")
			w.Header().Set("Pragma", "no-cache")
			fmt.Fprintf(w, `{"access_token": "%s","token_type": "%s","refresh_token": "%s","expires_in": %d,"id_token": "%s"}`, r.AccessToken, r.TokenType, r.RefreshToken, r.ExpiresIn, r.IdToken)
		} else {
			w.WriteHeader(http.StatusNotFound)
			fmt.Fprintf(w, "Not Found\n")
		}
	}
}

func (h *HttpContext) createIdToken(clientId string) string {
	now := time.Now()
	if clientId == "" {
		clientId = "clientId"
	}
	expiresAt := now.Add(time.Hour * time.Duration(1))
	idToken := jwt.NewWithClaims(jwt.SigningMethodRS256, &jwt.StandardClaims{
		Issuer:    h.cfg.Issuer,
		Subject:   "1",
		Audience:  clientId,
		ExpiresAt: expiresAt.Unix(),
		NotBefore: now.Unix(),
		IssuedAt:  now.Unix(),
		Id:        uuid.GenerateUUID(),
	})

	key, _ := jwt.ParseRSAPrivateKeyFromPEM(h.cfg.KeyData)
	signedIdToken, _ := idToken.SignedString(key)
	return signedIdToken
}