package user

import (
	"errors"
	"log"
	"net/http"
	"net/url"
	"strconv"

	"git.sr.ht/~evanj/cms/internal/c"
	"git.sr.ht/~evanj/cms/internal/m/space"
	"git.sr.ht/~evanj/cms/internal/m/tier"
	"git.sr.ht/~evanj/cms/internal/m/user"
	"git.sr.ht/~evanj/cms/internal/v"
)

var (
	indexHTML   = v.MustParse("html/index.html")
	ErrNoSignup = errors.New("signups are forbidden at this time")
	ErrNoTier   = errors.New("invalid tier")
)

type User struct {
	*c.Controller
	log           *log.Logger
	db            dber
	signupEnabled bool
	stripe        Striper
}

type dber interface {
	UserNew(username, password, verifyPassword string) (user.User, error)
	UserGet(username, password string) (user.User, error)
	UserGetFromToken(token string) (user.User, error)
	UserSetEmail(u user.User, email string) (user.User, error)
	SpacesPerUser(user user.User, before int) (space.SpaceList, error)
}

type Striper interface {
	StartCheckout(user user.User, t tier.Tier) (string, string, error)
	CancelSubscription(user user.User) error
}

func New(c *c.Controller, log *log.Logger, db dber, signupEnabled bool, s Striper) *User {
	return &User{
		c,
		log,
		db,
		signupEnabled,
		s,
	}
}

func (l *User) logout(w http.ResponseWriter, r *http.Request) {
	l.SetCookieUser(w, r, nil)
	l.Redirect(w, r, "/")
}

func (l *User) login(w http.ResponseWriter, r *http.Request) {
	username := r.FormValue("username")
	password := r.FormValue("password")

	user, err := l.db.UserGet(username, password)
	if err != nil {
		l.Error2(w, r, http.StatusBadRequest, err)
		return
	}

	l.SetCookieUser(w, r, user)
	l.Redirect(w, r, "/")
}

func (l *User) signup(w http.ResponseWriter, r *http.Request) {
	if !l.signupEnabled {
		l.Error2(w, r, http.StatusForbidden, ErrNoSignup)
		return
	}

	username := r.FormValue("username")
	password := r.FormValue("password")
	verify := r.FormValue("verify")
	t, ok := tier.ByName(r.FormValue("tier"))
	if !ok {
		l.Error2(w, r, http.StatusBadRequest, ErrNoTier)
		return
	}

	user, err := l.db.UserNew(username, password, verify)
	if err != nil {
		l.Error2(w, r, http.StatusBadRequest, err)
		return
	}
	l.SetCookieUser(w, r, user)

	if t.Is(tier.Free) {
		l.Redirect(w, r, "/")
		return
	}

	stripeCheckoutSessionID, stripePK, err := l.stripe.StartCheckout(user, t)
	if err != nil {
		l.Error2(w, r, http.StatusInternalServerError, err)
		return
	}

	form := url.Values{
		"StripeCheckoutSessionID": {stripeCheckoutSessionID},
		"StripePK":                {stripePK},
	}

	l.Redirect(w, r, "/page/stripe?"+form.Encode())
}

func (l *User) home(w http.ResponseWriter, r *http.Request) {
	user, err := l.GetCookieUser(w, r)
	if err != nil {
		l.HTML(w, r, indexHTML, map[string]interface{}{
			"Tiers": tier.Tiers,
		})
		return
	}

	// Don't care about the error value here. When error occurs before is zero
	// value.
	before, _ := strconv.Atoi(r.URL.Query().Get("before"))

	spaces, err := l.db.SpacesPerUser(user, before)
	if err != nil {
		l.Error(w, r, http.StatusInternalServerError, "failed to find spaces for user")
		return
	}

	l.HTML(w, r, indexHTML, map[string]interface{}{
		"Tiers":  tier.Tiers,
		"User":   user,
		"Spaces": spaces,
	})
}

func (l *User) updateEmail(w http.ResponseWriter, r *http.Request) {
	u, err := l.GetCookieUser(w, r)
	if err != nil {
		l.Error2(w, r, http.StatusInternalServerError, c.ErrNoLogin)
		return
	}

	if _, err := l.db.UserSetEmail(u, r.FormValue("email")); err != nil {
		l.Error2(w, r, http.StatusInternalServerError, err)
		return
	}

	l.Redirect(w, r, "/page/billing")
}

func (l *User) updateBilling(w http.ResponseWriter, r *http.Request) {
	u, err := l.GetCookieUser(w, r)
	if err != nil {
		l.Error2(w, r, http.StatusInternalServerError, c.ErrNoLogin)
		return
	}

	t, ok := tier.ByName(r.FormValue("tier"))
	if !ok || !(t.Is(tier.Business) || t.Is(tier.Enterprise)) {
		l.Error2(w, r, http.StatusBadRequest, ErrNoTier)
		return
	}

	if t.Is(tier.Free) {
		l.Redirect(w, r, "/")
		return
	}

	stripeCheckoutSessionID, stripePK, err := l.stripe.StartCheckout(u, t)
	if err != nil {
		l.Error2(w, r, http.StatusInternalServerError, err)
		return
	}

	form := url.Values{
		"StripeCheckoutSessionID": {stripeCheckoutSessionID},
		"StripePK":                {stripePK},
	}

	l.Redirect(w, r, "/page/stripe?"+form.Encode())
}

func (l *User) cancelBilling(w http.ResponseWriter, r *http.Request) {
	u, err := l.GetCookieUser(w, r)
	if err != nil {
		l.Error2(w, r, http.StatusInternalServerError, c.ErrNoLogin)
		return
	}

	if err := l.stripe.CancelSubscription(u); err != nil {
		l.Error2(w, r, http.StatusInternalServerError, err)
		return
	}

	l.Redirect(w, r, "/page/billing")
}

func (l *User) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	switch r.URL.Path {
	case "/":
		l.home(w, r)
		return
	case "/user/login":
		l.login(w, r)
		return
	case "/user/logout":
		l.logout(w, r)
		return
	case "/user/signup":
		l.signup(w, r)
		return
	case "/user/update/email":
		l.updateEmail(w, r)
		return
	case "/user/update/billing":
		l.updateBilling(w, r)
		return
	case "/user/cancel/billing":
		l.cancelBilling(w, r)
		return
	}

	http.NotFound(w, r)
}