package handlers

import (
	"context"
	"net/http"
	"time"

	"git.haelnorr.com/h/golib/hws"
	"github.com/pkg/errors"
	"github.com/uptrace/bun"

	"git.haelnorr.com/h/oslstats/internal/config"
	"git.haelnorr.com/h/oslstats/internal/db"
	"git.haelnorr.com/h/oslstats/internal/store"
	"git.haelnorr.com/h/oslstats/internal/view/page"
)

func Register(
	server *hws.Server,
	conn *bun.DB,
	cfg *config.Config,
	store *store.Store,
) http.Handler {
	return http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			attempts, exceeded, track := store.TrackRedirect(r, "/register", 3)

			if exceeded {
				err := errors.Errorf(
					"registration redirect loop detected after %d attempts | ip=%s ua=%s path=%s first_seen=%s ssl=%t",
					attempts,
					track.IP,
					track.UserAgent,
					track.Path,
					track.FirstSeen.Format("2006-01-02T15:04:05Z07:00"),
					cfg.HWSAuth.SSL,
				)

				store.ClearRedirectTrack(r, "/register")

				throwError(
					server,
					w,
					r,
					http.StatusBadRequest,
					"Registration failed: Cookies appear to be blocked or disabled. Please enable cookies in your browser and try again. If this problem persists, try a different browser or contact support.",
					err,
					"warn",
				)
				return
			}

			sessionCookie, err := r.Cookie("registration_session")
			if err != nil {
				http.Redirect(w, r, "/login", http.StatusSeeOther)
				return
			}
			details, ok := store.GetRegistrationSession(sessionCookie.Value)
			ok = false
			if !ok {
				http.Redirect(w, r, "/login", http.StatusSeeOther)
				return
			}

			store.ClearRedirectTrack(r, "/register")
			ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
			defer cancel()
			tx, err := conn.BeginTx(ctx, nil)
			if err != nil {
				throwInternalServiceError(server, w, r, "Database transaction failed", err)
				return
			}
			defer tx.Rollback()
			method := r.Method
			if method == "GET" {
				unique, err := db.IsUsernameUnique(ctx, tx, details.DiscordUser.Username)
				if err != nil {
					throwInternalServiceError(server, w, r, "Database query failed", err)
					return
				}
				tx.Commit()
				page.Register(details.DiscordUser.Username, unique).Render(r.Context(), w)
				return
			}
			if method == "POST" {
				// TODO: register the user

				// get the form data
				//
				return
			}
		},
	)
}

func IsUsernameUnique(
	server *hws.Server,
	conn *bun.DB,
	cfg *config.Config,
	store *store.Store,
) http.Handler {
	return http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			username := r.FormValue("username")
			ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
			defer cancel()
			tx, err := conn.BeginTx(ctx, nil)
			if err != nil {
				throwInternalServiceError(server, w, r, "Database transaction failed", err)
				return
			}
			defer tx.Rollback()
			unique, err := db.IsUsernameUnique(ctx, tx, username)
			if err != nil {
				throwInternalServiceError(server, w, r, "Database query failed", err)
				return
			}
			tx.Commit()
			if !unique {
				w.WriteHeader(http.StatusConflict)
			} else {
				w.WriteHeader(http.StatusOK)
			}
		},
	)
}