package handler

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

	"projectreshoot/internal/models"
	"projectreshoot/internal/view/component/form"
	"projectreshoot/internal/view/page"

	"git.haelnorr.com/h/golib/hws"
	"git.haelnorr.com/h/golib/hwsauth"

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

// Validates the username matches a user in the database and the password
// is correct. Returns the corresponding user
func validateLogin(
	ctx context.Context,
	tx bun.Tx,
	r *http.Request,
) (*models.UserBun, error) {
	formUsername := r.FormValue("username")
	formPassword := r.FormValue("password")
	user, err := models.GetUserByUsername(ctx, tx, formUsername)
	if err != nil {
		return nil, errors.Wrap(err, "db.GetUserFromUsername")
	}

	if user == nil {
		return nil, errors.New("Username or password incorrect")
	}

	err = user.CheckPassword(ctx, tx, formPassword)
	if err != nil {
		if !strings.Contains(err.Error(), "Username or password incorrect") {
			return nil, errors.Wrap(err, "user.CheckPassword")
		}
		return nil, errors.New("Username or password incorrect")
	}
	return user, nil
}

// Returns result of the "Remember me?" checkbox as a boolean
func checkRememberMe(r *http.Request) bool {
	rememberMe := r.FormValue("remember-me")
	if rememberMe == "on" {
		return true
	} else {
		return false
	}
}

// Handles an attempted login request. On success will return a HTMX redirect
// and on fail will return the login form again, passing the error to the
// template for user feedback
func LoginRequest(
	server *hws.Server,
	auth *hwsauth.Authenticator[*models.UserBun, bun.Tx],
	db *bun.DB,
) http.Handler {
	return http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
			defer cancel()

			// Start the transaction
			tx, err := db.BeginTx(ctx, nil)
			if err != nil {
				err := server.ThrowError(w, r, hws.HWSError{
					StatusCode: http.StatusServiceUnavailable,
					Message:    "Login failed",
					Error:      err,
				})
				if err != nil {
					server.ThrowFatal(w, err)
				}
				return
			}
			r.ParseForm()
			user, err := validateLogin(ctx, tx, r)
			if err != nil {
				tx.Rollback()
				if err.Error() != "Username or password incorrect" {
					err := server.ThrowError(w, r, hws.HWSError{
						StatusCode: http.StatusInternalServerError,
						Message:    "Login failed",
						Error:      err,
					})
					if err != nil {
						server.ThrowFatal(w, err)
					}
				} else {
					form.LoginForm("Username or password incorrect").Render(r.Context(), w)
				}
				return
			}

			rememberMe := checkRememberMe(r)
			err = auth.Login(w, r, user, rememberMe)
			if err != nil {
				tx.Rollback()
				err := server.ThrowError(w, r, hws.HWSError{
					StatusCode: http.StatusInternalServerError,
					Message:    "Login failed",
					Error:      err,
				})
				if err != nil {
					server.ThrowFatal(w, err)
				}
				return
			}

			tx.Commit()
			pageFrom := cookies.CheckPageFrom(w, r)
			w.Header().Set("HX-Redirect", pageFrom)
		},
	)
}

// Handles a request to view the login page. Will attempt to set "pagefrom"
// cookie so a successful login can redirect the user to the page they came
func LoginPage(trustedHost string) http.Handler {
	return http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			cookies.SetPageFrom(w, r, trustedHost)
			page.Login().Render(r.Context(), w)
		},
	)
}