package errors

import (
	"net/http"
	"strings"
	"extrovert/templates/layouts"
	"encoding/json"
)

type Error interface {
	Error() string
	Status() int
	ServeHTTP(w http.ResponseWriter, r *http.Request)
	Component() templ.Component
	JSON() string
}

type defaultErr struct{}

func (e defaultErr) Error() string {
	return "Error: This method should have been overridden :')"
}

func (e defaultErr) Status() int {
	return http.StatusNotImplemented
}

func (e defaultErr) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if strings.Contains(r.Header.Get("Accept"), "text/html") {
		w.Header().Set("Content-Type", "text/html")

		err := e.Component().Render(r.Context(), w)
		if err != nil {
			w.Header().Set("Content-Type", "text/plain")
			w.Write([]byte("Unable to render error message, using JSON representation: " + e.JSON()))
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
	} else {
		w.Header().Set("Content-Type", "application/json")

		_, err := w.Write([]byte(e.JSON()))
		if err != nil {
			w.Header().Set("Content-Type", "text/plain")
			w.Write([]byte("Unable to send error information due to: " + err.Error()))
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
	}
	w.WriteHeader(e.Status())
}

func (e defaultErr) JSON() string {
	type jsonErr struct {
		Error string `json:"error"`
		Info  any    `json:"info"`
	}
	js, err := json.Marshal(jsonErr{
		Error: e.Error(),
		Info:  e,
	})
	if err != nil {
		js, _ = json.Marshal(jsonErr{
			Error: "Unable to parse JSON of error",
			Info:  err.Error(),
		})
	}

	return string(js)
}

templ (e defaultErr) Component() {
	@layouts.Page("Error") {
		<dialog open>
			<article>
				<header>
					<p>Error</p>
				</header>
				<p>
					{ e.Error() }
				</p>
				<footer>
					<a href={ templ.SafeURL("/") }>
						<button>Return to homepage</button>
					</a>
				</footer>
			</article>
		</dialog>
	}
}