package http

import (
	"encoding/json"
	"io"
	"io/fs"
	"net/http"
	"os"

	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/logger"
)

const (
	ErrCodeForbidden     = "forbidden"
	ErrCodeInternalError = "internal-error"
	ErrCodeBadRequest    = "bad-request"
	ErrCodeNotFound      = "not-found"
)

type jsonErrorResponse struct {
	Error jsonErr `json:"error"`
}

type jsonErr struct {
	Code string `json:"code"`
}

func JSONError(w http.ResponseWriter, status int, code string) {
	w.Header().Add("Content-Type", "application/json")
	w.WriteHeader(status)

	encoder := json.NewEncoder(w)
	response := jsonErrorResponse{
		Error: jsonErr{
			Code: code,
		},
	}

	if err := encoder.Encode(response); err != nil {
		panic(errors.WithStack(err))
	}
}

func ServeFile(w http.ResponseWriter, r *http.Request, fs fs.FS, path string) {
	ctx := logger.With(r.Context(), logger.F("path", path))

	file, err := fs.Open(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)

			return
		}

		logger.Error(ctx, "error while opening fs file", logger.CapturedE(errors.WithStack(err)))
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)

		return
	}

	defer func() {
		if err := file.Close(); err != nil {
			logger.Error(ctx, "error while closing fs file", logger.CapturedE(errors.WithStack(err)))
		}
	}()

	info, err := file.Stat()
	if err != nil {
		logger.Error(ctx, "error while retrieving fs file stat", logger.CapturedE(errors.WithStack(err)))
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)

		return
	}

	reader, ok := file.(io.ReadSeeker)
	if !ok {
		return
	}

	http.ServeContent(w, r, path, info.ModTime(), reader)
}