package api

import (
	"errors"
	"io"
	"net/http"

	"git.golem15.com/golem15/sm-quizzes-plugin/classes"
	"git.golem15.com/golem15/summercms/modules/wire"
	"gorm.io/gorm"
)

// ImportQuiz answers POST /import?replace=: quizzes:import over HTTP, for
// the management API behind golem15.user's API token. The body is the
// import document. A document that does not parse is a 422 and writes
// nothing; an existing slug is a 409 unless replace is 1 or true.
func (h *Handlers) ImportQuiz(w http.ResponseWriter, r *http.Request) {
	raw, err := io.ReadAll(r.Body)
	var tooLarge *http.MaxBytesError
	switch {
	case errors.As(err, &tooLarge):
		wire.WriteJSON(w, http.StatusRequestEntityTooLarge, map[string]any{"error": true, "message": "Request body too large."})
		return
	case err != nil:
		wire.WriteJSON(w, http.StatusBadRequest, map[string]any{"error": true, "message": "Unreadable request body."})
		return
	}
	doc, err := classes.ParseImport(raw)
	if err != nil {
		wire.WriteJSON(w, http.StatusUnprocessableEntity, map[string]any{"message": err.Error()})
		return
	}
	var db *gorm.DB
	if h.App != nil {
		db, _ = h.App.Lookup[*gorm.DB]()
	}
	if db == nil {
		wire.WriteOpaque500(w)
		return
	}
	replace := r.URL.Query().Get("replace")
	res, err := classes.Import(r.Context(), db, doc, replace == "1" || replace == "true")
	if errors.Is(err, classes.ErrQuizExists) {
		wire.WriteJSON(w, http.StatusConflict, map[string]any{"error": true, "message": "A quiz with the slug " + doc.Slug + " already exists; pass replace=1 to replace its questions."})
		return
	}
	if err != nil {
		wire.WriteOpaque500(w)
		return
	}
	wire.WriteJSON(w, http.StatusOK, map[string]any{"data": map[string]any{
		"id":        res.Quiz.ID,
		"slug":      res.Quiz.Slug,
		"created":   res.Created,
		"questions": res.Questions,
		"answers":   res.Answers,
	}})
}