package stacks

import (
	"database/sql"
	"encoding/json"
	"io"
	"net/http"
	"os"
	"screenmark/screenmark/middleware"
	"screenmark/screenmark/models"

	"github.com/charmbracelet/log"
	"github.com/go-chi/chi/v5"
)

func writeJsonOrError[K any](logger *log.Logger, object K, w http.ResponseWriter) {
	jsonObject, err := json.Marshal(object)
	if err != nil {
		logger.Warn("could not marshal json object", "err", err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	w.Write(jsonObject)
	w.WriteHeader(http.StatusOK)
}

type StackHandler struct {
	logger     *log.Logger
	stackModel models.ListModel
}

func withValidatedPost[K any](
	fn func(request K, w http.ResponseWriter, r *http.Request),
) func(w http.ResponseWriter, r *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		request := new(K)

		body, err := io.ReadAll(r.Body)
		if err != nil {
			w.WriteHeader(http.StatusBadRequest)
			return
		}

		err = json.Unmarshal(body, request)
		if err != nil {
			w.WriteHeader(http.StatusBadRequest)
			return
		}

		fn(*request, w, r)
	}
}

func (h *StackHandler) getAllStacks(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	userID, err := middleware.GetUserID(ctx, h.logger, w)
	if err != nil {
		return
	}

	lists, err := h.stackModel.List(ctx, userID)
	if err != nil {
		h.logger.Warn("could not get stacks", "err", err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	writeJsonOrError(h.logger, lists, w)
}

func (h *StackHandler) getStackItems(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	_, err := middleware.GetUserID(ctx, h.logger, w)
	if err != nil {
		return
	}

	listID, err := middleware.GetPathParamID(h.logger, "listID", w, r)
	if err != nil {
		return
	}

	// TODO: must check for permission here.

	lists, err := h.stackModel.ListItems(ctx, listID)
	if err != nil {
		h.logger.Warn("could not get list items", "err", err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	writeJsonOrError(h.logger, lists, w)
}

type EditStack struct {
	Hello string `json:"hello"`
}

func (h *StackHandler) editStack(req EditStack, w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusNotImplemented)
}

type CreateStackBody struct {
	Title string `json:"title"`

	// We want a regular string because AI will take care of creating these for us.
	Fields string `json:"fields"`
}

func (h *StackHandler) createStack(body CreateStackBody, w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	userID, err := middleware.GetUserID(ctx, h.logger, w)
	if err != nil {
		return
	}

	err = h.stackModel.SaveProcessing(ctx, userID, body.Title, body.Fields)
	if err != nil {
		h.logger.Warn("could not save processing", "err", err)
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
}

func (h *StackHandler) CreateRoutes(r chi.Router) {
	h.logger.Info("Mounting stack router")

	r.Group(func(r chi.Router) {
		r.Use(middleware.ProtectedRoute)
		r.Use(middleware.SetJson)

		r.Get("/", h.getAllStacks)
		r.Get("/{listID}", h.getStackItems)

		r.Post("/", withValidatedPost(h.createStack))

		r.Patch("/{listID}", withValidatedPost(h.editStack))
	})
}

func CreateStackHandler(db *sql.DB) StackHandler {
	stackModel := models.NewListModel(db)
	logger := log.New(os.Stdout).WithPrefix("Stacks")

	return StackHandler{
		logger,
		stackModel,
	}
}