package auth

import (
	"encoding/json"
	"errors"
	"log/slog"
	"net/http"
)

type loginRequest struct {
	Email    string `json:"email"`
	Password string `json:"password"`
}

type refreshRequest struct {
	RefreshToken string `json:"refresh_token"`
}

type APIResponse struct {
	Status  string `json:"status"`
	Message string `json:"message"`
	Data    any    `json:"data,omitempty"`
}

type Handler struct {
	svc *Service
}

func NewHandler(svc *Service) *Handler {
	return &Handler{svc: svc}
}

// Login godoc
//
//	@Summary		Login user and issue token pair
//	@Description	Verifikasi email dan password, lalu mengembalikan profil user, access_token Bearer 1 jam, dan refresh_token 7 hari.
//	@Tags			auth
//	@Accept			json
//	@Produce		json
//	@Param			body	body		loginRequest	true	"Login credentials"
//	@Success		200		{object}	APIResponse{data=AuthResult}
//	@Failure		400		{object}	APIResponse
//	@Failure		401		{object}	APIResponse
//	@Failure		403		{object}	APIResponse
//	@Failure		404		{object}	APIResponse
//	@Failure		500		{object}	APIResponse
//	@Router			/api/login [post]
func (h *Handler) Login(w http.ResponseWriter, r *http.Request) {
	var req loginRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, APIResponse{Status: "error", Message: "invalid request body"})
		return
	}
	if req.Email == "" || req.Password == "" {
		writeJSON(w, http.StatusBadRequest, APIResponse{Status: "error", Message: "email and password are required"})
		return
	}

	result, err := h.svc.Login(r.Context(), req.Email, req.Password)
	if err != nil {
		h.writeAuthError(w, err)
		return
	}

	writeJSON(w, http.StatusOK, APIResponse{
		Status:  "success",
		Message: "login successful",
		Data:    result,
	})
}

// Refresh godoc
//
//	@Summary		Rotate refresh token and issue token pair
//	@Description	Menggunakan refresh_token aktif untuk menerbitkan access_token baru dan refresh_token pengganti. Refresh token lama tidak dapat dipakai ulang.
//	@Tags			auth
//	@Accept			json
//	@Produce		json
//	@Param			body	body		refreshRequest	true	"Refresh token"
//	@Success		200		{object}	APIResponse{data=AuthResult}
//	@Failure		400		{object}	APIResponse
//	@Failure		401		{object}	APIResponse
//	@Failure		403		{object}	APIResponse
//	@Failure		500		{object}	APIResponse
//	@Router			/api/refresh [post]
func (h *Handler) Refresh(w http.ResponseWriter, r *http.Request) {
	var req refreshRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, APIResponse{Status: "error", Message: "invalid request body"})
		return
	}
	if req.RefreshToken == "" {
		writeJSON(w, http.StatusBadRequest, APIResponse{Status: "error", Message: "refresh_token is required"})
		return
	}
	result, err := h.svc.Refresh(r.Context(), req.RefreshToken)
	if err != nil {
		h.writeAuthError(w, err)
		return
	}
	writeJSON(w, http.StatusOK, APIResponse{Status: "success", Message: "token refreshed", Data: result})
}

func (h *Handler) writeAuthError(w http.ResponseWriter, err error) {
	switch {
	case errors.Is(err, ErrUserNotFound):
		writeJSON(w, http.StatusNotFound, APIResponse{Status: "error", Message: "user not found"})
	case errors.Is(err, ErrInactive):
		writeJSON(w, http.StatusForbidden, APIResponse{Status: "error", Message: "user account is inactive"})
	case errors.Is(err, ErrWrongPassword):
		writeJSON(w, http.StatusUnauthorized, APIResponse{Status: "error", Message: "invalid credentials"})
	case errors.Is(err, ErrInvalidRefreshToken):
		writeJSON(w, http.StatusUnauthorized, APIResponse{Status: "error", Message: "invalid refresh token"})
	case errors.Is(err, ErrTokenServiceUnavailable):
		writeJSON(w, http.StatusInternalServerError, APIResponse{Status: "error", Message: "token service unavailable"})
	default:
		slog.Error("auth request failed", "err", err)
		writeJSON(w, http.StatusInternalServerError, APIResponse{Status: "error", Message: "internal server error"})
	}
}

func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(v)
}