package handlers

import (
	"net/http"
	"strconv"

	"github.com/labstack/echo/v4"

	"github.com/treytartt/honeydue-api/internal/apperrors"
	"github.com/treytartt/honeydue-api/internal/dto/responses"
	"github.com/treytartt/honeydue-api/internal/i18n"
	"github.com/treytartt/honeydue-api/internal/middleware"
	"github.com/treytartt/honeydue-api/internal/services"
)

// NotificationHandler handles notification-related HTTP requests
type NotificationHandler struct {
	notificationService *services.NotificationService
}

// NewNotificationHandler creates a new notification handler
func NewNotificationHandler(notificationService *services.NotificationService) *NotificationHandler {
	return &NotificationHandler{notificationService: notificationService}
}

// ListNotifications handles GET /api/notifications/
func (h *NotificationHandler) ListNotifications(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	limit := 50
	offset := 0
	if l := c.QueryParam("limit"); l != "" {
		if parsed, err := strconv.Atoi(l); err == nil && parsed > 0 {
			limit = parsed
		}
	}
	if limit > 200 {
		limit = 200
	}
	if o := c.QueryParam("offset"); o != "" {
		if parsed, err := strconv.Atoi(o); err == nil && parsed >= 0 {
			offset = parsed
		}
	}

	notifications, err := h.notificationService.GetNotifications(user.ID, limit, offset)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, map[string]interface{}{
		"count":   len(notifications),
		"results": notifications,
	})
}

// GetUnreadCount handles GET /api/notifications/unread-count/
func (h *NotificationHandler) GetUnreadCount(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	count, err := h.notificationService.GetUnreadCount(user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, map[string]interface{}{"unread_count": count})
}

// MarkAsRead handles POST /api/notifications/:id/read/
func (h *NotificationHandler) MarkAsRead(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	notificationID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		return apperrors.BadRequest("error.invalid_notification_id")
	}

	err = h.notificationService.MarkAsRead(uint(notificationID), user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, responses.MessageResponse{Message: i18n.LocalizedMessage(c, "message.notification_marked_read")})
}

// MarkAllAsRead handles POST /api/notifications/mark-all-read/
func (h *NotificationHandler) MarkAllAsRead(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	err = h.notificationService.MarkAllAsRead(user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, responses.MessageResponse{Message: i18n.LocalizedMessage(c, "message.all_notifications_marked_read")})
}

// GetPreferences handles GET /api/notifications/preferences/
func (h *NotificationHandler) GetPreferences(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	prefs, err := h.notificationService.GetPreferences(user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, prefs)
}

// UpdatePreferences handles PUT/PATCH /api/notifications/preferences/
func (h *NotificationHandler) UpdatePreferences(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	var req services.UpdatePreferencesRequest
	if err := c.Bind(&req); err != nil {
		return apperrors.BadRequest("error.invalid_request")
	}
	if err := c.Validate(&req); err != nil {
		return err
	}

	prefs, err := h.notificationService.UpdatePreferences(user.ID, &req)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, prefs)
}

// RegisterDevice handles POST /api/notifications/devices/
func (h *NotificationHandler) RegisterDevice(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	var req services.RegisterDeviceRequest
	if err := c.Bind(&req); err != nil {
		return apperrors.BadRequest("error.invalid_request")
	}
	if err := c.Validate(&req); err != nil {
		return err
	}

	device, err := h.notificationService.RegisterDevice(user.ID, &req)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusCreated, device)
}

// ListDevices handles GET /api/notifications/devices/
func (h *NotificationHandler) ListDevices(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	devices, err := h.notificationService.ListDevices(user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, devices)
}

// UnregisterDevice handles POST /api/notifications/devices/unregister/
// Accepts {registration_id, platform} and deactivates the matching device
func (h *NotificationHandler) UnregisterDevice(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	var req struct {
		RegistrationID string `json:"registration_id"`
		Platform       string `json:"platform"`
	}
	if err := c.Bind(&req); err != nil {
		return apperrors.BadRequest("error.invalid_request")
	}
	if req.RegistrationID == "" {
		return apperrors.BadRequest("error.registration_id_required")
	}
	if req.Platform == "" {
		return apperrors.BadRequest("error.platform_required")
	}
	if req.Platform != "ios" && req.Platform != "android" {
		return apperrors.BadRequest("error.invalid_platform")
	}

	err = h.notificationService.UnregisterDevice(req.RegistrationID, req.Platform, user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, responses.MessageResponse{Message: i18n.LocalizedMessage(c, "message.device_removed")})
}

// DeleteDevice handles DELETE /api/notifications/devices/:id/
func (h *NotificationHandler) DeleteDevice(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	deviceID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		return apperrors.BadRequest("error.invalid_device_id")
	}

	platform := c.QueryParam("platform")
	if platform == "" {
		return apperrors.BadRequest("error.platform_required")
	}
	if platform != "ios" && platform != "android" {
		return apperrors.BadRequest("error.invalid_platform")
	}

	err = h.notificationService.DeleteDevice(uint(deviceID), platform, user.ID)
	if err != nil {
		return err
	}

	return c.JSON(http.StatusOK, responses.MessageResponse{Message: i18n.LocalizedMessage(c, "message.device_removed")})
}
