package handlers

import (
	"Yimaru-Backend/internal/domain"
	"fmt"

	"github.com/gofiber/fiber/v2"
)

func (h *Handler) learnerHasSubscriptionCategory(c *fiber.Ctx, category domain.SubscriptionCategory) (bool, error) {
	userID, ok := c.Locals("user_id").(int64)
	if !ok || userID == 0 {
		return false, fiber.NewError(fiber.StatusUnauthorized, "Unauthorized")
	}
	return h.subscriptionsSvc.HasActiveSubscriptionByCategory(c.Context(), userID, category)
}

func (h *Handler) ensureLearnerExamPrepContentAccess(c *fiber.Ctx, contentCategory string) error {
	role, _ := c.Locals("role").(domain.Role)
	if !role.IsCustomerLearnerRole() {
		return nil
	}
	if !domain.IsExamPrepContentCategory(contentCategory) {
		return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
			Message: "Catalog course not found",
		})
	}
	active, err := h.learnerHasSubscriptionCategory(c, domain.SubscriptionCategory(contentCategory))
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(domain.ErrorResponse{
			Message: fmt.Sprintf("Failed to verify %s subscription", contentCategory),
			Error:   err.Error(),
		})
	}
	if !active {
		return c.Status(fiber.StatusForbidden).JSON(domain.ErrorResponse{
			Message: fmt.Sprintf("An active %s subscription is required", humanizeSubscriptionCategory(domain.SubscriptionCategory(contentCategory))),
		})
	}
	return nil
}

func (h *Handler) blockLearnerIfNotLMSProgram(c *fiber.Ctx, program domain.Program) error {
	role, _ := c.Locals("role").(domain.Role)
	if !role.IsCustomerLearnerRole() {
		return nil
	}
	if !domain.IsLMSContentCategory(program.Category) {
		return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
			Message: "Program not found",
		})
	}
	return nil
}

func humanizeSubscriptionCategory(category domain.SubscriptionCategory) string {
	switch category {
	case domain.SubscriptionCategoryLearnEnglish:
		return "learn english"
	case domain.SubscriptionCategoryIELTS:
		return "IELTS"
	case domain.SubscriptionCategoryDuolingo:
		return "Duolingo"
	default:
		return string(category)
	}
}

func filterExamPrepCatalogCoursesForLearner(items []domain.ExamPrepCatalogCourse, hasIELTS, hasDuolingo bool) []domain.ExamPrepCatalogCourse {
	filtered := make([]domain.ExamPrepCatalogCourse, 0, len(items))
	for _, item := range items {
		switch domain.SubscriptionCategory(item.Category) {
		case domain.SubscriptionCategoryIELTS:
			if hasIELTS {
				filtered = append(filtered, item)
			}
		case domain.SubscriptionCategoryDuolingo:
			if hasDuolingo {
				filtered = append(filtered, item)
			}
		}
	}
	return filtered
}