package handlers

import (
	"Yimaru-Backend/internal/domain"
	"Yimaru-Backend/internal/services/courses"
	"Yimaru-Backend/internal/services/programs"
	"context"
	"errors"
	"strconv"

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

// ReorderPrograms godoc
// @Summary Reorder all programs
// @Description Sets learning order of programs. Body must list every current program id exactly once, in the desired order (index 0 = first in path).
// @Tags programs
// @Accept json
// @Produce json
// @Param body body domain.ReorderIDsRequest true "New order: ordered_ids is the full set of program ids"
// @Success 200 {object} domain.Response
// @Failure 400 {object} domain.ErrorResponse
// @Router /api/v1/programs/reorder [put]
func (h *Handler) ReorderPrograms(c *fiber.Ctx) error {
	var req domain.ReorderIDsRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "Invalid request body",
			Error:   err.Error(),
		})
	}
	if req.OrderedIDs == nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "ordered_ids is required (use an empty array if there are no programs)",
			Error:   "missing ordered_ids",
		})
	}
	if err := h.programSvc.Reorder(c.Context(), req.OrderedIDs); err != nil {
		if errors.Is(err, domain.ErrReorderInvalidIDSet) {
			return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
				Message: err.Error(),
				Error:   "INVALID_REORDER",
			})
		}
		return c.Status(fiber.StatusInternalServerError).JSON(domain.ErrorResponse{
			Message: "Failed to reorder programs",
			Error:   err.Error(),
		})
	}
	actorID := c.Locals("user_id").(int64)
	actorRole := string(c.Locals("role").(domain.Role))
	ip := c.IP()
	ua := c.Get("User-Agent")
	go h.activityLogSvc.RecordAction(context.Background(), &actorID, &actorRole, domain.ActionProgramUpdated, domain.ResourceProgram, nil, "Reordered programs", nil, &ip, &ua)

	return c.JSON(domain.Response{
		Message:    "Programs reordered successfully",
		Success:    true,
		StatusCode: fiber.StatusOK,
	})
}

// ReorderCoursesInProgram godoc
// @Summary Reorder courses within a program
// @Param id path int true "Program ID"
// @Param body body domain.ReorderIDsRequest true "ordered_ids: every course id in this program, in the new order"
// @Tags courses
// @Router /api/v1/programs/{id}/courses/reorder [put]
func (h *Handler) ReorderCoursesInProgram(c *fiber.Ctx) error {
	programID, err := strconv.ParseInt(c.Params("id"), 10, 64)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "Invalid program id",
			Error:   err.Error(),
		})
	}
	var req domain.ReorderIDsRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "Invalid request body",
			Error:   err.Error(),
		})
	}
	if req.OrderedIDs == nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "ordered_ids is required (use an empty array if the program has no courses)",
			Error:   "missing ordered_ids",
		})
	}
	if err := h.courseSvc.ReorderInProgram(c.Context(), programID, req.OrderedIDs); err != nil {
		if errors.Is(err, programs.ErrProgramNotFound) {
			return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
				Message: "Program not found",
				Error:   err.Error(),
			})
		}
		if errors.Is(err, domain.ErrReorderInvalidIDSet) {
			return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
				Message: err.Error(),
				Error:   "INVALID_REORDER",
			})
		}
		return c.Status(fiber.StatusInternalServerError).JSON(domain.ErrorResponse{
			Message: "Failed to reorder courses",
			Error:   err.Error(),
		})
	}
	actorID := c.Locals("user_id").(int64)
	actorRole := string(c.Locals("role").(domain.Role))
	ip := c.IP()
	ua := c.Get("User-Agent")
	msg := "Reordered courses in program"
	go h.activityLogSvc.RecordAction(context.Background(), &actorID, &actorRole, domain.ActionCourseUpdated, domain.ResourceProgram, &programID, msg, nil, &ip, &ua)

	return c.JSON(domain.Response{
		Message:    "Courses reordered successfully",
		Success:    true,
		StatusCode: fiber.StatusOK,
	})
}

// ReorderModulesInCourse godoc
// @Summary Reorder modules within a course
// @Param courseId path int true "Course ID"
// @Param body body domain.ReorderIDsRequest true "ordered_ids: every module id in this course, in the new order"
// @Tags modules
// @Router /api/v1/courses/{courseId}/modules/reorder [put]
func (h *Handler) ReorderModulesInCourse(c *fiber.Ctx) error {
	courseID, err := strconv.ParseInt(c.Params("courseId"), 10, 64)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "Invalid course id",
			Error:   err.Error(),
		})
	}
	var req domain.ReorderIDsRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "Invalid request body",
			Error:   err.Error(),
		})
	}
	if req.OrderedIDs == nil {
		return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
			Message: "ordered_ids is required (use an empty array if the course has no modules)",
			Error:   "missing ordered_ids",
		})
	}
	if err := h.moduleSvc.ReorderInCourse(c.Context(), courseID, req.OrderedIDs); err != nil {
		if errors.Is(err, courses.ErrCourseNotFound) {
			return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
				Message: "Course not found",
				Error:   err.Error(),
			})
		}
		if errors.Is(err, domain.ErrReorderInvalidIDSet) {
			return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
				Message: err.Error(),
				Error:   "INVALID_REORDER",
			})
		}
		return c.Status(fiber.StatusInternalServerError).JSON(domain.ErrorResponse{
			Message: "Failed to reorder modules",
			Error:   err.Error(),
		})
	}
	actorID := c.Locals("user_id").(int64)
	actorRole := string(c.Locals("role").(domain.Role))
	ip := c.IP()
	ua := c.Get("User-Agent")
	go h.activityLogSvc.RecordAction(context.Background(), &actorID, &actorRole, domain.ActionModuleUpdated, domain.ResourceCourse, &courseID, "Reordered modules in course", nil, &ip, &ua)

	return c.JSON(domain.Response{
		Message:    "Modules reordered successfully",
		Success:    true,
		StatusCode: fiber.StatusOK,
	})
}