package handlers

import (
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/oklog/ulid/v2"
	"github.com/timetracker/backend/internal/api/utils"
	dto "github.com/timetracker/backend/internal/dtos"
	"github.com/timetracker/backend/internal/models"
)

// ActivityHandler handles activity-related API endpoints
type ActivityHandler struct{}

// NewActivityHandler creates a new ActivityHandler
func NewActivityHandler() *ActivityHandler {
	return &ActivityHandler{}
}

// GetActivities handles GET /activities
//
//	@Summary		Get all activities
//	@Description	Get a list of all activities
//	@Tags			activities
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Success		200	{object}	utils.Response{data=[]dto.ActivityDto}
//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/activities [get]
func (h *ActivityHandler) GetActivities(c *gin.Context) {
	// Get activities from the database
	activities, err := models.GetAllActivities(c.Request.Context())
	if err != nil {
		utils.InternalErrorResponse(c, "Error retrieving activities: "+err.Error())
		return
	}

	// Convert to DTOs
	activityDTOs := make([]dto.ActivityDto, len(activities))
	for i, activity := range activities {
		activityDTOs[i] = convertActivityToDTO(&activity)
	}

	utils.SuccessResponse(c, http.StatusOK, activityDTOs)
}

// GetActivityByID handles GET /activities/:id
//
//	@Summary		Get activity by ID
//	@Description	Get an activity by its ID
//	@Tags			activities
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			id	path		string	true	"Activity ID"
//	@Success		200	{object}	utils.Response{data=dto.ActivityDto}
//	@Failure		400	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		404	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/activities/{id} [get]
func (h *ActivityHandler) GetActivityByID(c *gin.Context) {
	// Parse ID from URL
	idStr := c.Param("id")
	id, err := ulid.Parse(idStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid activity ID format")
		return
	}

	// Get activity from the database
	activity, err := models.GetActivityByID(c.Request.Context(), models.FromULID(id))
	if err != nil {
		utils.InternalErrorResponse(c, "Error retrieving activity: "+err.Error())
		return
	}

	if activity == nil {
		utils.NotFoundResponse(c, "Activity not found")
		return
	}

	// Convert to DTO
	activityDTO := convertActivityToDTO(activity)

	utils.SuccessResponse(c, http.StatusOK, activityDTO)
}

// CreateActivity handles POST /activities
//
//	@Summary		Create a new activity
//	@Description	Create a new activity
//	@Tags			activities
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			activity	body		dto.ActivityCreateDto	true	"Activity data"
//	@Success		201			{object}	utils.Response{data=dto.ActivityDto}
//	@Failure		400			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500			{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/activities [post]
func (h *ActivityHandler) CreateActivity(c *gin.Context) {
	// Parse request body
	var activityCreateDTO dto.ActivityCreateDto
	if err := c.ShouldBindJSON(&activityCreateDTO); err != nil {
		utils.BadRequestResponse(c, "Invalid request body: "+err.Error())
		return
	}

	// Convert DTO to model
	activityCreate := convertCreateActivityDTOToModel(activityCreateDTO)

	// Create activity in the database
	activity, err := models.CreateActivity(c.Request.Context(), activityCreate)
	if err != nil {
		utils.InternalErrorResponse(c, "Error creating activity: "+err.Error())
		return
	}

	// Convert to DTO
	activityDTO := convertActivityToDTO(activity)

	utils.SuccessResponse(c, http.StatusCreated, activityDTO)
}

// UpdateActivity handles PUT /activities/:id
//
//	@Summary		Update an activity
//	@Description	Update an existing activity
//	@Tags			activities
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			id			path		string					true	"Activity ID"
//	@Param			activity	body		dto.ActivityUpdateDto	true	"Activity data"
//	@Success		200			{object}	utils.Response{data=dto.ActivityDto}
//	@Failure		400			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		404			{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500			{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/activities/{id} [put]
func (h *ActivityHandler) UpdateActivity(c *gin.Context) {
	// Parse ID from URL
	idStr := c.Param("id")
	id, err := ulid.Parse(idStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid activity ID format")
		return
	}

	// Parse request body
	var activityUpdateDTO dto.ActivityUpdateDto
	if err := c.ShouldBindJSON(&activityUpdateDTO); err != nil {
		utils.BadRequestResponse(c, "Invalid request body: "+err.Error())
		return
	}

	// Set ID from URL
	activityUpdateDTO.ID = id.String()

	// Convert DTO to model
	activityUpdate := convertUpdateActivityDTOToModel(activityUpdateDTO)

	// Update activity in the database
	activity, err := models.UpdateActivity(c.Request.Context(), activityUpdate)
	if err != nil {
		utils.InternalErrorResponse(c, "Error updating activity: "+err.Error())
		return
	}

	if activity == nil {
		utils.NotFoundResponse(c, "Activity not found")
		return
	}

	// Convert to DTO
	activityDTO := convertActivityToDTO(activity)

	utils.SuccessResponse(c, http.StatusOK, activityDTO)
}

// DeleteActivity handles DELETE /activities/:id
//
//	@Summary		Delete an activity
//	@Description	Delete an activity by its ID
//	@Tags			activities
//	@Accept			json
//	@Produce		json
//	@Security		BearerAuth
//	@Param			id	path		string	true	"Activity ID"
//	@Success		204	{object}	utils.Response
//	@Failure		400	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
//	@Router			/activities/{id} [delete]
func (h *ActivityHandler) DeleteActivity(c *gin.Context) {
	// Parse ID from URL
	idStr := c.Param("id")
	id, err := ulid.Parse(idStr)
	if err != nil {
		utils.BadRequestResponse(c, "Invalid activity ID format")
		return
	}

	// Delete activity from the database
	err = models.DeleteActivity(c.Request.Context(), models.FromULID(id))
	if err != nil {
		utils.InternalErrorResponse(c, "Error deleting activity: "+err.Error())
		return
	}

	utils.SuccessResponse(c, http.StatusNoContent, nil)
}

// Helper functions for DTO conversion

func convertActivityToDTO(activity *models.Activity) dto.ActivityDto {
	return dto.ActivityDto{
		ID:          activity.ID.String(),
		CreatedAt:   activity.CreatedAt,
		UpdatedAt:   activity.UpdatedAt,
		Name:        activity.Name,
		BillingRate: activity.BillingRate,
	}
}

func convertCreateActivityDTOToModel(dto dto.ActivityCreateDto) models.ActivityCreate {
	return models.ActivityCreate{
		Name:        dto.Name,
		BillingRate: dto.BillingRate,
	}
}

func convertUpdateActivityDTOToModel(dto dto.ActivityUpdateDto) models.ActivityUpdate {
	id, _ := ulid.Parse(dto.ID)
	update := models.ActivityUpdate{
		ID: models.FromULID(id),
	}

	if dto.Name != nil {
		update.Name = dto.Name
	}

	if dto.BillingRate != nil {
		update.BillingRate = dto.BillingRate
	}

	return update
}