package v1

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"
	"github.com/gochat/gochat/internal/service"
	applogger "github.com/gochat/gochat/pkg/logger"
	"github.com/gochat/gochat/pkg/pagination"
	"github.com/gochat/gochat/pkg/response"
)

// CategoryHandler handles Category CRUD endpoints.
type CategoryHandler struct {
	svc *service.CategoryService
}

func NewCategoryHandler(svc *service.CategoryService) *CategoryHandler {
	return &CategoryHandler{svc: svc}
}

// Create creates a new category.
// POST /api/v1/accounts/:account_id/portals/:portal_id/categories
func (h *CategoryHandler) Create(c *gin.Context) {
	portalID, err := strconv.ParseUint(c.Param("portal_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid portal_id")
		return
	}

	accountID, err := strconv.ParseUint(c.Param("account_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	// Chatwoot: params.require(:category) → {"category": {...}}
	var wrapper struct {
		Category service.CreateCategoryRequest `json:"category"`
	}
	if err := c.ShouldBindJSON(&wrapper); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}
	req := wrapper.Category

	category, err := h.svc.Create(c.Request.Context(), uint(portalID), uint(accountID), &req)
	if err != nil {
		applogger.L().Errorf("Create category: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to create category")
		return
	}

	response.Created(c, category)
}

// Get retrieves a category by ID.
// GET /api/v1/accounts/:account_id/portals/:portal_id/categories/:category_id
func (h *CategoryHandler) Get(c *gin.Context) {
	categoryID, err := strconv.ParseUint(c.Param("category_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid category_id")
		return
	}

	category, err := h.svc.GetByID(c.Request.Context(), uint(categoryID))
	if err != nil {
		applogger.L().Errorf("Get category: %v", err)
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "category not found")
		return
	}

	response.OK(c, category)
}

// Update modifies an existing category.
// PUT /api/v1/accounts/:account_id/portals/:portal_id/categories/:category_id
func (h *CategoryHandler) Update(c *gin.Context) {
	categoryID, err := strconv.ParseUint(c.Param("category_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid category_id")
		return
	}

	// Chatwoot: params.require(:category) → {"category": {...}}
	var wrapper struct {
		Category service.UpdateCategoryRequest `json:"category"`
	}
	if err := c.ShouldBindJSON(&wrapper); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}
	req := wrapper.Category

	category, err := h.svc.Update(c.Request.Context(), uint(categoryID), &req)
	if err != nil {
		applogger.L().Errorf("Update category: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to update category")
		return
	}

	response.OK(c, category)
}

// Delete removes a category.
// DELETE /api/v1/accounts/:account_id/portals/:portal_id/categories/:category_id
func (h *CategoryHandler) Delete(c *gin.Context) {
	categoryID, err := strconv.ParseUint(c.Param("category_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid category_id")
		return
	}

	if err := h.svc.Delete(c.Request.Context(), uint(categoryID)); err != nil {
		applogger.L().Errorf("Delete category: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to delete category")
		return
	}

	response.NoContent(c)
}

// List returns all categories for a portal.
// GET /api/v1/accounts/:account_id/portals/:portal_id/categories
func (h *CategoryHandler) List(c *gin.Context) {
	portalID, err := strconv.ParseUint(c.Param("portal_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid portal_id")
		return
	}

	locale := c.Query("locale")

	pg := pagination.Parse(c)
	categories, count, err := h.svc.ListByPortalID(c.Request.Context(), uint(portalID), locale, pg.Page, pg.PerPage)
	if err != nil {
		applogger.L().Errorf("List categories: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list categories")
		return
	}

	response.OKWithMeta(c, categories, pg.Page, pg.PerPage, count)
}

// Reorder updates the display order of categories.
// POST /api/v1/accounts/:account_id/portals/:portal_id/categories/reorder
func (h *CategoryHandler) Reorder(c *gin.Context) {
	var req reorderRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	positions := make(map[uint]int, len(req.Positions))
	for _, entry := range req.Positions {
		positions[entry.ID] = entry.Position
	}

	if err := h.svc.Reorder(c.Request.Context(), positions); err != nil {
		applogger.L().Errorf("Reorder categories: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to reorder categories")
		return
	}

	response.NoContent(c)
}