package handlers

import (
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
	"github.com/shopspring/decimal"
	"go.uber.org/zap"

	"rmser/internal/services/drafts"
	"rmser/pkg/logger"
)

type DraftsHandler struct {
	service *drafts.Service
}

func NewDraftsHandler(service *drafts.Service) *DraftsHandler {
	return &DraftsHandler{service: service}
}

func (h *DraftsHandler) GetDraft(c *gin.Context) {
	userID := c.MustGet("userID").(uuid.UUID)
	idStr := c.Param("id")
	id, err := uuid.Parse(idStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
		return
	}

	draft, err := h.service.GetDraft(id, userID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "draft not found"})
		return
	}
	c.JSON(http.StatusOK, draft)
}

func (h *DraftsHandler) GetDictionaries(c *gin.Context) {
	userID := c.MustGet("userID").(uuid.UUID)

	data, err := h.service.GetDictionaries(userID)
	if err != nil {
		logger.Log.Error("GetDictionaries error", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, data)
}

func (h *DraftsHandler) GetStores(c *gin.Context) {
	userID := c.MustGet("userID").(uuid.UUID)

	dict, err := h.service.GetDictionaries(userID)
	if err != nil {
		logger.Log.Error("GetStores error", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, dict["stores"])
}

// UpdateItemDTO обновлен: float64 -> *float64, добавлен edited_field
type UpdateItemDTO struct {
	ProductID   *string  `json:"product_id"`
	ContainerID *string  `json:"container_id"`
	Quantity    *float64 `json:"quantity"`
	Price       *float64 `json:"price"`
	Sum         *float64 `json:"sum"`
	EditedField string   `json:"edited_field"` // "quantity", "price", "sum"
}

func (h *DraftsHandler) AddDraftItem(c *gin.Context) {
	draftID, err := uuid.Parse(c.Param("id"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid draft id"})
		return
	}

	item, err := h.service.AddItem(draftID)
	if err != nil {
		logger.Log.Error("Failed to add item", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, item)
}

func (h *DraftsHandler) DeleteDraftItem(c *gin.Context) {
	draftID, err := uuid.Parse(c.Param("id"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid draft id"})
		return
	}
	itemID, err := uuid.Parse(c.Param("itemId"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid item id"})
		return
	}

	newTotal, err := h.service.DeleteItem(draftID, itemID)
	if err != nil {
		logger.Log.Error("Failed to delete item", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"status":    "deleted",
		"id":        itemID.String(),
		"total_sum": newTotal,
	})
}

// UpdateItem обновлен
func (h *DraftsHandler) UpdateItem(c *gin.Context) {
	draftID, _ := uuid.Parse(c.Param("id"))
	itemID, _ := uuid.Parse(c.Param("itemId"))

	var req UpdateItemDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var pID *uuid.UUID
	if req.ProductID != nil && *req.ProductID != "" {
		if uid, err := uuid.Parse(*req.ProductID); err == nil {
			pID = &uid
		}
	}

	var cID *uuid.UUID
	if req.ContainerID != nil {
		if *req.ContainerID == "" {
			// Сброс фасовки
			empty := uuid.Nil
			cID = &empty
		} else if uid, err := uuid.Parse(*req.ContainerID); err == nil {
			cID = &uid
		}
	}

	qty := decimal.Zero
	if req.Quantity != nil {
		qty = decimal.NewFromFloat(*req.Quantity)
	}

	price := decimal.Zero
	if req.Price != nil {
		price = decimal.NewFromFloat(*req.Price)
	}

	sum := decimal.Zero
	if req.Sum != nil {
		sum = decimal.NewFromFloat(*req.Sum)
	}

	// Дефолт, если фронт не прислал (для совместимости)
	editedField := req.EditedField
	if editedField == "" {
		if req.Sum != nil {
			editedField = "sum"
		} else if req.Price != nil {
			editedField = "price"
		} else {
			editedField = "quantity"
		}
	}

	if err := h.service.UpdateItem(draftID, itemID, pID, cID, qty, price, sum, editedField); err != nil {
		logger.Log.Error("Failed to update item", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"status": "updated"})
}

type CommitRequestDTO struct {
	DateIncoming   string `json:"date_incoming"` // YYYY-MM-DD
	StoreID        string `json:"store_id"`
	SupplierID     string `json:"supplier_id"`
	Comment        string `json:"comment"`
	IncomingDocNum string `json:"incoming_doc_num"`
}

func (h *DraftsHandler) CommitDraft(c *gin.Context) {
	userID := c.MustGet("userID").(uuid.UUID)
	draftID, err := uuid.Parse(c.Param("id"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid draft id"})
		return
	}

	var req CommitRequestDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	date, err := time.Parse("2006-01-02", req.DateIncoming)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid date format"})
		return
	}
	storeID, err := uuid.Parse(req.StoreID)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid store id"})
		return
	}
	supplierID, err := uuid.Parse(req.SupplierID)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid supplier id"})
		return
	}

	if err := h.service.UpdateDraftHeader(draftID, &storeID, &supplierID, date, req.Comment, req.IncomingDocNum); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to update header: " + err.Error()})
		return
	}

	docNum, err := h.service.CommitDraft(draftID, userID)
	if err != nil {
		logger.Log.Error("Commit failed", zap.Error(err))
		c.JSON(http.StatusBadGateway, gin.H{"error": "RMS error: " + err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"status": "completed", "document_number": docNum})
}

type AddContainerRequestDTO struct {
	ProductID string  `json:"product_id" binding:"required"`
	Name      string  `json:"name" binding:"required"`
	Count     float64 `json:"count" binding:"required,gt=0"`
}

func (h *DraftsHandler) AddContainer(c *gin.Context) {
	userID := c.MustGet("userID").(uuid.UUID)

	var req AddContainerRequestDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	pID, err := uuid.Parse(req.ProductID)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid product_id"})
		return
	}

	countDec := decimal.NewFromFloat(req.Count)

	newID, err := h.service.CreateProductContainer(userID, pID, req.Name, countDec)
	if err != nil {
		logger.Log.Error("Failed to create container", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"status": "created", "container_id": newID.String()})
}

func (h *DraftsHandler) GetDrafts(c *gin.Context) {
	userID := c.MustGet("userID").(uuid.UUID)

	fromStr := c.DefaultQuery("from", time.Now().AddDate(0, 0, -30).Format("2006-01-02"))
	toStr := c.DefaultQuery("to", time.Now().Format("2006-01-02"))

	from, _ := time.Parse("2006-01-02", fromStr)
	to, _ := time.Parse("2006-01-02", toStr)
	to = to.Add(23*time.Hour + 59*time.Minute + 59*time.Second)

	list, err := h.service.GetUnifiedList(userID, from, to)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, list)
}

func (h *DraftsHandler) DeleteDraft(c *gin.Context) {
	idStr := c.Param("id")
	id, err := uuid.Parse(idStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
		return
	}

	newStatus, err := h.service.DeleteDraft(id)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"status": newStatus, "id": id.String()})
}

// ReorderItems изменяет порядок позиции в черновике
func (h *DraftsHandler) ReorderItems(c *gin.Context) {
	type ReorderRequest struct {
		ItemID   uuid.UUID `json:"item_id" binding:"required"`
		NewOrder int       `json:"new_order" binding:"required"`
	}

	var req ReorderRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Получаем draftID из параметров пути
	draftID, err := uuid.Parse(c.Param("id"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid draft id"})
		return
	}

	if err := h.service.ReorderItem(draftID, req.ItemID, req.NewOrder); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"success": true})
}