package handler

import (
	"apskel-pos-be/internal/appcontext"
	"apskel-pos-be/internal/util"
	"strconv"
	"time"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/contract"
	"apskel-pos-be/internal/logger"
	"apskel-pos-be/internal/service"
	"apskel-pos-be/internal/validator"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
)

type PurchaseOrderHandler struct {
	purchaseOrderService   service.PurchaseOrderService
	purchaseOrderValidator validator.PurchaseOrderValidator
}

func NewPurchaseOrderHandler(
	purchaseOrderService service.PurchaseOrderService,
	purchaseOrderValidator validator.PurchaseOrderValidator,
) *PurchaseOrderHandler {
	return &PurchaseOrderHandler{
		purchaseOrderService:   purchaseOrderService,
		purchaseOrderValidator: purchaseOrderValidator,
	}
}

func (h *PurchaseOrderHandler) CreatePurchaseOrder(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	var req contract.CreatePurchaseOrderRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		logger.FromContext(c.Request.Context()).WithError(err).Error("PurchaseOrderHandler::CreatePurchaseOrder -> request binding failed")
		validationResponseError := contract.NewResponseError(constants.MissingFieldErrorCode, constants.RequestEntity, err.Error())
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::CreatePurchaseOrder")
		return
	}

	validationError, validationErrorCode := h.purchaseOrderValidator.ValidateCreatePurchaseOrderRequest(&req)
	if validationError != nil {
		validationResponseError := contract.NewResponseError(validationErrorCode, constants.RequestEntity, validationError.Error())
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::CreatePurchaseOrder")
		return
	}

	poResponse := h.purchaseOrderService.CreatePurchaseOrder(ctx, contextInfo, &req)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::CreatePurchaseOrder -> Failed to create purchase order from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::CreatePurchaseOrder")
}

func (h *PurchaseOrderHandler) UpdatePurchaseOrder(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	poIDStr := c.Param("id")
	poID, err := uuid.Parse(poIDStr)
	if err != nil {
		logger.FromContext(ctx).WithError(err).Error("PurchaseOrderHandler::UpdatePurchaseOrder -> Invalid purchase order ID")
		validationResponseError := contract.NewResponseError(constants.MalformedFieldErrorCode, constants.RequestEntity, "Invalid purchase order ID")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::UpdatePurchaseOrder")
		return
	}

	var req contract.UpdatePurchaseOrderRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		logger.FromContext(ctx).WithError(err).Error("PurchaseOrderHandler::UpdatePurchaseOrder -> request binding failed")
		validationResponseError := contract.NewResponseError(constants.MissingFieldErrorCode, constants.RequestEntity, "Invalid request body")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::UpdatePurchaseOrder")
		return
	}

	validationError, validationErrorCode := h.purchaseOrderValidator.ValidateUpdatePurchaseOrderRequest(&req)
	if validationError != nil {
		validationResponseError := contract.NewResponseError(validationErrorCode, constants.RequestEntity, validationError.Error())
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::UpdatePurchaseOrder")
		return
	}

	poResponse := h.purchaseOrderService.UpdatePurchaseOrder(ctx, contextInfo, poID, &req)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::UpdatePurchaseOrder -> Failed to update purchase order from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::UpdatePurchaseOrder")
}

func (h *PurchaseOrderHandler) DeletePurchaseOrder(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	poIDStr := c.Param("id")
	poID, err := uuid.Parse(poIDStr)
	if err != nil {
		logger.FromContext(ctx).WithError(err).Error("PurchaseOrderHandler::DeletePurchaseOrder -> Invalid purchase order ID")
		validationResponseError := contract.NewResponseError(constants.MalformedFieldErrorCode, constants.RequestEntity, "Invalid purchase order ID")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::DeletePurchaseOrder")
		return
	}

	poResponse := h.purchaseOrderService.DeletePurchaseOrder(ctx, contextInfo, poID)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::DeletePurchaseOrder -> Failed to delete purchase order from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::DeletePurchaseOrder")
}

func (h *PurchaseOrderHandler) GetPurchaseOrder(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	poIDStr := c.Param("id")
	poID, err := uuid.Parse(poIDStr)
	if err != nil {
		logger.FromContext(ctx).WithError(err).Error("PurchaseOrderHandler::GetPurchaseOrder -> Invalid purchase order ID")
		validationResponseError := contract.NewResponseError(constants.MalformedFieldErrorCode, constants.RequestEntity, "Invalid purchase order ID")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::GetPurchaseOrder")
		return
	}

	poResponse := h.purchaseOrderService.GetPurchaseOrderByID(ctx, contextInfo, poID)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::GetPurchaseOrder -> Failed to get purchase order from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::GetPurchaseOrder")
}

func (h *PurchaseOrderHandler) ListPurchaseOrders(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	req := &contract.ListPurchaseOrdersRequest{
		Page:  1,
		Limit: 10,
	}

	// Parse query parameters
	if pageStr := c.Query("page"); pageStr != "" {
		if page, err := strconv.Atoi(pageStr); err == nil {
			req.Page = page
		}
	}

	if limitStr := c.Query("limit"); limitStr != "" {
		if limit, err := strconv.Atoi(limitStr); err == nil {
			req.Limit = limit
		}
	}

	if search := c.Query("search"); search != "" {
		req.Search = search
	}

	if status := c.Query("status"); status != "" {
		req.Status = status
	}

	if vendorIDStr := c.Query("vendor_id"); vendorIDStr != "" {
		if vendorID, err := uuid.Parse(vendorIDStr); err == nil {
			req.VendorID = &vendorID
		}
	}

	if startDateStr := c.Query("start_date"); startDateStr != "" {
		if startDate, err := time.Parse("2006-01-02", startDateStr); err == nil {
			req.StartDate = &startDate
		}
	}

	if endDateStr := c.Query("end_date"); endDateStr != "" {
		if endDate, err := time.Parse("2006-01-02", endDateStr); err == nil {
			req.EndDate = &endDate
		}
	}

	validationError, validationErrorCode := h.purchaseOrderValidator.ValidateListPurchaseOrdersRequest(req)
	if validationError != nil {
		validationResponseError := contract.NewResponseError(validationErrorCode, constants.RequestEntity, validationError.Error())
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::ListPurchaseOrders")
		return
	}

	poResponse := h.purchaseOrderService.ListPurchaseOrders(ctx, contextInfo, req)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::ListPurchaseOrders -> Failed to list purchase orders from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::ListPurchaseOrders")
}

func (h *PurchaseOrderHandler) GetPurchaseOrdersByStatus(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	status := c.Param("status")
	if status == "" {
		validationResponseError := contract.NewResponseError(constants.MissingFieldErrorCode, constants.RequestEntity, "Status parameter is required")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::GetPurchaseOrdersByStatus")
		return
	}

	poResponse := h.purchaseOrderService.GetPurchaseOrdersByStatus(ctx, contextInfo, status)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::GetPurchaseOrdersByStatus -> Failed to get purchase orders by status from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::GetPurchaseOrdersByStatus")
}

func (h *PurchaseOrderHandler) GetOverduePurchaseOrders(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	poResponse := h.purchaseOrderService.GetOverduePurchaseOrders(ctx, contextInfo)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::GetOverduePurchaseOrders -> Failed to get overdue purchase orders from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::GetOverduePurchaseOrders")
}

func (h *PurchaseOrderHandler) UpdatePurchaseOrderStatus(c *gin.Context) {
	ctx := c.Request.Context()
	contextInfo := appcontext.FromGinContext(ctx)

	poIDStr := c.Param("id")
	poID, err := uuid.Parse(poIDStr)
	if err != nil {
		logger.FromContext(ctx).WithError(err).Error("PurchaseOrderHandler::UpdatePurchaseOrderStatus -> Invalid purchase order ID")
		validationResponseError := contract.NewResponseError(constants.MalformedFieldErrorCode, constants.RequestEntity, "Invalid purchase order ID")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::UpdatePurchaseOrderStatus")
		return
	}

	status := c.Param("status")
	if status == "" {
		validationResponseError := contract.NewResponseError(constants.MissingFieldErrorCode, constants.RequestEntity, "Status parameter is required")
		util.HandleResponse(c.Writer, c.Request, contract.BuildErrorResponse([]*contract.ResponseError{validationResponseError}), "PurchaseOrderHandler::UpdatePurchaseOrderStatus")
		return
	}

	poResponse := h.purchaseOrderService.UpdatePurchaseOrderStatus(ctx, contextInfo, poID, status)
	if poResponse.HasErrors() {
		errorResp := poResponse.GetErrors()[0]
		logger.FromContext(ctx).WithError(errorResp).Error("PurchaseOrderHandler::UpdatePurchaseOrderStatus -> Failed to update purchase order status from service")
	}

	util.HandleResponse(c.Writer, c.Request, poResponse, "PurchaseOrderHandler::UpdatePurchaseOrderStatus")
}