/**
 * Purchase Orders API Client
 * Handles all API calls for purchase orders
 *
 * UPDATED in Sprint 3: Purchase orders now managed by Procurement Service
 * Previously: Suppliers Service (/tenants/{id}/purchase-orders)
 * Now: Procurement Service (/tenants/{id}/procurement/purchase-orders)
 */

import { apiClient } from '../client';

export type PurchaseOrderStatus =
  | 'DRAFT'
  | 'PENDING_APPROVAL'
  | 'APPROVED'
  | 'SENT_TO_SUPPLIER'
  | 'CONFIRMED'
  | 'RECEIVED'
  | 'COMPLETED'
  | 'CANCELLED'
  | 'DISPUTED';

export type PurchaseOrderPriority = 'urgent' | 'high' | 'normal' | 'low';

export interface PurchaseOrderItem {
  id: string;
  inventory_product_id: string;
  product_code?: string;
  product_name?: string;
  ordered_quantity: number;
  unit_of_measure: string;
  unit_price: string; // Decimal as string
  line_total: string; // Decimal as string
  received_quantity: number;
  remaining_quantity: number;
  quality_requirements?: string;
  item_notes?: string;
}

export interface SupplierSummary {
  id: string;
  name: string;
  supplier_code: string;
  supplier_type: string;
  status: string;
  contact_person?: string;
  email?: string;
  phone?: string;
}

export interface PurchaseOrderSummary {
  id: string;
  po_number: string;
  supplier_id: string;
  supplier_name?: string;
  status: PurchaseOrderStatus;
  priority: PurchaseOrderPriority;
  order_date: string;
  required_delivery_date?: string;
  total_amount: string; // Decimal as string
  currency: string;
  created_at: string;
  reasoning_data?: any; // AI reasoning data for dashboard display
  ai_reasoning_summary?: string; // Human-readable summary
}

export interface PurchaseOrderDetail extends PurchaseOrderSummary {
  reference_number?: string;
  estimated_delivery_date?: string;

  // Financial information
  subtotal: string;
  tax_amount: string;
  shipping_cost: string;
  discount_amount: string;

  // Delivery information
  delivery_address?: string;
  delivery_instructions?: string;
  delivery_contact?: string;
  delivery_phone?: string;

  // Approval workflow
  requires_approval: boolean;
  approved_by?: string;
  approved_at?: string;
  rejection_reason?: string;

  // Communication tracking
  sent_to_supplier_at?: string;
  supplier_confirmation_date?: string;
  supplier_reference?: string;

  // Additional information
  notes?: string;
  internal_notes?: string;
  terms_and_conditions?: string;

  // Audit fields
  updated_at: string;
  created_by: string;
  updated_by: string;

  // Related data
  supplier?: SupplierSummary;
  items?: PurchaseOrderItem[];
}

export interface PurchaseOrderSearchParams {
  supplier_id?: string;
  status?: PurchaseOrderStatus;
  priority?: PurchaseOrderPriority;
  date_from?: string; // YYYY-MM-DD
  date_to?: string; // YYYY-MM-DD
  search_term?: string;
  limit?: number;
  skip?: number;  // ✅ Changed from "offset" to "skip" to match backend
}

export interface PurchaseOrderUpdateData {
  status?: PurchaseOrderStatus;
  priority?: PurchaseOrderPriority;
  notes?: string;
  rejection_reason?: string;
  internal_notes?: string;
}

export interface PurchaseOrderItemCreate {
  inventory_product_id: string;
  ordered_quantity: number;
  unit_price: string; // Decimal as string
  unit_of_measure: string;
  quality_requirements?: string;
  item_notes?: string;
}

export interface PurchaseOrderCreateData {
  supplier_id: string;
  required_delivery_date?: string;
  priority?: PurchaseOrderPriority;
  tax_amount?: number;
  shipping_cost?: number;
  discount_amount?: number;
  notes?: string;
  procurement_plan_id?: string;
  items: PurchaseOrderItemCreate[];
}

/**
 * Create a new purchase order
 */
export async function createPurchaseOrder(
  tenantId: string,
  data: PurchaseOrderCreateData
): Promise<PurchaseOrderDetail> {
  return apiClient.post<PurchaseOrderDetail>(
    `/tenants/${tenantId}/procurement/purchase-orders`,
    data
  );
}

/**
 * Get list of purchase orders with optional filters
 */
export async function listPurchaseOrders(
  tenantId: string,
  params?: PurchaseOrderSearchParams
): Promise<PurchaseOrderSummary[]> {
  return apiClient.get<PurchaseOrderSummary[]>(
    `/tenants/${tenantId}/procurement/purchase-orders`,
    { params }
  );
}

/**
 * Get purchase orders by status
 */
export async function getPurchaseOrdersByStatus(
  tenantId: string,
  status: PurchaseOrderStatus,
  limit: number = 50
): Promise<PurchaseOrderSummary[]> {
  return listPurchaseOrders(tenantId, { status, limit });
}

/**
 * Get pending approval purchase orders
 */
export async function getPendingApprovalPurchaseOrders(
  tenantId: string,
  limit: number = 50
): Promise<PurchaseOrderSummary[]> {
  return getPurchaseOrdersByStatus(tenantId, 'PENDING_APPROVAL', limit);
}

/**
 * Get a single purchase order by ID with full details
 */
export async function getPurchaseOrder(
  tenantId: string,
  poId: string
): Promise<PurchaseOrderDetail> {
  return apiClient.get<PurchaseOrderDetail>(
    `/tenants/${tenantId}/procurement/purchase-orders/${poId}`
  );
}

/**
 * Update purchase order
 */
export async function updatePurchaseOrder(
  tenantId: string,
  poId: string,
  data: PurchaseOrderUpdateData
): Promise<PurchaseOrderDetail> {
  return apiClient.put<PurchaseOrderDetail>(
    `/tenants/${tenantId}/procurement/purchase-orders/${poId}`,
    data
  );
}

/**
 * Approve a purchase order
 */
export async function approvePurchaseOrder(
  tenantId: string,
  poId: string,
  notes?: string
): Promise<PurchaseOrderDetail> {
  return apiClient.post<PurchaseOrderDetail>(
    `/tenants/${tenantId}/procurement/purchase-orders/${poId}/approve`,
    {
      action: 'approve',
      notes: notes || 'Approved from dashboard'
    }
  );
}

/**
 * Reject a purchase order
 */
export async function rejectPurchaseOrder(
  tenantId: string,
  poId: string,
  reason: string
): Promise<PurchaseOrderDetail> {
  return apiClient.post<PurchaseOrderDetail>(
    `/tenants/${tenantId}/procurement/purchase-orders/${poId}/approve`,
    {
      action: 'reject',
      notes: reason
    }
  );
}

/**
 * Bulk approve purchase orders
 */
export async function bulkApprovePurchaseOrders(
  tenantId: string,
  poIds: string[],
  notes?: string
): Promise<PurchaseOrderDetail[]> {
  const approvalPromises = poIds.map(poId =>
    approvePurchaseOrder(tenantId, poId, notes)
  );
  return Promise.all(approvalPromises);
}

/**
 * Delete purchase order
 */
export async function deletePurchaseOrder(
  tenantId: string,
  poId: string
): Promise<{ message: string }> {
  return apiClient.delete<{ message: string }>(
    `/tenants/${tenantId}/procurement/purchase-orders/${poId}`
  );
}

// ================================================================
// DELIVERY TYPES AND METHODS
// ================================================================

export interface DeliveryItemInput {
  purchase_order_item_id: string;
  inventory_product_id: string;
  ordered_quantity: number;
  delivered_quantity: number;
  accepted_quantity: number;
  rejected_quantity: number;
  batch_lot_number?: string;
  expiry_date?: string;
  quality_grade?: string;
  quality_issues?: string;
  rejection_reason?: string;
  item_notes?: string;
}

export interface CreateDeliveryInput {
  purchase_order_id: string;
  supplier_id: string;
  supplier_delivery_note?: string;
  scheduled_date?: string;
  estimated_arrival?: string;
  carrier_name?: string;
  tracking_number?: string;
  inspection_passed?: boolean;
  inspection_notes?: string;
  notes?: string;
  items: DeliveryItemInput[];
}

export interface DeliveryResponse {
  id: string;
  tenant_id: string;
  purchase_order_id: string;
  supplier_id: string;
  delivery_number: string;
  status: string;
  scheduled_date?: string;
  estimated_arrival?: string;
  actual_arrival?: string;
  completed_at?: string;
  inspection_passed?: boolean;
  inspection_notes?: string;
  notes?: string;
  created_at: string;
  updated_at: string;
}

/**
 * Create delivery for purchase order
 */
export async function createDelivery(
  tenantId: string,
  poId: string,
  deliveryData: CreateDeliveryInput
): Promise<DeliveryResponse> {
  return apiClient.post<DeliveryResponse>(
    `/tenants/${tenantId}/procurement/purchase-orders/${poId}/deliveries`,
    deliveryData
  );
}