import { api } from '@/lib/api'
import type {
  PaginatedResponse,
  PurchaseOrderResponse,
  GrnResponse,
  PurchaseOrderStatus,
  PurchaseReturnResponse,
} from '@/types/api'

import type { PageParams } from './master'

// ─── Purchase Orders ──────────────────────────────────────────────────────────

export interface PurchaseOrderItemBody {
  itemId: string
  quantity: number
  unitCost: number
}

export interface PurchaseOrderBody {
  supplierId: string
  items: PurchaseOrderItemBody[]
  // TEMPORARY: required while auth doesn't resolve a logged-in user server-side — see testbug.md #28.
  createdByUserId: string
}

export interface UpdatePurchaseOrderLineBody {
  purchaseOrderItemId?: string
  itemId: string
  quantity: number
  unitCost: number
}

export interface UpdatePurchaseOrderBody {
  items: UpdatePurchaseOrderLineBody[]
}

export interface PurchaseOrderListParams extends PageParams {
  supplierId?: string
  status?: PurchaseOrderStatus
}

export const purchaseOrders = {
  list: (params?: PurchaseOrderListParams) =>
    api.get<PaginatedResponse<PurchaseOrderResponse>>('/purchase-orders', { params }).then(r => r.data),

  get: (id: string) =>
    api.get<PurchaseOrderResponse>(`/purchase-orders/${id}`).then(r => r.data),

  create: (body: PurchaseOrderBody) =>
    api.post<PurchaseOrderResponse>('/purchase-orders', body).then(r => r.data),

  update: (id: string, body: UpdatePurchaseOrderBody) =>
    api.put<PurchaseOrderResponse>(`/purchase-orders/${id}`, body).then(r => r.data),

  cancel: (id: string, reason: string) =>
    api.post<PurchaseOrderResponse>(`/purchase-orders/${id}/cancel`, { reason }).then(r => r.data),
}

// ─── Goods Receipts (GRN) ─────────────────────────────────────────────────────

export interface GrnBatchLineBody {
  /** Null for an expiry-only lot (item tracks expiry but not batch numbers). */
  batchNumber: string | null
  expiryDate: string | null
  quantity: number
}

export interface GrnItemBody {
  /** Set for a PO receipt; omitted for a direct receipt (itemId is used instead). */
  purchaseOrderItemId?: string
  /** Set for a direct receipt line. */
  itemId?: string
  acceptedQuantity: number
  rejectedQuantity: number
  /** Only for items with TracksBatches and/or TracksExpiryDate. */
  batches?: GrnBatchLineBody[]
  /** Only for items with TracksSerialNumbers — exactly acceptedQuantity entries. */
  serialNumbers?: string[]
  /** Cost per base-UOM unit. Omitted on a PO line falls back to the PO line's cost. */
  unitCost?: number
  /** Omitted falls back to the GRN-wide percentage. */
  discountPercent?: number
  vatPercent?: number
  /** Free-issue units: stocked but not costed. Serials/batches must cover accepted + free. */
  freeQuantity?: number
}

export interface GrnBody {
  purchaseOrderId: string
  warehouseId: string
  receivedAt: string
  items: GrnItemBody[]
  /** GRN-wide defaults for lines that don't set their own. */
  discountPercent?: number
  vatPercent?: number
  // TEMPORARY: required while auth doesn't resolve a logged-in user server-side — see testbug.md #28.
  receivedByUserId: string
}

export interface DirectGrnBody {
  warehouseId: string
  supplierId?: string
  items: GrnItemBody[]
  discountPercent?: number
  vatPercent?: number
  // TEMPORARY: required while auth doesn't resolve a logged-in user server-side — see testbug.md #28.
  receivedByUserId: string
}

export const grn = {
  list: (params?: PageParams & { purchaseOrderId?: string }) =>
    api.get<PaginatedResponse<GrnResponse>>('/goods-receipts', { params }).then(r => r.data),

  get: (id: string) =>
    api.get<GrnResponse>(`/goods-receipts/${id}`).then(r => r.data),

  create: (body: GrnBody) =>
    api.post<GrnResponse>('/goods-receipts', body).then(r => r.data),

  /** Receive goods with no purchase order. */
  createDirect: (body: DirectGrnBody) =>
    api.post<GrnResponse>('/goods-receipts/direct', body).then(r => r.data),
}

// ─── Purchase Returns ─────────────────────────────────────────────────────────

export interface PurchaseReturnItemBody {
  itemId: string
  quantity: number
}

export interface PurchaseReturnBody {
  reason: string
  items: PurchaseReturnItemBody[]
  // TEMPORARY: required while auth doesn't resolve a logged-in user server-side — see testbug.md #28.
  createdByUserId: string
}

export const purchaseReturns = {
  get: (id: string) =>
    api.get<PurchaseReturnResponse>(`/purchase-returns/${id}`).then(r => r.data),

  listByPurchaseOrder: (purchaseOrderId: string) =>
    api.get<PurchaseReturnResponse[]>(`/purchase-orders/${purchaseOrderId}/returns`).then(r => r.data),

  create: (purchaseOrderId: string, body: PurchaseReturnBody) =>
    api.post<PurchaseReturnResponse>(`/purchase-orders/${purchaseOrderId}/returns`, body).then(r => r.data),
}