fix issues in sales and purchases module.

server/src/models/Bill.js

@@ -37,12 +37,55 @@ export default class Bill extends mixin(TenantModel, [CachableModel]) {
   }
 
   /**
-   * Retrieve the not found bills ids as array.
+   * Relationship mapping.
+   */
+  static get relationMappings() {
+    const Vendor = require('@/models/Vendor');
+    const ItemEntry = require('@/models/ItemEntry');
+
+    return {
+      /**
+       *
+       */
+      vendor: {
+        relation: Model.BelongsToOneRelation,
+        modelClass: this.relationBindKnex(Vendor.default),
+        join: {
+          from: 'bills.vendorId',
+          to: 'vendors.id',
+        },
+      },
+
+      /**
+       * 
+       */
+      entries: {
+        relation: Model.HasManyRelation,
+        modelClass: this.relationBindKnex(ItemEntry.default),
+        join: {
+          from: 'bills.id',
+          to: 'items_entries.referenceId',
+        },
+      },
+    };
+  }
+
+  /**
+   * Retrieve the not found bills ids as array that associated to the given vendor.
    * @param {Array} billsIds 
+   * @param {number} vendorId - 
    * @return {Array}
    */
-  static async getNotFoundBills(billsIds) {
-    const storedBills = await this.tenant().query().whereIn('id', billsIds);
+  static async getNotFoundBills(billsIds, vendorId) {
+    const storedBills = await this.tenant().query()
+      .onBuild((builder) => {
+        builder.whereIn('id', billsIds);
+
+        if (vendorId) {
+          builder.where('vendor_id', vendorId);
+        }
+      });
+      
     const storedBillsIds = storedBills.map((t) => t.id);
 
     const notFoundBillsIds = difference(
@@ -51,4 +94,12 @@ export default class Bill extends mixin(TenantModel, [CachableModel]) {
     );
     return notFoundBillsIds;
   }
+
+  static changePaymentAmount(billId, amount) {
+    const changeMethod = amount > 0 ? 'increment' : 'decrement';
+    return this.tenant()
+      .query()
+      .where('id', billId)
+      [changeMethod]('payment_amount', Math.abs(amount));
+  }
 }