feat(core): init filter types

packages/core/filter/operators.ts

@@ -0,0 +1,44 @@
+import { z } from 'zod'
+import type { INumberFieldValue } from '../field/number-field.type'
+import { numberFieldValue } from '../field/number-field.type'
+import type { ITextFieldValue } from '../field/text-field.type'
+import { textFieldValue } from '../field/text-field.type'
+
+type Filter<TSchema extends Record<string, ComparableFieldValue> = Record<string, ComparableFieldValue>> =
+  | RootOperator
+  | TSchema
+  | Record<string, Operator>
+
+export interface RootOperator {
+  $and?: Filter[]
+  $or?: Filter[]
+}
+
+type ComparableFieldValue = ITextFieldValue | INumberFieldValue
+
+type FieldOperator = {
+  $eq?: ComparableFieldValue
+  $neq?: ComparableFieldValue
+}
+
+export type Operator = ComparableFieldValue | FieldOperator
+
+const $comparableFieldValue: z.ZodOptional<z.ZodType<ComparableFieldValue>> = z
+  .union([textFieldValue, numberFieldValue])
+  .optional()
+
+export const $fieldOperator: z.ZodType<FieldOperator> = z.object({
+  $eq: $comparableFieldValue,
+  $neq: $comparableFieldValue,
+})
+
+export const $filter: z.ZodType<Filter> = z.lazy(() =>
+  z.union([$rootOperator, z.record(z.union([$comparableFieldValue, $fieldOperator]))]),
+)
+export type IFilter = z.infer<typeof $filter>
+
+const $filters = z.array($filter).optional()
+const $rootOperator: z.ZodType<RootOperator> = z.object({
+  $and: $filters,
+  $or: $filters,
+})