Csv

import {
  inferValueType,
  inferCsvTypes,
  isTypeCompatible,
} from "@/packages/resource-framework";
```typescript

### inferValueType

- **Signature**: `(value: unknown) => "null" | "number" | "boolean" | "date" | "string"`
- **Behavior**:
  - Returns `"null"` for `null`, `undefined`, or empty string
  - Detects native numbers, booleans, and `Date` instances
  - Detects ISO-like date strings: `YYYY-MM-DD` optionally with time
  - Detects numeric strings (integer/decimal, with optional sign)
  - Falls back to `"string"`

```typescript
inferValueType(null); // "null"
inferValueType(42); // "number"
inferValueType("2024-06-01"); // "date"
inferValueType("-12.5"); // "number"
inferValueType("hello"); // "string"
```typescript

### inferCsvTypes

- **Signature**: `(rows: Array<Record<string, any>>, headers: string[]) => Record<string, string>`
- **Behavior**:
  - Samples up to the first 200 rows
  - Tallies detected types per header using `inferValueType`
  - Returns the most frequent type per header, or `"unknown"` if no data

```typescript
const headers = ["id", "created_at", "active", "amount"];
const rows = [
  { id: "1", created_at: "2024-01-01", active: "true", amount: "10.50" },
  { id: 2, created_at: "2024-01-02", active: false, amount: 99 },
];
const types = inferCsvTypes(rows, headers);
// Example:
// { id: "number", created_at: "date", active: "boolean", amount: "number" }
```typescript

### isTypeCompatible

- **Signature**: `(csvType?: string, tableType?: string) => boolean`
- **Behavior**:
  - Permissive when CSV type is `"unknown"`/`"null"` or table type is missing
  - Maps CSV `"number"` to DB types matching `/int|numeric|decimal|double|real|float|number/`
  - Maps CSV `"boolean"` to DB types matching `/bool/`
  - Maps CSV `"date"` to DB types matching `/date|timestamp|time/`
  - `"string"` is allowed for any table type

```typescript
isTypeCompatible("number", "integer"); // true
isTypeCompatible("date", "timestamp with time zone"); // true
isTypeCompatible("boolean", "text"); // false
isTypeCompatible("string", "jsonb"); // true
```typescript

### Example: building column mappings

```typescript
const csvTypes = inferCsvTypes(csvRows, csvHeaders);
const compatibleColumns = destinationColumns.filter((c) =>
  isTypeCompatible(csvTypes["amount"], destinationTypes[c]),
);
```typescript