// Schema Evolution Demo
// Demonstrates version tracking using runtime Schema operations

// ============================================================
// PART 1: Runtime Schema Operations
// ============================================================

// Create versioned values at runtime
let user1 = Schema.versioned("User", 1, "Alice")
let user2 = Schema.versioned("User", 2, "Bob")

// Check versions
let v1 = Schema.getVersion(user1)  // 1
let v2 = Schema.getVersion(user2)  // 2

// Migrate to newer version (upgrade)
let upgraded = Schema.migrate(user1, 2)
let upgradedVersion = Schema.getVersion(upgraded)  // 2

// ============================================================
// PART 2: Practical Example - API Versioning
// ============================================================

// Simulate different API response versions
fn createResponseV1(data: String): { version: Int, payload: String } =
    { version: 1, payload: data }

fn createResponseV2(data: String, timestamp: Int): { version: Int, payload: String, meta: { ts: Int } } =
    { version: 2, payload: data, meta: { ts: timestamp } }

// Version-aware processing
fn getPayload(response: { version: Int, payload: String }): String =
    response.payload

let resp1 = createResponseV1("Hello")
let resp2 = createResponseV2("World", 1234567890)

let payload1 = getPayload(resp1)
let payload2 = resp2.payload

// ============================================================
// RESULTS
// ============================================================

fn main(): Unit with {Console} = {
    Console.print("=== Schema Evolution Demo ===")
    Console.print("")
    Console.print("Part 1: Runtime schema operations")
    Console.print("  User v1 version: " + toString(v1))
    Console.print("  User v2 version: " + toString(v2))
    Console.print("  After upgrade: " + toString(upgradedVersion))
    Console.print("")
    Console.print("Part 2: API versioning")
    Console.print("  Response v1 payload: " + payload1)
    Console.print("  Response v2 payload: " + payload2)
}

let output = run main() with {}