// ============================================================================
// 079 — Data Merge (Multi-Source Join)
// ============================================================================
// Combine data from multiple sources using joins.
//
// Run:   soma run 079_data_merge.cell run
// Expect:
//   === Merged Employee Report ===
//   Alice (Eng, West): salary=120, rating=4
//   Bob (Sales, East): salary=85, rating=3
//   Carol (Eng, West): salary=110, rating=5

cell DataMerge {

    on run() {
        // Source 1: employee roster
        let employees = list(
            map("id", 1, "name", "Alice", "dept", "Eng"),
            map("id", 2, "name", "Bob", "dept", "Sales"),
            map("id", 3, "name", "Carol", "dept", "Eng")
        )

        // Source 2: compensation data
        let compensation = list(
            map("id", 1, "salary", 120, "bonus", 15),
            map("id", 2, "salary", 85, "bonus", 10),
            map("id", 3, "salary", 110, "bonus", 12)
        )

        // Source 3: performance reviews
        let reviews = list(
            map("id", 1, "rating", 4, "region", "West"),
            map("id", 2, "rating", 3, "region", "East"),
            map("id", 3, "rating", 5, "region", "West")
        )

        // Multi-join: employees + compensation + reviews
        let merged = employees
            |> join(compensation, "id")
            |> join(reviews, "id")

        print("=== Merged Employee Report ===")
        for row in merged {
            print("{row.name} ({row.dept}, {row.region}): salary={row.salary}, rating={row.rating}")
        }

        return "done"
    }
}