sequenceDiagram
    participant Test as UserTest
    participant Wrapped as wrapped_sql()
    participant Parser as SQLParser (sqlglot)
    participant Rewriter as RewriteEngine
    participant StringLit as _string_literal_value (NEW)
    participant Fetch as fetch_url_bytes
    participant DuckDB as DuckDB Connection

    Test->>Wrapped: call wrapped_sql(read_csv("https://..."))
    Wrapped->>Parser: parse SQL to AST
    Parser-->>Wrapped: AST with read_csv Function
    Wrapped->>Rewriter: rewrite_remote_sources(AST)
    Rewriter->>Rewriter: find read_* functions
    Rewriter->>Rewriter: _read_function_source(args[0])

    Note over Rewriter: arg is exp.Column (double-quoted identifier)
    Rewriter->>StringLit: _string_literal_value(exp.Column)
    alt Identifier without table/db/catalog
        StringLit->>StringLit: check quoted identifier
        StringLit-->>Rewriter: "https://datasets.marimo.app/cars.csv"
    else old behavior (Identifier not Literal)
        Rewriter-->>Rewriter: would return None → raise error
    end

    Rewriter->>Rewriter: source is remote (https)
    Note over Rewriter: NEW: rewrite to use fetch_url_bytes
    Rewriter-->>Wrapped: rewritten SQL (fetches URL)
    Wrapped->>Fetch: fetch_url_bytes(url)
    Fetch-->>Wrapped: CSV bytes
    Wrapped->>DuckDB: execute(SELECT FROM read_csv_auto(bytes))
    DuckDB-->>Wrapped: relation
    Wrapped-->>Test: relation rows

    Note over Test,Fetch: Test asserts fetch_url_bytes called once