use myc::ast::environment::Environment;
use myc::ast::types::Value;

/// Verifies that bidirectional type inference correctly propagates stream inner types
/// into lambda parameters for `pipe` calls with a single stream in a vector `[src]`.
/// The lambda parameter should be inferred as the stream's Record type, not `Any`.
#[test]
fn test_pipe_infers_lambda_param_from_vector_input() {
    let env = Environment::new();
    let source = "(do
        (def src (create-random-ohlc 42 5))
        (pipe [src] (fn [tick] (.close tick)))
    )";
    let dump = env.dump_ast(source).expect("dump_ast failed");

    // The lambda parameter `tick` should be inferred as the OHLC Record type,
    // NOT as `Any`. This validates the Vector → Stream<T> → T hint resolution.
    assert!(
        !dump.contains("params: Tuple([Any])"),
        "Lambda params should NOT be Any — bidirectional inference failed.\nDump:\n{dump}"
    );
    // The pipe call should return Stream(Float), not Stream(Any)
    assert!(
        dump.contains("Stream(Float)"),
        "Pipe should produce Stream(Float), not Stream(Any).\nDump:\n{dump}"
    );

    // Also verify it runs correctly
    let res = env.run_script(source);
    assert!(res.is_ok(), "Script failed: {:?}", res.err());
}

/// Verifies bidirectional inference for pipe with multiple stream inputs in a tuple.
#[test]
fn test_pipe_infers_lambda_params_from_tuple_inputs() {
    let env = Environment::new();
    let source = "(do
        (def src1 (create-random-ohlc 42 5))
        (def src2 (create-random-ohlc 99 5))
        (pipe [src1 src2] (fn [t1 t2] (+ (.close t1) (.close t2))))
    )";
    let res = env.run_script(source);
    assert!(res.is_ok(), "Script failed: {:?}", res.err());
}

/// Verifies that PipeHook::finalize replaces the `pipe` identifier with a
/// pre-configured factory Constant — mirroring the SeriesHook pattern.
/// FAILS before PipeHook is implemented (callee is still `Identifier: pipe`).
#[test]
fn test_pipe_callee_is_factory_after_finalize() {
    let env = Environment::new();
    let dump = env.dump_ast("(do
        (def ohlc (create-random-ohlc 42 5))
        (pipe ohlc (fn [bar] (.close bar)))
    )").expect("dump_ast failed");

    assert!(
        !dump.contains("Identifier: pipe"),
        "PipeHook::finalize should replace `pipe` with a pre-configured factory Constant.\nDump:\n{dump}"
    );
}

/// Field accessor on unknown field in pipe lambda must be a compile-time error.
/// The lambda param is inferred as the concrete Record type (not Any),
/// so the compiler can validate field names.
#[test]
fn test_pipe_field_typo_is_compile_error() {
    let env = Environment::new();
    let valid = "(do (def ohlc (create-random-ohlc 42 5)) (pipe ohlc (fn [bar] (.close bar))))";
    assert!(env.run_script(valid).is_ok(), "Valid pipe should compile");

    let typo = "(do (def ohlc (create-random-ohlc 42 5)) (pipe ohlc (fn [bar] (.nonexistent bar))))";
    assert!(
        env.run_script(typo).is_err(),
        "Field typo in pipe lambda must be a compile error"
    );
}

/// A chained pipe (output feeds another pipe) must preserve concrete Stream types.
#[test]
fn test_pipe_chain_preserves_concrete_types() {
    let env = Environment::new();
    let source = "(do
        (def ohlc (create-random-ohlc 42 5))
        (def closes (pipe ohlc (fn [bar] (.close bar))))
        (pipe closes (fn [c] (* c 2.0)))
    )";
    let dump = env.dump_ast(source).expect("dump_ast failed");
    assert!(
        dump.contains("Stream(Float)"),
        "Both pipe stages should yield Stream(Float).\nDump:\n{dump}"
    );
    assert!(env.run_script(source).is_ok(), "Chained pipe failed at runtime");
}

/// Verifies that pipe with Optional return (filter pattern) still produces Stream(Float).
#[test]
fn test_pipeline_optional_type() {
    let env = Environment::new();
    // The lambda uses an `if` without an `else` returning a float constant.
    // The TypeChecker should deduce `Optional(Float)` for the lambda body,
    // and correctly unwrap it to `Series(Float)` for the pipeline output.
    let source = "(do
        (def src (create-random-ohlc 42 10))
        (def filtered
            (pipe [src]
                (fn [tick]
                    (if true
                        42.0
                    )
                )
            )
        )
        filtered
    )";
    let res = env.run_script(source);
    if let Err(e) = &res {
        panic!("Script failed to compile/run: {:?}", e);
    }

    let val = res.unwrap();
    if let Value::Stream(s) = val {
        assert_eq!(s.stream_type_name(), "stream");
    } else {
        panic!("Expected a Stream(StreamNode)");
    }
}