use std::{fs, path::Path, process::Command};

#[test]
fn struct_fixture_emits_llvm_field_read_shape() {
    let output = run_glagol(["../examples/struct.slo"]);
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    assert!(
        output.status.success(),
        "compiler rejected struct fixture\nstdout:\n{}\nstderr:\n{}",
        stdout,
        stderr
    );
    assert!(
        stdout.contains("define i32 @point_sum()")
            && stdout.contains("insertvalue { i32, i32 }")
            && stdout.contains("extractvalue { i32, i32 }")
            && stdout.contains("define i32 @main()"),
        "LLVM output did not contain expected struct field-read shape\nstdout:\n{}",
        stdout
    );
    assert!(
        !stdout.contains("struct field access"),
        "compiler emitted test metadata into LLVM output\nstdout:\n{}",
        stdout
    );
    assert!(
        !stdout.contains("type {"),
        "first-pass struct fixture should not emit aggregate layout promises\nstdout:\n{}",
        stdout
    );
    assert!(stderr.is_empty(), "compiler wrote stderr:\n{}", stderr);
}

#[test]
fn struct_value_flow_fixture_emits_llvm_aggregate_shape() {
    let output = run_glagol(["../examples/struct-value-flow.slo"]);
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    assert!(
        output.status.success(),
        "compiler rejected struct value-flow fixture\nstdout:\n{}\nstderr:\n{}",
        stdout,
        stderr
    );
    assert!(
        stdout.contains("define { i32, i32 } @make_point(i32 %x, i32 %y)")
            && stdout.contains("define i32 @point_x({ i32, i32 } %p)")
            && stdout.contains("define i32 @point_sum({ i32, i32 } %p)")
            && stdout.contains("alloca { i32, i32 }")
            && stdout.contains("call i32 @point_sum({ i32, i32 }"),
        "LLVM output did not contain expected struct value-flow shape\nstdout:\n{}",
        stdout
    );
    assert!(
        !stdout.contains("type {"),
        "struct value-flow fixture should not emit named layout promises\nstdout:\n{}",
        stdout
    );
    assert!(stderr.is_empty(), "compiler wrote stderr:\n{}", stderr);
}

#[test]
fn struct_fixture_runs_top_level_tests() {
    let output = run_glagol(["--run-tests", "../examples/struct.slo"]);
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    assert!(
        output.status.success(),
        "test runner rejected struct fixture\nstdout:\n{}\nstderr:\n{}",
        stdout,
        stderr
    );
    assert_eq!(
        stdout,
        concat!(
            "test \"struct field access\" ... ok\n",
            "test \"struct field compares\" ... ok\n",
            "2 test(s) passed\n",
        ),
        "test runner output drifted"
    );
    assert!(stderr.is_empty(), "test runner wrote stderr:\n{}", stderr);
}

#[test]
fn struct_value_flow_fixture_runs_top_level_tests() {
    let output = run_glagol(["--run-tests", "../examples/struct-value-flow.slo"]);
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    assert!(
        output.status.success(),
        "test runner rejected struct value-flow fixture\nstdout:\n{}\nstderr:\n{}",
        stdout,
        stderr
    );
    assert_eq!(
        stdout,
        concat!(
            "test \"struct local value flow\" ... ok\n",
            "test \"struct parameter value flow\" ... ok\n",
            "test \"stored struct field access\" ... ok\n",
            "3 test(s) passed\n",
        ),
        "test runner output drifted"
    );
    assert!(stderr.is_empty(), "test runner wrote stderr:\n{}", stderr);
}

#[test]
fn struct_fixture_is_formatter_stable() {
    let expected = fs::read_to_string("../tests/struct.slo").expect("read fixture");
    let output = run_glagol(["--format", "../tests/struct.slo"]);
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    assert!(
        output.status.success(),
        "formatter rejected struct fixture\nstdout:\n{}\nstderr:\n{}",
        stdout,
        stderr
    );
    assert_eq!(stdout, expected, "formatter output drifted");
    assert!(stderr.is_empty(), "formatter wrote stderr:\n{}", stderr);
}

#[test]
fn struct_value_flow_fixture_is_formatter_stable() {
    let expected = fs::read_to_string("../tests/struct-value-flow.slo").expect("read fixture");
    let output = run_glagol(["--format", "../tests/struct-value-flow.slo"]);
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    assert!(
        output.status.success(),
        "formatter rejected struct value-flow fixture\nstdout:\n{}\nstderr:\n{}",
        stdout,
        stderr
    );
    assert_eq!(stdout, expected, "formatter output drifted");
    assert!(stderr.is_empty(), "formatter wrote stderr:\n{}", stderr);
}

#[test]
fn struct_fixture_prints_lowered_shape() {
    let surface = run_glagol(["--inspect-lowering=surface", "../examples/struct.slo"]);
    let surface_stdout = String::from_utf8_lossy(&surface.stdout);
    let surface_stderr = String::from_utf8_lossy(&surface.stderr);
    assert!(
        surface.status.success(),
        "surface lowering rejected struct fixture\nstdout:\n{}\nstderr:\n{}",
        surface_stdout,
        surface_stderr
    );
    assert!(
        surface_stdout.contains("struct Point")
            && surface_stdout.contains("construct Point")
            && surface_stdout.contains("field-access x")
            && surface_stdout.contains("field-access y"),
        "surface lowering output lost struct shape\nstdout:\n{}",
        surface_stdout
    );
    assert!(
        surface_stderr.is_empty(),
        "surface lowering wrote stderr:\n{}",
        surface_stderr
    );

    let checked = run_glagol(["--inspect-lowering=checked", "../examples/struct.slo"]);
    let checked_stdout = String::from_utf8_lossy(&checked.stdout);
    let checked_stderr = String::from_utf8_lossy(&checked.stderr);
    assert!(
        checked.status.success(),
        "checked lowering rejected struct fixture\nstdout:\n{}\nstderr:\n{}",
        checked_stdout,
        checked_stderr
    );
    assert!(
        checked_stdout.contains("struct Point")
            && checked_stdout.contains("construct Point : Point")
            && checked_stdout.contains("field-access x : i32")
            && checked_stdout.contains("field-access y : i32"),
        "checked lowering output lost typed struct shape\nstdout:\n{}",
        checked_stdout
    );
    assert!(
        checked_stderr.is_empty(),
        "checked lowering wrote stderr:\n{}",
        checked_stderr
    );
}

#[test]
fn struct_value_flow_fixture_prints_lowered_shape() {
    let surface = run_glagol([
        "--inspect-lowering=surface",
        "../examples/struct-value-flow.slo",
    ]);
    let surface_stdout = String::from_utf8_lossy(&surface.stdout);
    let surface_stderr = String::from_utf8_lossy(&surface.stderr);
    assert!(
        surface.status.success(),
        "surface lowering rejected struct value-flow fixture\nstdout:\n{}\nstderr:\n{}",
        surface_stdout,
        surface_stderr
    );
    assert!(
        surface_stdout.contains("fn make_point(x: i32, y: i32) -> Point")
            && surface_stdout.contains("fn point_x(p: Point) -> i32")
            && surface_stdout.contains("local let p: Point")
            && surface_stdout.contains("field-access y"),
        "surface lowering output lost struct value-flow shape\nstdout:\n{}",
        surface_stdout
    );
    assert!(
        surface_stderr.is_empty(),
        "surface lowering wrote stderr:\n{}",
        surface_stderr
    );

    let checked = run_glagol([
        "--inspect-lowering=checked",
        "../examples/struct-value-flow.slo",
    ]);
    let checked_stdout = String::from_utf8_lossy(&checked.stdout);
    let checked_stderr = String::from_utf8_lossy(&checked.stderr);
    assert!(
        checked.status.success(),
        "checked lowering rejected struct value-flow fixture\nstdout:\n{}\nstderr:\n{}",
        checked_stdout,
        checked_stderr
    );
    assert!(
        checked_stdout.contains("fn make_point(x: i32, y: i32) -> Point")
            && checked_stdout.contains("fn point_x(p: Point) -> i32")
            && checked_stdout.contains("call make_point : Point")
            && checked_stdout.contains("var p : Point"),
        "checked lowering output lost typed struct value-flow shape\nstdout:\n{}",
        checked_stdout
    );
    assert!(
        checked_stderr.is_empty(),
        "checked lowering wrote stderr:\n{}",
        checked_stderr
    );
}

fn run_glagol<const N: usize>(args: [&str; N]) -> std::process::Output {
    Command::new(env!("CARGO_BIN_EXE_glagol"))
        .args(args)
        .current_dir(Path::new(env!("CARGO_MANIFEST_DIR")))
        .output()
        .expect("run glagol")
}