use std::env;
use std::path::PathBuf;
use std::process::Command;

fn run_c_example(name: &'static str, expected_out: &[u8]) {
    let cargo = env::var("MAKE").unwrap_or("make".to_string());
    let pkg_dir = env!("CARGO_MANIFEST_DIR");
    let examples_dir = PathBuf::from(pkg_dir).join("examples");
    let make_arg = format!("run-{}-c", name);
    let output = Command::new(cargo)
        .current_dir(examples_dir)
        .args(&["-s", &make_arg])
        .output()
        .expect("success");
    assert!(
        output.status.success(),
        "failed to execute the C example '{}': {}",
        name,
        String::from_utf8_lossy(&output.stderr),
    );
    assert_eq!(
        output.stdout.as_slice(),
        expected_out,
        "unexpected stdout from example: {}",
        String::from_utf8_lossy(&output.stdout),
    );
}

#[test]
fn test_run_hello_example() {
    run_c_example(
        "hello",
        br#"==== C hello ====
Initializing...
Loading binary...
Compiling module...
Creating callback...
Instantiating module...
Extracting export...
Calling export...
Calling back...
> Hello World!
Shutting down...
Done.
==== Done ====
"#,
    );
}

#[test]
fn test_run_memory_example() {
    run_c_example(
        "memory",
        br#"==== C memory ====
Initializing...
Loading binary...
Compiling module...
Instantiating module...
Extracting exports...
Checking memory...
Mutating memory...
Growing memory...
Creating stand-alone memory...
Shutting down...
Done.
==== Done ====
"#,
    );
}

#[test]
fn test_run_global_example() {
    run_c_example(
        "global",
        br#"==== C global ====
Initializing...
Loading binary...
Compiling module...
Creating globals...
Instantiating module...
Extracting exports...
Accessing globals...
Shutting down...
Done.
==== Done ====
"#,
    );
}

#[test]
fn test_run_callback_example() {
    run_c_example(
        "callback",
        br#"==== C callback ====
Initializing...
Loading binary...
Compiling module...
Creating callback...
Instantiating module...
Extracting export...
Calling export...
Calling back...
> 7
Calling back closure...
> 42
Printing result...
> 49
Shutting down...
Done.
==== Done ====
"#,
    );
}

#[test]
fn test_run_reflect_example() {
    run_c_example(
        "reflect",
        br#"==== C reflect ====
Initializing...
Loading binary...
Compiling module...
Instantiating module...
Extracting export...
> export 0 "func"
>> initial: func i32 f64 f32 -> i32
>> current: func i32 f64 f32 -> i32
>> in-arity: 3, out-arity: 1
> export 1 "global"
>> initial: global const f64
>> current: global const f64
> export 2 "table"
>> initial: table 0d 50d funcref
>> current: table 0d 50d funcref
> export 3 "memory"
>> initial: memory 1d
>> current: memory 1d
Shutting down...
Done.
==== Done ====
"#,
    );
}

#[test]
fn test_run_start_example() {
    run_c_example(
        "start",
        br#"==== C start ====
Initializing...
Loading binary...
Compiling module...
Instantiating module...
Printing message...
> wasm trap: unreachable, source location: @002e
Printing origin...
> Empty origin.
Printing trace...
> Empty trace.
Shutting down...
Done.
==== Done ====
"#,
    );
}

#[test]
fn test_run_trap_example() {
    run_c_example(
        "trap",
        br#"==== C trap ====
Initializing...
Loading binary...
Compiling module...
Creating callback...
Instantiating module...
Extracting exports...
Calling export 0...
Calling back...
Printing message...
> callback abort
Printing origin...
> Empty origin.
Printing trace...
> Empty trace.
Calling export 1...
Printing message...
> wasm trap: unreachable, source location: @0065
Printing origin...
> Empty origin.
Printing trace...
> Empty trace.
Shutting down...
Done.
==== Done ====
"#,
    );
}