struct Args {
    argc          u32
    argc_buf_size u32
}

fn wasi_args_sizes_get() {
    args := Args{}
    if WASM.args_sizes_get(&args.argc, &args.argc_buf_size) == 0 {
        println('args_sizes_get: ok')
    }
    if args.argc >= 1 {
        println('args_sizes_get: argc >= 1')
    }
    if args.argc_buf_size > 0 {
        println('args_sizes_get: argc_buf_size > 0')
    }
}

fn wasi_args_get() {
    unsafe {
        args := Args{}
        WASM.args_sizes_get(&args.argc, &args.argc_buf_size)

        mut argv_buf := malloc(args.argc_buf_size + 1)
        mut argv_ptrs := malloc(args.argc)

        if WASM.args_get(&argv_ptrs[0], &argv_buf[0]) == 0 {
            println('args_get: ok')
        }

        // @TODO: Check if the end ends with .wasm with a proper builtin
        if cstring_to_vstring(argv_buf).len == (args.argc_buf_size) - 1 {
            println('wasi_args_get: ok')
        }
    }
}

fn wasi_random_get() {
    mut random_table := [128]u8{}

    errno := WASM.random_get(&random_table[0], 128)
    if errno == 0 {
        println('random_get: ok')
    }

    mut min := u8(255)
    mut max := u8(0)
    mut all_same := true
    first_val := random_table[0]

    for i in 0 .. 128 {
        val := random_table[i]
        if val < min {
            min = val
        }
        if val > max {
            max = val
        }
        if val != first_val {
            all_same = false
        }
    }

    println('random_get: has low values = ${min < 200}')
    println('random_get: has high values = ${max > 55}')
    println('random_get: values vary = ${!all_same}')
}

fn wasi_fd_write() {
    message := 'fd_write: Hello from WASI WOORLD!\n'
    message_struct := CIOVec{
        buf: message.str
        len: usize(message.len)
    }

    if WASM.fd_write(1, &message_struct, 1, 0) == 0 {
        println('fd_write: ok')
    }
}

fn wasi_fd_write_multiple_iovecs() {
    msg1 := 'Multiple '
    msg2 := 'IO '
    msg3 := 'vectors yay!\n'

    iovs := [
        CIOVec{
            buf: msg1.str
            len: usize(msg1.len)
        },
        CIOVec{
            buf: msg2.str
            len: usize(msg2.len)
        },
        CIOVec{
            buf: msg3.str
            len: usize(msg3.len)
        },
    ]!

    if WASM.fd_write(1, &iovs[0], 3, 0) == 0 {
        println('fd_write_multi: ok')
    }
}

fn wasi_fd_sync() {
    // Flush stdout (fd 1)
    if WASM.fd_sync(1) == 0 {
        println('fd_sync: ok on stdout')
    }

    // Flush stderr (fd 2)
    if WASM.fd_sync(2) == 0 {
        println('fd_sync: ok on stderr')
    }
}

fn main() {
    wasi_args_sizes_get()
    wasi_args_get()
    wasi_random_get()
    wasi_fd_write()
    wasi_fd_write_multiple_iovecs()
    wasi_fd_sync()
    // @TODO: Find a way to test fd_read ?
}