import os

const vexe = @VEXE

fn missing_boehm_lib(output string) bool {
    mentions_gc := output.contains('libgc') || output.contains('-lgc')
        || output.contains("library 'gc'") || output.contains('bdw-gc')
    return mentions_gc && (output.contains('was not found')
        || output.contains('cannot find') || output.contains('not found')
        || output.contains('No such file'))
}

fn closure_skip_unused_source() string {
    return [
        'module main',
        'import builtin.closure',
        '',
        'fn make_cb(seed int) fn () int {',
        '\tvalues := []int{len: 8, init: seed + index}',
        '\treturn fn [values] () int {',
        '\t\treturn values[0] + values[7]',
        '\t}',
        '}',
        '',
        'fn no_capture_work() {}',
        '',
        'fn consume(i int) int {',
        '\th := fn [i] (x int) int {',
        '\t\treturn i + x',
        '\t}',
        '\treturn h(i + 1)',
        '}',
        '',
        'fn run() ! {',
        '\tmut lifetime := closure.new_lifetime()',
        '\tmut total := 0',
        '\tlifetime.frame(fn () {',
        '\t\tcb := make_cb(20)',
        '\t\tassert cb() == 47',
        '\t})!',
        '\tlifetime.suspend(fn () {',
        '\t\tcb := make_cb(30)',
        '\t\tassert cb() == 67',
        '\t})!',
        '\tlifetime.suspend(no_capture_work)!',
        '\tfor i in 0 .. 64 {',
        '\t\ttotal += consume(i)',
        '\t}',
        '\tlifetime.reclaim_all()!',
        '\tlifetime.dispose()!',
        '\tassert total == 4096',
        '\tprintln(total)',
        '}',
        '',
        'fn main() {',
        '\trun() or { panic(err) }',
        '}',
    ].join('\n')
}

fn run_closure_skip_unused_case(tmp_dir string, mode string) {
    source_path := os.join_path(tmp_dir, 'closure_skip_unused_${mode}.v')
    binary_path := os.join_path(tmp_dir, 'closure_skip_unused_${mode}')
    os.write_file(source_path, closure_skip_unused_source()) or { panic(err) }
    compile_cmd := '${os.quoted_path(vexe)} -skip-unused -gc ${mode} -o ${os.quoted_path(binary_path)} ${os.quoted_path(source_path)}'
    compile_res := os.execute(compile_cmd)
    if mode != 'none' && compile_res.exit_code != 0 && missing_boehm_lib(compile_res.output) {
        eprintln('skipping ${mode} closure skip-unused test: missing libgc')
        return
    }
    assert compile_res.exit_code == 0, compile_res.output
    if mode == 'boehm_leak' {
        return
    }
    run_res := os.execute(os.quoted_path(binary_path))
    assert run_res.exit_code == 0, run_res.output
    assert run_res.output.contains('4096'), run_res.output
}

fn test_closure_context_helpers_are_kept_with_skip_unused() {
    tmp_dir := os.join_path(os.vtmp_dir(), 'v_closure_context_skip_unused_${os.getpid()}')
    os.mkdir_all(tmp_dir) or { panic(err) }
    defer {
        os.rmdir_all(tmp_dir) or {}
    }
    for mode in ['boehm', 'boehm_leak', 'none'] {
        run_closure_skip_unused_case(tmp_dir, mode)
    }
}