module scripting

import os

pub fn set_verbose(on bool) {
	// setting a global here would be the obvious solution,
	// but V does not have globals normally.
	if on {
		os.setenv('VERBOSE', '1', true)
	}
	else {
		os.unsetenv('VERBOSE')
	}
}

pub fn verbose_trace(label string, message string) {
	if os.getenv('VERBOSE').len > 0 {
		slabel := 'scripting.${label}'
		println('# ${slabel:-25s} : $message')
	}
}

pub fn verbose_trace_exec_result(x os.Result) {
	if os.getenv('VERBOSE').len > 0 {
		println('#   cmd.exit_code : ${x.exit_code.str():-4s}  cmd.output:')
		println('# ----------------------------------- #')
		mut lnum := 1
		lines := x.output.split_into_lines()
		for line in lines {
			println('# ${lnum:3d}: $line')
			lnum++
		}
		println('# ----------------------------------- #')
	}
}

pub fn chdir(path string) {
	verbose_trace(@FN, 'cd $path')
	os.chdir(path)
}

pub fn rmrf(path string) {
	verbose_trace(@FN, 'rm -rf $path')
	if os.exists(path) {
		if os.is_dir(path) {
			os.rmdir_all(path)
		}else{
			os.rm(path)
		}
	}
}

pub fn run(cmd string) string {
	verbose_trace(@FN, cmd)
	x := os.exec(cmd) or {
		verbose_trace(@FN, '## failed.')
		return ''
	}
	verbose_trace_exec_result(x)
	if x.exit_code == 0 {
		return x.output
	}
	return ''
}

pub fn exit_0_status(cmd string) bool {
	verbose_trace(@FN, cmd)
	x := os.exec(cmd) or {
		verbose_trace(@FN, '## failed.')
		return false
	}
	verbose_trace_exec_result(x)
	if x.exit_code == 0 {
		return true
	}
	return false
}

pub fn tool_must_exist (toolcmd string) {
	verbose_trace(@FN, toolcmd)
	if exit_0_status('type $toolcmd') {
		return
	}
	eprintln('Missing tool: $toolcmd')
	eprintln('Please try again after you install it.')
	exit(1)
}

pub fn used_tools_must_exist(tools []string) {
	for t in tools {
		tool_must_exist(t)
	}
}

pub fn show_sizes_of_files(files []string) {
	for f in files {
		size := os.file_size(f)
		println('${size:10d} $f')
	}
}