/*
 * Copyright (C)2005-2017 Haxe Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

package sys.io;
import lua.Io;
import lua.lib.luv.Pipe;
import lua.lib.luv.Signal;
import lua.lib.luv.Loop;
import lua.Boot;
import lua.Table;

import haxe.io.Bytes;
import haxe.io.Error;
import haxe.io.Eof;

@:coreApi
class Process {
	var _pid : Int;
	var _handle  : lua.lib.luv.Process;
	var _code : Int;
	var closef : Int->Signal->Void;

	public var stdout(default,null) : haxe.io.Input;
	public var stderr(default,null) : haxe.io.Input;
	public var  stdin(default,null) : haxe.io.Output;

	static var argQuote = Sys.systemName() == "Windows" ? function(x) return StringTools.quoteWinArg(x,true) : StringTools.quoteUnixArg;
	static var _shell = Sys.systemName() == "Window" ? 'cmd.exe' : '/bin/bash';

	/**
	  Sets the args for the shell, which will include the cmd to be executed
	  by the shell.
	**/
	static function setArgs(cmd : String, ?args : Array<String>) : Table<Int,String>{
		var pargs = lua.Table.create();
		var idx = 1;
		if (sys.FileSystem.exists(cmd)) cmd = '"$cmd"'; // escape simple paths
		var all = [cmd];
		if (args != null) {
			for (a in args){
				all.push(argQuote(a));
			}
		}

		if (Sys.systemName() == "Windows") {
			pargs[idx++] = '/s';
			pargs[idx++] = '/c';
			pargs[idx++] = all.join(" ");
		} else {
			pargs[idx++] = "-c";
			pargs[idx++] = all.join(" ");
		}
		return pargs;
	}


	public function new( cmd : String, ?args : Array<String>, ?detached : Bool){
	
		if( detached ) throw "Detached process is not supported on this platform";
	
		var _stdout = new Pipe(false);
		var _stderr = new Pipe(false);
		var _stdin  = new Pipe(false);
		stdout = new ProcessInput(_stdout);
		stderr = new ProcessInput(_stderr);
		stdin  = new ProcessOutput(_stdin);
		var stdio = untyped __lua_table__([_stdin,_stdout,_stderr]);

		var opt = { args: setArgs(cmd, args), stdio : stdio };

		var p : lua.lib.luv.Process.LuvSpawn;
		p = lua.lib.luv.Process.spawn( _shell, opt, function(code : Int, signal : Signal){
			_code = code;
		});

		if (p.handle == null)  throw p.pid;
		_pid = p.pid;
		_handle = p.handle;
	}


	public function getPid() : Int {
		return _pid;
	}

	public function close() : Void {
		stdout.close();
		stdin.close();
		stderr.close();
		_handle.close();
	}

	public function exitCode( block : Bool = true ) : Null<Int> {
		if (!block) return _code;
		while (_handle.is_active()) {
			Loop.run(); // process io until the handle closes (emulate blocking)
		}
		return _code;
	}

	public function kill() : Void {
		_handle.kill("sigterm");
	}
}

class ProcessInput extends haxe.io.Input {
	var b : Pipe;
	var buf : String;
	var idx : Int;

	public function new(pipe:Pipe) {
		b = pipe;
	}

	override public function readByte() {
		var err_str = null;
		if (buf == null || idx >= buf.length){
			buf = null;
			idx = 0;
			var pending = true;
			b.read_start(function(err, chunk){
				if (chunk != null) buf = chunk;
				if (err != null) err_str = err;
				pending = false;
			});
			// process io until we read our input (emulate blocking)
			while (pending) Loop.run();
		}
		if (buf == null) throw new haxe.io.Eof();
		if (err_str != null) throw err_str;
		var code : Int =  cast buf.charCodeAt(idx++);
		return code;
	}

	override public function readAll( ?bufsize : Int ) : Bytes {
		if( bufsize == null ) bufsize = (1 << 14); // 16 Ko

		var buf = Bytes.alloc(bufsize);
		var total = new haxe.io.BytesBuffer();
		try {
			while( true ) {
				var len = readBytes(buf,0,bufsize);
				// don't throw blocked error here
				if (len != 0)
					total.addBytes(buf,0,len);
				if (len < bufsize)  break;
			}
		} catch( e : Eof ) {}
		return total.getBytes();
	}

}

class ProcessOutput extends haxe.io.Output {
	var b : Pipe;

	public function new(pipe:Pipe) {
		b = pipe;
		set_bigEndian(Boot.platformBigEndian);
	}

	override public function writeByte(c : Int ) : Void {
		b.write(String.fromCharCode(c));
	}

	override public function close(){
		b.close();
	}
}