/**
 * \file os_os2.C
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Ruurd A. Reitsma
 *
 * Full author contact details are available in file CREDITS.
 *
 * Various OS specific functions
 */

#include <config.h>

#include "os.h"
#include "support/filetools.h"
#define INCL_DOSFILEMGR
#define INCL_DOSMODULEMGR
#define INCL_DOSPROCESS
#define INCL_DOSNLS
#define INCL_DOSERRORS
#include <os2.h>

#include <boost/scoped_array.hpp>

using boost::scoped_array;

namespace {

string binpath_;
string binname_;
string tmpdir_;
os::shell_type shell_ = os::UNIX;
unsigned long cp_ = 0;

}


namespace os {


void init(int * argc, char ** argv[])
{
	if (argc != 0 /* This is a hack! */) {
		_wildcard(argc, argv);
		PTIB ptib = new TIB[1];
		PPIB ppib = new PIB[1];
		APIRET rc = DosGetInfoBlocks(&ptib, &ppib);
		if (rc != NO_ERROR)
			exit(rc);
		scoped_array<char> tmp(new char[256]);
		// This is the only reliable way to retrieve the executable name.
		rc = DosQueryModuleName(ppib->pib_hmte, 256L, tmp);
		if (rc != NO_ERROR)
			exit(rc);
		string p = tmp.get();
		p = slashify_path(p);
		binname_ = OnlyFilename(p);
		binname_.erase(binname_.length()-4, string::npos);
		binpath_ = OnlyPath(p);

		// OS/2 cmd.exe has another use for '&'
		string sh = OnlyFilename(GetEnvPath("EMXSHELL"));
		if (sh.empty()) {
			// COMSPEC is set, unless user unsets
			sh = OnlyFilename(GetEnvPath("COMSPEC"));
			if (sh.empty())
				sh = "cmd.exe";
		}
		sh = lowercase(sh);	// DosMapCase() is an overkill here
		if (contains(sh, "cmd.exe") || contains(sh, "4os2.exe"))
			shell_ = os::CMD_EXE;
		else
			shell_ = os::UNIX;
	}

	static bool initialized = false;
	if (initialized)
		return;
	initialized = true;

	ULONG CPList[3] = {0};
	ULONG CPList_size;
	APIRET rc = DosQueryCp(3 * sizeof(ULONG), CPList, &CPList_size);
	if (rc != NO_ERROR)
		exit(rc);
	// CPList[0] == process current codepage,
	// CPList[1] == system default codepage, the rest are auxilary.
	// Once cp_ is correctly set, you can call other routines.
	cp_ = CPList[1];
}


void warn(string const & /*mesg*/)
{
	return;
}


string current_root()
{
	APIRET rc;
	ULONG drv_num;
	ULONG drv_map;
	rc = DosQueryCurrentDisk(&drv_num, &drv_map);
	if (rc != NO_ERROR)
		exit(rc);
	char drive = 'A' + drv_num -1;
	string tmp(1, drive);
	tmp  += ":/";
	return tmp;
}


string::size_type common_path(string const & p1, string const & p2)
{
	static bool initialized = false;
	if (!initialized) {
		init(0, 0);
		initialized = true;
	}

	COUNTRYCODE cntry;
	cntry.country = 0;
	cntry.codepage = cp_;
	string temp1 = slashify_path(p1);
	string temp2 = slashify_path(p2);
	char * tmp1 = const_cast<char *> (temp1.c_str());
	char * tmp2 = const_cast<char *> (temp2.c_str());
	/* rc = */ DosMapCase(p1.length(), &cntry, tmp1);
	// if (rc != NO_ERROR)
	//	exit(rc);
	/* rc = */ DosMapCase(p2.length(), &cntry, tmp2);
	// if (rc != NO_ERROR)
	//	exit(rc);
	// This algorithm works only if paths are slashified on DBCS systems.
	string::size_type i = 0;
	string::size_type p1_len = p1.length();
	string::size_type p2_len = p2.length();
	while (i < p1_len && i < p2_len && tmp1[i] == tmp2[i])
		++i;
	if ((i < p1_len && i < p2_len)
	    || (i < p1_len && tmp1[i] != '/' && i == p2_len)
	    || (i < p2_len && tmp2[i] != '/' && i == p1_len))
	{
		if (i)
			--i;     // here was the last match
		while (i && tmp1[i] != '/')
			--i;
	}
	return i;
}


string slashify_path(string const & p)
{
	static bool initialized = false;
	static bool leadbyte[256] = {false};
	if (!initialized) {
		init(0, 0);
		COUNTRYCODE cntry;
		cntry.country = 0;
		cntry.codepage = cp_;
		unsigned char *DBCSinfo = new unsigned char[12];
		/* rc = */ DosQueryDBCSEnv(12, &cntry, (char*) DBCSinfo);
		// if (rc != NO_ERROR)
		//	exit(rc);
		for (int j = 1; j < 12; j += 2)
			DBCSinfo[j]++;
		unsigned char i = 0;
		bool isLeadByte = false;
		while (*DBCSinfo != 0) {
			if (i == *DBCSinfo) {
				isLeadByte = !isLeadByte;
				DBCSinfo++;
			}
			leadbyte[i++] = isLeadByte;
		}
		initialized = true;
	}
	string::iterator lit = p.begin();
	string::iterator end = p.end();
	for (; lit < end; ++lit) {
		if (leadbyte[(*lit)])
			lit += 2;
		if ((*lit) == '\\')
			(*lit) = '/';
	}
	p = subst(p, "//", "/");
	return p;
}


string external_path(string const & p)
{
	return p;
}


string internal_path(string const & p)
{
	return p;
}


bool is_absolute_path(string const & p)
{
	return (p.length() > 1
		&& isalpha(static_cast<unsigned char>(p[0]))
		&& p[1] == ':');
}


// returns a string suitable to be passed to popen when
// reading a pipe
char const * popen_read_mode()
{
	return "r";
}


string binpath()
{
	return binpath_;
}


string binname()
{
	return binname_;
}


void setTmpDir(string const & p)
{
	tmpdir_ = p;
}


string getTmpDir()
{
	return tmpdir_;
}


shell_type shell()
{
	return shell_;
}

} // end namespace os