/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

/*
 * This code is based on the original source code of Lord Avalot d'Argent version 1.3.
 * Copyright (c) 1994-1995 Mike, Mark and Thomas Thurman.
 */

/*$M 10000,0,1000*/ /*$V-*/

/*#include "Dos.h"*/
/*#include "Tommys.h"*/

namespace Avalanche {

struct ednahead { /* Edna header */
	/* This header starts at byte offset 177 in the .ASG file. */
	array<1, 9, char> id;   /* signature */
	word revision; /* EDNA revision, here 2 (1=dna256) */
	varying_string<50> game; /* Long name, eg Lord Avalot D'Argent */
	varying_string<15> shortname; /* Short name, eg Avalot */
	word number; /* Game's code number, here 2 */
	word ver; /* Version number as integer (eg 1.00 = 100) */
	varying_string<5> verstr; /* Vernum as string (eg 1.00 = "1.00" */
	varying_string<12> filename; /* Filename, eg AVALOT.EXE */
	byte osbyte; /* Saving OS (here 1=DOS. See below for others.*/
	varying_string<5> os; /* Saving OS in text format. */

	/* Info on this particular game */

	varying_string<8> fn; /* Filename (not extension ('cos that's .ASG)) */
	byte d, m; /* D, M, Y are the Day, Month & Year this game was... */
	word y;  /* ...saved on. */
	varying_string<40> desc; /* Description of game (same as in Avaricius!) */
	word len; /* Length of DNA (it's not going to be above 65535!) */

	/* Quick reference & miscellaneous */

	word saves; /* no. of times this game has been saved */
	integer cash; /* contents of your wallet in numerical form */
	varying_string<20> money; /* ditto in string form (eg 5/-, or 1 denarius)*/
	word points; /* your score */

	/* DNA values follow, then footer (which is ignored) */
};

/* Possible values of edhead.os:
     1 = DOS        4 = Mac
     2 = Windows    5 = Amiga
     3 = OS/2       6 = ST
     7 = Archimedes */

typedef array<1, 4, char> fourtype;

struct avaricius_dna {
	varying_string<39> desc;
	array<1, 256, integer> dna;
};

const string ednaid = string("TT") + '\261' + '\60' + '\1' + '\165' + '\261' + '\231' + '\261';
const fourtype avaricius_file = "Avvy";

string filename;
boolean quiet, info;
ednahead eh;

boolean avaricius;
fourtype id4;
avaricius_dna av_eh;
varying_string<4> av_ver;

boolean ok;

string first_dir;

void explain() {
	output << "EDNA Bucket v1.0 (c) 1993 Thomas Thurman." << NL;
	output << "  To load Avvy files." << NL;
	output << NL;
	output << "Associate .ASG files with EDNA.EXE to load them directly." << NL;
	output << NL;
	output << "Switches:" << NL;
	output << "  /q (quiet) will stop EDNA from printing text to the screen." << NL;
	output << "  /i (info) will print info about the file, but won't load it." << NL;
	output << NL;
	exit(1);
}

void fix_filename() {
	string p, n, groi;

	fsplit(filename, p, n, groi);
	filename = p + n + ".ASG";
}

void error(string x) {
	output << "EDNA : " << x << NL;
	exit(255);
}

void paramparse() {
	byte fv;
	string x;

	if (paramcount == 0)  explain();

	filename = "";
	quiet = false;
	info = false;

	for (fv = 1; fv <= paramcount; fv ++) {
		x = paramstr(fv);

		if ((x[1] == '/') || (x[1] == '-'))
			switch (upcase(x[2])) { /* Parse switches */
			case 'Q':
				quiet = ! quiet;
				break;
			case 'I':
				info = ! info;
				break;
			default:
				error(string("Unknown switch! (") + x[2] + ')');
			}
		else if (filename == "")  filename = x;
		else error("Please, only one filename at a time!");
	}

	if (quiet && info)  error("How can you give info quietly??");

	if (filename == "")  error("No filename given! Use EDNA alone for help.");

	fix_filename();
}

void getfile() {
	untyped_file f;

	assign(f, filename);
	/*$I-*/
	reset(f, 1);
	/*$I+*/
	if (ioresult != 0)  error(string("Can't read file \"") + filename + "\".");

	seek(f, 11);
	blockread(f, id4, 4);
	avaricius = id4 == avaricius_file;

	if (avaricius) {
		seek(f, 47);
		blockread(f, av_eh, sizeof(av_eh));
		av_ver[0] = '\4';
		seek(f, 31);
		blockread(f, av_ver[1], 4);
	} else {
		seek(f, 177);
		blockread(f, eh, sizeof(eh));
	}

	close(f);
}

string plural(byte x) {
	string plural_result;
	if (x == 1)  plural_result = "";
	else plural_result = 's';
	return plural_result;
}

void show_info() {
	string _game, _shortname, _verstr, _filename, _os, _fn, _desc, _money;
	integer _revision, _number, _d, _m, _y, _saves, _points;
	boolean readable, understandable;

	output << "Info on file " << filename << ':' << NL;
	output << NL;
	if (avaricius) {
		/* DNA-256 file. */
		_verstr = av_ver;
		_game = "Denarius Avaricius Sextus";
		_shortname = "Avaricius";
		_filename = "AVVY.EXE";
		_os = "DOS";
		_desc = av_eh.desc;
		_revision = 1;
		_number = 1;
		_fn = "(as above)";

		_money = strf(av_eh.dna[30]) + " denari";
		if (av_eh.dna[30] == 1)  _money = _money + "us";
		else _money = _money + 'i';
		_d = av_eh.dna[7];
		_m = av_eh.dna[8];
		_y = av_eh.dna[9];
		_saves = av_eh.dna[6];
		_points = av_eh.dna[36];

		readable = true;
		understandable = true;
	} else {
		if (eh.id == ednaid) {
			/* EDNA file. */
			_game = eh.game;
			_shortname = eh.shortname;
			_verstr = eh.verstr;
			_filename = eh.filename;
			_os = eh.os;
			_fn = eh.fn;
			_desc = eh.desc;
			_money = eh.money;
			_revision = eh.revision;
			_number = eh.number;
			_d = eh.d;
			_m = eh.m;
			_y = eh.y;
			_saves = eh.saves;
			_points = eh.points;

			readable = true;
			understandable = eh.revision == 2;
		} else {
			output << "Unknown format." << NL;
			readable = false;
		}
	}

	if (_desc == "")  _desc = "<none>";

	if (readable) {
		output << "Signature is valid." << NL;
		output << "Revision of .ASG format: " << _revision << NL;
		output << NL;
		if (understandable) {
			output << "The file was saved by " << _game << '.' << NL;
			output << "Game number " << _number << " (" << _shortname << "), version " <<
			       _verstr << ", filename " << _filename << '.' << NL;
			output << "Saved under " << _os << '.' << NL;
			output << NL;
			output << "This is " << _fn << ".ASG, saved on " << _d << '/' << _m << '/' << _y << " (d/m/y)." << NL;
			output << "Description: " << _desc << NL;
			output << "It has been saved " << _saves << " time" << plural(_saves) <<
			       ". You have " << _points << " point" << plural(_points) << ',' << NL;
			output << "and " << _money << " in cash." << NL;
		} else output << "Nothing else can be discovered." << NL;
	}

	exit(2);
}

void load_file() {
	string progname, gamename, shortname, listname, exname, prog_dir;

	string localdir, groi;

	string x, y;

	text t;

	integer i, ii;

	gamename = fexpand(filename);
	fsplit(fexpand(paramstr(0)), localdir, groi, groi);
	listname = localdir + "EDNA.DAT";

	if (avaricius) {
		shortname = "Avaricius";
		exname = "AVVY";
	} else {
		shortname = eh.shortname;
		fsplit(eh.filename, groi, exname, groi);
	}

	assign(t, listname);
	/*$I-*/
	reset(t);
	/*$I+*/
	progname = "";
	if (ioresult == 0) {
		do {
			t >> x >> NL;
			t >> y >> NL;
			if (x == shortname) {
				progname = y;
				flush();
			}
		} while (!(eof(t)));
	}

	if (progname == "") {
		/* No entry in EDNA.DAT */
		output << "This file was saved by " << shortname << '.' << NL;
		output << "However, no entry was found in EDNA.DAT for that game." << NL;
		output << NL;
		output << "Please give the full path to that game, or press Enter to cancel." << NL;
		output << string("(Example: C:\\") + exname + '\\' + exname + ".EXE)" << NL;
		output << NL;
		input >> progname >> NL;
		if (progname == "")  exit(254); /* Quick exit! */

		/*$I-*/
		append(t);
		if (ioresult != 0)  rewrite(t);

		t << shortname << NL;
		t << progname << NL;

		if (ioresult != 0) {
			output << "Strange... could not write to EDNA.DAT. (Disk read-only or full?)" << NL;
			output << "The path will be used this time only." << NL;
			output << "Press Enter...";
			input >> NL;
		}
		close(t);
		/*$I+*/
	}

	if (! quiet)  output << "Running " << shortname << ": " << progname << "..." << NL;

	fsplit(fexpand(progname), prog_dir, groi, groi);
	if (prog_dir[length(prog_dir)] == '\\')  prog_dir[0] -= 1;

	/*$I-*/
	chdir(prog_dir);
	i = ioresult;
	swapvectors;
	exec(progname, gamename);
	ii = ioresult;
	swapvectors;
	chdir(first_dir);
	/*$I+*/

	if ((i != 0) || (ii != 0)) {
		output << "WARNING: DOS reported an error. This probably means that the entry" << NL;
		output << "for this game in " << listname << " is wrong." << NL;
		output << NL;
		output << "Please edit this file, using" << NL;
		output << NL;
		if (lo(dosversion) < 0x5)
			output << "  edlin " << listname << " (or similar)" << NL;
		else
			output << "  edit " << listname << NL;
		output << NL;
		output << "and change the line after \"" << shortname << "\" to show the correct path." << NL;
		output << NL;
		output << "More info is in the Avvy documentation. Good luck!" << NL;
		output << NL;
		output << "Press Enter...";
		input >> NL;
	}
}

int main(int argc, const char *argv[]) {
	pio_initialize(argc, argv);
	getdir(0, first_dir);
	paramparse();
	getfile();
	if (info)  show_info();
	load_file();
	return EXIT_SUCCESS;
}

} // End of namespace Avalanche.