#include "zxcc.h"

/* Global variables */

char* progname;
char** argv;
int argc;

byte cpm_drive;
byte cpm_user;
extern byte cpm_error;

char bindir80[CPM_MAXPATH] = "";
char libdir80[CPM_MAXPATH] = "";
char incdir80[CPM_MAXPATH] = "";

#ifndef _WIN32
struct termios tc_orig;
#endif

byte RAM[65536]; /* The Z80's address space */

void load_comfile(void);	/* Forward declaration */

static int deinit_term, deinit_gsx;
static void mkpath(char* fullpath, char* path, char* subdir);

void dump_regs(FILE* fp, byte a, byte b, byte c, byte d, byte e, byte f,
	byte h, byte l, word pc, word ix, word iy)
{
	fprintf(fp, "\tAF=%02x%02x BC=%02x%02x DE=%02x%02x HL=%02x%02x\n"
		"\tIX=%04x IY=%04x PC=%04x\n",
		a, f, b, c, d, e, h, l, pc, ix, iy);
}

char* parse_to_fcb(char* s, int afcb)
{
	byte* fcb = &RAM[afcb + 1];

	RAM[afcb] = 0;
	memset(fcb, ' ', 11);

	while (s[0] == ' ')	/* skip leading spaces */
	{
		s++;
	}
	while (1)
	{
		if (s[0] == 0) break;
		if (s[0] == ' ') break;
		if (s[1] == ':')
		{
			RAM[afcb] = s[0] - '@';
			if (RAM[afcb] > 16) RAM[afcb] -= 0x20;
			s += 2;
			continue;
		}
		if (s[0] == '.')
		{
			++s;
			fcb = &RAM[afcb + 9];
			continue;
		}
		*fcb = *s;  if (islower(*fcb)) *fcb = toupper(*fcb);
		++s;
		++fcb;
		if (fcb >= &RAM[afcb + 12]) break;
	}
	return s;
}

void ed_fe(byte* a, byte* b, byte* c, byte* d, byte* e, byte* f,
	byte* h, byte* l, word* pc, word* ix, word* iy)
{
	switch (*a)
	{
	case 0xC0:
		cpmbdos(a, b, c, d, e, f, h, l, pc, ix, iy);
		break;

	case 0xC1:
		load_comfile();
		break;

	case 0xC2:
		fprintf(stderr, "%s: Incompatible BIOS.BIN\n", progname);
		zxcc_term();
		zxcc_exit(1);

	case 0xC3:
		cpmbios(a, b, c, d, e, f, h, l, pc, ix, iy);
		break;

	default:
		fprintf(stderr, "%s: Z80 encountered invalid trap\n", progname);
		dump_regs(stderr, *a, *b, *c, *d, *e, *f, *h, *l, *pc, *ix, *iy);
		zxcc_term();
		zxcc_exit(1);

	}
}

/*
 * load_bios() loads the minimal CP/M BIOS and BDOS.
 *
 */

void load_bios(void)
{
	char dir[CPM_MAXPATH + 1], fname[CPM_MAXPATH + 1];
	char* q;
	size_t bios_len;

	FILE* fp = fopen("bios.bin", "rb");
	if (!fp)
	{
		strcpy(fname, bindir80);
		strcat(fname, "bios.bin");
		fp = fopen(fname, "rb");
	}
	if (!fp)
	{
#ifdef _WIN32
		dir[0] = 0;	/* use strncat in case the path is very long */
		strncat(dir, _pgmptr, CPM_MAXPATH - 8);   /* copy the executable path */
#elif defined(__APPLE__)
		uint32_t size = CPM_MAXPATH - 8;
		_NSGetExecutablePath(dir, &size);
#else
		readlink("/proc/self/exe", dir, CPM_MAXPATH - 8);   /* allow room for bios.bin */
#endif
		q = strrchr(dir, DIRSEPCH);
		*++q = 0;
		strcpy(fname, dir);
		strcat(fname, "bios.bin");
		fp = fopen(fname, "rb");
	}
	if (!fp)
	{
		fprintf(stderr, "%s: Cannot locate bios.bin\n", progname);
		zxcc_term();
		zxcc_exit(1);
	}
	bios_len = fread(RAM + 0xFE00, 1, 512, fp);
	if (bios_len < 1 || ferror(fp))
	{
		fclose(fp);
		fprintf(stderr, "%s: Cannot load bios.bin\n", progname);
		zxcc_term();
		zxcc_exit(1);
	}
	fclose(fp);

	DBGMSGV("Loaded %d bytes of BIOS\n", bios_len);
}
/*
 * try_com() attempts to open file, file.com, file.COM, file.cpm and file.CPM
 *
 */

FILE* try_com(char* s)
{
	char fname[CPM_MAXPATH + 1];
	FILE* fp;

	strcpy(fname, s);
	fp = fopen(s, "rb"); if (fp) return fp;
	sprintf(s, "%s.com", fname); fp = fopen(s, "rb"); if (fp) return fp;
	sprintf(s, "%s.COM", fname); fp = fopen(s, "rb"); if (fp) return fp;
	sprintf(s, "%s.cpm", fname); fp = fopen(s, "rb"); if (fp) return fp;
	sprintf(s, "%s.CPM", fname); fp = fopen(s, "rb"); if (fp) return fp;

	strcpy(s, fname);
	return NULL;
}

/*
 * load_comfile() loads the COM file whose name was passed as a parameter.
 *
 */


void load_comfile(void)
{
	size_t com_len;
	char fname[CPM_MAXPATH + 1];
	FILE* fp;

	/* Look in current directory first */
	strcpy(fname, argv[1]);
	fp = try_com(fname);
	if (!fp)
	{
		strcpy(fname, bindir80);
		strcat(fname, argv[1]);
		fp = try_com(fname);
	}
	if (!fp)
	{
		fprintf(stderr, "%s: Cannot locate %s, %s.com, %s.COM, %s.cpm _or_ %s.CPM\n",
			progname, argv[1], argv[1], argv[1], argv[1], argv[1]);
		zxcc_term();
		zxcc_exit(1);
	}
	com_len = fread(RAM + 0x0100, 1, 0xFD00, fp);
	if (com_len < 1 || ferror(fp))
	{
		fclose(fp);
		fprintf(stderr, "%s: Cannot load %s\n", progname, fname);
		zxcc_term();
		zxcc_exit(1);
	}
	fclose(fp);

	/* read() can corrupt buffer area following data read if length
	 * of data read is less than buffer.  Clean it up. */
	memset(RAM + 0x0100 + com_len, 0, 0xFD00 - com_len);

	DBGMSGV("Loaded %d bytes from %s\n", com_len, fname);
}

unsigned int in() { return 0; }
unsigned int out() { return 0; }

/*
 * xltname: Convert a unix filepath into a CP/M compatible drive:name form.
 *          The unix filename must be 8.3 or the CP/M code will reject it.
 *
 * This uses the library xlt_name to do the work, and then just strcat()s
 * the result to the command line.
 */

void zxcc_xltname(char* name, char* pcmd)
{
	char nbuf[CPM_MAXPATH + 1];

	xlt_name(pcmd, nbuf);

	strcat(name, nbuf);
}

/* main() parses the arguments to CP/M form. argv[1] is the name of the CP/M
  program to load; the remaining arguments are arguments for the CP/M program.

  main() also loads the vestigial CP/M BIOS and does some sanity checks
		 on the endianness of the host CPU and the sizes of data types.
 */

int main(int ac, char** av)
{
	int n;
	char* pCmd, * str;
	char* tmpenv;

	argc = ac;
	argv = av;
#ifdef __PACIFIC__ 		/* Pacific C doesn't support argv[0] */
	progname = "ZXCC";
#endif
	progname = argv[0];

	/* DJGPP includes the whole path in the program name, which looks
	 * untidy...
	 */
	while ((str = strpbrk(progname, DIRSEP)))
		progname = str + 1;

#ifdef DEBUG
	fprintf(stderr, "\n\n");
	DBGMSG("Start of execution: ");
	for (n = 0; n < argc; n++)
		fprintf(stderr, " %s", argv[n]);
	fprintf(stderr, "\n");
#endif

	term_init();

	if (sizeof(int) > 8 || sizeof(byte) != 1 || sizeof(word) != 2)
	{
		fprintf(stderr, "%s: type lengths incorrect; edit typedefs "
			"and recompile.\n", progname);
		zxcc_exit(1);
	}

	if (argc < 2)
	{
		fprintf(stderr, "%s: No CP/M program name provided.\n", progname);
		zxcc_exit(1);
	}

	/* Parse arguments. An argument can be either:

	  * preceded by a '-', in which case it is copied in as-is, less the
		dash;
	  * preceded by a '+', in which case it is parsed as a filename and
		then concatenated to the previous argument;
	  * preceded by a '+-', in which case it is concatenated without
		parsing;
	  * not preceded by either, in which case it is parsed as a filename.

	  So, the argument string "--a -b c +-=q --x +/dev/null" would be rendered
	  into CP/M form as "-a b p:c=q -xd:null" */

	if (!fcb_init())
	{
		fprintf(stderr, "Could not initialise CPMREDIR library\n");
		zxcc_exit(1);
	}
	
#ifdef FILETRACKER
	DBGMSG("File tracking is ENABLED\n");
#else
	DBGMSG("File tracking is DISABLED\n");
#endif

	/* allow environment variables to override default locations */
	/* two options are supported, explicit overrides for each directory
	 * (BINDIR80, LIBDIR80, INCDIR80)
	 * or a common directory prefix override (CPMDIR80)
	 * the explict override takes precedence
	 */
	if ((tmpenv = getenv("CPMDIR80"))) {
		mkpath(bindir80, tmpenv, BIN80);    /* use CPMDIR80 & std subdirs */
		mkpath(libdir80, tmpenv, LIB80);
		mkpath(incdir80, tmpenv, INC80);
	}
	if ((tmpenv = getenv("BINDIR80")))
		mkpath(bindir80, tmpenv, "");

	if ((tmpenv = getenv("LIBDIR80")))
		mkpath(libdir80, tmpenv, "");

	if ((tmpenv = getenv("INCDIR80")))
		mkpath(incdir80, tmpenv, "");

	DBGMSGV("BINDIR80=\"%s\"\n", bindir80);
	DBGMSGV("LIBDIR80=\"%s\"\n", libdir80);
	DBGMSGV("INCDIR80=\"%s\"\n", incdir80);

	xlt_map(0, bindir80);	/* Establish the 3 fixed mappings */
	xlt_map(1, libdir80);
	xlt_map(2, incdir80);

	pCmd = (char*)RAM + 0x81;

	for (n = 2; n < argc; n++)
	{
		if (argv[n][0] == '+' && argv[n][1] == '-')
		{
			/* Append, no parsing */
			strcat(pCmd, argv[n] + 2);
		}
		else if (!argv[n][0] || argv[n][0] == '-')
		{
			/* Append with space; no parsing. */
			strcat(pCmd, " ");
			strcat(pCmd, argv[n] + 1);
		}
		else if (argv[n][0] == '+')
		{
			zxcc_xltname(pCmd, argv[n] + 1);
		}
		else /* Translate a filename */
		{
			strcat(pCmd, " ");
			zxcc_xltname(pCmd, argv[n]);
		}

	}
	pCmd[0x7F] = 0;	/* Truncate to fit the buffer */
	RAM[0x80] = (byte)strlen(pCmd);

	str = parse_to_fcb(pCmd, 0x5C);
	parse_to_fcb(str, 0x6C);

	// This statement is very useful when creating a client like zxc or zxas
	DBGMSGV("Command tail is \"%s\"\n", pCmd);

	load_bios();

	memset(RAM + 0xFE9C, 0, 0x64);	/* Zap the SCB */
	RAM[0xFE98] = 0x06;
	RAM[0xFE99] = 0xFE;		/* FE06, BDOS entry */
	RAM[0xFEA1] = 0x31;		/* BDOS 3.1 */
	RAM[0xFEA8] = 0x01;		/* UK date format */
	RAM[0xFEAF] = 0x0F;		/* CCP drive */

#ifdef USE_CPMIO
	RAM[0xFEB6] = cpm_term_direct(CPM_TERM_WIDTH, -1);
	RAM[0xFEB8] = cpm_term_direct(CPM_TERM_HEIGHT, -1);
#else
	RAM[0xFEB6] = 79;
	RAM[0xFEB8] = 23;
#endif
	RAM[0xFED1] = 0x80;	/* Buffer area */
	RAM[0xFED2] = 0xFF;
	RAM[0xFED3] = '$';
	RAM[0xFED6] = 0x9C;
	RAM[0xFED7] = 0xFE;	/* SCB address */
	RAM[0xFED8] = 0x80;	/* DMA address */
	RAM[0xFED9] = 0x00;
	RAM[0xFEDA] = 0x0F;	/* P: */
	RAM[0xFEE6] = 0x01;	/* Multi sector count */
	RAM[0xFEFE] = 0x06;
	RAM[0xFEFF] = 0xFE;	/* BDOS */

	cpm_drive = 0x0F;	/* Start logged into P: */
	cpm_user = 0;		/* and user 0 */

#ifdef USE_CPMIO
	cpm_scr_init(); deinit_term = 1;
#endif
#ifdef USE_CPMGSX
	gsx_init();	deinit_gsx = 1;
#endif

	/* Start the Z80 at 0xFF00, with stack at 0xFE00 */
	mainloop(0xFF00, 0xFE00);

	return zxcc_term();
}

void zxcc_exit(int code)
{
#ifdef USE_CPMIO
	if (deinit_term) cpm_scr_unit();
#endif
#ifdef USE_CPMGSX
	if (deinit_gsx) gsx_deinit();
#endif
	exit(code);
}

int zxcc_term(void)
{
	word n;

	//n = RAM[0x81]; /* Get the return code. This is Hi-Tech C */
	//n = (n << 8) | RAM[0x80]; /* specific and fails with other COM files */
	n = 0;

	putchar('\n');

	if (cpm_error != 0)	/* The CP/M "set return code" call was used */
	{			/* (my modified Hi-Tech C library uses this */
		n = cpm_error;	/*  call) */
	}

	if (n < 256 || n == 0xFFFF)
		DBGMSGV("Return code %d\n", n);
	else
		n = 0;

	term_reset();

	return n;
}

/* helper function to build full path */
/* make sure that a / or \ is present at the end of path
 * before appending the subdir
 */
static void mkpath(char* fullpath, char* path, char* subdir) {
	char* s;
	strcpy(fullpath, path);
	s = strchr(fullpath, '\0');
	if (*fullpath && !ISDIRSEP(s[-1]))  /* make sure we have dir sep */
		*s++ = '/';
	strcpy(s, subdir);
}

#ifndef _WIN32

void raw_init(void)
{
	struct termios tc_raw;

	DBGMSG("Enabling RAW Terminal IO\n");

	if (tcgetattr(STDIN_FILENO, &tc_orig) == -1)
	{
		DBGMSG("Failed to enable RAW Terminal IO - tcgetattr() failed\n");
		zxcc_exit(1);;
	}

	//tc_raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
	//tc_raw.c_oflag &= ~(OPOST);
	//tc_raw.c_cflag |= (CS8);
	//tc_raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
	//tc_raw.c_cc[VMIN] = 1;
	//tc_raw.c_cc[VTIME] = 0;

	tc_raw.c_iflag &= ~(ICRNL | INPCK | ISTRIP | IXON);
	tc_raw.c_oflag &= ~(OPOST);
	tc_raw.c_cflag |= (CS8);
	tc_raw.c_lflag &= ~(ECHO | ICANON | IEXTEN);
	tc_raw.c_cc[VMIN] = 1;
	tc_raw.c_cc[VTIME] = 0;

	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &tc_raw) == -1)
	{
		DBGMSG("Failed to enable RAW Terminal IO - tcsetattr() failed\n");
		zxcc_exit(1);
	}

	DBGMSG("Enabled RAW Terminal IO\n");

	return;
}

void deinit_raw(void)
{
	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &tc_orig) == -1)
	{
		DBGMSG("Failed to disable RAW Terminal IO - tcsetattr() failed\n");
		return;
	}

	DBGMSG("Disabled RAW Terminal IO\n");

	return;
}

#endif

void term_init(void)
{
#ifdef _WIN32
	setmode(STDIN_FILENO, O_BINARY);
	setmode(STDOUT_FILENO, O_BINARY);
#else
	if (_isatty(STDIN_FILENO))
		raw_init();
#endif

	if (_isatty(STDIN_FILENO))
		DBGMSG("Using interactive console mode\n");
	else
		DBGMSG("Using standard input/output mode\n");

	return;
}

void term_reset(void)
{
#ifndef _WIN32
	if (_isatty(STDIN_FILENO))
		deinit_raw();
#endif
}