#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>

#include <math.h>
#include <errno.h>

#include "bas.h"
#include "bcdfp.h"
#include "tokens.h"
#include "atables.h"

#define COLOR_FMT "\x1b[%d;3%dm"  /* 1st %d is 1 for bold, 2nd is color */

#define COLOR_OFF "\x1b[0m" /* clears inverse, too! */
#define INV_OFF   "\x1b[0m" /* clears color, too! */

/* These would be better to use, allow turning off color and inverse
   independently, but are not as widely supported by various terminals. */
/* #define COLOR_OFF "\x1b[39;49m" */
/* #define INV_OFF   "\x1b[27m"" */

#define INV_ON   "\x1b[7m"  /* goes all the way back to the original VT100 */
#define ULINE_ON "\x1b[4m"

#define MAG_INV  "{inv}"
#define MAG_NORM "{norm}"

/* colors. don't use blue, it's fugly. */
#define NO_COLOR -1
#define C_RED     1
#define C_GREEN   2
#define C_YELLOW  3
#define C_PURPLE  5
#define C_CYAN    6

#define ENV_OPTS "LISTBAS_OPTS"
#define ENV_MAX_ARGS 64
/* #define DEBUG_ENV */

/* output modes */
#define M_UTF8    0   /* default */
#define M_UTF8_I  1   /* -x */
#define M_ATASCII 2   /* -a      */
#define M_MAG     3   /* -m      */
#define M_DOTS    4   /* -d      */

int output_mode = M_UTF8;

int bold =      0;  /* 1 with -b */
int color =     1;  /* 0 with -n */
int immediate = 0;  /* 1 with -i */
int underline = 0;  /* 1 with -u */

int color_cmd =       C_YELLOW;
int color_op  =       C_GREEN;
int color_func =      C_PURPLE;
int color_const =     C_RED;
int color_lineno =    C_CYAN;
int color_text =      C_CYAN;
int color_varnames  = NO_COLOR;

int badtok =     0; /* set to 1 if we find a bad token */
int inv =        0; /* set to 1 when we're printing inverse */
int cur_color = -1; /* -1 = no color */
FILE *outfh;

int parse_color(char c) {
	if(c == 'n')
		return NO_COLOR;

	if(c >= '0' && c <= '7')
		return c - '0';

	fprintf(stderr, "%s: Invalid color '%c'.\n", self, c);
	exit(1);
}

void parse_color_scheme(const char *arg) {
	if(!arg) return;

	if(strlen(arg) != 7)
		die("Color scheme must be 7 characters.");

	color_cmd =       parse_color(arg[0]);
	color_op  =       parse_color(arg[1]);
	color_func =      parse_color(arg[2]);
	color_const =     parse_color(arg[3]);
	color_lineno =    parse_color(arg[4]);
	color_text =      parse_color(arg[5]);
	color_varnames  = parse_color(arg[6]);
}

void print_help(void) {
	printf("Usage: %s [-a | -d | -m | -x] [-b] [-i] [-n] [-v] [-c *colors*] <inputfile>\n", self);
	printf("  -U: output ATASCII as Unicode/UTF-8 (this is the default).\n");
	printf("  -a: output raw ATASCII.\n");
	printf("  -d: use dots instead of Unicode/UTF-8.\n");
	printf("  -m: magazine style listing (see a8cat(1)).\n");
	printf("  -x: XL international character set (UTF-8).\n");
	printf("  -b: use bold for color output.\n");
	printf("  -i: show immediate mode command (line 32768).\n");
	printf("  -C: enable color syntax highlighting (this is the default).\n");
	printf("  -n: disable color syntax highlighting.\n");
	printf("  -u: use underline for inverse video.\n");
	printf("  -c: use custom colors (see man page).\n");
	printf("  -v: verbose.\n");
}

void parse_args(int argc, char **argv, int from_env) {
	int opt;

	optind = 1;

	while( (opt = getopt(argc, argv, "UCviamnbdhxuc:")) != -1) {
		switch(opt) {
			case 'U': output_mode = M_UTF8;    break;
			case 'a': output_mode = M_ATASCII; break;
			case 'm': output_mode = M_MAG;     break;
			case 'd': output_mode = M_DOTS;    break;
			case 'x': output_mode = M_UTF8_I;  break;
			case 'v': verbose =   1; break;
			case 'i': immediate = 1; break;
			case 'b': bold =      1; break;
			case 'u': underline = 1; break;
			case 'C': color =     1; break;
			case 'n': color =     0; break;
			case 'c': parse_color_scheme(optarg); break;
			case 'h': print_help(); exit(0);
			default:
				print_help();
				exit(1);
		}
	}

	if(!from_env) {
		if(optind >= argc)
			die("No input file given (use - for stdin).");
		else
			open_input(argv[optind]);
	}
}

/* make a fake argv and argc */
void parse_env_args(void) {
	int fargc;
	char *fargv[ENV_MAX_ARGS + 1];
	char *env, *p;

	env = getenv(ENV_OPTS);
	if(!env) return;

#ifdef DEBUG_ENV
	fprintf(stderr, "%s: " ENV_OPTS " is set in the env, using it.\n", self);
#endif

	fargv[0] = (char *)self;
	fargv[1] = env;
	fargc = 2;

	for(p = env; *p; p++) {
		if(*p == ' ' || *p == '\t') {
			*p = '\0';
			if(fargc == ENV_MAX_ARGS) {
				/* not gonna bother with the man page for this, it's
				   long enough already. it's a pathological case. */
				fprintf(stderr, "%s: Too many spaces in " ENV_OPTS " (max %d)\n", self, ENV_MAX_ARGS - 1);
				break;
			}
			fargv[fargc++] = p + 1;
		}
	}

	fargv[fargc] = NULL;

#ifdef DEBUG_ENV
	{
		char **p;
		fprintf(stderr, "%s: Read options from environment:\n", self);
		for(p = fargv + 1; *p; p++) {
			fprintf(stderr, "\t%s\n", *p);
		}
	}
#endif

	parse_args(fargc, fargv, 1);
}

void setup_outfh(void) {
	if(output_mode == M_ATASCII) {
		if(isatty(fileno(stdout))) {
			die("Refusing to write ATASCII data to the terminal.");
		}
	}
	outfh = freopen(NULL, "wb", stdout);
	if(!outfh) {
		perror("freopen()");
		die("Can't reopen standard output in binary mode.");
	}
	return;
}

void outchr(char c) {
	putc(c, outfh);
}

/* this should probably be moved to bcdfp.c */
double bcd2double(const unsigned char *num) {
	double result = 0, sign;
	int exp, i;

	exp = *num;
	if(!exp) {
		return 0.0;
	}

	sign = (exp & 0x80 ? -1.0 : 1.0);
	exp &= 0x7f;
	exp -= 0x40;

	for(i = 1; i < 6; i++) {
		result *= 100.0;
		result += bcd2int(num[i]);
	}

	result *= pow(100, exp - 4);
	result *= sign;

	return result;
}

void color_on(unsigned char c) {
	cur_color = c;
	if(c != NO_COLOR)
		printf(COLOR_FMT, bold, c);
}

void color_off(void) {
	cur_color = -1;
	fputs(COLOR_OFF, outfh);
}

void print_number(unsigned int pos) {
	if(color) color_on(color_const);
	fprintf(outfh, "%G", bcd2double(program + pos));
	if(color) color_off();
}

/* only called in magazine mode. cursor control characters
   like a bell in the middle of a non-inverse string
   should not cause it to print {inv}{bell}{norm}. The {bell}
   is "inherently" inverse (since its high bit is set) but doesn't
   need to be printed that way. */
int affects_inv(unsigned char c) {
	switch(c) {
		case 0x1b: /* esc */
		case 0x1c: /* up */
		case 0x1d: /* down */
		case 0x1e: /* left */
		case 0x1f: /* right */
		case 0x9b: /* EOL */
		case 0x9c: /* del line */
		case 0x9d: /* ins line */
		case 0x9e: /* clear tab */
		case 0x9f: /* set tab */
		case 0x7d: /* cls */
		case 0x7e: /* BS */
		case 0x7f: /* tab */
		case 0xfd: /* bell */
		case 0xfe: /* del chr */
		case 0xff: /* ins chr */
			return 0;
		default:
			return 1;
	}
}

void start_inv(unsigned char c) {
	switch(output_mode) {
		case M_DOTS:
		case M_UTF8:
		case M_UTF8_I:
			if(underline)
				fputs(ULINE_ON, outfh);
			else
				fputs(INV_ON, outfh);
			inv = 1;
			break;
		case M_MAG:
			if(affects_inv(c)) {
				fputs(MAG_INV, outfh);
				inv = 1;
			}
			break;
		case M_ATASCII:
		default:
			break;
	}
}

void end_inv(unsigned char c) {
	switch(output_mode) {
		case M_DOTS:
		case M_UTF8:
		case M_UTF8_I:
			fputs(INV_OFF, outfh);
			inv = 0;
			/* work around INV_OFF also turning off color. */
			if(cur_color > -1)
				color_on(cur_color);
			break;
		case M_MAG:
			if(affects_inv(c)) {
				fputs(MAG_NORM, outfh);
				inv = 0;
			}
			break;
		case M_ATASCII:
		default:
			break;
	}
}

void print_ata_chr(unsigned char c) {
	if(c & 0x80) {
		if(!inv) {
			start_inv(c);
		}
	} else {
		if(inv) {
			end_inv(c);
		}
	}

	switch(output_mode) {
		case M_DOTS:
			fputc(isprint(c & 0x7f) ? c & 0x7f : '.', outfh);
			break;
		case M_UTF8:
			fputs(ata2utf[c & 0x7f], outfh);
			break;
		case M_UTF8_I:
			fputs(ics2utf[c & 0x7f], outfh);
			break;
		case M_MAG:
			fputs(ata2mag[c & 0x7f], outfh);
			break;
		case M_ATASCII:
		default:
			outchr(c);
			break;
	}
}

void print_string(unsigned int pos, unsigned int len) {
	inv = 0;
	outchr('"');
	if(color) color_on(color_const);
	while(len--) print_ata_chr(program[pos++]);
	if(inv) {
		end_inv(0);
	}
	if(color) color_off();
	outchr('"');
}

CALLBACK(print_lineno) {
	if(color) color_on(color_lineno);
	fprintf(outfh, "%d ", lineno);
	if(color) color_off();
}

CALLBACK(print_cmd) {
	const char *name;

	if(tok == CMD_ILET) return;

	if(color) color_on(color_cmd);
	if(tok > last_command || (!(name = commands[tok]))) {
		fprintf(outfh, "(bad cmd token $%02x) ", tok);
		badtok = 1;
	} else {
		fprintf(outfh, "%s ", name);
	}
	if(color) color_off();
}

CALLBACK(print_op) {
	const char *name;

	switch(tok) {
		case OP_NUMCONST:
			print_number(pos + 1);
			return;
		case OP_STRCONST:
			print_string(pos + 2, program[pos + 1]);
			return;
		case OP_EOL:
			return;
		default: break;
	}

	if(color) {
		if(tok > 0x3c)
			color_on(color_func);
		else if(tok == OP_UMINUS || tok == OP_UPLUS)
			color_on(color_const); /* show leading sign in same color as the number */
		else if((tok >= 0x17 && tok <= 0x1b) || (tok >= 0x28 && tok <= 0x2a))
			color_on(color_cmd);
		else
			color_on(color_op);
	}
	if(tok > last_operator || (!(name = operators[tok]))) {
		fprintf(outfh, "(bad op token $%02x)", tok);
		badtok = 1;
	} else {
		fprintf(outfh, "%s", name);
	}
	if(color) color_off();
}

CALLBACK(print_varname) {
	int i, count;
	unsigned char c;

	if(color) color_on(color_varnames);

	tok &= 0x7f;
	for(i = vnstart, count = 0; count < tok; i++) {
		if(program[i] & 0x80) count++;
	}
	do {
		c = program[i++];
		if(color && c == ('(' | 0x80)) {
			if(color) color_on(color_op);
		}
		outchr(c & 0x7f);
	} while (c < 0x80);
	if(color) color_off();
}

CALLBACK(print_text) {
	unsigned char c, is_data = program[pos - 1] == CMD_DATA, comma = 0;

	inv = 0;
	if(color) color_on(color_text);
	while(program[pos] != 0x9b) {
		c = program[pos++];
		if(color && is_data && c == ',') {
			color_off();
			comma = 1;
		} else {
			comma = 0;
		}
		print_ata_chr(c);
		if(comma)
			color_on(color_text);
	}
	if(inv) end_inv(0);
	if(color) color_off();
}

CALLBACK(print_newline) {
	if(output_mode == M_ATASCII)
		outchr(0x9b);
	else
		outchr('\n');
}

CALLBACK(code_prot) {
	fprintf(stderr, "%s: Program is code-protected, stopping at line %d.\n", self, lineno);
	exit(0);
}

void list(void) {
	on_start_line = print_lineno;
	on_cmd_token = print_cmd;
	on_exp_token = print_op;
	on_var_token = print_varname;
	on_end_line = print_newline;
	on_text = print_text;
	on_bad_line_length = code_prot;
	walk_code(0, 32767 + immediate);
}

int main(int argc, char **argv) {
	set_self(*argv);
	parse_general_args(argc, argv, print_help);
	parse_env_args();
	parse_args(argc, argv, 0);

	readfile();
	parse_header();

	if(!vntable_ok())
		die("Program is variable-protected; unprotect it first.");

	setup_outfh();
	list();

	if(badtok) {
		fprintf(stderr, "%s: Program has unknown tokens; maybe Turbo BASIC or BASIC XL/XE?\n", self);
		return 2;
	}

	return 0;
}