#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 <sys/wait.h>

#include "bas.h"
#include "bcdfp.h"
#include "tokens.h"
#include "turbo_tokens.h"
#include "aplus_tokens.h"
#include "bxl_tokens.h"
#include "bxe_tokens.h"
#include "atables.h"
#include "whichbas.h"

#define B_ATARI SRET_ATARI
#define B_TURBO SRET_TURBO
#define B_APLUS SRET_APLUS
#define B_BXL   SRET_BXL
#define B_BXE   SRET_BXE

#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. */
#define NO_COLOR -1
#define C_RED     1
#define C_GREEN   2
#define C_YELLOW  3
#define C_BLUE    4
#define C_PURPLE  5
#define C_CYAN    6
#define C_WHITE   7

#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      */

const char *cmd_tokens[256];
const char  *op_tokens[256];

int bas_type = B_ATARI; /* -b */

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 skip_lineno = 0;  /* 1 with -l */
int dump_tables = 0;  /* 1 with -D */
int autodetect  = 0;  /* 1 with -a */

/* change these with -c */
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_rem =       C_BLUE;
int color_data =      C_CYAN;
int color_varnames  = NO_COLOR;

const char *input_filename;

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) != 8)
		die("Color scheme must be 8 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_rem =       parse_color(arg[5]);
	color_data =      parse_color(arg[6]);
	color_varnames  = parse_color(arg[7]);
}

int get_bas_type(char *arg) {
	if(arg[0] == 't')
		return B_TURBO;

	if(arg[0] == 'a') {
		if(arg[1] == '+')
			return B_APLUS;
		else
			return B_ATARI;
	}

	if(arg[0] == 'x') {
		if(arg[1] == 'l')
			return B_BXL;
		else if(arg[1] == 'e')
			return B_BXE;
	}

	fprintf(stderr, "%s: Invalid BASIC type for -b option: %s\n", self, arg);
	exit(1);
}

void print_help(void) {
	printf("Usage: %s [-a|-d|-m|-x|-U] [-B] [-i] [-l] [-u] [-n|-C] [-v] [-c *colors*] <inputfile>\n", self);
	printf("  -b <XX>: set BASIC type. XX is: a = atari, t = turbo, xl, xe, a+.\n");
	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("  -l: don't print line numbers.\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, "ADb:UCviamnBdhxulc:")) != -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 'A': autodetect =  1; break;
			case 'D': dump_tables = 1; 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 'l': skip_lineno = 1; break;
			case 'b': bas_type = get_bas_type(optarg); 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 {
			input_filename = argv[optind];
			open_input(input_filename);
		}
	}
}

/* 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(int 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_mixed_case(const char *name) {
	char c;

	if(*name == ' ')
		outchr(*name++);
	outchr(*name++);
	while(( c = *name++)) {
		if(c >= 'A' && c <= 'Z')
			c |= 0x20;
		if(color && c == '(') color_on(color_op);
		outchr(c);
	}
}

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

const char *get_bxl_ext_name(unsigned char tok) {
	switch(tok) {
		case 0x10:
			return "Local";
		case 0x11:
			return "Exit";
		case 0x12:
			return "Procedure";
		case 0x13:
			return "Call";
		case 0x14:
			return "Sortup";
		case 0x15:
			return "Sortdown";
		default:
			return "(bad BXL ext token)";
	}
}

CALLBACK(print_lineno) {
	if(skip_lineno) return;
	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((!(name = cmd_tokens[tok]))) {
		fprintf(outfh, "(bad cmd token $%02x) ", tok);
		badtok = 1;
	} else {
		if(bas_type == B_BXL && tok == 0x5a)
			name = get_bxl_ext_name(program[pos + 1]);

		if(bas_type == B_BXL || bas_type == B_BXE) {
			print_mixed_case(name);
			outchr(' ');
		} else {
			fprintf(outfh, "%s ", name);
		}
	}

	if(color) color_off();
}

void aplus_op_color_on(unsigned char tok) {
	switch(tok) {
		default:
			break;
	}

	color_on(color_op);
}

void op_color_on(unsigned char tok) {
	if(!color) return;

	if(bas_type == B_APLUS) {
		aplus_op_color_on(tok);
		return;
	}

	/* common ops for Atari, Turbo, BXL, BXE */
	if(tok <= last_operator) {
		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);
		return;
	}

	if(bas_type == B_TURBO) {
		switch(tok) {
			case 0x55:
			case 0x58:
			case 0x59: /* pseudo-func */
			case 0x5b:
			case 0x5c:
			case 0x5e:
			case 0x5f: /* pseudo-func */
			case 0x60: /* pseudo-func */
			case 0x63: /* pseudo-func */
			case 0x64:
			case 0x65:
			case 0x6b:
			case 0x6c: /* pseudo-func */
			case 0x6d: /* pseudo-func */
				color_on(color_func);
				return;
			case 0x5a:
			case 0x5d:
			case 0x61:
			case 0x62:
			case 0x6a:
				color_on(color_cmd);
				return;
			default:
				break;
		}
	}

	color_on(color_op);
}

CALLBACK(print_op) {
	const char *name;

	switch(tok) {
		case OP_HEXCONST:
			if(color) color_on(color_op);
			outchr('$');
			if(color) color_off();
			/* fall thru */
		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) op_color_on(tok);

	if((!(name = op_tokens[tok]))) {
		fprintf(outfh, "(bad op token $%02x)", tok);
		badtok = 1;
	} else {
		if(bas_type == B_BXL || bas_type == B_BXE)
			print_mixed_case(name);
		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++;
		if(i == codestart) {
			fprintf(outfh, "(bad var tok $%02x)", tok | 0x80);
			return;
		}
	}

	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(is_data ? color_data : color_rem);
	while(program[pos] != 0x9b) {
		c = program[pos++];
		if(color && is_data && c == ',') {
			color_on(color_op);
			comma = 1;
		} else {
			comma = 0;
		}
		print_ata_chr(c);
		if(comma)
			color_on(is_data ? color_data : color_rem);
	}
	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);
}

void init_bas_tables() {
	memmove(cmd_tokens, commands, (last_command + 1) * sizeof(char *));
	memmove(op_tokens, operators, (last_operator + 1) * sizeof(char *));
}

void init_aplus_tables() {
	memmove(cmd_tokens, aplus_cmds, aplus_cmd_size);
	memmove(op_tokens, aplus_ops, aplus_ops_size);
}

void init_turbo_tables() {
	memmove(cmd_tokens + last_command  + 1, turbo_cmds, turbo_cmd_size);
	memmove(op_tokens  + last_operator + 1, turbo_ops,  turbo_ops_size);
}

void init_bxl_tables() {
	memmove(cmd_tokens + last_command  + 1, bxl_cmds, bxl_cmd_size);
	memmove(op_tokens  + last_operator + 1, bxl_ops,  bxl_ops_size);
}

/* BXE's token table is identical to BXL's, and the commands are the
   same up to token 0x56 (FAST). */
void init_bxe_tables() {
	init_bxl_tables();
	memmove(cmd_tokens + 0x57, bxe_cmds, bxe_cmd_size);
}

void init_token_tables() {
	if(bas_type == B_APLUS) {
		init_aplus_tables();
		return;
	}

	init_bas_tables();

	if(bas_type == B_TURBO)
		init_turbo_tables();
	else if(bas_type == B_BXL)
		init_bxl_tables();
	else if(bas_type == B_BXE)
		init_bxe_tables();

	if(dump_tables) {
		int i;
		printf("commands:\n\n");
		for(i = 0; i < 0x65; i++)
			printf("%s $%02x\n", (cmd_tokens[i] ? cmd_tokens[i] : "(null)"), i);
		printf("operators:\n\n");
		for(i = 0x12; i < 0x69; i++)
			printf("%s $%02x\n", (op_tokens[i] ? op_tokens[i] : "(null)"), i);
		exit(0);
	}
}

void set_bas_dialect(int d) {
	if(verbose)
		fprintf(stderr, "set_bas_dialect(%d)\n", d);

	switch(d) {
		case 0:
		case 1:
			die("whichbas child process failed");
			break;
		case SRET_ATARI:
		case SRET_APLUS:
		case SRET_TURBO:
		case SRET_BXL:
		case SRET_BXE:
			bas_type = d;
			break;
		default:
			fprintf(stderr, "whichbas results ambiguous; guessing Turbo BASIC\n");
			bas_type = SRET_TURBO;
			break;
	}
}

void detect_bas_dialect() {
	pid_t pid, status;
	int wstatus;
	const char *args[4];

	args[0] = "whichbas";
	args[1] = "-s";
	args[2] = input_filename;
	args[3] = 0;

	pid = fork();
	if(pid == -1) {
		perror("fork()");
		die("Can't spawn child process");
	} else if(pid) {
		/* we are the parent */
		status = waitpid(pid, &wstatus, 0);
		if(status < 0) {
			perror("waitpid()");
			die("Child process went south");
		}
		if(!WIFEXITED(wstatus)) {
			die("Child process went south");
		}
		set_bas_dialect(WEXITSTATUS(wstatus));
	} else {
		/* we are the child */
		if(execvp(args[0], (char * const *)args) < 0) {
			perror("exec()");
			exit(1);
		}
	}
}

void init_bas_dialect() {
	if(autodetect)
		detect_bas_dialect();

	if(bas_type == B_BXL || bas_type == B_BXE)
		allow_hex_const = 1;

	if(bas_type == B_APLUS)
		aplus_errtok_hack = 1;

	if(bas_type == B_BXL)
		bxl_exttok_hack = 1;
}

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

	init_bas_dialect();
	init_token_tables();

	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; wrong BASIC dialect?\n", self);
		return 2;
	}

	return 0;
}