#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"

int immediate = 0, a8utf8 = 0, a8eol = 1;

FILE *outfh;

void print_help(void) {
	printf("Usage: %s [-v] [-i] [-a|-u] <inputfile>\n", self);
	printf("  -v: verbose.\n");
	printf("  -i: show immediate mode command (line 32768).\n");
	printf("  -a: output raw ATASCII.\n");
	printf("  -u: output Unicode.\n");
}

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

	while( (opt = getopt(argc, argv, "viau")) != -1) {
		switch(opt) {
			case 'v': verbose = 1; break;
			case 'i': immediate = 1; break;
			case 'a': a8utf8 = a8eol = 0; break;
			case 'u': a8utf8 = 1; a8eol = 0; break;
			default:
				print_help();
				exit(1);
		}
	}

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

void setup_outfh(void) {
	const char *cmd;

	/* search current dir before PATH. no easy way to detect errors here,
	   have to wait until we call pclose(). */
	if(a8eol) {
		cmd = "./a8eol -u -c 2>/dev/null || a8eol -u -c 2>/dev/null || exit 1";
	} else if(a8utf8) {
		cmd = "./a8utf8 2>/dev/null || a8utf8 2>/dev/null || exit 1";
	} else {
		if(isatty(fileno(stdout))) {
			die("Refusing to write ATASCII data to the terminal.");
		}
		outfh = stdout;
		return;
	}

	outfh = popen(cmd, "w");
	if(!outfh) {
		/* fork() or pipe() failed. does NOT detect if the command
		   wasn't found. */
		perror(self);
		exit(1);
	}
}

void close_outfh(void) {
	if(a8eol || a8utf8) {
		if(pclose(outfh)) {
			die("output filter failed; a8eol or a8utf8 not in current dir or $PATH.");
		}
	}
}

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 print_number(unsigned int pos) {
	fprintf(outfh, "%G", bcd2double(program + pos));
}

void print_string(unsigned int pos, unsigned int len) {
	outchr('"');
	while(len--) outchr(program[pos++]);
	outchr('"');
}

CALLBACK(print_lineno) {
	fprintf(outfh, "%d ", lineno);
}

CALLBACK(print_cmd) {
	const char *name;

	if(tok == CMD_ILET) return;

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

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(tok > last_operator || (!(name = operators[tok])))
		fprintf(outfh, "(bad op token $%02x)", tok);
	else
		fprintf(outfh, "%s", name);
}

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

	tok &= 0x7f;
	for(i = vnstart, count = 0; count < tok; i++) {
		if(program[i] & 0x80) count++;
	}
	while(1) {
		c = program[i++];
		outchr(c & 0x7f);
		if(c & 0x80) break;
	}
}

CALLBACK(print_text) {
	while(program[pos] != 0x9b) outchr(program[pos++]);
}

CALLBACK(print_newline) {
	outchr(0x9b);
}

CALLBACK(code_prot) {
	fprintf(stderr, "%s: Program is code-protected, stopping at line %d.\n", self, lineno);
	close_outfh();
	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_args(argc, argv);

	readfile();
	parse_header();

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

	setup_outfh();
	list();
	close_outfh();

	return 0;
}