#define _POSIX_C_SOURCE 200809L
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include "aplwc_repl.h"

int
main(int argc, char *argv[])
{
	struct aplwc *aplwc;
	struct aplwc_line *line;
	struct aplwc_value *value;
	uint8_t *data;
	char *input, *src;
	int ret, exit_code, line_number;
	size_t memsize, input_size, src_size, i;
	int opt, xflag, input_file;
	long tmp;
	FILE *f;

	input = NULL;
	line = NULL;
	value = NULL;
	xflag = 0;
	input_file = 0;
	exit_code = 0;
	line_number = 0;

	while((opt = getopt(argc, argv, "x")) != -1){
		switch(opt){
		case 'x':
			xflag = 1;
			break;
		default:
usage:
			fprintf(stderr, "Usage: %s [-x] [file]\n", argv[0]);
			return 1;
		}
	}

	if((optind+1) == argc){
		input_file = 1;
		f = fopen(argv[optind], "r");
		if(f == NULL){
			fprintf(stderr, "Could not open file: %s: %s\n", argv[optind], strerror(errno));
			return 1;
		}
	}else if(optind == argc)
		f = stdin;
	else
		goto usage;

	memsize = getenv_ulong("APLWC_MEM", APLWC_MIN_MEM);

	data = malloc(memsize);
	if(data == NULL){
		fprintf(stderr, "Couldn't allocate memory\n");
		return 1;
	}

	ret = aplwc_new(&aplwc, data, memsize);
	if(ret){
		fprintf(stderr, "Couldn't create new aplwc instance: %s\n", aplwc_errstr_rc(ret));
		free(data);
		return 1;
	}

	if(input_file){
		if(fseek(f, 0, SEEK_END)){
file_size:
			fprintf(stderr, "Failed to determine file size\n");
			return 1;
		}
		tmp = ftell(f);
		if(tmp < 0)
			goto file_size;
		input_size = tmp;
		rewind(f);
		input = malloc(input_size);
		if(input == NULL){
			fprintf(stderr, "Failed to allocate space for file contents\n");
			return 1;
		}
		if(fread(input, 1, input_size, f) < input_size){
			fprintf(stderr, "Failed to read file contents\n");
			return 1;
		}
		fclose(f);

		src = input;
		src_size = input_size;
		if((input_size > 2) && (input[0] == '#') && (input[1] == '!')){
			for(i = 0; i < input_size; i++){
				if(input[i] == '\n'){
					src += i;
					src_size -= i;
					xflag = 1;
					break;
				}
			}
		}

		ret = aplwc_load_module(aplwc, "Main", src, src_size);
		if(ret){
			fprintf(stderr, "Couldn't load Main module from file %s: %s\n", argv[optind], aplwc_errstr_rc(ret));
			return 1;
		}
		free(input);
		input = NULL;
	}

	if(xflag)
		goto exit;

	for(;;){
		if(input)
			free(input);
		if(line)
			aplwc_free_line(line);
		if(value)
			aplwc_free_value(value);

		input = NULL;
		if(getline(&input, &input_size, stdin) < 0){
			free(input);
			break;
		}else{
			line_number++;
			line = aplwc_read(aplwc, input);
			if(line == NULL){
line_error:
				fprintf(stderr, "error on line %d: %s: %s\n", line_number, aplwc_errstr(aplwc), input);
				if(input_file){
					exit_code = 1;
					goto exit;
				}
				continue;
			}
			value = aplwc_eval(line);
			if(value == NULL)
				goto line_error;
			fprintf(stdout, "%s\n", aplwc_value_string(value));
		}
	}

exit:
	if(input)
		free(input);
	if(line)
		aplwc_free_line(line);
	if(value)
		aplwc_free_value(value);

	aplwc_destroy(aplwc);
	free(data);
	return exit_code;
}