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

#include "types.h"

#define size(arr) sizeof(arr) / sizeof(arr[0])

char *keywords[] = {
	"int",
	"char",
	"return",
	"for",
	"while",
	"if", 
	"else",
	"elif"
};


char *saveptr = NULL;

int lexchar(lexobj *l, char *line, char c) {
	if (line[0] == c) {
		l->data = NULL;
		l->t = c;
		saveptr = line + 1;
		return 1;
	}
	return 0;
}

int lexchars(lexobj *l, char *line, char *cs) {
	for (int i = 0; i < strlen(cs); i++) {
		if (lexchar(l, line, cs[i])) return 1;
	}
	return 0;
}

lexobj lex(char *line) {
removepadding:
	if (line[0] == ' ') line++;
	if (line[0] == ' ') goto removepadding;

	static lexobj l;

	if (isdigit(line[0])) {
		static char num[256];
		int ptr = 0;
		while (isdigit(line[0])) {
			num[ptr] = line[0];
			ptr++;
			line++;
		}
		num[ptr] = 0;
		saveptr = line;
		l.data = num;
		l.t = INTLIT;
		return l;
	}

	if (lexchars(&l, line, "(){};+-*/")) return l;

	for (int i = 0; i < size(keywords); i++) {
		if (strstr(line, keywords[i]) == line) {
			line += strlen(keywords[i]);
			saveptr = line;
			if (line[0] != ' ') goto retry;
			l.data = keywords[i];
			l.t = KEYWORD;
			return l;
		}
retry:
		continue;
	}

	char *data = strchr(line, '(');
	*data = 0;
	l.data = strdup(line);
	line += data - line;
	*data = '(';
	saveptr = line;

	return l;
}

void stripwhitespace(char *line) {
	char *out = malloc(256);
	int ptr = 0;
	for (int i = 0; i < strlen(line); i++) {
		if (line[i] == '\t' || line[i] == '\n'
				|| line[i] == '\v') continue;
		else {
			out[ptr] = line[i];
			ptr++;
		}
	}
	out[ptr] = 0;

	memcpy(line, out, 256);
}