#include <errno.h>
#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include <limits.h>
#include <stdlib.h>

#include <lyn/lyn.h>
#include <lyn/parser.h>
#include <lyn/debug.h>

struct lyn lyn_create()
{
	return (struct lyn){};
}

int lyn_eval_str(struct lyn *lyn, const char *name, const char *str)
{
	struct parser *p = create_parser();
	if (!p)
		return -1;

	parse(p, name, str);
	struct ast *ast = p->tree;
	bool failed = p->failed;
	destroy_parser(p);

	if (!failed) {
		ast_dump_list(0, ast);
	}

	return failed;
}

/**
 * Read whole file into a buffer and return pointer to buffer.
 * Possibly kind of silly to have both \p file and \p f.
 * Apparently there's no standardized way to get the file name of a
 * file pointer.
 *
 * @param file Name of file to read.
 * @param f File pointer.
 * @return Pointer to buffer with file contents.
 */
static char *read_file(const char *file, FILE *f)
{
	fseek(f, 0, SEEK_END);
	/** @todo check how well standardized this actually is */
	long s = ftell(f);
	if (s == LONG_MAX) {
		error("%s might be a directory", file);
		return NULL;
	}

	fseek(f, 0, SEEK_SET);

	char *buf = malloc((size_t)(s + 1));
	if (!buf)
		return NULL;

	fread(buf, (size_t)(s + 1), 1, f);
	/* remember terminating null */
	buf[s] = 0;
	return buf;
}

int lyn_eval_file(struct lyn *lyn, const char *fname)
{
	FILE *f = fopen(fname, "rb");
	if (!f) {
		error("failed opening %s: %s\n", fname, strerror(errno));
		return -1;
	}

	char *buf = read_file(fname, f);
	fclose(f);

	if (!buf)
		return -1;

	int ret = lyn_eval_str(lyn, fname, buf);
	free(buf);

	return ret;
}

void lyn_destroy(struct lyn *lyn)
{
}