/*
 * Copyright 2013 (c) Anna Schumaker.
 */
#include <core/file.h>
#include <core/string.h>
#include <errno.h>

#ifdef CONFIG_TESTING
const gchar *OCARINA_DIR = "ocarina-test";
#elif CONFIG_DEBUG
const gchar *OCARINA_DIR = "ocarina-debug";
#else
const gchar *OCARINA_DIR = "ocarina";
#endif

#define REPORT_ERROR(fname) \
	printf("%s (%s:%d): %s: %s\n", __func__, __FILE__, __LINE__, fname, strerror(errno))


static gchar *__file_path(gchar *name)
{
	return g_strjoin("/", g_get_user_data_dir(), OCARINA_DIR, name, NULL);
}

static bool __file_mkdir()
{
	gchar *dir = __file_path(NULL);
	int    ret = g_mkdir_with_parents(dir, 0755);

	g_free(dir);
	if (ret != 0)
		REPORT_ERROR(dir);
	return ret == 0;
}


void file_init(struct file *file, const gchar *name, unsigned int version)
{
	file->f_mode = OPEN_READ;
	file->f_version = version;
	file->f_prev = 0;
	file->f_file = NULL;
	g_strlcpy(file->f_name, (name == NULL) ? "" : name, FILE_MAX_LEN);
}

gchar *file_path(struct file *file)
{
	if (strlen(file->f_name) != 0)
		return __file_path(file->f_name);
	return g_strdup("");
}

const unsigned int file_version(struct file *file)
{
	if (file->f_file && (file->f_mode == OPEN_READ))
		return file->f_prev;
	return file->f_version;
}

bool file_exists(struct file *file)
{
	gchar *path = file_path(file);
	bool    ret = g_file_test(path, G_FILE_TEST_EXISTS);

	g_free(path);
	return ret;
}

static bool __file_open_common(struct file *file, enum open_mode mode)
{
	gchar *path  = file_path(file);
	file->f_file = g_fopen(path, (mode == OPEN_READ) ? "r" : "w");
	g_free(path);

	if (!file->f_file) {
		REPORT_ERROR(file->f_name);
		return false;
	}

	file->f_mode = mode;
	return true;
}

static bool __file_open_read(struct file *file)
{
	if (!file_exists(file))
		return false;
	if (!__file_open_common(file, OPEN_READ))
		return false;
	return file_readf(file, "%u\n", &file->f_prev) == 1;
}

static bool __file_open_write(struct file *file)
{
	if (!__file_mkdir())
		return false;
	if (!__file_open_common(file, OPEN_WRITE))
		return false;
	return file_writef(file, "%d\n", file->f_version) > 0;
}

bool file_open(struct file *file, enum open_mode mode)
{
	if ((strlen(file->f_name) == 0) || (file->f_file != NULL))
		return false;

	if (mode == OPEN_READ)
		return __file_open_read(file);
	return __file_open_write(file);
}

void file_close(struct file *file)
{
	if (file->f_file)
		fclose(file->f_file);
	file->f_file = NULL;
}

int file_readf(struct file *file, const char *fmt, ...)
{
	va_list argp;
	int ret;

	va_start(argp, fmt);
	ret = vfscanf(file->f_file, fmt, argp);
	va_end(argp);

	return ret;
}

gchar *file_readl(struct file *file)
{
	gchar *res;

	if (file_readf(file, "%m[^\n]\n", &res) == 0)
		return g_strdup("");

	g_strstrip(res);
	return res;
}

int file_writef(struct file *file, const char *fmt, ...)
{
	va_list argp;
	int ret;

	va_start(argp, fmt);
	ret = g_vfprintf(file->f_file, fmt, argp);
	va_end(argp);

	if (ret < 0)
		REPORT_ERROR(file->f_name);
	return ret;
}