#include "posix.h"

#include <blue/core/stringstream.h>
#include <blue/io/file.h>
#include <blue/io/path.h>
#include <blue/object/string.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

struct b_path {
	struct b_object base;
	struct b_string *pathstr;
};

static void path_release(struct b_object *obj);
static void path_to_string(const struct b_object *obj, struct b_stream *out);

static struct b_object_type path_type = {
	.t_name = "corelib::path",
	.t_flags = B_OBJECT_FUNDAMENTAL,
	.t_id = B_OBJECT_TYPE_PATH,
	.t_instance_size = sizeof(struct b_path),
	.t_release = path_release,
	.t_to_string = path_to_string,
};

struct b_path *b_path_create()
{
	struct b_path *path
		= (struct b_path *)b_object_type_instantiate(&path_type);
	if (!path) {
		return NULL;
	}

	path->pathstr = b_string_create();
	if (!path->pathstr) {
		b_path_release(path);
		return NULL;
	}

	return path;
}

struct b_path *b_path_create_root()
{
	const char *system_drive = "/";
	size_t system_drive_len = strlen(system_drive);

	struct b_path *path = b_path_create();
	if (!path) {
		return NULL;
	}

	b_string_append_cstr(path->pathstr, system_drive);
	if (system_drive[system_drive_len - 1] != '\\') {
		b_string_append_c(path->pathstr, '\\');
	}

	return path;
}

struct b_path *b_path_create_cwd()
{
	const long buf_len = 2048;
	char *buf = malloc(buf_len);
	if (!buf) {
		return NULL;
	}

	if (!getcwd(buf, buf_len)) {
		free(buf);
		return NULL;
	}

	struct b_path *path = b_path_create();
	if (!path) {
		free(buf);
		return NULL;
	}

	b_string_append_cstr(path->pathstr, buf);
	free(buf);

	return path;
}

struct b_path *b_path_create_from_cstr(const char *cstr)
{
	struct b_path *path = b_path_create();
	if (!path) {
		return NULL;
	}

	char prev = 0;

	for (size_t i = 0; cstr[i]; i++) {
		char c = cstr[i];
		if (c == '\\') {
			c = '/';
		}

		if (prev == '/' && c == '/') {
			continue;
		}

		b_string_append_c(path->pathstr, c);
		prev = c;
	}

	while (b_string_back(path->pathstr) == '/') {
		b_string_pop_back(path->pathstr);
	}

	return path;
}

struct b_path *b_path_duplicate(const struct b_path *path)
{
	struct b_path *new_path = b_path_create();
	if (!path) {
		return NULL;
	}

	new_path->pathstr = b_string_duplicate(path->pathstr);
	if (!new_path->pathstr) {
		b_path_release(new_path);
		return NULL;
	}

	return new_path;
}

static void append_path(struct b_path *dest, const struct b_path *src)
{
	if (b_path_is_absolute(src)) {
		b_string_clear(dest->pathstr);
		b_string_append_s(dest->pathstr, src->pathstr);
		return;
	}

	if (b_string_get_size(dest->pathstr, B_STRLEN_NORMAL) > 0
	    && b_string_back(dest->pathstr) != '/'
	    && b_string_front(src->pathstr) != '/') {
		char s[] = {'/', 0};
		b_string_append_cstr(dest->pathstr, s);
	}

	b_string_append_s(dest->pathstr, src->pathstr);
}

struct b_path *b_path_join(const b_path *paths[], size_t nr_paths)
{
	struct b_path *result = b_path_create();
	if (!result) {
		return NULL;
	}

	for (size_t i = 0; i < nr_paths; i++) {
		if (paths[i]) {
			append_path(result, paths[i]);
		}
	}

	return result;
}

struct b_path *b_path_make_absolute(const struct b_path *in)
{
	return NULL;
}

struct b_path *b_path_make_relative(const struct b_path *in)
{
	return NULL;
}

struct b_path *b_path_make_canonical(const struct b_path *in)
{
	return NULL;
}

bool b_path_is_absolute(const struct b_path *path)
{
	const char *s = b_string_ptr(path->pathstr);
	return s[0] == '/';
}

bool b_path_exists(const struct b_path *path)
{
	b_file_info info;
	if (!B_OK(b_path_stat(path, &info))) {
		return false;
	}

	return true;
}

bool b_path_is_file(const struct b_path *path)
{
	b_file_info info;
	if (!B_OK(b_path_stat(path, &info))) {
		return false;
	}

	return (info.attrib & B_FILE_ATTRIB_NORMAL) != 0;
}

bool b_path_is_directory(const struct b_path *path)
{
	b_file_info info;
	if (!B_OK(b_path_stat(path, &info))) {
		return false;
	}

	return (info.attrib & B_FILE_ATTRIB_DIRECTORY) != 0;
}

enum b_status b_path_stat(const b_path *path, struct b_file_info *out)
{
	struct stat st;
	int err = stat(b_path_ptr(path), &st);

	if (err != 0) {
		return b_status_from_errno(errno, B_ERR_IO_FAILURE);
	}

	memset(out, 0x0, sizeof *out);

	return b_file_info_from_stat(&st, out);
}

enum b_status b_path_unlink(const b_path *path)
{
	int err = remove(b_string_ptr(path->pathstr));
	return err == 0 ? B_SUCCESS : b_status_from_errno(errno, B_ERR_IO_FAILURE);
}

enum b_status b_path_get_directory(
	const struct b_path *path, struct b_path **out_dir_path)
{
	struct b_string *path_str = path->pathstr;
	long len = b_string_get_size(path_str, B_STRLEN_NORMAL);

	const char *path_cstr = b_string_ptr(path_str);
	char *sep = strrchr(path_cstr, '/');

	if (!sep) {
		*out_dir_path = b_path_create();
		return B_SUCCESS;
	}

	size_t dir_path_len = (size_t)(sep - path_cstr);
	struct b_string *dir_path_s = b_string_substr(path_str, 0, dir_path_len);

	struct b_path *dir_path
		= b_path_create_from_cstr(b_string_ptr(dir_path_s));
	b_string_release(dir_path_s);

	*out_dir_path = dir_path;

	return B_SUCCESS;
}

enum b_status b_path_get_filename(
	const struct b_path *path, struct b_string *out_name)
{
	struct b_string *path_str = path->pathstr;
	long len = b_string_get_size(path_str, B_STRLEN_NORMAL);

	char *sep = strrchr(b_string_ptr(path_str), '/');

	if (!sep) {
		b_string_append_s(out_name, path_str);
		return B_SUCCESS;
	}

	const char *filename = sep;
	while (*filename == '/' && *filename != '\0') {
		filename++;
	}

	if (*filename == '\0') {
		b_string_clear(out_name);
		return B_SUCCESS;
	}

	b_string_append_cstr(out_name, filename);

	return B_SUCCESS;
}

const char *b_path_ptr(const struct b_path *path)
{
	return b_string_ptr(path->pathstr);
}

size_t b_path_length(const struct b_path *path)
{
	return b_string_get_size(path->pathstr, B_STRLEN_NORMAL);
}

void path_release(struct b_object *obj)
{
	struct b_path *path = (struct b_path *)obj;

	b_string_release(path->pathstr);
}

void path_to_string(const struct b_object *obj, struct b_stream *out)
{
	struct b_path *path = (struct b_path *)obj;

	b_stream_write_string(out, b_string_ptr(path->pathstr), NULL);
}