// Files and folders: bytes, folders, listing, and a place for a program's own files.
//
//   import fs
//   data := try fs.read_bytes("atlas.png")      the whole file as []u8 (any bytes, NUL included)
//   try fs.write_bytes("out.bin", data)
//   try fs.mkdir("saves/slot1")                  with the folders above it
//   names := try fs.list("saves")                the names in a folder, sorted
//   fs.exists(p)   fs.is_dir(p)   try fs.remove_dir(p)
//   dir := try fs.data_dir("MyGame")             a folder for this user's saves, made if needed
import "finch_fs.h"

fn read_bytes(str path) -> []u8! {
    text := try read_file(path)
    return text.bytes()
}

fn write_bytes(str path, []u8 data) -> ! {
    try write_file(path, str(data))
}

fn exists(str path) -> bool {
    return finch_fs_exists(path) != 0
}

fn is_dir(str path) -> bool {
    return finch_fs_is_dir(path) != 0
}

fn mkdir(str path) -> ! {
    if finch_fs_mkdir(path) == 0 {
        return error("can't make the folder \"" + path + "\"")
    }
}

// only an empty folder
fn remove_dir(str path) -> ! {
    if finch_fs_remove_dir(path) == 0 {
        return error("can't remove the folder \"" + path + "\" (is it empty?)")
    }
}

fn list(str path) -> []str! {
    l := finch_fs_list_open(path)
    if l == null {
        return error("can't list the folder \"" + path + "\"")
    }
    []str names
    while true {
        name := finch_fs_list_next(l)
        if name.len == 0 {
            break
        }
        names.push(name)
    }
    finch_fs_list_close(l)
    names.sort()
    return names
}

// The folder where a program keeps this user's files (saves, settings), made if it isn't there:
// ~/.local/share/<app> on Linux, ~/Library/Application Support/<app> on macOS, %APPDATA%\<app> on Windows.
fn data_dir(str app) -> str! {
    home := finch_fs_data_home()
    if home.len == 0 {
        return error("this system doesn't say where programs keep their files")
    }
    dir := home + "/" + app
    try mkdir(dir)
    return dir
}