#![no_std]
#[macro_use]
extern crate alloc;
#[macro_use]
extern crate sys;
extern crate playdate_fs as fs;

use core::ptr::NonNull;
use alloc::string::String;

use sys::EventLoopCtrl;
use sys::ffi::*;
use fs::prelude::*;
use system::prelude::*;


fn list_bundle_dir() -> Result<(), fs::error::ApiError> {
	let fs = Fs::Default();
	let include_hidden = true;
	println!("Listing root dir...");
	fs.read_dir("/", |path| println!("  {path}"), include_hidden)?;
	Ok(())
}


const DIR: &Path = "temp";
const FILE: &Path = "temp/temp-file";


fn write_file() -> Result<(), fs::error::ApiError> {
	let fs = Fs::Cached();

	let exists = fs.metadata(FILE).is_ok();

	if exists {
		println!("file already exists, overwriting");
	} else {
		println!("file doesn't exists, creating new");

		// Create dir:
		fs.create_dir(DIR)?;
	}

	let text = "Hello, World!";
	println!("writing '{text}' to '{FILE}'");

	let mut file = fs.open(FILE, FileOptions::new().write(true))?;
	let bytes_written = fs.write(&mut file, text.as_bytes())?;
	println!("written {bytes_written} bytes");

	Ok(())
}


fn read_file() -> Result<(), fs::error::ApiError> {
	let fs = Fs::Cached();

	println!("reading file metadata");
	let info = fs.metadata(&FILE)?;
	println!("info: {info:?}");


	// Prepare prefilled buffer:
	println!("preparing buffer for {} bytes", info.size);
	let mut buf = vec![0_u8; info.size as usize];

	let mut file = fs.open(FILE, FileOptions::new().read(true).read_data(true))?;

	println!("reading '{FILE}'");
	let bytes_read = file.read(&mut buf, info.size)?;
	println!("read {bytes_read} bytes");

	let result = String::from_utf8(buf)?;
	println!("content:\n{result}");
	Ok(())
}


fn read_package_info() -> Result<(), fs::error::ApiError> {
	println!("reading pdxinfo");
	let text = fs::read_to_string("pdxinfo", false)?;
	println!("{text}");
	Ok(())
}


/// Entry point / event handler
#[no_mangle]
fn event_handler(_: NonNull<PlaydateAPI>, event: SystemEvent, _: u32) -> EventLoopCtrl {
	// Ignore any other events, just for this minimalistic example
	if !matches!(event, SystemEvent::Init) {
		return EventLoopCtrl::Continue;
	}

	list_bundle_dir().expect("list_bundle_dir");
	write_file().expect("write_file");
	read_file().expect("read_file");
	read_package_info().expect("read_package_info");

	// Set no-op update callback
	system::System::Default().set_update_callback_boxed(|_| UpdateCtrl::Continue, ());

	EventLoopCtrl::Continue
}


// Needed for debug build
ll_symbols!();