use anyhow::Context;

use std::env;

use std::fs;

use std::fs::File;

use std::io::{copy, Write};

use std::path::Path;

use std::process::Command;

fn main() {

match run() {

Ok(_) => (),

Err(e) => panic!("{:?}", e),

}

}

fn run() -> anyhow::Result<()> {

let path = format!("{}/minecraft", env::var("OUT_DIR")?);

let path_1_15 = format!("{}/minecraft-1.15", env::var("OUT_DIR")?);

download_version("https://launcher.mojang.com/v1/objects/3737db93722a9e39eeada7c27e7aca28b144ffa7/server.jar", &path, true).context("failed to download 1.13 data")?;

download_version("https://launcher.mojang.com/v1/objects/bb2b6b1aefcd70dfd1892149ac3a215f6c636b07/server.jar", &path_1_15, false).context("failed to download 1.15 data")?;

clone_minecraft_data().context("failed to clone PrismarineJS/minecraft-data")?;

println!(

"cargo:rerun-if-changed={}",

concat!(env!("CARGO_MANIFEST_DIR"), "/build.rs")

);

Ok(())

}

fn download_version(url: &str, path: &str, do_generate: bool) -> anyhow::Result<()> {

let path = Path::new(&path);

let path_server = path.join("server.jar");

if data_exists(path).unwrap_or(false) {

println!("cargo:rerun-if-changed={}", &path.display());

println!(

"cargo:rerun-if-changed={}",

concat!(env!("CARGO_MANIFEST_DIR"), "/build.rs")

);

return Ok(());

}

let _ = fs::remove_dir_all(path);

fs::create_dir_all(path).context("failed to create target directory for downloaded data")?;

download(url, &path_server).context("failed to download vanilla server JAR")?;

println!(

"after download: {:?}",

std::fs::read_dir(path)?.collect::<Vec<_>>()

);

if do_generate {

generate(path).context(

"failed to generate vanilla server reports. (is Java installed and in your PATH?)",

)?;

}

extract(path).context("failed to extract vanilla assets. (are the Java developer tools (`jar`) installed and in your PATH?)")?;

println!(

"after extract: {:?}",

std::fs::read_dir(path)?.collect::<Vec<_>>()

);

Ok(())

}

fn data_exists(path: &Path) -> anyhow::Result<bool> {

Ok(File::open(path.join("server.jar")).is_ok()

&& File::open(path.join("assets")).is_ok()

&& File::open(path.join("data")).is_ok()

&& File::open(path.join("generated")).is_ok())

}

fn download<P: AsRef<Path>>(url: &str, server: P) -> anyhow::Result<()> {

let mut response = reqwest::blocking::get(url)?;

let mut dest = File::create(server)

.context("failed to create destination file for server JAR download")?;

copy(&mut response, &mut dest)?;

dest.flush()?;

Ok(())

}

fn generate<P: AsRef<Path>>(working: P) -> anyhow::Result<()> {

let status = Command::new("java")

.current_dir(working.as_ref())

.args(&["-cp", "server.jar", "net.minecraft.data.Main", "--reports"])

.status()?;

if !status.success() {

anyhow::bail!(

"process to generate server reports was not successful (exit status {}, JAR path {})",

status,

working.as_ref().display(),

)

}

Ok(())

}

fn extract<P: AsRef<Path>>(working: P) -> anyhow::Result<()> {

println!(

"{:?}",

std::fs::read_dir(working.as_ref())?.collect::<Vec<_>>()

);

let status = Command::new("jar")

.current_dir(working)

.args(&["xf", "server.jar", "assets/", "data/"])

.status()?;

if !status.success() {

anyhow::bail!(

"JAR extraction process was not successful (exit status {})",

status

)

}

Ok(())

}

fn clone_minecraft_data() -> anyhow::Result<()> {

let path = format!("{}/minecraft-data", env::var("OUT_DIR")?);

if Path::new(&path).exists() {

// Already cloned - no need to do so again

return Ok(());

}

if !Command::new("git")

.arg("clone")

.arg("https://github.com/PrismarineJS/minecraft-data.git")

.arg(&path)

.status()?

.success()

{

Err(anyhow::anyhow!(

"failed to clone minecraft-data repository: please ensure git is installed"

))

} else {

Ok(())

}

}