use std::{io::Read,path::PathBuf};
use clap::{Args,Parser,Subcommand};
use anyhow::Result as AResult;
use futures::StreamExt;
use rbx_dom_weak::types::Ref;
use tokio::io::AsyncReadExt;

type AssetID=u64;
type AssetIDFileMap=Vec<(AssetID,PathBuf)>;
const CONCURRENT_DECODE:usize=8;
const CONCURRENT_REQUESTS:usize=32;

#[derive(Parser)]
#[command(author,version,about,long_about=None)]
#[command(propagate_version = true)]
struct Cli{
	#[command(subcommand)]
	command:Commands,
}

#[derive(Subcommand)]
enum Commands{
	DownloadHistory(DownloadHistorySubcommand),
	Download(DownloadSubcommand),
	Upload(UploadSubcommand),
	Compile(CompileSubcommand),
	Decompile(DecompileSubcommand),
	DecompileHistoryIntoGit(DecompileHistoryIntoGitSubcommand),
	DownloadAndDecompileHistoryIntoGit(DownloadAndDecompileHistoryIntoGitSubcommand),
}

#[derive(Args)]
struct DownloadHistorySubcommand{
	asset_id:AssetID,
	cookie_type:CookieType,
	cookie:String,
	output_folder:Option<PathBuf>,
	continue_from_versions:Option<bool>,
	start_version:Option<u64>,
	end_version:Option<u64>,
}
#[derive(Args)]
struct DownloadSubcommand{
	cookie_type:CookieType,
	cookie:String,
	output_folder:Option<PathBuf>,
	asset_id_list:Vec<AssetID>,
}
#[derive(Args)]
struct UploadSubcommand{
	asset_id:AssetID,
	cookie_type:CookieType,
	cookie:String,
	input_file:PathBuf,
	group:Option<u64>,
}
#[derive(Args)]
struct CompileSubcommand{
	input_folder:PathBuf,
	output_file:PathBuf,
	style:Option<DecompileStyle>,
	template:Option<PathBuf>,
}
#[derive(Args)]
struct DecompileSubcommand{
	input_file:PathBuf,
	output_folder:PathBuf,
	style:DecompileStyle,
	write_template:Option<bool>,
	write_models:Option<bool>,
	write_scripts:Option<bool>,
}
#[derive(Args)]
struct DecompileHistoryIntoGitSubcommand{
	input_folder:PathBuf,
	//currently output folder must be the current folder due to git2 limitations
	//output_folder:cli.output.unwrap(),
	style:DecompileStyle,
	git_committer_name:String,
	git_committer_email:String,
	write_template:Option<bool>,
	write_models:Option<bool>,
	write_scripts:Option<bool>,
}
#[derive(Args)]
struct DownloadAndDecompileHistoryIntoGitSubcommand{
	asset_id:AssetID,
	cookie_type:CookieType,
	cookie:String,
	//currently output folder must be the current folder due to git2 limitations
	//output_folder:cli.output.unwrap(),
	style:DecompileStyle,
	git_committer_name:String,
	git_committer_email:String,
	write_template:Option<bool>,
	write_models:Option<bool>,
	write_scripts:Option<bool>,
}

#[derive(Clone,clap::ValueEnum)]
enum CookieType{
	Literal,
	Environment,
	File,
}

#[derive(Clone,Copy,Debug,clap::ValueEnum)]
enum DecompileStyle{
	Rox,
	Rojo,
	RoxRojo,
}

#[derive(serde::Deserialize)]
#[allow(nonstandard_style,dead_code)]
struct VersionPage{
	previousPageCursor:Option<String>,
	nextPageCursor:Option<String>,
	data:Vec<AssetVersion>,
}
#[derive(serde::Deserialize,serde::Serialize)]
#[allow(nonstandard_style,dead_code)]
struct AssetVersion{
	Id:u64,
	assetId:AssetID,
	assetVersionNumber:u64,
	creatorType:String,
	creatorTargetId:u64,
	creatingUniverseId:Option<u64>,
	created:chrono::DateTime<chrono::Utc>,
	isPublished:bool,
}

#[tokio::main]
async fn main()->AResult<()>{
	let cli=Cli::parse();
	match cli.command{
		Commands::DownloadHistory(subcommand)=>download_history(DownloadHistoryConfig{
			continue_from_versions:subcommand.continue_from_versions.unwrap_or(false),
			end_version:subcommand.end_version,
			start_version:subcommand.start_version.unwrap_or(0),
			output_folder:subcommand.output_folder.unwrap_or_else(||std::env::current_dir().unwrap()),
			cookie:Cookie::from_type(subcommand.cookie_type,subcommand.cookie).await?.0,
			asset_id:subcommand.asset_id,
		}).await,
		Commands::Download(subcommand)=>{
			let output_folder=subcommand.output_folder.unwrap_or_else(||std::env::current_dir().unwrap());
			download_list(
				Cookie::from_type(subcommand.cookie_type,subcommand.cookie).await?.0,
				subcommand.asset_id_list.into_iter().map(|asset_id|{
					let mut path=output_folder.clone();
					path.push(asset_id.to_string());
					(asset_id,path)
				}).collect()
			).await
		},
		Commands::Upload(subcommand)=>upload_list(
			Cookie::from_type(subcommand.cookie_type,subcommand.cookie).await?.0,
			subcommand.group,
			vec![(subcommand.asset_id,subcommand.input_file)]
		).await,
		Commands::Compile(subcommand)=>compile(CompileConfig{
			input_folder:subcommand.input_folder,
			output_file:subcommand.output_file,
			template:subcommand.template,
			style:subcommand.style,
		}).await,
		Commands::Decompile(subcommand)=>decompile(DecompileConfig{
			style:subcommand.style,
			input_file:subcommand.input_file,
			output_folder:subcommand.output_folder,
			write_template:subcommand.write_template.unwrap_or(false),
			write_models:subcommand.write_models.unwrap_or(false),
			write_scripts:subcommand.write_scripts.unwrap_or(true),
		}).await,
		Commands::DecompileHistoryIntoGit(subcommand)=>decompile_history_into_git(DecompileHistoryConfig{
			git_committer_name:subcommand.git_committer_name,
			git_committer_email:subcommand.git_committer_email,
			input_folder:subcommand.input_folder,
			output_folder:std::env::current_dir()?,
			style:subcommand.style,
			write_template:subcommand.write_template.unwrap_or(false),
			write_models:subcommand.write_models.unwrap_or(false),
			write_scripts:subcommand.write_scripts.unwrap_or(true),
		 }).await,
		Commands::DownloadAndDecompileHistoryIntoGit(subcommand)=>download_and_decompile_history_into_git(DownloadAndDecompileHistoryConfig{
			git_committer_name:subcommand.git_committer_name,
			git_committer_email:subcommand.git_committer_email,
			cookie:Cookie::from_type(subcommand.cookie_type,subcommand.cookie).await?.0,
			asset_id:subcommand.asset_id,
			output_folder:std::env::current_dir()?,
			style:subcommand.style,
			write_template:subcommand.write_template.unwrap_or(false),
			write_models:subcommand.write_models.unwrap_or(false),
			write_scripts:subcommand.write_scripts.unwrap_or(true),
		 }).await,
	}
}

struct Cookie(String);
impl Cookie{
	async fn from_type(cookie_type:CookieType,cookie_string:String)->AResult<Self>{
		Ok(Self(format!(".ROBLOSECURITY={}",match cookie_type{
			CookieType::Literal=>cookie_string,
			CookieType::Environment=>std::env::var(cookie_string)?,
			CookieType::File=>tokio::fs::read_to_string(cookie_string).await?,
		})))
	}
}

enum ReaderType<R:Read>{
	GZip(flate2::read::GzDecoder<std::io::BufReader<R>>),
	Raw(std::io::BufReader<R>),
}

fn maybe_gzip_decode<R:Read>(input:R)->AResult<ReaderType<R>>{
	let mut buf=std::io::BufReader::new(input);
	let peek=std::io::BufRead::fill_buf(&mut buf)?;
	match &peek[0..2]{
		b"\x1f\x8b"=>Ok(ReaderType::GZip(flate2::read::GzDecoder::new(buf))),
		_=>Ok(ReaderType::Raw(buf)),
	}
}

async fn upload_list(cookie:String,group:Option<u64>,asset_id_file_map:AssetIDFileMap)->AResult<()>{
	let client=reqwest::Client::new();
	futures::stream::iter(asset_id_file_map.into_iter()
	.map(|(asset_id,file)|{
		let client=&client;
		let cookie=cookie.as_str();
		let group=&group;
		async move{
			let mut url=reqwest::Url::parse("https://data.roblox.com/Data/Upload.ashx?json=1&type=Model&genreTypeId=1")?;
			//url borrow scope
			{
				let mut query=url.query_pairs_mut();//borrow here
				query.append_pair("assetid",asset_id.to_string().as_str());
				match group{
					Some(group_id)=>{query.append_pair("groupId",group_id.to_string().as_str());},
					None=>(),
				}
			}
			
			let body=tokio::fs::read_to_string(file).await?;
			let mut resp=client.post(url.clone())
			.header("Cookie",cookie)
			.body(body.clone())
			.send().await?;

			//This is called a CSRF challenge apparently
			if resp.status()==reqwest::StatusCode::FORBIDDEN{
				if let Some(csrf_token)=resp.headers().get("X-CSRF-Token"){
					resp=client.post(url)
					.header("X-CSRF-Token",csrf_token)
					.header("Cookie",cookie)
					.body(body)
					.send().await?;
				}else{
					Err(anyhow::Error::msg("Roblox returned 403 with no CSRF"))?;
				}
			}

			Ok((asset_id,resp.bytes().await?))
		}
	}))
	.buffer_unordered(CONCURRENT_REQUESTS)
	.for_each(|b:AResult<_>|async{
			match b{
				Ok((asset_id,body))=>{
					println!("asset_id={} response.body={:?}",asset_id,body);
				},
				Err(e)=>eprintln!("ul error: {}",e),
			}
		}).await;
	Ok(())
}

fn read_readable(mut readable:impl Read)->AResult<Vec<u8>>{
	let mut contents=Vec::new();
	readable.read_to_end(&mut contents)?;
	Ok(contents)
}

async fn download_list(cookie:String,asset_id_file_map:AssetIDFileMap)->AResult<()>{
	let client=reqwest::Client::new();
	futures::stream::iter(asset_id_file_map.into_iter()
	.map(|(asset_id,file)|{
		let client=&client;
		let cookie=cookie.as_str();
		async move{
			let resp=client.get(format!("https://assetdelivery.roblox.com/v1/asset/?ID={}",asset_id))
			.header("Cookie",cookie)
			.send().await?;
			Ok((file,resp.bytes().await?))
		}
	}))
	.buffer_unordered(CONCURRENT_REQUESTS)
	.for_each(|b:AResult<_>|async{
			match b{
				Ok((dest,body))=>{
					let contents=match maybe_gzip_decode(&mut std::io::Cursor::new(body)){
						Ok(ReaderType::GZip(readable))=>read_readable(readable),
						Ok(ReaderType::Raw(readable))=>read_readable(readable),
						Err(e)=>Err(e),
					};
					match contents{
						Ok(data)=>match tokio::fs::write(dest,data).await{
							Err(e)=>eprintln!("fs error: {}",e),
							_=>(),
						},
						Err(e)=>eprintln!("gzip error: {}",e),
					};
				},
				Err(e)=>eprintln!("dl error: {}",e),
			}
		}).await;
	Ok(())
}

async fn download_page(client:&reqwest::Client,cookie:&str,asset_id:AssetID,cursor:Option<String>)->AResult<VersionPage>{
	let mut url=reqwest::Url::parse(format!("https://develop.roblox.com/v1/assets/{}/saved-versions",asset_id).as_str())?;
	//url borrow scope
	{
		let mut query=url.query_pairs_mut();//borrow here
		//query.append_pair("sortOrder","Asc");
		//query.append_pair("limit","100");
		//query.append_pair("count","100");
		match cursor.as_deref(){
			Some(next_page)=>{query.append_pair("cursor",next_page);}
			None=>(),
		}
	}
	println!("page url={}",url);
	let resp=client.get(url)
	.header("Cookie",cookie)
	.send().await?;
	Ok(resp.json::<VersionPage>().await?)
}

async fn get_version_history(client:&reqwest::Client,cookie:&str,asset_id:AssetID)->AResult<Vec<AssetVersion>>{
	let mut cursor:Option<String>=None;
	let mut asset_list=Vec::new();
	loop{
		let mut page=download_page(client,cookie,asset_id,cursor).await?;
		asset_list.append(&mut page.data);
		if page.nextPageCursor.is_none(){
			break;
		}
		cursor=page.nextPageCursor;
	}
	asset_list.sort_by(|a,b|a.assetVersionNumber.cmp(&b.assetVersionNumber));
	Ok(asset_list)
}

async fn download_asset_version(client:&reqwest::Client,cookie:&str,asset_id_str:&str,asset_version_str:&str)->AResult<reqwest::Response>{
	let mut url=reqwest::Url::parse("https://assetdelivery.roblox.com/v1/asset/")?;
	//url borrow scope
	{
		let mut query=url.query_pairs_mut();//borrow here
		query.append_pair("ID",asset_id_str);
		query.append_pair("version",asset_version_str);
	}
	println!("download url={}",url);
	for i in 0..8{
		let resp=client.get(url.clone())
		.header("Cookie",cookie)
		.send().await?;

		if !resp.status().is_success(){
			println!("request {} failed",i);
			continue;
		}

		return Ok(resp);
	}
	Err(anyhow::Error::msg("all requests failed"))
}

struct DownloadHistoryConfig{
	continue_from_versions:bool,
	end_version:Option<u64>,
	start_version:u64,
	output_folder:PathBuf,
	cookie:String,
	asset_id:AssetID,
}

async fn download_history(mut config:DownloadHistoryConfig)->AResult<()>{
	let mut asset_list_contents=std::collections::HashSet::new();
	let mut asset_list:Vec<AssetVersion>=Vec::new();
	if config.end_version.is_none()&&config.continue_from_versions{
		//load prexisting versions list
		let mut versions_path=config.output_folder.clone();
		versions_path.push("versions.json");
		match std::fs::File::open(versions_path){
			Ok(versions_file)=>asset_list.append(&mut serde_json::from_reader(versions_file)?),
			Err(e)=>match e.kind(){
				std::io::ErrorKind::NotFound=>Err(anyhow::Error::msg("Cannot continue from versions.json - file does not exist"))?,
				_=>Err(e)?,
			}
		}
		//write down which versions are contained
		for asset_version in &asset_list{
			asset_list_contents.insert(asset_version.assetVersionNumber);
		}
		//find the highest number
		match asset_list.iter().map(|asset_version|asset_version.assetVersionNumber).max(){
			Some(max)=>{
				//count down contiguously until a number is missing
				for i in (1..=max).rev(){
					if !asset_list_contents.contains(&i){
						//that is end_version
						config.end_version=Some(i);
						break;
					}
				}
				//if all versions are contained, set start_version to the max + 1
				if config.end_version.is_none(){
					config.start_version=max+1;
				}
			},
			None=>Err(anyhow::Error::msg("Cannot continue from versions.json - there are no previous versions"))?,
		}
	}
	let client=reqwest::Client::new();

	let asset_id_string=config.asset_id.to_string();

	//limit concurrent downloads
	let mut join_set=tokio::task::JoinSet::new();

	//poll paged list of all asset versions
	let mut cursor:Option<String>=None;
	loop{
		let mut page=download_page(&client,config.cookie.as_str(),config.asset_id,cursor).await?;
		let client=&client;
		let cookie=config.cookie.clone();
		let asset_id_str=asset_id_string.clone();
		let output_folder=config.output_folder.clone();
		let data=&page.data;
		let asset_list_contents=&asset_list_contents;
		let join_set=&mut join_set;
		let error_catcher=||async move{
		let mut cancel_paging=false;
		for asset_version in data{
			let version_number=asset_version.assetVersionNumber;
			//skip assets beyond specified end_version
			if config.end_version.is_some_and(|v|v<version_number){
				continue;
			}
			//skip assets lower than start_version and cancel paging asset versions
			if version_number<config.start_version{
				cancel_paging=true;
				continue;//don't trust roblox returned order
			}
			//skip previously downloaded assets
			if asset_list_contents.contains(&version_number){
				continue;
			}
			while CONCURRENT_REQUESTS<=join_set.len(){
				join_set.join_next().await.unwrap()??;
			}
			let client=client.clone();
			let cookie=cookie.clone();
			let asset_id_str=asset_id_str.clone();
			let mut path=output_folder.clone();
			path.push(format!("{}_v{}.rbxl",config.asset_id,version_number));
			join_set.spawn(async move{
				let resp=download_asset_version(&client,cookie.as_str(),asset_id_str.as_str(),version_number.to_string().as_str()).await?;
				let contents=match maybe_gzip_decode(std::io::Cursor::new(resp.bytes().await?))?{
					ReaderType::GZip(readable)=>read_readable(readable)?,
					ReaderType::Raw(readable)=>read_readable(readable)?,
				};

				tokio::fs::write(path,contents).await?;

				Ok::<_,anyhow::Error>(())
			});
		}
		Ok::<_,anyhow::Error>(cancel_paging)
		};
		let cancel_paging=match error_catcher().await{
			Ok(cancel)=>cancel,
			Err(e)=>{
				println!("download error: {}",e);
				//cancel download and write versions
				true
			},
		};
		if page.nextPageCursor.is_none()||cancel_paging{
			for asset_version in page.data.into_iter(){
				if !(asset_list_contents.contains(&asset_version.assetVersionNumber)
				||config.end_version.is_some_and(|v|v<asset_version.assetVersionNumber)
				||asset_version.assetVersionNumber<config.start_version){
					asset_list.push(asset_version);
				}
			}
			break;
		}else{
			asset_list.append(&mut page.data);
		}
		cursor=page.nextPageCursor;
	}

	asset_list.sort_by(|a,b|a.assetVersionNumber.cmp(&b.assetVersionNumber));

	let mut path=config.output_folder.clone();
	path.set_file_name("versions.json");
	tokio::fs::write(path,serde_json::to_string(&asset_list)?).await?;

	while let Some(result)=join_set.join_next().await{
		result??;
	}

	Ok(())
}

fn load_dom<R:Read>(input:R)->AResult<rbx_dom_weak::WeakDom>{
	let mut buf=std::io::BufReader::new(input);
	let peek=std::io::BufRead::fill_buf(&mut buf)?;
	match &peek[0..4]{
		b"<rob"=>{
			match &peek[4..8]{
				b"lox!"=>return rbx_binary::from_reader(buf).map_err(anyhow::Error::msg),
				b"lox "=>return rbx_xml::from_reader_default(buf).map_err(anyhow::Error::msg),
				other=>Err(anyhow::Error::msg(format!("Unknown Roblox file type {:?}",other))),
			}
		},
		_=>Err(anyhow::Error::msg("unsupported file type")),
	}
}

#[derive(PartialEq)]
enum Class{
	Folder,
	ModuleScript,
	LocalScript,
	Script,
	Model,
}

struct TreeNode{
	name:String,
	referent:Ref,
	parent:Ref,
	class:Class,
	children:Vec<Ref>,
}
impl TreeNode{
	fn new(name:String,referent:Ref,parent:Ref,class:Class)->Self{
		Self{
			name,
			referent,
			parent,
			class,
			children:Vec::new(),
		}
	}
}

enum TrimStackInstruction{
	Referent(Ref),
	IncrementScript,
	DecrementScript,
}

enum WriteStackInstruction<'a>{
	Node(&'a TreeNode,u32),//(Node,NameTally)
	PushFolder(String),
	PopFolder,
	Destroy(Ref),
}

#[derive(Default)]
struct PropertiesOverride{
	name:Option<String>,
	class:Option<String>,
}
impl PropertiesOverride{
	fn is_some(&self)->bool{
		self.name.is_some()
		||self.class.is_some()
	}
}
impl std::fmt::Display for PropertiesOverride{
	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
		if let Some(name)=self.name.as_deref(){
			writeln!(f,"--!Properties.Name = \"{}\"",name)?;
		}
		if let Some(class)=self.class.as_deref(){
			writeln!(f,"--!Properties.ClassName = \"{}\"",class)?;
		}
		Ok(())
	}
}

fn sanitize<'a>(s:&'a str)->std::borrow::Cow<'a,str>{
	lazy_regex::regex!(r"[^A-z0-9.-]").replace_all(s,"_")
}

fn write_item(dom:&rbx_dom_weak::WeakDom,mut file:PathBuf,node:&TreeNode,node_name_override:String,mut properties:PropertiesOverride,style:DecompileStyle,write_models:bool,write_scripts:bool)->AResult<()>{
	file.push(sanitize(node_name_override.as_str()).as_ref());
	match node.class{
		Class::Folder=>(),
		Class::ModuleScript|Class::LocalScript|Class::Script=>{
			if !write_scripts{
				return Ok(())
			}

			//set extension
			match style{
				DecompileStyle::Rox=>assert!(file.set_extension("lua"),"could not set extension"),
				DecompileStyle::RoxRojo|DecompileStyle::Rojo=>{
					match properties.class.as_deref(){
						Some("LocalScript")=>{
							file.set_extension("client.lua");
							properties.class=None;
						},
						Some("Script")=>{
							file.set_extension("server.lua");
							properties.class=None;
						},
						// Some("ModuleScript")=>{
						// 	file.set_extension("module");
						// 	properties.class=None;
						// },
						None=>assert!(file.set_extension("lua"),"could not set extension"),
						Some(other)=>Err(anyhow::Error::msg(format!("Attempt to write a {} as a script",other)))?,
					}
				}
			}

			if let Some(item)=dom.get_by_ref(node.referent){
				//TODO: delete disabled scripts
				if let Some(rbx_dom_weak::types::Variant::String(source))=item.properties.get("Source"){
					if properties.is_some(){
						//rox style
						let source=properties.to_string()+source.as_str();
						std::fs::write(file,source)?;
					}else{
						std::fs::write(file,source)?;
					}
				}
			}
		},
		Class::Model=>{
			if !write_models{
				return Ok(())
			}
			assert!(file.set_extension("rbxmx"));
			let output=std::io::BufWriter::new(std::fs::File::create(file)?);
			rbx_xml::to_writer_default(output,dom,&[node.referent])?;
		},
	}
	Ok(())
}

struct DecompiledContext{
	dom:rbx_dom_weak::WeakDom,
	tree_refs:std::collections::HashMap<rbx_dom_weak::types::Ref,TreeNode>,
}

fn generate_decompiled_context<R:Read>(input:R)->AResult<DecompiledContext>{
	let dom=load_dom(input)?;

	let mut tree_refs=std::collections::HashMap::new();
	tree_refs.insert(dom.root_ref(),TreeNode::new(
		"src".to_owned(),
		dom.root_ref(),
		Ref::none(),
		Class::Folder
	));

	//run rules
	let mut stack=vec![dom.root()];
	while let Some(item)=stack.pop(){
		let class=match item.class.as_str(){
			"ModuleScript"=>Class::ModuleScript,
			"LocalScript"=>Class::LocalScript,
			"Script"=>Class::Script,
			"Model"=>Class::Model,
			_=>Class::Folder,
		};
		let skip=match class{
			Class::Model=>true,
			_=>false,
		};
		if let Some(parent_node)=tree_refs.get_mut(&item.parent()){
			let referent=item.referent();
			let node=TreeNode::new(item.name.clone(),referent,parent_node.referent,class);
			parent_node.children.push(referent);
			tree_refs.insert(referent,node);
		}
		//look no further, turn this node and all its children into a model
		if skip{
			continue;
		}
		for &referent in item.children(){
			if let Some(c)=dom.get_by_ref(referent){
				stack.push(c);
			}
		}
	}

	//trim empty folders
	let mut script_count=0;
	let mut stack:Vec<TrimStackInstruction>=tree_refs.get(&dom.root_ref()).unwrap().children
	.iter().map(|&c|TrimStackInstruction::Referent(c)).collect();
	while let Some(instruction)=stack.pop(){
		match instruction{
			TrimStackInstruction::IncrementScript=>script_count+=1,
			TrimStackInstruction::DecrementScript=>script_count-=1,
			TrimStackInstruction::Referent(referent)=>{
				let mut delete=None;
				if let Some(node)=tree_refs.get_mut(&referent){
					if node.class==Class::Folder&&script_count!=0{
						node.class=Class::Model
					}
					if node.class==Class::Folder&&node.children.len()==0{
						delete=Some(node.parent);
					}else{
						//how the hell do I do this better without recursion
						let is_script=match node.class{
							Class::ModuleScript|Class::LocalScript|Class::Script=>true,
							_=>false,
						};
						//stack is popped from back
						if is_script{
							stack.push(TrimStackInstruction::DecrementScript);
						}
						for &child_referent in &node.children{
							stack.push(TrimStackInstruction::Referent(child_referent));
						}
						if is_script{
							stack.push(TrimStackInstruction::IncrementScript);
						}
					}
				}
				//trim referent
				if let Some(parent_ref)=delete{
					let parent_node=tree_refs.get_mut(&parent_ref)
					.expect("parent_ref does not exist in tree_refs");
					parent_node.children.remove(
						parent_node.children.iter()
						.position(|&r|r==referent)
						.expect("parent.children does not contain referent")
					);
					tree_refs.remove(&referent);
				}
			},
		}
	}

	Ok(DecompiledContext{
		dom,
		tree_refs,
	})
}

struct WriteConfig{
	style:DecompileStyle,
	output_folder:PathBuf,
	write_template:bool,
	write_models:bool,
	write_scripts:bool,
}

async fn write_files(config:WriteConfig,mut context:DecompiledContext)->AResult<()>{
	let mut write_queue=Vec::new();
	let mut destroy_queue=Vec::new();

	let mut name_tally=std::collections::HashMap::<String,u32>::new();
	let mut folder=config.output_folder.clone();
	let mut stack=vec![WriteStackInstruction::Node(context.tree_refs.get(&context.dom.root_ref()).unwrap(),0)];
	while let Some(instruction)=stack.pop(){
		match instruction{
			WriteStackInstruction::PushFolder(component)=>folder.push(component),
			WriteStackInstruction::PopFolder=>assert!(folder.pop(),"weirdness"),
			WriteStackInstruction::Destroy(referent)=>destroy_queue.push(referent),
			WriteStackInstruction::Node(node,name_count)=>{
				//track properties that must be overriden to compile folder structure back into a place file
				let mut properties=PropertiesOverride::default();
				let has_children=node.children.len()!=0;
				match node.class{
					Class::Folder=>(),
					Class::ModuleScript=>(),//.lua files are ModuleScript by default
					Class::LocalScript=>properties.class=Some("LocalScript".to_owned()),
					Class::Script=>properties.class=Some("Script".to_owned()),
					Class::Model=>(),
				}
				let name_override=if 0<name_count{
					properties.name=Some(node.name.clone());
					format!("{}_{}",node.name,name_count)
				}else{
					node.name.clone()
				};

				if has_children{
					//push temp subfolder
					let mut subfolder=folder.clone();
					subfolder.push(sanitize(name_override.as_str()).as_ref());
					//make folder
					tokio::fs::create_dir(subfolder.clone()).await?;

					let name_final=match config.style{
						DecompileStyle::Rox
						|DecompileStyle::RoxRojo=>name_override.clone(),
						DecompileStyle::Rojo=>"init".to_owned(),
					};

					//write item in subfolder
					write_queue.push((subfolder,node,name_final,properties,config.style));
				}else{
					//write item
					write_queue.push((folder.clone(),node,name_override.clone(),properties,config.style));
				}
				//queue item to be deleted from dom after child objects are handled (stack is popped from the back)
				match node.class{
					Class::Folder=>(),
					_=>stack.push(WriteStackInstruction::Destroy(node.referent)),
				}
				if has_children{
					stack.push(WriteStackInstruction::PopFolder);
					name_tally.clear();
					for referent in &node.children{
						if let Some(c)=context.tree_refs.get(referent){
							let v=name_tally.entry(c.name.clone()).and_modify(|v|*v+=1).or_default();
							stack.push(WriteStackInstruction::Node(c,*v));
						}
					}
					stack.push(WriteStackInstruction::PushFolder(sanitize(name_override.as_str()).to_string()));
				}
			},
		}
	}

	//run the async
	{
		let dom=&context.dom;
		let write_models=config.write_models;
		let write_scripts=config.write_scripts;
		let results:Vec<AResult<()>>=rayon::iter::ParallelIterator::collect(rayon::iter::ParallelIterator::map(rayon::iter::IntoParallelIterator::into_par_iter(write_queue),|(write_path,node,node_name_override,properties,style)|{
			write_item(&dom,write_path,node,node_name_override,properties,style,write_models,write_scripts)
		}));
		for result in results{
			result?;
		}
	}

	//run the destroy
	for destroy_ref in destroy_queue{
		context.dom.destroy(destroy_ref);
	}

	//write what remains in template.rbxlx
	if config.write_template{
		let mut file=config.output_folder.clone();
		file.push("template");
		assert!(file.set_extension("rbxlx"));
		let output=std::io::BufWriter::new(std::fs::File::create(file)?);
		rbx_xml::to_writer_default(output,&context.dom,context.dom.root().children())?;
	}

	Ok(())
}

struct DecompileConfig{
	style:DecompileStyle,
	input_file:PathBuf,
	output_folder:PathBuf,
	write_template:bool,
	write_models:bool,
	write_scripts:bool,
}

async fn decompile(config:DecompileConfig)->AResult<()>{
	//rules:
	//Class Script|LocalScript|ModuleScript->$Name.lua
	//Class Model->$Name.rbxmx
	//overrides.json per-folder [Override{name,class}]
	//Everything else goes into template.rbxlx

	//read file
	let context=generate_decompiled_context(std::io::BufReader::new(std::fs::File::open(config.input_file)?))?;

	//generate folders, models, and scripts
	//delete models and scripts from dom
	write_files(WriteConfig{
		style:config.style,
		output_folder:config.output_folder,
		write_template:config.write_template,
		write_models:config.write_models,
		write_scripts:config.write_scripts,
	},context).await?;

	Ok(())
}

struct WriteCommitConfig{
	git_committer_name:String,
	git_committer_email:String,
	output_folder:PathBuf,
	style:DecompileStyle,
	write_template:bool,
	write_models:bool,
	write_scripts:bool,
}

async fn write_commit(config:WriteCommitConfig,b:Result<AResult<(AssetVersion,DecompiledContext)>,tokio::task::JoinError>,repo:&git2::Repository)->AResult<()>{
	let (asset_version,context)=b??;
	println!("writing files for version {}",asset_version.assetVersionNumber);

	//clean output dir
	if config.write_models||config.write_scripts{
		let mut src=config.output_folder.clone();
		src.push("src");
		match std::fs::remove_dir_all(src){
			Ok(())=>(),
			Err(e)=>println!("remove_dir_all src failed {}",e),
		}
	}
	if config.write_template{
		let mut template=config.output_folder.clone();
		template.push("template.rbxlx");
		match std::fs::remove_file(template){
			Ok(())=>(),
			Err(e)=>println!("remove_file template.rbxlx failed {}",e),
		}
	}

	//write files
	write_files(WriteConfig{
		style:config.style,
		output_folder:config.output_folder.clone(),
		write_template:config.write_template,
		write_models:config.write_models,
		write_scripts:config.write_scripts,
	},context).await?;

	let date=asset_version.created;
	//let sig=repo.signature()?; //this pulls default name and email
	let sig=git2::Signature::new(config.git_committer_name.as_str(),config.git_committer_email.as_str(),&git2::Time::new(date.timestamp(),0)).unwrap();
	let tree_id={
		let mut tree_index = repo.index()?;
		match tree_index.add_all(std::iter::once(config.output_folder.as_path()),git2::IndexAddOption::DEFAULT,None){
			Ok(_)=>(),
			Err(e)=>println!("tree_index.add_all error: {}",e),
		}
		match tree_index.update_all(std::iter::once(config.output_folder.as_path()),None){
			Ok(_)=>(),
			Err(e)=>println!("tree_index.update_all error: {}",e),
		}
		tree_index.write()?;
		tree_index.write_tree()?
	};
	let tree=repo.find_tree(tree_id)?;

	let mut parents=Vec::new();

	match repo.head(){
		Ok(reference)=>{
			let commit=reference.peel_to_commit()?;

			//test tree against commit tree to see if there is any changes
			let commit_tree=commit.tree()?;
			let diff=repo.diff_tree_to_tree(Some(&commit_tree),Some(&tree),None)?;
			if diff.get_delta(0).is_none(){
				println!("no changes");
				return Ok(());
			}

			parents.push(commit);
		},
		Err(e)=>println!("repo head error {:?}",e),
	};

	repo.commit(
		Some("HEAD"),//update_ref
		&sig,//author
		&sig,//commiter
		&format!("v{}", asset_version.assetVersionNumber),//message
		&tree,//tree (basically files)
		parents.iter().collect::<Vec<&git2::Commit<'_>>>().as_slice(),//parents
	)?;

	//commit
	Ok(())
}

struct DecompileHistoryConfig{
	git_committer_name:String,
	git_committer_email:String,
	input_folder:PathBuf,
	style:DecompileStyle,
	output_folder:PathBuf,
	write_template:bool,
	write_models:bool,
	write_scripts:bool,
}

async fn decompile_history_into_git(config:DecompileHistoryConfig)->AResult<()>{
	//use prexisting versions list
	let mut versions_path=config.input_folder.clone();
	versions_path.push("versions.json");
	let asset_list:Vec<AssetVersion>=serde_json::from_reader(std::fs::File::open(versions_path)?)?;

	let repo=git2::Repository::init(config.output_folder.as_path())?;

	//decompile all versions
	futures::stream::iter(asset_list.into_iter()
	.map(|asset_version|{
		let mut file_path=config.input_folder.clone();
		tokio::task::spawn_blocking(move||{
			file_path.push(format!("{}_v{}.rbxl",asset_version.assetId,asset_version.assetVersionNumber));
			let file=std::fs::File::open(file_path)?;
			let contents=generate_decompiled_context(file)?;
			Ok::<_,anyhow::Error>((asset_version,contents))
		})
	}))
	.buffered(CONCURRENT_DECODE)
	.for_each(|join_handle_result|async{
		match write_commit(WriteCommitConfig{
			git_committer_name:config.git_committer_name.clone(),
			git_committer_email:config.git_committer_email.clone(),
			style:config.style,
			output_folder:config.output_folder.clone(),
			write_template:config.write_template,
			write_models:config.write_models,
			write_scripts:config.write_scripts,
		},join_handle_result,&repo).await{
			Ok(())=>(),
			Err(e)=>println!("decompile/write/commit error: {}",e),
		}
	}).await;
	Ok(())
}

struct DownloadAndDecompileHistoryConfig{
	cookie:String,
	asset_id:AssetID,
	git_committer_name:String,
	git_committer_email:String,
	style:DecompileStyle,
	output_folder:PathBuf,
	write_template:bool,
	write_models:bool,
	write_scripts:bool,
}

async fn download_and_decompile_history_into_git(config:DownloadAndDecompileHistoryConfig)->AResult<()>{
	let client=reqwest::Client::new();

	//poll paged list of all asset versions
	let asset_list=get_version_history(&client,&config.cookie.as_str(),config.asset_id).await?;

	let repo=git2::Repository::init(config.output_folder.clone())?;

	//download all versions
	let asset_id_string=config.asset_id.to_string();
	futures::stream::iter(asset_list.into_iter()
	.map(|asset_version|{
		let client=client.clone();
		let cookie=config.cookie.clone();
		let asset_id_str=asset_id_string.clone();
		tokio::task::spawn(async move{
			let resp=download_asset_version(&client,cookie.as_str(),asset_id_str.as_str(),asset_version.assetVersionNumber.to_string().as_str()).await?;
			let contents=match maybe_gzip_decode(std::io::Cursor::new(resp.bytes().await?))?{
				ReaderType::GZip(readable)=>generate_decompiled_context(readable)?,
				ReaderType::Raw(readable)=>generate_decompiled_context(readable)?,
			};
			Ok::<_,anyhow::Error>((asset_version,contents))
		})
	}))
	.buffered(CONCURRENT_DECODE)
	.for_each(|join_handle_result|async{
		match write_commit(WriteCommitConfig{
			style:config.style,
			git_committer_name:config.git_committer_name.clone(),
			git_committer_email:config.git_committer_email.clone(),
			output_folder:config.output_folder.clone(),
			write_template:config.write_template,
			write_models:config.write_models,
			write_scripts:config.write_scripts,
		},join_handle_result,&repo).await{
			Ok(())=>(),
			Err(e)=>println!("download/unzip/decompile/write/commit error: {}",e),
		}
	}).await;
	Ok(())
}

//holy smokes what am I doing lmao
//This giant machine is supposed to search for files according to style rules
//e.g. ScriptName.server.lua or init.lua
//Obviously I got carried away
//I could use an enum!
//I could use a struct!
//I could use a trait!
//I could use an error!
//I could use a match!
//I could use a function!
//eventually:
#[derive(Debug)]
enum QueryResolveError{
	NotFound,//0 results
	Ambiguous,//>1 results
	JoinError(tokio::task::JoinError),
	IO(std::io::Error),
}
impl std::fmt::Display for QueryResolveError{
	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
		write!(f,"{self:?}")
	}
}
impl std::error::Error for QueryResolveError{}

struct FileWithName{
	file:tokio::fs::File,
	name:String,
}

async fn get_file_async(mut path:PathBuf,file_name:impl AsRef<std::path::Path>)->Result<FileWithName,QueryResolveError>{
	let name=file_name.as_ref().to_str().unwrap().to_owned();
	path.push(file_name);
	match tokio::fs::File::open(path).await{
		Ok(file)=>Ok(FileWithName{file,name}),
		Err(e)=>match e.kind(){
			std::io::ErrorKind::NotFound=>Err(QueryResolveError::NotFound),
			_=>Err(QueryResolveError::IO(e)),
		},
	}
}
type QueryHintResult=Result<FileHint,QueryResolveError>;
trait Query{
	async fn resolve(self)->QueryHintResult;
}
type QueryHandle=tokio::task::JoinHandle<Result<FileWithName,QueryResolveError>>;
struct QuerySingle{
	script:QueryHandle,
}
impl QuerySingle{
	fn rox(search_path:&PathBuf,search_name:&str)->Self{
		Self{
			script:tokio::spawn(get_file_async(search_path.clone(),format!("{}.lua",search_name)))
		}
	}
}
impl Query for QuerySingle{
	async fn resolve(self)->QueryHintResult{
		match self.script.await{
			Ok(Ok(file))=>Ok(FileHint{file,hint:ScriptHint::ModuleScript}),
			Ok(Err(e))=>Err(e),
			Err(e)=>Err(QueryResolveError::JoinError(e)),
		}
	}
}
struct QueryTriple{
	module:QueryHandle,
	server:QueryHandle,
	client:QueryHandle,
}
impl QueryTriple{
	fn rox_rojo(search_path:&PathBuf,search_name:&str,search_module:bool)->Self{
		//this should be implemented as constructors of Triplet and Quadruplet to fully support Trey's suggestion
		let module_name=if search_module{
			format!("{}.module.lua",search_name)
		}else{
			format!("{}.lua",search_name)
		};
		Self{
			module:tokio::spawn(get_file_async(search_path.clone(),module_name)),
			server:tokio::spawn(get_file_async(search_path.clone(),format!("{}.server.lua",search_name))),
			client:tokio::spawn(get_file_async(search_path.clone(),format!("{}.client.lua",search_name))),
		}
	}
	fn rojo(search_path:&PathBuf)->Self{
		QueryTriple::rox_rojo(search_path,"init",false)
	}
}
//these functions can be achieved with macros, but I have not learned that yet
fn mega_triple_join(query_triplet:(QueryHintResult,QueryHintResult,QueryHintResult))->QueryHintResult{
	match query_triplet{
		//unambiguously locate file
		(Ok(f),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))
		|(Err(QueryResolveError::NotFound),Ok(f),Err(QueryResolveError::NotFound))
		|(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Ok(f))=>Ok(f),
		//multiple files located
		(Ok(_),Ok(_),Err(QueryResolveError::NotFound))
		|(Ok(_),Err(QueryResolveError::NotFound),Ok(_))
		|(Err(QueryResolveError::NotFound),Ok(_),Ok(_))
		|(Ok(_),Ok(_),Ok(_))=>Err(QueryResolveError::Ambiguous),
		//no files located
		(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))=>Err(QueryResolveError::NotFound),
		//other error
		(Err(e),_,_)
		|(_,Err(e),_)
		|(_,_,Err(e))=>Err(e),
	}
}
//LETS GOOOOOOOOOOOOOOOO
fn mega_quadruple_join(query_quad:(QueryHintResult,QueryHintResult,QueryHintResult,QueryHintResult))->QueryHintResult{
	match query_quad{
		//unambiguously locate file
		(Ok(f),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))
		|(Err(QueryResolveError::NotFound),Ok(f),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))
		|(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Ok(f),Err(QueryResolveError::NotFound))
		|(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Ok(f))=>Ok(f),
		//multiple files located
		(Ok(_),Ok(_),Ok(_),Err(QueryResolveError::NotFound))
		|(Ok(_),Ok(_),Err(QueryResolveError::NotFound),Ok(_))
		|(Ok(_),Ok(_),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))
		|(Ok(_),Err(QueryResolveError::NotFound),Ok(_),Ok(_))
		|(Ok(_),Err(QueryResolveError::NotFound),Ok(_),Err(QueryResolveError::NotFound))
		|(Ok(_),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Ok(_))
		|(Err(QueryResolveError::NotFound),Ok(_),Ok(_),Ok(_))
		|(Err(QueryResolveError::NotFound),Ok(_),Ok(_),Err(QueryResolveError::NotFound))
		|(Err(QueryResolveError::NotFound),Ok(_),Err(QueryResolveError::NotFound),Ok(_))
		|(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Ok(_),Ok(_))
		|(Ok(_),Ok(_),Ok(_),Ok(_))=>Err(QueryResolveError::Ambiguous),
		//no files located
		(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))=>Err(QueryResolveError::NotFound),
		//other error
		(Err(e),_,_,_)
		|(_,Err(e),_,_)
		|(_,_,Err(e),_)
		|(_,_,_,Err(e))=>Err(e),
	}
}
impl Query for QueryTriple{
	async fn resolve(self)->QueryHintResult{
		let (module,server,client)=tokio::join!(self.module,self.server,self.client);
		mega_triple_join((
			module.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::ModuleScript}),
			server.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::Script}),
			client.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::LocalScript}),
		))
	}
}
struct QueryQuad{
	module_implicit:QueryHandle,
	module_explicit:QueryHandle,
	server:QueryHandle,
	client:QueryHandle,
}
impl QueryQuad{
	fn rox_rojo(search_path:&PathBuf,search_name:&str)->Self{
		let fill=QueryTriple::rox_rojo(search_path,search_name,true);
		Self{
			module_implicit:QuerySingle::rox(search_path,search_name).script,//Script.lua
			module_explicit:fill.module,//Script.module.lua
			server:fill.server,
			client:fill.client,
		}
	}
}
impl Query for QueryQuad{
	async fn resolve(self)->QueryHintResult{
		let (module_implicit,module_explicit,server,client)=tokio::join!(self.module_implicit,self.module_explicit,self.server,self.client);
		mega_quadruple_join((
			module_implicit.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::ModuleScript}),
			module_explicit.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::ModuleScript}),
			server.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::Script}),
			client.map_err(|e|QueryResolveError::JoinError(e))?.map(|file|FileHint{file,hint:ScriptHint::LocalScript}),
		))
	}
}

struct ScriptWithOverrides{
	overrides:PropertiesOverride,
	source:String,
}

fn extract_script_overrides(mut source:String)->AResult<ScriptWithOverrides>{
	let mut overrides=PropertiesOverride::default();
	let mut count=0;
	for line in source.lines(){
		//only string type properties are supported atm
		if let Some(captures)=lazy_regex::regex!(r#"^\-\-\!\s*Properties\.([A-z]\w*)\s*\=\s*"(\w+)"$"#)
		.captures(line){
			count+=line.len();
			match &captures[1]{
				"Name"=>overrides.name=Some(captures[2].to_owned()),
				"ClassName"=>overrides.class=Some(captures[2].to_owned()),
				other=>Err(anyhow::Error::msg(format!("Unimplemented property {other}")))?,
			}
		}else{
			break;
		}
	}
	Ok(ScriptWithOverrides{overrides,source:source.split_off(count)})
}

async fn script_node(search_name:&str,mut file:FileWithName,hint:ScriptHint)->AResult<CompileNode>{
	//read entire file
	let mut buf=String::new();
	file.file.read_to_string(&mut buf).await?;
	//regex script according to Properties lines at the top
	let script_with_overrides=extract_script_overrides(buf)?;
	//script
	Ok(CompileNode{
		blacklist:Some(file.name),
		name:script_with_overrides.overrides.name.unwrap_or_else(||search_name.to_owned()),
		class:match (script_with_overrides.overrides.class.as_deref(),hint){
			(Some("ModuleScript"),_)
			|(None,ScriptHint::ModuleScript)=>CompileClass::ModuleScript(script_with_overrides.source),
			(Some("LocalScript"),_)
			|(None,ScriptHint::Script)=>CompileClass::LocalScript(script_with_overrides.source),
			(Some("Script"),_)
			|(None,ScriptHint::LocalScript)=>CompileClass::Script(script_with_overrides.source),
			other=>Err(anyhow::Error::msg(format!("Invalid hint or class {other:?}")))?,
		},
	})
}

async fn model_node(search_name:&str,mut file:FileWithName)->AResult<CompileNode>{
	//read entire file
	let mut buf=Vec::new();
	file.file.read_to_end(&mut buf).await?;
	//model
	Ok(CompileNode{
		blacklist:Some(file.name),
		name:search_name.to_owned(),//wrong but gets overwritten by internal model name
		class:CompileClass::Model(buf),
	})
}

async fn locate_override_file(entry:&tokio::fs::DirEntry,style:Option<DecompileStyle>)->AResult<CompileNode>{
	let contents_folder=entry.path();
	let file_name=entry.file_name();
	let search_name=file_name.to_str().unwrap();
	//scan inside the folder for an object to define the class of the folder
	let script_query=async {match style{
		Some(DecompileStyle::Rox)=>QuerySingle::rox(&contents_folder,search_name).resolve().await,
		Some(DecompileStyle::RoxRojo)=>QueryQuad::rox_rojo(&contents_folder,search_name).resolve().await,
		Some(DecompileStyle::Rojo)=>QueryTriple::rojo(&contents_folder).resolve().await,
		//try all three and complain if there is ambiguity
		None=>mega_triple_join(tokio::join!(
			QuerySingle::rox(&contents_folder,search_name).resolve(),
			//true=search for module here to avoid ambiguity with QuerySingle::rox results
			QueryTriple::rox_rojo(&contents_folder,search_name,true).resolve(),
			QueryTriple::rojo(&contents_folder).resolve(),
		))
	}};
	//model files are rox & rox-rojo only, so it's a lot less work...
	let model_query=get_file_async(contents_folder.clone(),format!("{}.rbxmx",search_name));
	//model? script? both?
	Ok(match tokio::join!(script_query,model_query){
		(Ok(FileHint{file,hint}),Err(QueryResolveError::NotFound))=>script_node(search_name,file,hint).await?,
		(Err(QueryResolveError::NotFound),Ok(file))=>model_node(search_name,file).await?,
		(Ok(_),Ok(_))=>Err(QueryResolveError::Ambiguous)?,
		//neither
		(Err(QueryResolveError::NotFound),Err(QueryResolveError::NotFound))=>CompileNode{
			name:search_name.to_owned(),
			blacklist:None,
			class:CompileClass::Folder,
		},
		//other error
		(Err(e),_)
		|(_,Err(e))=>Err(e)?
	})
}


enum FileDiscernment{
	Model,
	Script(ScriptHint),
}

async fn discern_file(entry:&tokio::fs::DirEntry,style:Option<DecompileStyle>)->AResult<CompileNode>{
	let mut file_name=entry
	.file_name()
	.into_string()
	.map_err(|e|anyhow::Error::msg(format!("insane file name {e:?}")))?;
	//reject goobers
	let is_goober=match style{
		Some(DecompileStyle::Rojo)=>true,
		_=>false,
	};
	let (ext_len,file_discernment)={
		if let Some(captures)=lazy_regex::regex!(r"^.*(.module.lua|.client.lua|.server.lua)$")
		.captures(file_name.as_str()){
			let ext=&captures[1];
			(ext.len(),match ext{
				".module.lua"=>{
					if is_goober{
						Err(anyhow::Error::msg(format!("File extension {ext} not supported in style {style:?}")))?;
					}
					FileDiscernment::Script(ScriptHint::ModuleScript)
				},
				".client.lua"=>FileDiscernment::Script(ScriptHint::LocalScript),
				".server.lua"=>FileDiscernment::Script(ScriptHint::Script),
				_=>panic!("Regex failed"),
			})
		}else if let Some(captures)=lazy_regex::regex!(r"^.*(.rbxmx|.lua)$")
		.captures(file_name.as_str()){
			let ext=&captures[1];
			(ext.len(),match ext{
				".rbxmx"=>{
					if is_goober{
						Err(anyhow::Error::msg(format!("File extension {ext} not supported in style {style:?}")))?;
					}
					FileDiscernment::Model
				},
				".lua"=>FileDiscernment::Script(ScriptHint::ModuleScript),
				_=>panic!("Regex failed"),
			})
		}else{
			return Err(anyhow::Error::msg("No file extension"));
		}
	};
	file_name.truncate(file_name.len()-ext_len);
	let file=tokio::fs::File::open(entry.path()).await?;
	Ok(match file_discernment{
		FileDiscernment::Model=>model_node(file_name.as_str(),FileWithName{file,name:file_name.clone()}).await?,
		FileDiscernment::Script(hint)=>script_node(file_name.as_str(),FileWithName{file,name:file_name.clone()},hint).await?,
	})
}

#[derive(Debug)]
enum ScriptHint{
	Script,
	LocalScript,
	ModuleScript,
}
struct FileHint{
	file:FileWithName,
	hint:ScriptHint,
}

enum PreparedData{
	Model(rbx_dom_weak::WeakDom),
	Builder(rbx_dom_weak::InstanceBuilder),
}

enum CompileClass{
	Folder,
	Script(String),
	LocalScript(String),
	ModuleScript(String),
	Model(Vec<u8>),
}

struct CompileNode{
	name:String,
	blacklist:Option<String>,
	class:CompileClass,
}

enum CompileStackInstruction{
	TraverseReferent(rbx_dom_weak::types::Ref,Option<String>),
	PopFolder,
}

struct CompileConfig{
	input_folder:PathBuf,
	output_file:PathBuf,
	template:Option<PathBuf>,
	style:Option<DecompileStyle>,
}

fn script_builder(class:&str,name:&str,source:String)->rbx_dom_weak::InstanceBuilder{
	let mut builder=rbx_dom_weak::InstanceBuilder::new(class);
	builder.set_name(name);
	builder.add_property("Source",rbx_dom_weak::types::Variant::String(source));
	builder
}

enum TooComplicated<T>{
	Stop,
	Value(T),
	Skip,
}

async fn compile(config:CompileConfig)->AResult<()>{
	//basically decompile in reverse order
	//load template dom
	let input={
		let template_path=config.template.unwrap_or_else(||{
			let mut template_path=config.input_folder.clone();
			template_path.push("template.rbxlx");
			template_path
		});
		//mr dom doesn't like tokio files
		std::io::BufReader::new(std::fs::File::open(template_path)?)
	};
	let mut dom=load_dom(input)?;

	//add in scripts and models
	let mut folder=config.input_folder.clone();
	folder.push("src");
	let mut stack:Vec<CompileStackInstruction>=dom.root().children().into_iter().map(|&referent|CompileStackInstruction::TraverseReferent(referent,None)).collect();
	while let Some(instruction)=stack.pop(){
		match instruction{
			CompileStackInstruction::TraverseReferent(item_ref,blacklist)=>{
				let sans={
					let item=dom.get_by_ref(item_ref).ok_or(anyhow::Error::msg("null child ref"))?;
					sanitize(item.name.as_str()).to_string()
				};
				folder.push(sans.as_str());
				stack.push(CompileStackInstruction::PopFolder);
				//check if a folder exists with item.name
				if let Ok(dir)=tokio::fs::read_dir(folder.as_path()).await{
					let mut exist_names:std::collections::HashSet<String>={
						let item=dom.get_by_ref(item_ref).ok_or(anyhow::Error::msg("null child ref"))?;
						//push existing dom children objects onto stack (unrelated to exist_names)
						stack.extend(item.children().into_iter().map(|&referent|CompileStackInstruction::TraverseReferent(referent,None)));
						//get names of existing objects
						item.children().into_iter().map(|&child_ref|{
							let child=dom.get_by_ref(child_ref).ok_or(anyhow::Error::msg("null child ref"))?;
							Ok::<_,anyhow::Error>(sanitize(child.name.as_str()).to_string())
						}).collect::<AResult<_>>()?
					};
					if let Some(dont)=blacklist{
						exist_names.insert(dont);
					}
					//generate children from folder contents UNLESS! item already has a child of the same name

					let style=config.style;
					let exist_names=&exist_names;
					futures::stream::unfold(dir,|mut dir1|async{
						//thread the needle! follow the path that dir takes!
						let ret1={
							//capture a scoped mutable reference so we can forward dir to the next call even on an error
							let dir2=&mut dir1;
							(||async move{//error catcher so I can use ?
								let ret2=if let Some(entry)=dir2.next_entry().await?{
									//cull early even if supporting things with identical names is possible
									if exist_names.contains(entry.file_name().to_str().unwrap()){
										TooComplicated::Skip
									}else{
										TooComplicated::Value(entry)
									}
								}else{
									TooComplicated::Stop
								};
								Ok::<_,anyhow::Error>(ret2)
							})().await
						};
						match ret1{
							Ok(TooComplicated::Stop)=>None,
							Ok(TooComplicated::Skip)=>Some((Ok(None),dir1)),
							Ok(TooComplicated::Value(v))=>Some((Ok(Some(v)),dir1)),
							Err(e)=>Some((Err(e),dir1)),
						}
					})

					//gotta spawn off the worker threads (Model is slow)
					.then(|bog|async{
						match bog{
							Ok(Some(entry))=>tokio::spawn(async move{
								let met=entry.metadata().await?;
								//discern that bad boy
								let compile_class=match met.is_dir(){
									true=>locate_override_file(&entry,style).await?,
									false=>discern_file(&entry,style).await?,
								};
								//prepare data structure
								Ok(Some((compile_class.blacklist,match compile_class.class{
									CompileClass::Folder=>PreparedData::Builder(rbx_dom_weak::InstanceBuilder::new("Folder").with_name(compile_class.name.as_str())),
									CompileClass::Script(source)=>PreparedData::Builder(script_builder("Script",compile_class.name.as_str(),source)),
									CompileClass::LocalScript(source)=>PreparedData::Builder(script_builder("LocalScript",compile_class.name.as_str(),source)),
									CompileClass::ModuleScript(source)=>PreparedData::Builder(script_builder("ModuleScript",compile_class.name.as_str(),source)),
									CompileClass::Model(buf)=>PreparedData::Model(rbx_xml::from_reader_default(std::io::Cursor::new(buf))?),
								})))
							}).await?,
							Ok(None)=>Ok(None),
							Err(e)=>Err(e),
						}
					})

					//is this even what I want?
					.map(|f|async{f}).buffer_unordered(32)

					//begin processing immediately
					.fold((&mut stack,&mut dom),|(stack,dom),bog:Result<_,anyhow::Error>|async{
						//push child objects onto dom serially as they arrive
						match bog{
							Ok(Some((blacklist,data)))=>{
								let referent=match data{
									PreparedData::Model(mut model_dom)=>{
										let referent=model_dom.root().children()[0];
										model_dom.transfer(referent,dom,item_ref);
										referent
									},
									PreparedData::Builder(script)=>dom.insert(item_ref,script),
								};
								//new children need to be traversed
								stack.push(CompileStackInstruction::TraverseReferent(referent,blacklist));
							},
							Ok(None)=>(),
							Err(e)=>println!("error lole {e:?}"),
						}
						(stack,dom)
					}).await;
				}
			},
			CompileStackInstruction::PopFolder=>assert!(folder.pop(),"pop folder bad"),
		}
	}

	let mut output_place=config.output_file.clone();
	if output_place.extension().is_none()&&tokio::fs::try_exists(output_place.as_path()).await?{
		output_place.push("place.rbxl");
	}
	let output=std::io::BufWriter::new(std::fs::File::create(output_place)?);
	//write inner objects
	rbx_binary::to_writer(output,&dom,dom.root().children())?;
	Ok(())
}