import path from 'node:path';
import express from 'express';
import {Liquid} from 'liquidjs';
import {RateLimit} from 'async-sema';
import fileUpload from 'express-fileupload';

import Graph from 'graphology';
import forceAtlas2 from 'graphology-layout-forceatlas2';
import circular from 'graphology-layout/circular';
import {assignLayout} from 'graphology-layout/utils';

import {singleSource, singleSourceLength} from 'graphology-shortest-path/unweighted';

import Pep440Version, {Pep440VersionRule} from './pep440version.ts';
import {version} from 'bun';

const liquidEngine = new Liquid({root: path.resolve(__dirname, 'views/'), jsTruthy: true});

const app = express();

app.use(express.json()); // To support JSON-encoded bodies
app.use(express.urlencoded()); // To support URL-encoded bodies
app.use(fileUpload({
  limits: { fileSize: 50 * 1024 * 1024 },
}));

app.engine('liquid', liquidEngine.express());
app.set('views', [path.join(__dirname, 'views')]);
app.set('view engine', 'liquid');

app.use('/static', express.static('static'));

app.get('/', (request, res) => {
	res.render('index');
});


declare class RateLimit {
	constructor(max: number);
}

const rateLimit: any = new RateLimit(5);



function extractInfoFromPythonDepString(depstring: string) {
	const parts = depstring.split(';');

	const namever = parts[0];

	// https://stackoverflow.com/questions/24470567/what-are-the-requirements-for-naming-python-modules
	const match = namever.match(/^(?<name>[a-zA-Z_\-][\w\-]*)((?<operator>.=)(?<version>.+))?/);


	if (match !== null && match.groups !== undefined) {
		let rule;

		if( match.groups.version ) {
			const version = new Pep440Version(match.groups.version);

			rule = new Pep440VersionRule(
				version, 
				match.groups.operator
			)
		}
		else {
			rule = Pep440VersionRule.getRuleMatchingAnyVersion()
		}

		return {
			name: match.groups.name,
			rule: rule
		};
	}
	else {
		return undefined;
	}
}

async function getRawPackageInfo(packagename: string) {
	await rateLimit();

	const pypires = await fetch(`https://pypi.org/pypi/${packagename}/json`);
	const json = await pypires.json();

	return json;
}


interface PipReleaseFile {
	size: number;
	packagetype: string;
	upload_time_iso_8601: string;
	[key: string]: any;
}





async function getFullPackageInfo(packagename: string, rule: Pep440VersionRule = Pep440VersionRule.getRuleMatchingAnyVersion(), fromGraph = new Graph()) {
	const dependencyGraph = fromGraph;

	// Analyse the requested package

	const packageJson = await getRawPackageInfo(packagename);

	let longestDependencyChain = 0;
	
	//const dependenciesList = packageJson.info.requires_dist ?? [];
	
	const recurseDepsPackageInfo = async (packagename: string, rule: Pep440VersionRule = Pep440VersionRule.getRuleMatchingAnyVersion(), descPath: string = "") => {
		console.log(`[Recurse] Going to scan package ${packagename}`);

		if( descPath == "" ) {
			descPath = packagename;
		}
		else {
			descPath += `/${packagename}`
		}

		if( dependencyGraph.hasNode(packagename) ) {
			// figure out if the current path taken to this package is shorter than the one in the graph

			// have to add the current package name manually as it isn't added yet
			const paramPathParts: string[] = descPath.split('/');
			const graphPathParts: string[] = dependencyGraph.getNodeAttribute(packagename, 'path').split('/');

			if( paramPathParts.length < graphPathParts.length ) {
				// if so, change the graph path to the current one
				dependencyGraph.setNodeAttribute(packagename, 'path', descPath)
				console.log(`[Recurse] Found better way of getting to ${packagename}: ${descPath}`);
			}

			const shortestDist = Math.min( paramPathParts.length, graphPathParts.length );
			if( longestDependencyChain < shortestDist ) {
				longestDependencyChain = shortestDist;
			}
		
			console.log(`[Recurse] Already scanned ${packagename} ; skipping.`);
			return;
		}

		console.log(`[Recurse] Scanning package ${packagename}`);

		const json = await getRawPackageInfo(packagename);

		// ==================================================
		// 1. get biggest file of highest possible version
		// TODO: don't choose biggest file, choose in a smart way (like asking the user's OS and arch)

		const releasesEntries = Object.entries(json.releases as {[key: string]: PipReleaseFile[]});
		
		const releases: {[key: string]: PipReleaseFile[]} = {};

		for( const [version, data] of releasesEntries ) {
			try {
				releases[new Pep440Version(version).releaseString()] = data;
			}
			catch {
				console.log(`Failed to parse version: ${version}`);
			}
		}

		const versions = Object.keys(releases).map( v => {
			console.log(`[Recurse] Parsing version ${v} for ${packagename}`);
			return new Pep440Version(v);
		}); 
		const highestVersions = rule.getSortedMatchingVersions(versions);

		if( highestVersions.length === 0 ) {
			throw new Error("MERDE!");
		}

		
		let highestVersion: undefined | Pep440Version = undefined;

		for( const version of highestVersions ) {
			if( releases[version.releaseString()].length !== 0 ) {
				highestVersion = version;
				break;
			}
		}

		if( highestVersion === undefined ) {
			throw new Error("MERDE!");
		}

		const highestRelease = releases[highestVersion.releaseString()];
		const biggestFile = highestRelease.sort( (a, b) => b.size - a.size )[0];

		console.log(`[Recurse] ${packagename} has highest version ${highestVersion.releaseString()}`);

		// ==================================================
		// 2. add to the graph

		const summary = json.summary;
	
		dependencyGraph.addNode(packagename, {
			label: packagename,
			size: 10,

			summary: summary,
			version: highestVersion.releaseString(),
			weight: biggestFile.size,
			path: descPath
		});

		

		/////////////////

		const dependenciesList = packageJson.info.requires_dist ?? [];

		console.log(`[Recurse] ${packagename} has deps:\n - ${dependenciesList.join('\n - ')}`);

		for( const depString of dependenciesList ) {
			console.log(`[Recurse] ${packagename} depends on: ${depString}`);

			const info = extractInfoFromPythonDepString(depString);

			if( info === undefined ) continue;

			await recurseDepsPackageInfo(info.name, info.rule, descPath);

			if( dependencyGraph.hasEdge(packagename, info.name) === false ) {
				dependencyGraph.addEdge(packagename, info.name);
			}
		}
	}

	await recurseDepsPackageInfo(packagename, rule);

	console.log(`Longest dependency chain is ${longestDependencyChain}`);



	//const paths = singleSource(dependencyGraph, packagename)

	

	const depthColors = [
		"#D14D41",
		"#DA702C",
		"#D0A215",
		"#879A39",
		"#3AA99F",
		"#4385BE",
		"#8B7EC8",
		"#CE5D97",
	]

	const lengthmap = singleSourceLength(dependencyGraph, packagename);
	const longestPathLength = Math.max(...Object.values(lengthmap))

	for( const [node, dist] of Object.entries(lengthmap) ) {
		dependencyGraph.setNodeAttribute(node, 'color', depthColors[dist + 1] )
		dependencyGraph.setNodeAttribute(node, 'actual_depth', dist )
	}


	dependencyGraph.forEachEdge((edge, attrs, source, target, sourceAttrs, targetAttrs) => {
		const sourceDepth = sourceAttrs.actual_depth; //.path.split('/').length - 1;
		const targetDepth = targetAttrs.actual_depth; //.path.split('/').length - 1;

		if( sourceDepth >= targetDepth ) {
			dependencyGraph.setEdgeAttribute( edge, "color", "#B7B5AC")
			dependencyGraph.setEdgeAttribute( edge, "size", 1)

			dependencyGraph.setEdgeAttribute( edge, "weight", 1)
		}
		else {
			dependencyGraph.setEdgeAttribute( edge, "color", depthColors[ sourceDepth ])
			dependencyGraph.setEdgeAttribute( edge, "size", 3 + 3 * (longestPathLength - sourceDepth))

			dependencyGraph.setEdgeAttribute( edge, "weight", 3 + 3 * (longestPathLength - sourceDepth))
		}

		dependencyGraph.setEdgeAttribute( edge, "type", "arrow");
	});


	


	

	//circular.assign(dependencyGraph, {scale: 100});
	//forceAtlas2.assign(dependencyGraph, 100)


	dependencyGraph.setNodeAttribute(packagename, 'size', 20)
	//dependencyGraph.setNodeAttribute(packagename, 'x', 0)
	//dependencyGraph.setNodeAttribute(packagename, 'y', 0)



	circular.assign(dependencyGraph, {scale: 100});


	
	const positions = forceAtlas2(dependencyGraph, {
		iterations: 50,
		settings: {
			edgeWeightInfluence: 1,
			...forceAtlas2.inferSettings(dependencyGraph),
		}
	});

	assignLayout(dependencyGraph, positions);


	return dependencyGraph;
}

app.get('/graph/:packagename', (req, res) => {
	const packagename = req.params.packagename;

	res.render('graph', {
		packagename: packagename,
	})
}); 

app.get('/api/graph/:packagename', async (req, res) => {
	const packagename = req.params.packagename;

	const depGraph = await getFullPackageInfo(packagename);

	const serializedDepGraph = depGraph.export();

	let totalDownloadSize = 0;

	depGraph.forEachNode((node, attrs) => {
		totalDownloadSize += attrs.weight;
	})
	
	const units = [
		'b',
		'kb',
		'Mb',
		'Gb'
	]

	let currentUnit = 0;
	while( totalDownloadSize > 1000 ) {
		totalDownloadSize = totalDownloadSize / 1000;
		currentUnit++;
	}

	const unit = units[currentUnit];

	res.json({
		weight: totalDownloadSize,
		weightUnit: unit,
		graph: serializedDepGraph
	});
});


app.post('/api/upload-requirements', async (req, res) => {
	// get the uploaded requirements.txt file, from the input with the name "file"
	const files = req.files;

	if( files === undefined || files === null ) {
		res.status(400);
		res.send("No file uploaded");
		return;
	}

	const file = files.requirementsFile;

	if( file === undefined || file === null ) {
		res.status(400);
		res.send("No file uploaded");
		return;
	}

	if( Array.isArray(file) ) {
		res.status(400);
		res.send("Don't send multiple files.");
		return;
	}

	// convert to string
	const content = '' + file.data;
	const infos = content.replaceAll('\r\n', '\n').split('\n').map(extractInfoFromPythonDepString);

	let dependencyGraph = new Graph();
	for( const info of infos ) {
		if( info === undefined ) {
			console.log(`Got an undefined info !`)
			continue;
		}

		dependencyGraph = await getFullPackageInfo(info.name, info.rule, dependencyGraph);
	}

	const serializedDepGraph = dependencyGraph.export();




	const getHumanWeight = (weight: number) => {
		const units = [
			'b',
			'kb',
			'Mb',
			'Gb'
		]

		let currentUnit = 0;
		while( weight > 1000 ) {
			weight = weight / 1000;
			currentUnit++;
		}

		return `${Math.round(weight)}${units[currentUnit]}`
	}



	let nbNodes = 0;
	let totalDownloadSize = 0;

	dependencyGraph.forEachNode((node, attrs) => {
		nbNodes++;
		totalDownloadSize += attrs.weight;
	})


	let packageByWeight: {name: string, weight: number, humanWeight: string}[] = [];

	dependencyGraph.forEachNode((node, attrs) => {
		packageByWeight.push({
			name: node,
			weight: attrs.weight,
			humanWeight: getHumanWeight(attrs.weight),
		})
	});

	packageByWeight = packageByWeight.sort( (a, b) => b.weight - a.weight);



	const humanDownloadSize = getHumanWeight(totalDownloadSize);

	

	
	res.render('fullgraph', {
		//packagename: packagename,
		nb_deps: nbNodes,
		totalWeight: {
			raw: totalDownloadSize,
			value: humanDownloadSize,
		},
		graph: serializedDepGraph,
		packageByWeight: packageByWeight
	});
})



/**
	* Get info about a package
	*/ /*
async function getFullPackageInfo(packagename: string, versionRequirement={operator: "", version: ""}, seenBefore: Set<string> = new Set([])) {
	const packagejson = await getRawPackageInfo(packagename);

	const name = packagejson.info.name;

	const summary = packagejson.info.summary;

	const dependenciesList = packagejson.info.requires_dist ?? [];


	const builtDepsList: Map<string, {[key: string]: string]}>


	for( const depString of dependenciesList ) {
		const dep = extractInfoFromPythonDepString(depString);

		if( seenBefore.has(dep.name) ) {
			continue;
		}

		const json = await getRawPackageInfo(dep.name, dep.version)


	}


}*/






/*
app.post('/api/dependency-tree', async (request, res) => {
	const packagename = request.body.package;
	console.log("Requested package: ", packagename);

	const json = await getRawPackageInfo(packagename);

	const name = json.info.name;
	const summary = json.info.summary;

	let deps = json.info.requires_dist ? json.info.requires_dist.map(e => extractInfoFromPythonDepString(e)) : [];
	// avoid duplicates (sometimes packages list themselves as a dependency to create "dependency groups" (?))
	deps = deps.filter( dep => dep.name !== packagename );

	const versions = Object.entries(json.releases).filter( ([k, v]) => v.length > 0 );

	// sort by size, preferring wheels
	const versionsSorted = versions.map( ([versionNumber, filesArray]) => {
			const wheels = filesArray.filter( file => file.packagetype === 'bdist_wheel' );

			if( wheels.length > 0 ) {
				// sort by size
				const biggestWheel = wheels.sort( (a, b) => b.size - a.size )[0];

				return [versionNumber, biggestWheel];
			}
			else {
				const biggestFile = filesArray.sort( (a, b) => b.size - a.size )[0];

				return [versionNumber, biggestFile];
			}
		});


	//const sorted = filesArray.sort( (a, b) => b.upload_time_iso8601 - a.upload_time_iso8601 );

	const [latestVersionNumber, latestVersion] = versions[0];
	
	const sortedFiles = latestVersion.sort((a, b) => b.size - a.size);
	const size = sortedFiles[0].size;

	res.render('dependency', {
		name,
		summary,
		weight: size,
		dependencies: deps,
		// DEBUG
		has_parent: request.body.isfirst !== "true",
	});
});*/

app.listen(8080);