/**
 * Fetch and edit constants from the skyblock-constants repo
 */

import fetch from 'node-fetch'
import { Agent } from 'https'
import NodeCache from 'node-cache'

const httpsAgent = new Agent({
	keepAlive: true
})

const githubApiBase = 'https://api.github.com'
const owner = 'skyblockstats'
const repo = 'skyblock-constants'

/**
 * Send a request to the GitHub API
 * @param method The HTTP method, for example GET, PUT, POST, etc
 * @param route The route to send the request to
 * @param headers The extra headers
 * @param json The JSON body, only applicable for some types of methods
 */
async function fetchGithubApi(method: string, route: string, headers?: any, json?: any) {
	return await fetch(
		githubApiBase + route,
		{
			agent: () => httpsAgent,
			body: json ? JSON.stringify(json) : null,
			method,
			headers: Object.assign({
				'Authorization': `token ${process.env.github_token}`
			}, headers),
		}
	)
}

interface GithubFile {
	path: string
	content: string
	sha: string
}

// cache files for an hour
const fileCache = new NodeCache({
	stdTTL: 60 * 60,
	checkperiod: 60,
	useClones: false,
})


/**
 * Fetch a file from skyblock-constants
 * @param path The file path, for example stats.json
 */
async function fetchFile(path: string): Promise<GithubFile> {
	if (fileCache.has(path))
		return fileCache.get(path)

	const r = await fetchGithubApi(
		'GET',
		`/repos/${owner}/${repo}/contents/${path}`,
		{
			'Accept': 'application/vnd.github.v3+json',
			'Authorization': undefined
		},
	)
	const data = await r.json()
	const file = {
		path: data.path,
		content: Buffer.from(data.content, data.encoding).toString(),
		sha: data.sha
	}
	fileCache.set(path, file)
}

/**
 * Edit a file on skyblock-constants
 * @param file The GithubFile you got from fetchFile
 * @param message The commit message
 * @param newContent The new content in the file
 */
async function editFile(file: GithubFile, message: string, newContent: string) {
	fileCache.set(file.path, newContent)
	await fetchGithubApi(
		'PUT',
		`/repos/${owner}/${repo}/contents/${file.path}`,
		{ 'Content-Type': 'application/json' },
		{
			message: message,
			content: Buffer.from(newContent).toString('base64'),
			sha: file.sha,
			branch: 'main'
		}
	)
}

/** Fetch all the known SkyBlock stats as an array of strings */
export async function fetchStats(): Promise<string[]> {
	const file = await fetchFile('stats.json')
	try {
		return JSON.parse(file.content)
	} catch {
		// probably invalid json, return an empty array
		return []
	}
}

/** Fetch all the known SkyBlock collections as an array of strings */
export async function fetchCollections(): Promise<string[]> {
	const file = await fetchFile('collections.json')
	try {
		return JSON.parse(file.content)
	} catch {
		// probably invalid json, return an empty array
		return []
	}
}

/** Add stats to skyblock-constants. This has caching so it's fine to call many times */
export async function addStats(addingStats: string[]) {
	if (addingStats.length === 0) return // no stats provided, just return

	const file = await fetchFile('stats.json')
	if (!file.path)
		return
	let oldStats: string[]
	try {
		oldStats = JSON.parse(file.content)
	} catch {
		// invalid json, set it as an empty array
		oldStats = []
	}
	const updatedStats = oldStats
		.concat(addingStats)
		// remove duplicates
		.filter((value, index, array) => array.indexOf(value) === index)
		.sort((a, b) => a.localeCompare(b))
	const newStats = updatedStats.filter(value => !oldStats.includes(value))

	// there's not actually any new stats, just return
	if (newStats.length === 0) return

	const commitMessage = newStats.length >= 2 ? `Add ${newStats.length} new stats` : `Add '${newStats[0]}'`

	await editFile(file, commitMessage, JSON.stringify(updatedStats, null, 2))
}

/** Add stats to skyblock-constants. This has caching so it's fine to call many times */
export async function addCollections(addingCollections: string[]) {
	if (addingCollections.length === 0) return // no stats provided, just return

	const file = await fetchFile('collections.json')
	if (!file.path)
		return
	let oldCollections: string[]
	try {
		oldCollections = JSON.parse(file.content)
	} catch {
		// invalid json, set it as an empty array
		oldCollections = []
	}
	const updatedCollections = oldCollections
		.concat(addingCollections)
		// remove duplicates
		.filter((value, index, array) => array.indexOf(value) === index)
		.sort((a, b) => a.localeCompare(b))
	const newCollections = updatedCollections.filter(value => !oldCollections.includes(value))

	// there's not actually any new stats, just return
	if (newCollections.length === 0) return

	const commitMessage = newCollections.length >= 2 ? `Add ${newCollections.length} new collections` : `Add '${newCollections[0]}'`

	await editFile(file, commitMessage, JSON.stringify(updatedCollections, null, 2))
}