const axios = require('axios')
const fsp = require('fs').promises
const { existsSync, createWriteStream } = require('fs')

const endpoint = "https://api.mobygames.com/v1"

const delay = ms => new Promise(resolve => setTimeout(resolve, ms))

// TODO move AC code to axios, move this to utilities.js
async function download(url, filename) {
	console.log(` -- mobygames: downloading file ${url}...`)
	const result = await axios({
		url,
		method: 'GET',
		responseType: 'stream'
	})
	await result.data.pipe(createWriteStream(filename))
}

/**
game example from cache:
{
  "game_id": 138,
  "moby_url": "http://www.mobygames.com/game/pac-man",
  "title": "Pac-Man"
}
*/
async function collectScreenshotsFor(game, buddyConfig) {
	const { platform, mobyGamesToken } = buddyConfig

	const id = game['game_id']
	const ext = url => url.split(".").pop()

	const screenshots = (await axios.get(`${endpoint}/games/${id}/platforms/${platform}/screenshots?api_key=${mobyGamesToken}`)).data.screenshots

	const titleshots = screenshots.filter(s => s.caption?.toLowerCase()?.indexOf("title screen") >= 0)
	const titleshot = titleshots.length == 0 ? screenshots[0].image : titleshots[0].image
	const titleshotfile = `data/mobygames/title_${id}_1.${ext(titleshot)}`

	// not sure if this is ok, we now take the SECOND LAST screenshot that doesn't contain 'title screen'
	// however, the screenshot could be a dull one, but taking something random isn't great either
	const gameshots = screenshots.filter(s => s.caption?.toLowerCase()?.indexOf("title screen") == -1)
	const gameshot = gameshots[gameshots.length < 2 ? 0 : gameshots.length - 2].image
	const gameshotfile = `data/mobygames/title_${id}_2.${ext(gameshot)}`

	await download(titleshot, titleshotfile)
	await download(gameshot, gameshotfile)

	return [ titleshotfile, gameshotfile ]
}

// for the gameboy: 10, 688 - see https://www.mobygames.com/browse/games/gameboy/list-games/
async function collect(buddyConfig) {
	const { platform, totalAmountOfGamesForPlatform, mobyGamesToken } = buddyConfig

	const overviewFile = `data/mobygames/games_${platform}.json`
	if(existsSync(overviewFile)) {
		console.log(' -- mobygames: retrieving list from cache...')
		const fileData = await fsp.readFile(overviewFile)
		return JSON.parse(fileData)
	}

	console.log(' -- mobygames: no overview json file found for platform, fetching...')
	const allGames = []
	for(let offset = 0; offset < totalAmountOfGamesForPlatform; offset += 100) {
		console.log(` -- mobygames: fetching platform ${platform} offset ${offset}...`)
		const result = await axios.get(`${endpoint}/games?platform=${platform}&api_key=${mobyGamesToken}&offset=${offset}`)
		allGames.push(result.data.games)

		// there's a rate limit of 1 request per second.
		await delay(1200)
	}

	const games = allGames.flat()
	await fsp.writeFile(overviewFile, JSON.stringify({ games }, null, 2))
	console.log(` -- mobygames: done collecting, result in games_${platform}.json!`)

	return { games }
}

module.exports = {
	collect,
	collectScreenshotsFor
}