import axios from "axios";
import * as bluebird from "bluebird";
import * as fs from "fs";
import * as path from "path";
import * as chalk from 'chalk';
import * as config from "../common/config";

import {
    getChainAssetLogoPath,
    getChainBlacklistPath
} from "../common/repo-structure";

const binanceChain = "binance"
const binanceAssetsUrl = config.getConfig("binance_assets_url", "https://explorer.binance.org/api/v1/assets?page=1&rows=1000");

async function retrieveBep2AssetList() {
    console.log(`Retrieving assets info from: ${binanceAssetsUrl}`);
    const { assetInfoList } = await axios.get(binanceAssetsUrl).then(r => r.data);
    console.log(`Retrieved ${assetInfoList.length} asset infos`);
    return assetInfoList
}

function fetchImage(url) {
    return axios.get(url, { responseType: "stream" })
        .then(r => r.data)
        .catch(err => {
            throw `Error fetchImage: ${url} ${err.message}`;
        });
}

/// Return: array with images to fetch; {asset, assetImg}
export function findImagesToFetch(assetInfoList: any, blacklist: string[]): any[] {
    let toFetch: any[] = [];
    console.log(`Checking for asset images to be fetched`);
    assetInfoList.forEach(({asset, assetImg}) => {
        process.stdout.write(`.${asset} `);
        if (assetImg) {
            if (blacklist.indexOf(asset) != -1) {
                console.log();
                console.log(`${asset} is blacklisted`);
            } else {
                const imagePath = getChainAssetLogoPath(binanceChain, asset);
                if (!fs.existsSync(imagePath)) {
                    console.log(chalk.red(`Missing image: ${asset}`));
                    toFetch.push({asset, assetImg});
                }
            }
        }
    });
    console.log();
    console.log(`${toFetch.length} asset image(s) to be fetched`);
    return toFetch;
}


async function fetchMissingImages(toFetch: any[]): Promise<string[]> {
    console.log(`Attempting to fetch ${toFetch.length} asset image(s)`);
    let fetchedAssets: string[] = [];
    await bluebird.each(toFetch, async ({ asset, assetImg }) => {
        if (assetImg) {
            const imagePath = getChainAssetLogoPath(binanceChain, asset);
            fs.mkdir(path.dirname(imagePath), err => {
                if (err && err.code != `EEXIST`) throw err;
            });
            await fetchImage(assetImg).then(buffer => {
                buffer.pipe(fs.createWriteStream(imagePath));
                fetchedAssets.push(asset)
                console.log(`Fetched image ${asset} ${imagePath} from ${assetImg}`)
            });
        }
    });
    console.log();
    return fetchedAssets;
}

export async function update() {
    // retrieve missing token images; BEP2 (bep8 not supported)
    const bep2InfoList = await retrieveBep2AssetList();
    const blacklist: string[] = require(getChainBlacklistPath(binanceChain));

    const toFetch = findImagesToFetch(bep2InfoList, blacklist);
    const fetchedAssets = await fetchMissingImages(toFetch);

    if (fetchedAssets.length > 0) {
        console.log(`Fetched ${fetchedAssets.length} asset(s):`);
        fetchedAssets.forEach(asset => console.log(`  ${asset}`));
    }
}