const fs = require('fs');
const path = require('path');
const { CEIType, loadJavaLibraryCacheFile } = require('java-mti');
const analytics = require('../analytics');
const { trace, time, timeEnd } = require('../logging');

/**
 * @param {string} extensionPath install path of extension
 * @param {string[]} additional_libs set of androidx library names to include eg: ["androidx.activity:activity"]
 * @returns {Promise<Map<string,CEIType>>}
 */
async function loadAndroidSystemLibrary(extensionPath, additional_libs) {
    analytics.time('android-library-load');
    time('android-library-load');
    let library;
    try {
        if (!extensionPath) {
            throw new Error('Missing extension path')
        }
        const cache_folder = path.join(extensionPath, 'langserver', '.library-cache');
        trace(`loading android library from ${cache_folder} with androidx libs: ${JSON.stringify(additional_libs)}`)
        const typemap = await loadJavaLibraryCacheFile(path.join(cache_folder, 'android-34.zip'));
        if (Array.isArray(additional_libs) && additional_libs.length) {
            await loadJavaLibraryCacheFile(path.join(cache_folder, 'androidx-20200701.zip'), additional_libs, typemap);
        }
        trace(`loaded ${typemap.size} types into android library`);
        library = typemap;
    } finally {
        timeEnd('android-library-load');
        analytics.timeEnd('android-library-load', 'ms', { libs: additional_libs, typecount: library ? library.size : 0 });
    }
    return library;
}

/**
 * @param {string} cache_folder 
 */
async function loadHighestAPIPlatform(cache_folder) {
    /** @type {fs.Dirent[]} */
    const files = await new Promise((res, rej) => {
        fs.readdir(cache_folder, {withFileTypes: true}, (err, files) => err ? rej(err) : res(files));
    });

    // find the file with the highest API level
    let best_match = {
        api: 0,
        /** @type {fs.Dirent} */
        file: null,
    };
    files.forEach(file => {
        const m = file.name.match(/^android-(\d+)\.zip$/);
        if (!m) return;
        const api = parseInt(m[1], 10);
        if (api > best_match.api) {
            best_match = {
                api,
                file,
            }
        }
    });
    if (!best_match.file) {
        throw new Error(`No valid platform cache files found in ${cache_folder}`)
    }
    console.log(`loading android platform cache: ${best_match.file.name}`);

    const cache_file = path.join(cache_folder, best_match.file.name);
    const typemap = loadJavaLibraryCacheFile(cache_file);

    return typemap;
}

exports.loadAndroidSystemLibrary = loadAndroidSystemLibrary;