import fs from "fs";
import path from "path";
import { createServer } from 'http-server';
import {
    Builder,
    By,
    until,
} from "selenium-webdriver";
import chrome from "selenium-webdriver/chrome.js";
import { } from "chromedriver";
import imghash from "imghash";
import hex64 from "hex64";
import leven from "leven";
import pixelmatch from "pixelmatch";
import { PNG } from "pngjs";

describe("Layout Rendering Tests", function () {
    this.timeout(90000);

    let driver, serverProcess;

    const LAYOUTS_FOLDER = "test/layouts";
    const SCREENSHOTS_FOLDER = "test/screenshots";
    const SPLITS_FOLDER = "test/splits";

    const startServer = async () => {
        return new Promise((resolve) => {
            serverProcess = createServer({ root: "./dist" });
            serverProcess.listen(8081, () => {
                resolve();
            });
        });
    };

    const findElement = async (selector) => {
        return driver.wait(until.elementLocated(selector));
    };

    const clickElement = async (selector) => {
        const element = await findElement(selector);
        await element.click();
    }

    const loadFile = async (filePath) => {
        const inputElement = await findElement(By.id("file-input"));
        await inputElement.sendKeys(path.resolve(filePath));
        await driver.sleep(500);
    }

    const hashToBinary = (hash) => {
        const buffer = Buffer.from(hash, "base64");
        const values = Array.from(buffer.values());
        return values.map((value) => value.toString(2).padStart(8, "0")).join("");
    };

    before(async () => {
        console.log('Starting server...');

        await startServer();

        console.log('Server started!');
        console.log('Preparing WebDriver for tests...');

        const options = new chrome.Options().windowSize({ width: 1200, height: 2400 }).addArguments("--headless");
        driver = await new Builder().forBrowser("chrome").setChromeOptions(options).build();

        await driver.get("http://localhost:8081");

        await driver.executeScript(() => {
            HTMLInputElement.prototype.click = function () {
                const existingFileInput = document.getElementById("file-input");
                if (existingFileInput) {
                    existingFileInput.remove();
                }
                this.style.display = "none";
                this.id = "file-input";
                document.body.appendChild(this);
            }
        });

        if (!fs.existsSync(SCREENSHOTS_FOLDER)) {
            fs.mkdirSync(SCREENSHOTS_FOLDER);
        }

        console.log('Ready to run tests!');
    });

    const testRendering = (layoutName, splitsName, expectedHash) => {
        it(`Renders the ${layoutName} layout with the ${splitsName} splits correctly`, async function () {
            this.timeout(10000);

            await clickElement(By.xpath(".//button[contains(text(), 'Layout')]"));
            await clickElement(By.xpath(".//button[contains(text(), 'Import')]"));
            await loadFile(`${LAYOUTS_FOLDER}/${layoutName}.ls1l`);
            await clickElement(By.xpath(".//button[contains(text(), 'Back')]"));

            await clickElement(By.xpath(".//button[contains(text(), 'Splits')]"));
            await clickElement(By.xpath(".//button[contains(text(), 'Import')]"));
            await loadFile(`${SPLITS_FOLDER}/${splitsName}.lss`);
            await clickElement(By.xpath("(.//button[contains(@aria-label, 'Open Splits')])[last()]"));
            await clickElement(By.xpath(".//button[contains(text(), 'Back')]"));

            const layoutElement = await findElement(By.className("layout"));

            // The icons load asynchronously, so we need to wait for them to load.
            await driver.sleep(500);

            const layoutScreenshot = await layoutElement.takeScreenshot();

            const tempFilePath = `${SCREENSHOTS_FOLDER}/${layoutName}.png`;

            fs.writeFileSync(tempFilePath, layoutScreenshot, "base64");
            const actualHashHex = await imghash.hash(tempFilePath, 24);
            const actualHash = hex64.encode(actualHashHex);

            const actualScreenshotPath = `${SCREENSHOTS_FOLDER}/${layoutName}_${splitsName}_${actualHash.replace("/", "$")}.png`;
            const expectedScreenshotPath = `${SCREENSHOTS_FOLDER}/${layoutName}_${splitsName}_${expectedHash.replace("/", "$")}.png`;

            fs.renameSync(tempFilePath, actualScreenshotPath);

            const actualBinary = hashToBinary(actualHash);
            const expectedBinary = hashToBinary(expectedHash);
            const distance = leven(actualBinary, expectedBinary);

            if (distance > 1) {
                let showWarning = false;
                try {
                    if (fs.existsSync(expectedScreenshotPath)) {
                        const actualImage = PNG.sync.read(fs.readFileSync(actualScreenshotPath));
                        const expectedImage = PNG.sync.read(fs.readFileSync(expectedScreenshotPath));
                        const { width, height } = actualImage;
                        const diff = new PNG({ width, height });

                        const numPixelsDifferent = pixelmatch(actualImage.data, expectedImage.data, diff.data, width, height, { threshold: 0.2 });

                        if (numPixelsDifferent === 0) {
                            showWarning = true;
                        }

                        fs.writeFileSync(`${SCREENSHOTS_FOLDER}/${layoutName}_${splitsName}_diff.png`, PNG.sync.write(diff));
                    }
                }
                finally {
                    if (showWarning) {
                        console.warn(`Render match despite mismatching hashes (${layoutName} layout with ${splitsName} splits)! ` +
                            `Expected hash: ${expectedHash}, actual hash: ${actualHash}`);
                    } else {
                        throw Error(`Render mismatch (${layoutName} layout with ${splitsName} splits)! ` +
                            `Expected hash: ${expectedHash}, actual hash: ${actualHash}`)
                    }
                }
            }
        });
    }

    testRendering("all_components", "default", "PwD-XAAAAAA2AAAO____________________AAAAAAAAAAAA____AAAA____AAAA____AAAAf_AAd_AAAAD-Nz___34HbwAG");
    testRendering("all_components", "pmw3", "PwD-XAAAAAA2AAAO_________sAPf8AAf4AC3_AH_-AOX-APXfAGX-AP18AOf-APXeAOX-AOD7AOQIAIAAD-b_j_____LwBs");
    testRendering("default", "default", "________8AADVVVVAAAAAAAAAAAA____________AAAAAAAAAAAA____VVVVAAAA____AAAAVVVVAAAAAADgAAD_________");
    testRendering("default", "pmw3", "b_gAb9-HV8AG__AHV_AG7kAGX-AGV-AOX8APX_gOX-AP28AO_-APX-APXeAOUQAOX-AOX_gP_-AfAAAAAADgAAD_q97_____");
    testRendering("splits_two_rows", "celeste", "b4AAYAAH________bwAA4AAHb-AA4AAHb-AAYAAHbwAA____bwAAYAAH_9VV____b_AAYAAH__wA____b_AAYAAPb8AAYAAP");
    testRendering("splits_with_labels", "celeste", "AAAAAAA8AAA3AAA3AAA3________WAAHfwAHfwAHTwAHVVVVAAAA0gAH_wAH_wAH3wAH_________IAP34AP34AP38APAAAA");
    testRendering("title_centered_no_game_icon", "celeste", "________MzMzADAAADwAADwA________VX1VADwAAAAAAAAA____ABkAAP8DAP8DAP8DAP8D________V_1XAGAAAAAAAAAA");
    testRendering("title_centered_with_game_icon", "celeste", "________AiIiQDAAYDwAYDwA________YDwAYDwAYAAAYAAAd393YBkAYL8DYP8DYP8DYP8D________d_1XYGAAAAAAAAAA");
    testRendering("title_left_no_attempt_count", "celeste", "________MzMz4AAA8AAA-AAA_________VVV-AAAAAAAAAAA____GQAA_wAA_wAA_wAA_wAA________f_1XIAAAAAAAAAAA");

    after(async () => {
        await driver.quit();
        serverProcess.close();
    });
});