/**
 * Copyright 2017 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var fs = require('fs');
var path = require('path');
var rm = require('rimraf').sync;
var Browser = require('../lib/Browser');
var StaticServer = require('./StaticServer');
var PNG = require('pngjs').PNG;
var pixelmatch = require('pixelmatch');

var PORT = 8907;
var STATIC_PREFIX = 'http://localhost:' + PORT;
var EMPTY_PAGE = STATIC_PREFIX + '/empty.html';

var GOLDEN_DIR = path.join(__dirname, 'golden');
var OUTPUT_DIR = path.join(__dirname, 'output');
var PROJECT_DIR = path.join(__dirname, '..');

describe('Puppeteer', function() {
    var browser;
    var staticServer;
    var page;

    beforeAll(function() {
        browser = new Browser();
        staticServer = new StaticServer(path.join(__dirname, 'assets'), PORT);
        if (fs.existsSync(OUTPUT_DIR))
            rm(OUTPUT_DIR);
    });

    afterAll(function() {
        browser.close();
        staticServer.stop();
    });

    beforeEach(SX(async function() {
        page = await browser.newPage();
        jasmine.addMatchers(customMatchers);
    }));

    afterEach(function() {
        page.close();
    });

    describe('Page.evaluate', function() {
        it('should work', SX(async function() {
            var result = await page.evaluate(() => 7 * 3);
            expect(result).toBe(21);
        }));
        it('should await promise', SX(async function() {
            var result = await page.evaluate(() => Promise.resolve(8 * 7));
            expect(result).toBe(56);
        }));
        it('should work from-inside inPageCallback', SX(async function() {
            // Setup inpage callback, which calls Page.evaluate
            await page.setInPageCallback('callController', async function(a, b) {
                return await page.evaluate((a, b) => a * b, a, b);
            });
            var result = await page.evaluate(function() {
                return callController(9, 3);
            });
            expect(result).toBe(27);
        }));
        it('should reject promise with exception', SX(async function() {
            var error = null;
            try {
                await page.evaluate(() => not.existing.object.property);
            } catch (e) {
                error = e;
            }
            expect(error).toBeTruthy();
            expect(error.message).toContain('not is not defined');
        }));
    });

    it('Page Events: ConsoleMessage', SX(async function() {
        var msgs = [];
        page.on('consolemessage', msg => msgs.push(msg));
        await page.evaluate(() => console.log('Message!'));
        expect(msgs).toEqual(['Message!']);
    }));

    describe('Page.navigate', function() {
        it('should fail when navigating to bad url', SX(async function() {
            var success = await page.navigate('asdfasdf');
            expect(success).toBe(false);
        }));
        it('should succeed when navigating to good url', SX(async function() {
            var success = await page.navigate(EMPTY_PAGE);
            expect(success).toBe(true);
        }));
    });

    describe('Page.setInPageCallback', function() {
        it('should work', SX(async function() {
            await page.setInPageCallback('callController', function(a, b) {
                return a * b;
            });

            var result = await page.evaluate(function() {
                return callController(9, 4);
            });
            expect(result).toBe(36);
        }));
        it('should survive navigation', SX(async function() {
            await page.setInPageCallback('callController', function(a, b) {
                return a * b;
            });

            await page.navigate(EMPTY_PAGE);
            var result = await page.evaluate(function() {
                return callController(9, 4);
            });
            expect(result).toBe(36);
        }));
        it('should await returned promise', SX(async function() {
            await page.setInPageCallback('callController', function(a, b) {
                return Promise.resolve(a * b);
            });

            var result = await page.evaluate(function() {
                return callController(3, 5);
            });
            expect(result).toBe(15);
        }));
    });

    describe('Page.setRequestInterceptor', function() {
        it('should intercept', SX(async function() {
            page.setRequestInterceptor(request => {
                expect(request.url()).toContain('empty.html');
                expect(request.headers()['User-Agent']).toBeTruthy();
                expect(request.method()).toBe('GET');
                expect(request.postData()).toBe(undefined);
                request.continue();
            });
            var success = await page.navigate(EMPTY_PAGE);
            expect(success).toBe(true);
        }));
        it('should show extraHTTPHeaders', SX(async function() {
            await page.setExtraHTTPHeaders({
                foo: 'bar'
            });
            page.setRequestInterceptor(request => {
                expect(request.headers()['foo']).toBe('bar');
                request.continue();
            });
            var success = await page.navigate(EMPTY_PAGE);
            expect(success).toBe(true);
        }));
        it('should be abortable', SX(async function() {
            page.setRequestInterceptor(request => {
                if (request.url().endsWith('.css'))
                    request.abort();
                else
                    request.continue();
            });
            var failedResources = 0;
            page.on('resourceloadingfailed', event => ++failedResources);
            var success = await page.navigate(STATIC_PREFIX + '/one-style.html');
            expect(success).toBe(true);
            expect(failedResources).toBe(1);
        }));
    });

    describe('Page.Events.Dialog', function() {
        it('should fire', function(done) {
            page.on('dialog', dialog => {
                expect(dialog.type).toBe('alert');
                expect(dialog.message()).toBe('yo');
                done();
            });
            page.evaluate(() => alert('yo'));
        });
        // TODO Enable this when crbug.com/718235 is fixed.
        xit('should allow accepting prompts', SX(async function(done) {
            page.on('dialog', dialog => {
                expect(dialog.type).toBe('prompt');
                expect(dialog.message()).toBe('question?');
                dialog.accept('answer!');
            });
            var result = await page.evaluate(() => prompt('question?'));
            expect(result).toBe('answer!');
        }));
    });

    describe('Page.Events.Error', function() {
        it('should fire', function(done) {
            page.on('error', error => {
                expect(error.message).toContain('Fancy');
                done();
            });
            page.navigate(STATIC_PREFIX + '/error.html');
        });
    });

    describe('Page.screenshot', function() {
        it('should work', SX(async function() {
            await page.setViewportSize({width: 500, height: 500});
            await page.navigate(STATIC_PREFIX + '/grid.html');
            var screenshot = await page.screenshot();
            expect(screenshot).toBeGolden('screenshot-sanity.png');
        }));
        it('should clip rect', SX(async function() {
            await page.setViewportSize({width: 500, height: 500});
            await page.navigate(STATIC_PREFIX + '/grid.html');
            var screenshot = await page.screenshot({
                clip: {
                    x: 50,
                    y: 100,
                    width: 150,
                    height: 100
                }
            });
            expect(screenshot).toBeGolden('screenshot-clip-rect.png');
        }));
        it('should work for offscreen clip', SX(async function() {
            await page.setViewportSize({width: 500, height: 500});
            await page.navigate(STATIC_PREFIX + '/grid.html');
            var screenshot = await page.screenshot({
                clip: {
                    x: 50,
                    y: 600,
                    width: 100,
                    height: 100
                }
            });
            expect(screenshot).toBeGolden('screenshot-offscreen-clip.png');
        }));
        it('should run in parallel', SX(async function() {
            await page.setViewportSize({width: 500, height: 500});
            await page.navigate(STATIC_PREFIX + '/grid.html');
            var promises = [];
            for (var i = 0; i < 3; ++i) {
                promises.push(page.screenshot({
                    clip: {
                        x: 50 * i,
                        y: 0,
                        width: 50,
                        height: 50
                    }
                }));
            }
            var screenshot = await promises[1];
            expect(screenshot).toBeGolden('screenshot-parallel-calls.png');
        }));
    });
});

var customMatchers = {
    toBeGolden: function(util, customEqualityTesters) {
        return {
            compare: function(actual, expected) {
                return compareImageToGolden(actual, expected);
            }
        }
    }
}

/**
 * @param {?Buffer} imageBuffer
 * @param {string} goldenName
 * @return {!{pass: boolean, message: (undefined|string)}}
 */
function compareImageToGolden(imageBuffer, goldenName) {
    if (!imageBuffer || !(imageBuffer instanceof Buffer)) {
        return {
            pass: false,
            message: 'Test did not return Buffer with image.'
        };
    }
    var expectedPath = path.join(GOLDEN_DIR, goldenName);
    var actualPath = path.join(OUTPUT_DIR, goldenName);
    var diffPath = addSuffix(path.join(OUTPUT_DIR, goldenName), '-diff');
    var helpMessage = 'Output is saved in ' + path.relative(PROJECT_DIR, OUTPUT_DIR);

    if (!fs.existsSync(expectedPath)) {
        ensureOutputDir();
        fs.writeFileSync(actualPath, imageBuffer);
        return {
            pass: false,
            message: goldenName + ' is missing in golden results. ' + helpMessage
        };
    }
    var actual = PNG.sync.read(imageBuffer);
    var expected = PNG.sync.read(fs.readFileSync(expectedPath));
    if (expected.width !== actual.width || expected.height !== actual.height) {
        ensureOutputDir();
        fs.writeFileSync(actualPath, imageBuffer);
        var message = `Sizes differ: expected image ${expected.width}px X ${expected.height}px, but got ${actual.width}px X ${actual.height}px. `;
        return {
            pass: false,
            message: message + helpMessage
        };
    }
    var diff = new PNG({width: expected.width, height: expected.height});
    var count = pixelmatch(expected.data, actual.data, diff.data, expected.width, expected.height, {threshold: 0.1});
    if (count > 0) {
        ensureOutputDir();
        fs.writeFileSync(actualPath, imageBuffer);
        fs.writeFileSync(diffPath, PNG.sync.write(diff));
        return {
            pass: false,
            message: goldenName + ' mismatch! ' + helpMessage
        };
    }
    return {
        pass: true
    };
}

function ensureOutputDir() {
    if (!fs.existsSync(OUTPUT_DIR))
        fs.mkdirSync(OUTPUT_DIR);
}

/**
 * @param {string} filePath
 * @param {string} suffix
 * @return {string}
 */
function addSuffix(filePath, suffix) {
    var dirname = path.dirname(filePath);
    var ext = path.extname(filePath);
    var name = path.basename(filePath, ext);
    return path.join(dirname, name + suffix + ext);
}


// Since Jasmine doesn't like async functions, they should be wrapped
// in a SX function.
function SX(fun) {
    return done => Promise.resolve(fun()).then(done).catch(done.fail);
}