/*
       Licensed to the Apache Software Foundation (ASF) under one
       or more contributor license agreements.  See the NOTICE file
       distributed with this work for additional information
       regarding copyright ownership.  The ASF licenses this file
       to you 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.
*/

const execa = require('execa');
const fs = require('fs-extra');
const android_versions = require('android-versions');
const path = require('path');
const Adb = require('./Adb');
const events = require('cordova-common').events;
const CordovaError = require('cordova-common').CordovaError;
const android_sdk = require('./android_sdk');
const which = require('which');

// constants
const ONE_SECOND = 1000; // in milliseconds
const CHECK_BOOTED_INTERVAL = 3 * ONE_SECOND; // in milliseconds

function forgivingWhichSync (cmd) {
    const whichResult = which.sync(cmd, { nothrow: true });

    // On null, returns empty string to maintain backwards compatibility
    // realpathSync follows symlinks
    return whichResult === null ? '' : fs.realpathSync(whichResult);
}

module.exports.list_images_using_avdmanager = function () {
    return execa('avdmanager', ['list', 'avd']).then(({ stdout: output }) => {
        const response = output.split('\n');
        const emulator_list = [];
        for (let i = 1; i < response.length; i++) {
            // To return more detailed information use img_obj
            const img_obj = {};
            if (response[i].match(/Name:\s/)) {
                img_obj.name = response[i].split('Name: ')[1].replace('\r', '');
                if (response[i + 1].match(/Device:\s/)) {
                    i++;
                    img_obj.device = response[i].split('Device: ')[1].replace('\r', '');
                }
                if (response[i + 1].match(/Path:\s/)) {
                    i++;
                    img_obj.path = response[i].split('Path: ')[1].replace('\r', '');
                }
                if (response[i + 1].match(/Target:\s/)) {
                    i++;
                    if (response[i + 1].match(/ABI:\s/)) {
                        img_obj.abi = response[i + 1].split('ABI: ')[1].replace('\r', '');
                    }
                    // This next conditional just aims to match the old output of `android list avd`
                    // We do so so that we don't have to change the logic when parsing for the
                    // best emulator target to spawn (see below in `best_image`)
                    // This allows us to transitionally support both `android` and `avdmanager` binaries,
                    // depending on what SDK version the user has
                    if (response[i + 1].match(/Based\son:\s/)) {
                        img_obj.target = response[i + 1].split('Based on:')[1];
                        if (img_obj.target.match(/Tag\/ABI:\s/)) {
                            img_obj.target = img_obj.target.split('Tag/ABI:')[0].replace('\r', '').trim();
                            if (img_obj.target.indexOf('(') > -1) {
                                img_obj.target = img_obj.target.substr(0, img_obj.target.indexOf('(') - 1).trim();
                            }
                        }
                        const version_string = img_obj.target.replace(/Android\s+/, '');

                        const api_level = android_sdk.version_string_to_api_level[version_string];
                        if (api_level) {
                            img_obj.target += ' (API level ' + api_level + ')';
                        }
                    }
                }
                if (response[i + 1].match(/Skin:\s/)) {
                    i++;
                    img_obj.skin = response[i].split('Skin: ')[1].replace('\r', '');
                }

                emulator_list.push(img_obj);
            }
            /* To just return a list of names use this
            if (response[i].match(/Name:\s/)) {
                emulator_list.push(response[i].split('Name: ')[1].replace('\r', '');
            } */
        }
        return emulator_list;
    });
};

/**
 * Returns a Promise for a list of emulator images in the form of objects
 * {
       name   : <emulator_name>,
       device : <device>,
       path   : <path_to_emulator_image>,
       target : <api_target>,
       abi    : <cpu>,
       skin   : <skin>
   }
 */
module.exports.list_images = function () {
    return Promise.resolve().then(function () {
        if (forgivingWhichSync('avdmanager')) {
            return module.exports.list_images_using_avdmanager();
        } else {
            return Promise.reject(new CordovaError('Could not find `avdmanager` on your $PATH! Are you sure the Android SDK is installed and available?'));
        }
    }).then(function (avds) {
        // In case we're missing the Android OS version string from the target description, add it.
        return avds.map(function (avd) {
            if (avd.target && avd.target.indexOf('Android API') > -1 && avd.target.indexOf('API level') < 0) {
                const api_level = avd.target.match(/\d+/);
                if (api_level) {
                    const level = android_versions.get(api_level);
                    if (level) {
                        avd.target = 'Android ' + level.semver + ' (API level ' + api_level + ')';
                    }
                }
            }
            return avd;
        });
    });
};

/**
 * Returns the best image (if any) for given target.
 *
 * @param {Number} project_target Android targetSDK API level
 * @return {{name: string} | undefined} the closest avd to the given target
 * or undefined if no avds exist.
 */
module.exports.best_image = function (project_target) {
    return this.list_images().then(function (images) {
        // Just return undefined if there is no images
        if (images.length === 0) return;

        let closest = 9999;
        let best = images[0];
        for (const i in images) {
            const target = images[i].target;
            if (target && target.indexOf('API level') > -1) {
                const num = parseInt(target.split('(API level ')[1].replace(')', ''));
                if (num === project_target) {
                    return images[i];
                } else if (project_target - num < closest && project_target > num) {
                    closest = project_target - num;
                    best = images[i];
                }
            }
        }
        return best;
    });
};

exports.list_started = async () => {
    return (await Adb.devices())
        .filter(id => id.startsWith('emulator-'));
};

/*
 * Gets unused port for android emulator, between 5554 and 5584
 * Returns a promise.
 */
module.exports.get_available_port = function () {
    const self = this;

    return self.list_started().then(function (emulators) {
        for (let p = 5584; p >= 5554; p -= 2) {
            if (emulators.indexOf('emulator-' + p) === -1) {
                events.emit('verbose', 'Found available port: ' + p);
                return p;
            }
        }
        throw new CordovaError('Could not find an available avd port');
    });
};

/*
 * Starts an emulator with the given ID,
 * and returns the started ID of that emulator.
 * If no boot timeout is given or the value is negative it will wait forever for
 * the emulator to boot
 *
 * Returns a promise.
 */
module.exports.start = function (emulatorId, boot_timeout) {
    const self = this;

    return Promise.resolve().then(function () {
        if (!emulatorId) {
            throw new CordovaError('No emulator ID given');
        }

        return self.get_available_port().then(function (port) {
            // Figure out the directory the emulator binary runs in, and set the cwd to that directory.
            // Workaround for https://code.google.com/p/android/issues/detail?id=235461
            const emulator_dir = path.dirname(which.sync('emulator'));
            const args = ['-avd', emulatorId, '-port', port];
            // Don't wait for it to finish, since the emulator will probably keep running for a long time.
            execa('emulator', args, { stdio: 'inherit', detached: true, cwd: emulator_dir })
                .unref();

            // wait for emulator to start
            events.emit('log', 'Waiting for emulator to start...');
            return self.wait_for_emulator(port);
        });
    }).then(function (emulatorId) {
        if (!emulatorId) { return Promise.reject(new CordovaError('Failed to start emulator')); }

        // wait for emulator to boot up
        process.stdout.write('Waiting for emulator to boot (this may take a while)...');
        return self.wait_for_boot(emulatorId, boot_timeout).then(function (success) {
            if (success) {
                events.emit('log', 'BOOT COMPLETE');
                // unlock screen
                return Adb.shell(emulatorId, 'input keyevent 82').then(function () {
                    // return the new emulator id for the started emulators
                    return emulatorId;
                });
            } else {
                // We timed out waiting for the boot to happen
                return null;
            }
        });
    });
};

/*
 * Waits for an emulator to boot on a given port.
 * Returns this emulator's ID in a promise.
 */
module.exports.wait_for_emulator = function (port) {
    const self = this;
    return Promise.resolve().then(function () {
        const emulator_id = 'emulator-' + port;
        return Adb.shell(emulator_id, 'getprop dev.bootcomplete').then(function (output) {
            if (output.indexOf('1') >= 0) {
                return emulator_id;
            }
            return self.wait_for_emulator(port);
        }, function (error) {
            if ((error && error.message &&
            (error.message.indexOf('not found') > -1)) ||
            (error.message.indexOf('device offline') > -1) ||
            (error.message.indexOf('device still connecting') > -1) ||
            (error.message.indexOf('device still authorizing') > -1)) {
                // emulator not yet started, continue waiting
                return self.wait_for_emulator(port);
            } else {
                // something unexpected has happened
                throw error;
            }
        });
    });
};

/*
 * Waits for the core android process of the emulator to start. Returns a
 * promise that resolves to a boolean indicating success. Not specifying a
 * time_remaining or passing a negative value will cause it to wait forever
 */
module.exports.wait_for_boot = function (emulator_id, time_remaining) {
    const self = this;
    return Adb.shell(emulator_id, 'getprop sys.boot_completed').then(function (output) {
        if (output.match(/1/)) {
            return true;
        } else if (time_remaining === 0) {
            return false;
        } else {
            process.stdout.write('.');

            return new Promise(resolve => {
                const delay = time_remaining < CHECK_BOOTED_INTERVAL ? time_remaining : CHECK_BOOTED_INTERVAL;

                setTimeout(() => {
                    const updated_time = time_remaining >= 0 ? Math.max(time_remaining - CHECK_BOOTED_INTERVAL, 0) : time_remaining;
                    resolve(self.wait_for_boot(emulator_id, updated_time));
                }, delay);
            });
        }
    });
};