////////////////////////////////////////////////////////////////////////////
//
// Copyright 2016 Realm Inc.
//
// 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.
//
////////////////////////////////////////////////////////////////////////////

'use strict';

const URL = require('url-parse');

let getOwnPropertyDescriptors = Object.getOwnPropertyDescriptors || function(obj) {
    return Object.getOwnPropertyNames(obj).reduce(function (descriptors, name) {
        descriptors[name] = Object.getOwnPropertyDescriptor(obj, name);
        return descriptors;
    }, {});
};

const subscriptionObjectNameRegex = /^(class_)?(.*?)(_matches)?$/gm;

function setConstructorOnPrototype(klass) {
    if (klass.prototype.constructor !== klass) {
        Object.defineProperty(klass.prototype, 'constructor', { value: klass, configurable: true, writable: true });
    }
}

/**
 * Finds the permissions associated with a given Role or create them as needed.
 *
 * @param {RealmObject} Container RealmObject holding the permission list.
 * @param {List<Realm.Permissions.Permission>} list of permissions.
 * @param {string} name of the role to find or create permissions for.
 */
function findOrCreatePermissionForRole(realmObject, permissions, roleName) {
    let realm = realmObject._realm;
    if (!realm.isInTransaction) {
        throw Error("'findOrCreate' can only be called inside a write transaction.");
    }
    let permissionsObj = permissions.filtered(`role.name = '${roleName}'`)[0];
    if (permissionsObj === undefined) {
        let role = realm.objects("__Role").filtered(`name = '${roleName}'`)[0];
        if (role === undefined) {
            role = realm.create("__Role", {'name': roleName});
        }
        // Create new permissions object with all privileges disabled
        permissionsObj = realm.create("__Permission", { 'role': role });
        permissions.push(permissionsObj);
    }
    return permissionsObj;
}

/**
 * Adds the schema object if one isn't already defined
 */
function addSchemaIfNeeded(schemaList, schemaObj) {
    const name = schemaObj.schema.name;
    if (schemaList.find((obj) => obj && (obj.name === name || (obj.schema && obj.schema.name === name))) === undefined) {
        schemaList.push(schemaObj);
    }
}

module.exports = function(realmConstructor) {
    // Add the specified Array methods to the Collection prototype.
    Object.defineProperties(realmConstructor.Collection.prototype, require('./collection-methods'));

    setConstructorOnPrototype(realmConstructor.Collection);
    setConstructorOnPrototype(realmConstructor.List);
    setConstructorOnPrototype(realmConstructor.Results);
    setConstructorOnPrototype(realmConstructor.Object);

    //Add static methods to the Realm object
    Object.defineProperties(realmConstructor, getOwnPropertyDescriptors({

        open(config) {
            // If no config is defined, we should just open the default realm
            if (config === undefined) { config = {}; }

            // For local Realms we open the Realm and return it in a resolved Promise.
            if (!("sync" in config)) {
                let promise = Promise.resolve(new realmConstructor(config));
                promise.progress = (callback) => { };
                return promise;
            }

            let syncSession;
            let promise = new Promise((resolve, reject) => {
                syncSession = realmConstructor._asyncOpen(config, (realm, error) => {
                    if (error) {
                        setTimeout(() => { reject(error); }, 1);
                    }
                    else {
                        setTimeout(() => { resolve(realm); }, 1);
                    }
                });
            });

            promise.progress = (callback) => {
                if (syncSession) {
                    syncSession.addProgressNotification('download', 'forCurrentlyOutstandingWork', callback);
                }

                return promise;
            };
            return promise;
        },

        openAsync(config, callback, progressCallback) {
            const message = "Realm.openAsync is now deprecated in favor of Realm.open. This function will be removed in future versions.";
            (console.warn || console.log).call(console, message);

            let promise = this.open(config)
            if (progressCallback) {
                promise.progress(progressCallback)
            }

            promise.then(realm => {
                callback(null, realm)
            }).catch(error => {
                callback(error);
            });
        },

        createTemplateObject(objectSchema) {
            let obj = {};
            for (let key in objectSchema.properties) {

                let type;
                if (typeof objectSchema.properties[key] === 'string' || objectSchema.properties[key] instanceof String) {
                    // Simple declaration of the type
                    type = objectSchema.properties[key];
                } else {
                    // Advanced property setup
                    const property = objectSchema.properties[key];

                    // if optional is set, it wil take precedence over any `?` set on the type parameter
                    if (property.optional === true) {
                        continue;
                    }

                    // If a default value is explicitly set, always set the property
                    if (property.default !== undefined) {
                        obj[key] = property.default;
                        continue;
                    }

                    type = property.type;
                }

                // Set the default value for all required primitive types.
                // Lists are always treated as empty if not specified and references to objects are always optional
                switch (type) {
                    case 'bool': obj[key] = false; break;
                    case 'int': obj[key] = 0; break;
                    case 'float': obj[key] = 0.0; break;
                    case 'double': obj[key] = 0.0; break;
                    case 'string': obj[key] = ""; break;
                    case 'data': obj[key] = new ArrayBuffer(0); break;
                    case 'date': obj[key] = new Date(0); break;
                }
            }
            return obj;
        }
    }));

    // Add sync methods
    if (realmConstructor.Sync) {
        let userMethods = require('./user-methods');
        Object.defineProperties(realmConstructor.Sync.User, getOwnPropertyDescriptors(userMethods.static));
        Object.defineProperties(realmConstructor.Sync.User.prototype, getOwnPropertyDescriptors(userMethods.instance));
        Object.defineProperty(realmConstructor.Sync.User, '_realmConstructor', { value: realmConstructor });
        realmConstructor.Sync.Credentials = {};
        Object.defineProperties(realmConstructor.Sync.Credentials, getOwnPropertyDescriptors(userMethods.credentials));
        realmConstructor.Sync.AuthError = require('./errors').AuthError;

        if (realmConstructor.Sync.removeAllListeners) {
            process.on('exit', realmConstructor.Sync.removeAllListeners);
            process.on('SIGINT', function () {
                realmConstructor.Sync.removeAllListeners();
                process.exit(2);
            });
            process.on('uncaughtException', function(e) {
                realmConstructor.Sync.removeAllListeners();
                /* eslint-disable no-console */
                console.log(e.stack);
                process.exit(99);
            });
        }

        setConstructorOnPrototype(realmConstructor.Sync.User);
        setConstructorOnPrototype(realmConstructor.Sync.Session);

        // A configuration for a default Realm
        realmConstructor.automaticSyncConfiguration = function() {
            let user;

            if (arguments.length === 0) {
                let users = this.Sync.User.all;
                let identities = Object.keys(users);
                if (identities.length === 1) {
                    user = users[identities[0]];
                } else {
                    new Error(`One and only one user should be logged in but found ${users.length} users.`);
                }
            } else if (arguments.length === 1) {
                user = arguments[0];
            } else {
                new Error(`Zero or one argument expected.`);
            }

            let url = new URL(user.server);
            let secure = (url.protocol === 'https:')?'s':'';
            let port = (url.port === undefined)?'9080':url.port
            let realmUrl = `realm${secure}://${url.hostname}:${port}/default`;

            let config = {
                sync: {
                    user: user,
                    url: realmUrl,
                }
            };
            return config;
        };

        if (realmConstructor.Sync._setFeatureToken) {
            realmConstructor.Sync.setFeatureToken = function(featureToken) {
                console.log('Realm.Sync.setFeatureToken() is deprecated and you can remove any calls to it.');
            }
        }

        // Keep these value in sync with subscription_state.hpp
        realmConstructor.Sync.SubscriptionState = {
            Error: -1,      // An error occurred while creating or processing the partial sync subscription.
            Creating: 2,    // The subscription is being created.
            Pending: 0,     // The subscription was created, but has not yet been processed by the sync server.
            Complete: 1,    // The subscription has been processed by the sync server and data is being synced to the device.
            Invalidated: 3, // The subscription has been removed.
        };

        realmConstructor.Sync.ConnectionState = {
            Disconnected: "disconnected",
            Connecting: "connecting",
            Connected: "connected",
        };

        // Define the permission schemas as constructors so that they can be
        // passed into directly to functions which want object type names
        const Permission = function() {};
        Permission.schema = Object.freeze({
            name: '__Permission',
            properties: {
                role: '__Role',
                canRead: {type: 'bool', default: false},
                canUpdate: {type: 'bool', default: false},
                canDelete: {type: 'bool', default: false},
                canSetPermissions: {type: 'bool', default: false},
                canQuery: {type: 'bool', default: false},
                canCreate: {type: 'bool', default: false},
                canModifySchema: {type: 'bool', default: false},
            }
        });

        const User = function() {};
        User.schema = Object.freeze({
            name: '__User',
            primaryKey: 'id',
            properties: {
                id: 'string',
                role: '__Role'
            }
        });

        const Role = function() {};
        Role.schema = Object.freeze({
            name: '__Role',
            primaryKey: 'name',
            properties: {
                name: 'string',
                members: '__User[]'
            }
        });

        const Class = function() {};
        Class.schema = Object.freeze({
            name: '__Class',
            primaryKey: 'name',
            properties: {
                name: 'string',
                permissions: '__Permission[]'
            }
        });
        Class.prototype.findOrCreate = function(roleName) {
            return findOrCreatePermissionForRole(this, this.permissions, roleName);
        };

        const Realm = function() {};
        Realm.schema = Object.freeze({
            name: '__Realm',
            primaryKey: 'id',
            properties: {
                id: 'int',
                permissions: '__Permission[]'
            }
        });
        Realm.prototype.findOrCreate = function(roleName) {
            return findOrCreatePermissionForRole(this, this.permissions, roleName);
        };

        const permissionsSchema = {
            'Class': Class,
            'Permission': Permission,
            'Realm': Realm,
            'Role': Role,
            'User': User,
        };

        if (!realmConstructor.Permissions) {
            Object.defineProperty(realmConstructor, 'Permissions', {
                value: permissionsSchema,
                configurable: false
            });
        }

        const ResultSets = function() {};
        ResultSets.schema = Object.freeze({
            name: '__ResultSets',
            properties: {
                name: { type: 'string', indexed: true },
                query: 'string',
                matches_property: 'string',
                status: 'int',
                error_message: 'string',
                query_parse_counter: 'int'
            }
        });

        const subscriptionSchema = {
            'ResultSets': ResultSets
        };

        if (!realmConstructor.Subscription) {
            Object.defineProperty(realmConstructor, 'Subscription', {
                value: subscriptionSchema,
                configurable: false,
            });
        }

        // Add instance methods to the Realm object that are only applied if Sync is
        Object.defineProperties(realmConstructor.prototype, getOwnPropertyDescriptors({
            permissions(arg) {
                // If no argument is provided, return the Realm-level permissions
                if (arg === undefined) {
                    return this.objects('__Realm').filtered(`id = 0`)[0];
                } else {
                    // Else try to find the corresponding Class-level permissions
                    let schemaName = this._schemaName(arg);
                    let classPermissions = this.objects('__Class').filtered(`name = '${schemaName}'`);
                    if (classPermissions.length === 0) {
                        throw Error(`Could not find Class-level permissions for '${schemaName}'`);
                    }
                    return classPermissions[0];
                }
            },

            subscriptions(name) {
                let all_subscriptions = this.objects('__ResultSets');
                if (name) {
                    if (typeof(name) !== 'string') {
                        throw new Error(`string expected - got ${typeof(name)}.`);
                    }
                    if (name.includes('*') || name.includes('?')) {
                        all_subscriptions = all_subscriptions.filtered(`name LIKE '${name}'`);
                    } else {
                        all_subscriptions = all_subscriptions.filtered(`name == '${name}'`);
                    }
                }
                let listOfSubscriptions = [];
                for (var subscription of all_subscriptions) {
                    let matches_property = subscription['matches_property'];
                    let sub = {
                        name: subscription['name'],
                        objectType: matches_property.replace(subscriptionObjectNameRegex, '$2'),
                        query: subscription['query'],
                    }
                    listOfSubscriptions.push(sub);
                }
                return listOfSubscriptions;
            },

            unsubscribe(name) {
                if (typeof(name) === 'string') {
                    if (name !== '') {
                        let named_subscriptions = this.objects('__ResultSets').filtered(`name == '${name}'`);
                        if (named_subscriptions.length === 0) {
                            return;
                        }
                        let doCommit = false;
                        if (!this.isInTransaction) {
                            this.beginTransaction();
                            doCommit = true;
                        }
                        this.delete(named_subscriptions);
                        if (doCommit) {
                            this.commitTransaction();
                        }
                    } else {
                        throw new Error('Non-empty string expected.');
                    }
                } else {
                    throw new Error(`string expected - got ${typeof(name)}.`);
                }
            }
        }));

        Object.defineProperties(realmConstructor, getOwnPropertyDescriptors({
            _extendQueryBasedSchema(schema) {
                addSchemaIfNeeded(schema, realmConstructor.Permissions.Class);
                addSchemaIfNeeded(schema, realmConstructor.Permissions.Permission);
                addSchemaIfNeeded(schema, realmConstructor.Permissions.Realm);
                addSchemaIfNeeded(schema, realmConstructor.Permissions.Role);
                addSchemaIfNeeded(schema, realmConstructor.Permissions.User);
                addSchemaIfNeeded(schema, realmConstructor.Subscription.ResultSets);
            },
        }));
    }

    // TODO: Remove this now useless object.
    var types = Object.freeze({
        'BOOL': 'bool',
        'INT': 'int',
        'FLOAT': 'float',
        'DOUBLE': 'double',
        'STRING': 'string',
        'DATE': 'date',
        'DATA': 'data',
        'OBJECT': 'object',
        'LIST': 'list',
    });
    Object.defineProperty(realmConstructor, 'Types', {
        get: function() {
            if (typeof console != 'undefined') {
                /* global console */
                /* eslint-disable no-console */
                var stack = new Error().stack.split("\n").slice(2).join("\n");
                var msg = '`Realm.Types` is deprecated! Please specify the type name as lowercase string instead!\n'+stack;
                if (console.warn != undefined) {
                    console.warn(msg);
                }
                else {
                    console.log(msg);
                }
                /* eslint-enable no-console */
            }
            return types;
        },
        configurable: true
    });
}