import _ from "lodash";
import {default as axios, Method} from "axios";
import {UserAgentApplicationExtended} from "./UserAgentApplicationExtended";
import {
    Auth,
    Request,
    Graph,
    CacheOptions,
    Options,
    DataObject,
    CallbackQueueObject,
    AuthError,
    AuthResponse,
    MSALBasic,
    GraphEndpoints,
    GraphDetailedObject,
    CategorizedGraphRequests
} from './types';

export class MSAL implements MSALBasic {
    private lib: any;
    private tokenExpirationTimers: {[key: string]: undefined | number} = {};
    public data: DataObject = {
        isAuthenticated: false,
        accessToken: '',
        idToken: '',
        user: {},
        graph: {},
        custom: {}
    };
    public callbackQueue: CallbackQueueObject[] = [];
    private readonly auth: Auth = {
        clientId: '',
        authority: '',
        tenantId: 'common',
        tenantName: 'login.microsoftonline.com',
        validateAuthority: true,
        redirectUri: window.location.href,
        postLogoutRedirectUri: window.location.href,
        navigateToLoginRequestUrl: true,
        requireAuthOnInitialize: false,
        autoRefreshToken: true,
        onAuthentication: (error, response) => {},
        onToken: (error, response) => {},
        beforeSignOut: () => {}
    };
    private readonly cache: CacheOptions = {
        cacheLocation: 'localStorage',
        storeAuthStateInCookie: true
    };
    private readonly request: Request = {
        scopes: ["user.read"]
    };
    private readonly graph: Graph = {
        callAfterInit: false,
        endpoints: {profile: '/me'},
        baseUrl: 'https://graph.microsoft.com/v1.0',
        onResponse: (response) => {}
    };
    constructor(private readonly options: Options) {
        if (!options.auth.clientId) {
            throw new Error('auth.clientId is required');
        }
        this.auth = Object.assign(this.auth, options.auth);
        this.cache = Object.assign(this.cache, options.cache);
        this.request = Object.assign(this.request, options.request);
        this.graph = Object.assign(this.graph, options.graph);

        this.lib = new UserAgentApplicationExtended({
            auth: {
                clientId: this.auth.clientId,
                authority: this.auth.authority || `https://${this.auth.tenantName}/${this.auth.tenantId}`,
                validateAuthority: this.auth.validateAuthority,
                redirectUri: this.auth.redirectUri,
                postLogoutRedirectUri: this.auth.postLogoutRedirectUri,
                navigateToLoginRequestUrl: this.auth.navigateToLoginRequestUrl
            },
            cache: this.cache,
            system: options.system
        });

        this.getSavedCallbacks();
        this.executeCallbacks();
        // Register Callbacks for redirect flow
        this.lib.handleRedirectCallback((error: AuthError, response: AuthResponse) => {
            if (!this.isAuthenticated()) {
                this.saveCallback('auth.onAuthentication', error, response);
            } else {
                this.acquireToken();
            }
        });

        if (this.auth.requireAuthOnInitialize) {
            this.signIn()
        }
        this.data.isAuthenticated = this.isAuthenticated();
        if (this.data.isAuthenticated) {
            this.data.user = this.lib.getAccount();
            this.acquireToken().then(() => {
                if (this.graph.callAfterInit) {
                    this.initialMSGraphCall();
                }
            });
        }
        this.getStoredCustomData();
    }
    signIn() {
        if (!this.lib.isCallback(window.location.hash) && !this.lib.getAccount()) {
            // request can be used for login or token request, however in more complex situations this can have diverging options
            this.lib.loginRedirect(this.request);
        }
    }
    async signOut() {
        if (this.options.auth.beforeSignOut) {
            await this.options.auth.beforeSignOut(this);
        }
        this.lib.logout();
    }
    isAuthenticated() {
        return !this.lib.isCallback(window.location.hash) && !!this.lib.getAccount();
    }
    async acquireToken(request = this.request, retries = 0) {
        try {
            //Always start with acquireTokenSilent to obtain a token in the signed in user from cache
            const response = await this.lib.acquireTokenSilent(request);
            this.handleTokenResponse(null, response);
            return response;
        } catch (error) {
            // Upon acquireTokenSilent failure (due to consent or interaction or login required ONLY)
            // Call acquireTokenRedirect
            if (this.requiresInteraction(error.errorCode)) {
                this.lib.acquireTokenRedirect(request);
            } else if(retries > 0) {
                return await new Promise((resolve) => {
                    setTimeout(async () => {
                        const res = await this.acquireToken(request, retries-1);
                        resolve(res);
                    }, 60 * 1000);
                })
            }
            return false;
        }
    }
    private handleTokenResponse(error, response) {
        if (error) {
            this.saveCallback('auth.onToken', error, null);
            return;
        }
        let setCallback = false;
        if(response.tokenType === 'access_token' && this.data.accessToken !== response.accessToken) {
            this.setToken('accessToken', response.accessToken, response.expiresOn, response.scopes);
            setCallback = true;
        }
        if(this.data.idToken !== response.idToken.rawIdToken) {
            this.setToken('idToken', response.idToken.rawIdToken, new Date(response.idToken.expiration * 1000), [this.auth.clientId]);
            setCallback = true;
        }
        if(setCallback) {
            this.saveCallback('auth.onToken', null, response);
        }
    }
    private setToken(tokenType:string, token: string, expiresOn: Date, scopes: string[]) {
        const expirationOffset = this.lib.config.system.tokenRenewalOffsetSeconds * 1000;
        const expiration = expiresOn.getTime() - (new Date()).getTime() - expirationOffset;
        if (expiration >= 0) {
            this.data[tokenType] = token;
        }
        if (this.tokenExpirationTimers[tokenType]) clearTimeout(this.tokenExpirationTimers[tokenType]);
        this.tokenExpirationTimers[tokenType] = window.setTimeout(async () => {
            if (this.auth.autoRefreshToken) {
                await this.acquireToken({ scopes }, 3);
            } else {
                this.data[tokenType] = '';
            }
        }, expiration)
    }
    private requiresInteraction(errorCode: string) {
        if (!errorCode || !errorCode.length) {
            return false;
        }
        return errorCode === "consent_required" ||
            errorCode === "interaction_required" ||
            errorCode === "login_required";
    }
    // MS GRAPH
    async initialMSGraphCall() {
        const {onResponse: callback} = this.graph;
        let initEndpoints = this.graph.endpoints;

        if (typeof initEndpoints === 'object' && !_.isEmpty(initEndpoints)) {
            const resultsObj = {};
            const forcedIds: string[] = [];
            try {
                const endpoints: { [id: string]: GraphDetailedObject & { force?: Boolean } } = {};
                for (const id in initEndpoints) {
                    endpoints[id] = this.getEndpointObject(initEndpoints[id]);
                    if (endpoints[id].force) {
                        forcedIds.push(id);
                    }
                }
                let storedIds: string[] = [];
                let storedData = this.lib.store.getItem(`msal.msgraph-${this.data.accessToken}`);
                if (storedData) {
                    storedData = JSON.parse(storedData);
                    storedIds = Object.keys(storedData);
                    Object.assign(resultsObj, storedData);
                }
                const {singleRequests, batchRequests} = this.categorizeRequests(endpoints, _.difference(storedIds, forcedIds));
                const singlePromises = singleRequests.map(async endpoint => {
                    const res = {};
                    res[endpoint.id as string] = await this.msGraph(endpoint);
                    return res;
                });
                const batchPromises = Object.keys(batchRequests).map(key => {
                    const batchUrl = (key === 'default') ? undefined : key;
                    return this.msGraph(batchRequests[key], batchUrl);
                });
                const mixedResults = await Promise.all([...singlePromises, ...batchPromises]);
                mixedResults.map((res) => {
                    for (const key in res) {
                        res[key] = res[key].body;
                    }
                    Object.assign(resultsObj, res);
                });
                const resultsToSave = {...resultsObj};
                forcedIds.map(id => delete resultsToSave[id]);
                this.lib.store.setItem(`msal.msgraph-${this.data.accessToken}`, JSON.stringify(resultsToSave));
                this.data.graph = resultsObj;
            } catch (error) {
                console.error(error);
            }
            if (callback)
                this.saveCallback('graph.onResponse', this.data.graph);
        }
    }
    async msGraph(endpoints: GraphEndpoints, batchUrl: string | undefined = undefined) {
        try {
            if (Array.isArray(endpoints)) {
                return await this.executeBatchRequest(endpoints, batchUrl);
            } else {
                return await this.executeSingleRequest(endpoints);
            }
        } catch (error) {
            throw error;
        }
    }
    private async executeBatchRequest(endpoints: Array<string | GraphDetailedObject>, batchUrl = this.graph.baseUrl) {
        const requests = endpoints.map((endpoint, index) => this.createRequest(endpoint, index));
        const {data} = await axios.request({
            url: `${batchUrl}/$batch`,
            method: 'POST' as Method,
            data: {requests: requests},
            headers: {Authorization: `Bearer ${this.data.accessToken}`},
            responseType: 'json'
        });
        let result = {};
        data.responses.map(response => {
            let key = response.id;
            delete response.id;
            return result[key] = response
        });
        // Format result
        const keys = Object.keys(result);
        const numKeys = keys.sort().filter((key, index) => {
            if (key.search('defaultID-') === 0) {
                key = key.replace('defaultID-', '');
            }
            return parseInt(key) === index;
        });
        if (numKeys.length === keys.length) {
            result = _.values(result);
        }
        return result;
    }
    private async executeSingleRequest(endpoint: string | GraphDetailedObject) {
        const request = this.createRequest(endpoint);
        if (request.url.search('http') !== 0) {
            request.url = this.graph.baseUrl + request.url;
        }
        const res = await axios.request(_.defaultsDeep(request, {
            url: request.url,
            method: request.method as Method,
            responseType: 'json',
            headers: {Authorization: `Bearer ${this.data.accessToken}`}
        }));
        return {
            status: res.status,
            headers: res.headers,
            body: res.data
        }
    }
    private createRequest(endpoint: string | GraphDetailedObject, index = 0) {
        const request = {
            url: '',
            method: 'GET',
            id: `defaultID-${index}`
        };
        endpoint = this.getEndpointObject(endpoint);
        if (endpoint.url) {
            Object.assign(request, endpoint);
        } else {
            throw ({error: 'invalid endpoint', endpoint: endpoint});
        }
        return request;
    }
    private categorizeRequests(endpoints: { [id:string]: GraphDetailedObject & { batchUrl?: string } }, excludeIds: string[]): CategorizedGraphRequests {
        let res: CategorizedGraphRequests = {
            singleRequests: [],
            batchRequests: {}
        };
        for (const key in endpoints) {
            const endpoint = {
                id: key,
                ...endpoints[key]
            };
            if (!_.includes(excludeIds, key)) {
                if (endpoint.batchUrl) {
                    const {batchUrl} = endpoint;
                    delete endpoint.batchUrl;
                    if (!res.batchRequests.hasOwnProperty(batchUrl)) {
                        res.batchRequests[batchUrl] = [];
                    }
                    res.batchRequests[batchUrl].push(endpoint);
                } else {
                    res.singleRequests.push(endpoint);
                }
            }
        }
        return res;
    }
    private getEndpointObject(endpoint: string | GraphDetailedObject): GraphDetailedObject {
        if (typeof endpoint === "string") {
            endpoint = {url: endpoint}
        }
        if (typeof endpoint === "object" && !endpoint.url) {
            throw new Error('invalid endpoint url')
        }
        return endpoint;
    }
    // CUSTOM DATA
    saveCustomData(key: string, data: any) {
        if (!this.data.custom.hasOwnProperty(key)) {
            this.data.custom[key] = null;
        }
        this.data.custom[key] = data;
        this.storeCustomData();
    }
    private storeCustomData() {
        if (!_.isEmpty(this.data.custom)) {
            this.lib.store.setItem('msal.custom', JSON.stringify(this.data.custom));
        } else {
            this.lib.store.removeItem('msal.custom');
        }
    }
    private getStoredCustomData() {
        let customData = {};
        const customDataStr = this.lib.store.getItem('msal.custom');
        if (customDataStr) {
            customData = JSON.parse(customDataStr);
        }
        this.data.custom = customData;
    }
    // CALLBACKS
    private saveCallback(callbackPath: string, ...args: any[]) {
        if (_.get(this.options, callbackPath)) {
            const callbackQueueObject: CallbackQueueObject = {
                id: _.uniqueId(`cb-${callbackPath}`),
                callback: callbackPath,
                arguments: args
            };
            _.remove(this.callbackQueue, (obj) => obj.id === callbackQueueObject.id);
            this.callbackQueue.push(callbackQueueObject);
            this.storeCallbackQueue();
            this.executeCallbacks([callbackQueueObject]);
        }
    }
    private getSavedCallbacks() {
        const callbackQueueStr = this.lib.store.getItem('msal.callbackqueue');
        if (callbackQueueStr) {
            this.callbackQueue = [...this.callbackQueue, ...JSON.parse(callbackQueueStr)];
        }
    }
    private async executeCallbacks(callbacksToExec: CallbackQueueObject[] = this.callbackQueue) {
        if (callbacksToExec.length) {
            for (let i in callbacksToExec) {
                const cb = callbacksToExec[i];
                const callback = _.get(this.options, cb.callback);
                try {
                    await callback(this, ...cb.arguments);
                    _.remove(this.callbackQueue, function (currentCb) {
                        return cb.id === currentCb.id;
                    });
                    this.storeCallbackQueue();
                } catch (e) {
                    console.warn(`Callback '${cb.id}' failed with error: `, e.message);
                }
            }
        }
    }
    private storeCallbackQueue() {
        if (this.callbackQueue.length) {
            this.lib.store.setItem('msal.callbackqueue', JSON.stringify(this.callbackQueue));
        } else {
            this.lib.store.removeItem('msal.callbackqueue');
        }
    }
}