// Module imports
import { Client, SearchResponse, MSearchResponse, ConfigOptions } from 'elasticsearch';
import * as handlebars from 'handlebars';
const hbs = require('nymag-handlebars')();

// Internal imports
import { 
    IRouteMatch, ISearchTemplate, ISearchResponseSet, 
    ISearchQuery, IDocumentResult, IPaging, INamedPattern, 
    INamedTemplate, IContext, IMenus, IMenuItem,
    IRouteLayouts, IRouteLayout, IRouteResponse
} from './interfaces';
import { Route } from './route';
import { SearchTemplate, SearchTemplateSet } from './search-template';
import { MapJsonify } from './map-jsonify';
import { Helpers } from './helpers';

/** Class that handles matched routes and gets results */
export class RouteMatch implements IRouteMatch {
    name: string = '_default';
    metaData: any = {};
    pattern: string|INamedPattern = null;
    queryDelimiter: string = '&';
    queryEquals: string = '=';
    primarySearchTemplate: SearchTemplate;
    supplimentarySearchTemplates: SearchTemplateSet = {};
    primaryResponse: SearchResponse<IDocumentResult> = null;
    supplimentaryResponses: ISearchResponseSet = {};
    elasticsearchConfig: ConfigOptions = null;
    defaultParams: any = {};
    layouts: IRouteLayouts = null;
    layoutName: string = 'default';
    response: IRouteResponse = {
        contentBody: '',
        contentType: 'text/html',
        statusCode: 200
    }

    get defaultParamsCopy(): any {
        var copy = {};
        Object.assign(copy, this.defaultParams);
        return copy;
    }

    // Used to remember which order our supplimentary queries were executed in
    private orderMap: string[] = [];

    private _primaryQuery: ISearchQuery = null;
    // Build our primary query
    get primaryQuery() {
        if(!this._primaryQuery){
            // If we haven't already got this query we need to generate it
            this._primaryQuery = this.primarySearchTemplate.getPrimary(this.params);
        }
        return this._primaryQuery;
    }

    private _supplimentaryQueries: any = null;
    // Build all supplimentary queries extending our parameters with the primary results we already have
    get supplimentaryQueries(): any {
        if(!this._supplimentaryQueries){
            // If we haven't already got these queries we need to generate them

            // Extend our parameters that will be used when generating supplimentary queries
            // by adding the primary result set
            var supplimentaryParams = this.params;
            supplimentaryParams.primaryResponse = this.primaryResponse;

            this._supplimentaryQueries = { body: [] };

            // Loop through all supplimentary queries
            Object.keys(this.supplimentarySearchTemplates).forEach((key: string, order: number) => {
                // Elasticsearch return msearch results in order, we need to keep
                // track of what order our supplimentary results are expected in
                // to assign them back to the correctly keyed result set
                this.orderMap[order] = key;

                var searchTemplate = this.supplimentarySearchTemplates[key];

                // Get both the head and body for our msearch
                var head = searchTemplate.getHead();
                var body = searchTemplate.getBody(supplimentaryParams);

                // Add them to our query array
                this._supplimentaryQueries.body.push(head);
                this._supplimentaryQueries.body.push(body);
            });
        }
        return this._supplimentaryQueries;
    }

    private _esClient: Client = null;
    private get esClient(): Client {
        if(!this._esClient){
            var config = Object.assign({}, this.elasticsearchConfig);
            this._esClient = new Client(config);
        }
        return this._esClient;
    }

    public get paging(): IPaging {
        var from = this.primaryQuery.body.from || 0;
        var size = this.primaryQuery.body.size || 10;
        var sort = this.primaryQuery.body.sort || null;
        var totalResults = this.primaryResponse.hits.total || 0;
        var totalPages = Math.ceil(totalResults / size);
        var currentPage = Math.floor(from / size) + 1;

        var nextPage = currentPage < totalPages ? Math.floor(currentPage + 1) : null;
        var prevPage = currentPage > 1 ? Math.floor(currentPage - 1) : null;

        // Setup an array (range) of 10 numbers surrounding our current page
        var pageRange = Array.from(new Array(9).keys(), (p, i) => i + (currentPage - 4));

        // Move range forward until none of the numbers are less than 1
        var rangeMin = pageRange[0];
        var positiveShift = rangeMin < 1 ? 1 - rangeMin : 0;
        pageRange = pageRange.map(p => p + positiveShift);

        // Move range backwards until none of the numbers are greater than totalPages
        var rangeMax = pageRange[pageRange.length - 1];
        var negativeShift = rangeMax > totalPages ? rangeMax - totalPages : 0;
        pageRange = pageRange.map(p => p - negativeShift);

        // Prune everything that appears outside of our 1 to totalPages range
        pageRange = pageRange.filter(p => p >= 1 && p <= totalPages);

        var pages = [];

        pageRange.forEach((page: number) => {
            var distance: number = Math.abs(currentPage - page);
            pages.push({
                pageNumber: Math.floor(page),
                distance: distance,
            });
        });

        var paging = {
            from: from,
            size: size,
            sort: sort,
            totalResults: totalResults,

            totalPages: totalPages,
            currentPage: currentPage,

            nextPage: nextPage,
            prevPage: prevPage,

            pageRange: pages
        };
        return paging;
    }
    
    _domainStripper: RegExp = null;
    get domainStripper(): RegExp {
        if(!this._domainStripper){
            var stripDomains = this.context.domains.map((domain: string) => { return domain.replace(/\./g, '\\.'); });
            var domainRegexString = '((https?)?:\\/\\/)((' + stripDomains.join(')|(') + '))';
            this._domainStripper = new RegExp(domainRegexString, 'ig');
        }
        return this._domainStripper;
    }

    public toJSON(): any {
        var templates = MapJsonify<ISearchTemplate>(this.supplimentarySearchTemplates);
        var responses = MapJsonify<SearchResponse<IDocumentResult>>(this.supplimentaryResponses);
        return {
            name: this.name,
            metaData: this.metaData,
            pattern: this.pattern,
            queryDelimiter: this.queryDelimiter,
            queryEquals: this.queryEquals,
            primarySearchTemplate: this.primarySearchTemplate.toJSON(),
            primaryQuery: this.primaryQuery,
            supplimentarySearchTemplates: templates,
            supplimentaryQueries: this.supplimentaryQueries,
            primaryResponse: this.primaryResponse,
            supplimentaryResponses: responses,
            elasticsearchConfig: this.elasticsearchConfig,
            layouts: this.layouts,
            response: this.response,
            params: this.params,
            paging: this.paging,
            defaultParams: this.defaultParams,
            context: null,
            layoutName: this.layoutName,
        };
    }

    /**
     * Create a matched route to get results using parameters
     * @param {Route} route - The route that has been matched
     * @param {any} params - The parameters that the route recognizer has found
     */
    constructor(route: Route, public params: any, public context: IContext){
        // Implement route
        Object.assign(this, route);

        Helpers.register(handlebars);
        Object.keys(context.templatePartials).forEach((name: string) => {
            handlebars.registerPartial(name, context.templatePartials[name]);
        });
    
        Object.keys(this.context.menus).forEach((name: string) => {
            this.context.menus[name] = this.traverseMenu(this.context.menus[name]);
        });
        
        Object.keys(this.layouts).forEach((name: string) => {
            if (name === 'default' || this.layoutName !== 'default') return;
            if (this.context.layouts.hasOwnProperty(name)) {
                var pattern = this.context.layouts[name].pattern;
                var regex = new RegExp(pattern, 'ig');
                if (regex.test(this.params.uri.href)) {
                    this.layoutName = name;
                    this.response.contentType = this.context.layouts[name].contentType;
                } else { 
                }
            }
        });
    }

    traverseMenu(menuItems: IMenuItem[], level: number = 0): IMenuItem[] {
        menuItems.forEach((menuItem) => {
            var pattern = new RegExp(menuItem.route, 'i');
            menuItem.match = pattern.test(this.params.uri.path);
            menuItem.level = level;
            if (menuItem.children) {
                menuItem.children = this.traverseMenu(menuItem.children, level + 1);
            }
        });

        return menuItems;
    }

    /**
     * Get primary and supplimentary results for this route match
     * @return {Promise<void>} A promise to tell when results have been fetched
     */
    getResults(): Promise<void> {
        return new Promise<void>((resolve, reject) => {
            //console.log('#### ROUTE NAME:', this.name, '####');
            // Perform our primary search
            this.esClient.search(this.primaryQuery, (err: any, primaryResponse: SearchResponse<IDocumentResult>) => {
                if(err) return reject(err);
                // Save the results for use in our rendered template
                this.primaryResponse = primaryResponse;

                if(Object.keys(this.supplimentarySearchTemplates).length > 0){
                    // If we have any supplimentary searches to do, do them
                    this.esClient.msearch(this.supplimentaryQueries, (err: any, supplimentaryResponses: MSearchResponse<IDocumentResult>) => {
                        if(err) return reject(err);
                        // Loop through each of our supplimentary responses
                        supplimentaryResponses.responses.map((supplimentaryResponse: SearchResponse<IDocumentResult>, i: number) => {
                            // Find out the name/key of the associated supplimentary search
                            var responseName = this.orderMap[i];
                            // Save the response to the appropriately named property of our supplimentary responses
                            this.supplimentaryResponses[responseName] = supplimentaryResponse;
                        });

                        this.renderResults();

                        // We're done so let the promise owner know
                        resolve();
                    });
                }else{
                    this.renderResults();

                    // We don't need to get anything else so let the promise owner know
                    resolve();
                }
            });
        });
    }

    renderResults() {
        try {
            // Compile our template
            var routeTemplateData: any = {
                name: this.name,
                primaryResponse: this.primaryResponse,
                supplimentaryResponses: this.supplimentaryResponses,
                params: this.params,
                metaData: this.metaData,
                paging: this.paging,
                context: this.context,
            };
           
            var sections: IRouteLayout = {};
            Object.keys(this.layouts[this.layoutName]).forEach((sectionName: string) => {
                var template = handlebars.compile(this.layouts[this.layoutName][sectionName]);
                var output = template(routeTemplateData);
                var doNotStripDomains = this.context.layouts[this.layoutName].doNotStripDomains;
                if (!doNotStripDomains) {
                    output = output.replace(this.domainStripper, '');
                }
                sections[sectionName] = output;
            });

            var contextData = {
                metaData: this.context.metaData,
                domains: this.context.domains,
                menus: this.context.menus,
                routes: this.context.routes,
                route: this.toJSON(),
                uaId: this.context.uaId,
                templatePartials: this.context.templatePartials,
            };
           
            var template = handlebars.compile(this.context.layouts[this.layoutName].template);
            var output = template(contextData);

            output = output.replace(/(<!--{section:)([a-z0-9_-]+)(}-->)/ig, (match, m1, m2, m3) => {
                if (sections.hasOwnProperty(m2)) {
                    return sections[m2];
                } else { 
                    return match;
                }
            });

            this.response.contentBody = output;
        } catch (err) {
            console.error('Error rendering route:', err);
            this.response.contentBody = JSON.stringify(err);
            this.response.statusCode = 500;
            this.response.contentType = 'application/json';  
        }
    }
}