import { AnimationPlayer } from "@angular/animations";
import { AnimationDriver } from "@angular/animations/browser";
import { ProxyViewContainer } from "tns-core-modules/ui/proxy-view-container";
import { eachDescendant } from "tns-core-modules/ui/core/view";

import { NativeScriptAnimationPlayer } from "./animation-player";
import {
    Keyframe,
    dashCaseToCamelCase,
} from "./utils";
import { NgView, InvisibleNode } from "../element-registry";
import { animationsLog as traceLog } from "../trace";

import { createSelector, SelectorCore } from "tns-core-modules/ui/styling/css-selector";

interface ViewMatchResult {
    found: boolean;
}

interface ViewMatchParams {
    originalView: NgView;
}

interface QueryParams {
    selector: Selector;
    multi: boolean;
}

interface QueryResult {
    matches: NgView[];
}

class Selector {
    private nsSelectors: SelectorCore[];
    private classSelectors: string[];

    constructor(rawSelector: string) {
        this.parse(rawSelector);
    }

    match(element: NgView): boolean {
        return this.nsSelectorMatch(element) || this.classSelectorsMatch(element);
    }

    private parse(rawSelector: string) {
        const selectors = rawSelector.split(",").map(s => s.trim());

        this.nsSelectors = selectors.map(createSelector);
        this.classSelectors = selectors
            .filter(s => s.startsWith("."))
            .map(s => s.substring(1));
    }

    private nsSelectorMatch(element: NgView) {
        return this.nsSelectors.some(s => s.match(element));
    }

    private classSelectorsMatch(element: NgView) {
        return this.classSelectors.some(s => this.hasClass(element, s));
    }

    // we're using that instead of match for classes
    // that are dynamically added by the animation engine
    // such as .ng-trigger, that's added for every :enter view
    private hasClass(element: NgView, cls: string) {
        return element && element["$$classes"] && element["$$classes"][cls];
    }
}

export class NativeScriptAnimationDriver implements AnimationDriver {
    matchesElement(element: NgView, rawSelector: string): boolean {
        traceLog(
            `NativeScriptAnimationDriver.matchesElement ` +
            `element: ${element}, selector: ${rawSelector}`
        );

        const selector = this.makeSelector(rawSelector);
        return selector.match(element);
    }


    containsElement(elm1: NgView, elm2: NgView): boolean {
        traceLog(
            `NativeScriptAnimationDriver.containsElement ` +
            `element1: ${elm1}, element2: ${elm2}`
        );

        const params: ViewMatchParams = { originalView: elm2 };
        const result: ViewMatchResult = this.visitDescendants(elm1, viewMatches, params);

        return result.found;
    }

    query(element: NgView, rawSelector: string, multi: boolean): NgView[] {
        traceLog(
            `NativeScriptAnimationDriver.query ` +
            `element: ${element}, selector: ${rawSelector} ` +
            `multi: ${multi}`
        );

        const selector = this.makeSelector(rawSelector);
        const params: QueryParams = { selector, multi };
        const result: QueryResult = this.visitDescendants(element, queryDescendants, params);

        return result.matches || [];
    }

    computeStyle(element: NgView, prop: string): string {
        traceLog(
            `NativeScriptAnimationDriver.computeStyle ` +
            `element: ${element}, prop: ${prop}`
        );

        const camelCaseProp = dashCaseToCamelCase(prop);
        return element.style[camelCaseProp];
    }

    animate(
        element: NgView,
        keyframes: Keyframe[],
        duration: number,
        delay: number,
        easing: string
    ): AnimationPlayer {
        traceLog(
            `NativeScriptAnimationDriver.animate ` +
            `element: ${element}, keyframes: ${keyframes} ` +
            `duration: ${duration}, delay: ${delay} ` +
            `easing: ${easing}`
        );

        return new NativeScriptAnimationPlayer(
            element, keyframes, duration, delay, easing);
    }

    private makeSelector(rawSelector: string): Selector {
        return new Selector(rawSelector);
    }

    private visitDescendants(
        element: NgView,
        cb: (child: NgView, result: any, params: any) => boolean,
        cbParams: any): any {

        const result = {};
        // fill the result obj with the result from the callback function
        eachDescendant(element, (child: NgView) => cb(child, result, cbParams));

        return result;
    }
}

function viewMatches(
    element: NgView,
    result: ViewMatchResult,
    params: ViewMatchParams
): boolean {

    if (element === params.originalView) {
        result.found = true;
    }

    return !result.found;
}

function queryDescendants(
    element: NgView,
    result: QueryResult,
    params: QueryParams
): boolean {

    if (!result.matches) {
        result.matches = [];
    }

    const { selector, multi } = params;

    // skip comment and text nodes
    // because they are not actual Views
    // and cannot be animated
    if (element instanceof InvisibleNode || !selector.match(element)) {
        return true;
    }

    if (element instanceof ProxyViewContainer) {
        element.eachChild((child: NgView) => {
            result.matches.push(child);
            return true;
        });
    } else {
        result.matches.push(element);
    }

    return multi;
}
