import * as zrUtil from 'zrender/src/core/util';
import env from 'zrender/src/core/env';
import {makeInner} from '../../util/model';

var inner = makeInner();
var each = zrUtil.each;

/**
 * @param {string} key
 * @param {module:echarts/ExtensionAPI} api
 * @param {Function} handler
 *      param: {string} currTrigger
 *      param: {Array.<number>} point
 */
export function register(key, api, handler) {
    if (env.node) {
        return;
    }

    var zr = api.getZr();
    inner(zr).records || (inner(zr).records = {});

    initGlobalListeners(zr, api);

    var record = inner(zr).records[key] || (inner(zr).records[key] = {});
    record.handler = handler;
}

function initGlobalListeners(zr, api) {
    if (inner(zr).initialized) {
        return;
    }

    inner(zr).initialized = true;

    useHandler('click', zrUtil.curry(doEnter, 'click'));
    useHandler('mousemove', zrUtil.curry(doEnter, 'mousemove'));
    // useHandler('mouseout', onLeave);
    useHandler('globalout', onLeave);

    function useHandler(eventType, cb) {
        zr.on(eventType, function (e) {
            var dis = makeDispatchAction(api);

            each(inner(zr).records, function (record) {
                record && cb(record, e, dis.dispatchAction);
            });

            dispatchTooltipFinally(dis.pendings, api);
        });
    }
}

function dispatchTooltipFinally(pendings, api) {
    var showLen = pendings.showTip.length;
    var hideLen = pendings.hideTip.length;

    var actuallyPayload;
    if (showLen) {
        actuallyPayload = pendings.showTip[showLen - 1];
    }
    else if (hideLen) {
        actuallyPayload = pendings.hideTip[hideLen - 1];
    }
    if (actuallyPayload) {
        actuallyPayload.dispatchAction = null;
        api.dispatchAction(actuallyPayload);
    }
}

function onLeave(record, e, dispatchAction) {
    record.handler('leave', null, dispatchAction);
}

function doEnter(currTrigger, record, e, dispatchAction) {
    record.handler(currTrigger, e, dispatchAction);
}

function makeDispatchAction(api) {
    var pendings = {
        showTip: [],
        hideTip: []
    };
    // FIXME
    // better approach?
    // 'showTip' and 'hideTip' can be triggered by axisPointer and tooltip,
    // which may be conflict, (axisPointer call showTip but tooltip call hideTip);
    // So we have to add "final stage" to merge those dispatched actions.
    var dispatchAction = function (payload) {
        var pendingList = pendings[payload.type];
        if (pendingList) {
            pendingList.push(payload);
        }
        else {
            payload.dispatchAction = dispatchAction;
            api.dispatchAction(payload);
        }
    };

    return {
        dispatchAction: dispatchAction,
        pendings: pendings
    };
}

/**
 * @param {string} key
 * @param {module:echarts/ExtensionAPI} api
 */
export function unregister(key, api) {
    if (env.node) {
        return;
    }
    var zr = api.getZr();
    var record = (inner(zr).records || {})[key];
    if (record) {
        inner(zr).records[key] = null;
    }
}