import {
    HorizontalLayout,
    Widget,
    shortcut,
    extend,
    emptyFn,
    result,
    isKey,
    createWidget,
    map,
    stripEL,
    formatEL,
    Controller,
    Events,
    MIN,
    MAX
} from "@/core";
import { Label } from "../single";
import { ButtonGroup } from "../combination";

/**
 * 分页控件
 *
 * Created by GUY on 2015/8/31.
 * @class Pager
 * @extends Widget
 */

@shortcut()
export class Pager extends Widget {
    _defaultConfig() {
        return extend(super._defaultConfig(...arguments), {
            baseCls: "bi-pager",
            behaviors: {},
            layouts: [
                {
                    type: HorizontalLayout.xtype,
                    hgap: 10,
                    vgap: 0,
                }
            ],

            dynamicShow: true, // 是否动态显示上一页、下一页、首页、尾页， 若为false，则指对其设置使能状态
            // dynamicShow为false时以下两个有用
            dynamicShowFirstLast: false, // 是否动态显示首页、尾页
            dynamicShowPrevNext: false, // 是否动态显示上一页、下一页
            pages: false, // 总页数
            curr: () => 1, // 初始化当前页
            groups: 0, // 连续显示分页数
            jump: emptyFn, // 分页的回调函数
            first: false, // 是否显示首页
            last: false, // 是否显示尾页
            prev: "上一页",
            next: "下一页",

            firstPage: 1,
            lastPage: () =>
                // 在万不得已时才会调用这个函数获取最后一页的页码,  主要作用于setValue方法
                1,
            hasPrev: emptyFn, // pages不可用时有效
            hasNext: emptyFn, // pages不可用时有效
        });
    }

    static xtype = "bi.pager";
    static EVENT_CHANGE = "EVENT_CHANGE";
    static EVENT_AFTER_POPULATE = "EVENT_AFTER_POPULATE";
    render() {
        this.currPage = result(this.options, "curr");
        // 翻页太灵敏
        // this._lock = false;
        // this._debouce = debounce(function () {
        //     self._lock = false;
        // }, 300);
        this._populate();
    }

    _populate() {
        const o = this.options,
            view = [],
            dict = {};
        const { dynamicShow, dynamicShowPrevNext, hasPrev, dynamicShowFirstLast, hasNext, behaviors, layouts, jump } =
            this.options;
        this.empty();
        const pages = result(o, "pages");
        const curr = result(this, "currPage");
        let groups = result(o, "groups");
        let first = result(o, "first");
        let last = result(o, "last");
        const prev = result(o, "prev");
        const next = result(o, "next");

        if (pages === false) {
            groups = 0;
            first = false;
            last = false;
        } else {
            groups > pages && (groups = pages);
        }

        // 计算当前组
        dict.index = Math.ceil((curr + (groups > 1 && groups !== pages ? 1 : 0)) / (groups === 0 ? 1 : groups));

        // 当前页非首页，则输出上一页
        if (((!dynamicShow && !dynamicShowPrevNext) || curr > 1) && prev !== false) {
            if (isKey(prev)) {
                view.push({
                    text: prev,
                    value: "prev",
                    disabled: pages === false ? hasPrev(curr) === false : !(curr > 1 && prev !== false),
                });
            } else {
                view.push({
                    el: extend(
                        {
                            disabled: pages === false ? hasPrev(curr) === false : !(curr > 1 && prev !== false),
                        },
                        prev
                    ),
                });
            }
        }

        // 当前组非首组，则输出首页
        if (((!dynamicShow && !dynamicShowFirstLast) || (dict.index > 1 && groups !== 0)) && first) {
            view.push({
                text: first,
                value: "first",
                disabled: !(dict.index > 1 && groups !== 0),
            });
            if (dict.index > 1 && groups !== 0 && groups !== pages - 1) {
                view.push({
                    type: Label.xtype,
                    cls: "page-ellipsis",
                    text: "\u2026",
                });
            }
        }

        // 输出当前页组
        dict.poor = Math.floor((groups - 1) / 2);
        dict.start = dict.index > 1 ? curr - dict.poor : 1;
        dict.end =
            dict.index > 1
                ? (function () {
                    const max = curr + (groups - dict.poor - 1);

                    return max > pages ? pages : max;
                }())
                : groups;
        if (dict.end - dict.start < groups - 1) {
            // 最后一组状态
            dict.start = dict.end - groups + 1;
        }
        let s = dict.start,
            e = dict.end;
        if (first && last && dict.index > 1 && groups !== 0 && pages > groups && dict.end < pages && groups !== 0) {
            s++;
            e--;
        }
        for (; s <= e; s++) {
            if (s === curr) {
                view.push({
                    text: s,
                    value: s,
                    selected: true,
                });
            } else {
                view.push({
                    text: s,
                    value: s,
                });
            }
        }

        // 总页数大于连续分页数，且当前组最大页小于总页，输出尾页
        if (((!dynamicShow && !dynamicShowFirstLast) || (pages > groups && dict.end < pages && groups !== 0)) && last) {
            if (pages > groups && dict.end < pages && groups !== 0 && groups !== pages - 1) {
                view.push({
                    type: Label.xtype,
                    cls: "page-ellipsis",
                    text: "\u2026",
                });
            }
            view.push({
                text: last,
                value: "last",
                disabled: !(pages > groups && dict.end < pages && groups !== 0),
            });
        }

        // 当前页不为尾页时，输出下一页
        dict.flow = !prev && groups === 0;
        if ((!dynamicShow && !dynamicShowPrevNext && next) || (curr !== pages && next) || dict.flow) {
            view.push(
                (function () {
                    if (isKey(next)) {
                        if (pages === false) {
                            return { text: next, value: "next", disabled: hasNext(curr) === false };
                        }

                        return dict.flow && curr === pages
                            ? { text: next, value: "next", disabled: true }
                            : { text: next, value: "next", disabled: !((curr !== pages && next) || dict.flow) };
                    }

                    return {
                        el: extend(
                            {
                                disabled:
                                    pages === false
                                        ? hasNext(curr) === false
                                        : !((curr !== pages && next) || dict.flow),
                            },
                            next
                        ),
                    };
                })()
            );
        }

        this.button_group = createWidget({
            type: ButtonGroup.xtype,
            element: this,
            items: map(view, (idx, v) => {
                v = extend(
                    {
                        cls: "bi-list-item-select bi-border-radius",
                        height: 23,
                        hgap: v.el ? 0 : 10,
                        stopPropagation: true,
                    },
                    stripEL(v)
                );

                return formatEL(v);
            }),
            behaviors,
            layouts,
        });
        this.button_group.on(Controller.EVENT_CHANGE, (type, value, obj, ...args) => {
            // if (self._lock === true) {
            //     return;
            // }
            // self._lock = true;
            // self._debouce();
            if (type === Events.CLICK) {
                const v = this.button_group.getValue()[0];
                switch (v) {
                    case "first":
                        this.currPage = 1;
                        break;
                    case "last":
                        this.currPage = pages;
                        break;
                    case "prev":
                        this.currPage--;
                        break;
                    case "next":
                        this.currPage++;
                        break;
                    default:
                        this.currPage = v;
                        break;
                }
                jump.apply(this, [
                    {
                        pages,
                        curr: this.currPage,
                    }
                ]);
                this._populate();
                this.fireEvent(Pager.EVENT_CHANGE, obj);
            }
            this.fireEvent(Controller.EVENT_CHANGE, type, value, obj, ...args);
        });
        this.fireEvent(Pager.EVENT_AFTER_POPULATE);
    }

    getCurrentPage() {
        return this.currPage;
    }

    setAllPages(pages) {
        this.options.pages = pages;
        this._populate();
    }

    hasPrev(v) {
        v || (v = 1);
        const { pages, hasPrev } = this.options;

        return pages === false ? hasPrev(v) : v > 1;
    }

    hasNext(v) {
        v || (v = 1);
        const { pages, hasNext } = this.options;

        return pages === false ? hasNext(v) : v < pages;
    }

    setValue(v) {
        const o = this.options;
        const { pages } = this.options;
        v = v || 0;
        v = v < 1 ? 1 : v;
        if (pages === false) {
            const lastPage = result(o, "lastPage");
            let firstPage = 1;
            this.currPage =
                v > lastPage ? lastPage : ((firstPage = result(o, "firstPage")), v < firstPage ? firstPage : v);
        } else {
            v = v > pages ? pages : v;
            this.currPage = v;
        }
        this._populate();
    }

    getValue() {
        const val = this.button_group.getValue()[0];
        switch (val) {
            case "prev":
                return -1;
            case "next":
                return 1;
            case "first":
                return MIN;
            case "last":
                return MAX;
            default:
                return val;
        }
    }

    attr(key, value) {
        super.attr(...arguments);
        if (key === "curr") {
            this.currPage = result(this.options, "curr");
        }
    }

    populate() {
        this._populate();
    }
}