import PropTypes from '../_util/vue-types';
import BaseMixin from '../_util/BaseMixin';
import { hasProp, getComponentFromProp } from '../_util/props-util';
import Pager from './Pager';
import Options from './Options';
import LOCALE from './locale/zh_CN';
import KEYCODE from './KeyCode';

function noop() {}

// 是否是正整数
function isInteger(value) {
  return typeof value === 'number' && isFinite(value) && Math.floor(value) === value;
}

function defaultItemRender(page, type, element) {
  return element;
}

function calculatePage(p, state, props) {
  let pageSize = p;
  if (typeof pageSize === 'undefined') {
    pageSize = state.statePageSize;
  }
  return Math.floor((props.total - 1) / pageSize) + 1;
}

export default {
  name: 'Pagination',
  mixins: [BaseMixin],
  model: {
    prop: 'current',
    event: 'change.current',
  },
  props: {
    disabled: PropTypes.bool,
    prefixCls: PropTypes.string.def('rc-pagination'),
    selectPrefixCls: PropTypes.string.def('rc-select'),
    current: PropTypes.number,
    defaultCurrent: PropTypes.number.def(1),
    total: PropTypes.number.def(0),
    pageSize: PropTypes.number,
    defaultPageSize: PropTypes.number.def(10),
    hideOnSinglePage: PropTypes.bool.def(false),
    showSizeChanger: PropTypes.bool.def(false),
    showLessItems: PropTypes.bool.def(false),
    // showSizeChange: PropTypes.func.def(noop),
    selectComponentClass: PropTypes.any,
    showPrevNextJumpers: PropTypes.bool.def(true),
    showQuickJumper: PropTypes.oneOfType([PropTypes.bool, PropTypes.object]).def(false),
    showTitle: PropTypes.bool.def(true),
    pageSizeOptions: PropTypes.arrayOf(PropTypes.string),
    buildOptionText: PropTypes.func,
    showTotal: PropTypes.func,
    simple: PropTypes.bool,
    locale: PropTypes.object.def(LOCALE),
    itemRender: PropTypes.func.def(defaultItemRender),
    prevIcon: PropTypes.any,
    nextIcon: PropTypes.any,
    jumpPrevIcon: PropTypes.any,
    jumpNextIcon: PropTypes.any,
  },
  data() {
    const hasOnChange = this.onChange !== noop;
    const hasCurrent = hasProp(this, 'current');
    if (hasCurrent && !hasOnChange) {
      console.warn(
        'Warning: You provided a `current` prop to a Pagination component without an `onChange` handler. This will render a read-only component.',
      ); // eslint-disable-line
    }
    let current = this.defaultCurrent;
    if (hasCurrent) {
      current = this.current;
    }

    let pageSize = this.defaultPageSize;
    if (hasProp(this, 'pageSize')) {
      pageSize = this.pageSize;
    }

    return {
      stateCurrent: current,
      stateCurrentInputValue: current,
      statePageSize: pageSize,
    };
  },
  watch: {
    current(val) {
      this.setState({
        stateCurrent: val,
        stateCurrentInputValue: val,
      });
    },
    pageSize(val) {
      const newState = {};
      let current = this.stateCurrent;
      const newCurrent = calculatePage(val, this.$data, this.$props);
      current = current > newCurrent ? newCurrent : current;
      if (!hasProp(this, 'current')) {
        newState.stateCurrent = current;
        newState.stateCurrentInputValue = current;
      }
      newState.statePageSize = val;
      this.setState(newState);
    },
    stateCurrent(val, oldValue) {
      // When current page change, fix focused style of prev item
      // A hacky solution of https://github.com/ant-design/ant-design/issues/8948
      this.$nextTick(() => {
        if (this.$refs.paginationNode) {
          const lastCurrentNode = this.$refs.paginationNode.querySelector(
            `.${this.prefixCls}-item-${oldValue}`,
          );
          if (lastCurrentNode && document.activeElement === lastCurrentNode) {
            lastCurrentNode.blur();
          }
        }
      });
    },
  },
  methods: {
    getJumpPrevPage() {
      return Math.max(1, this.stateCurrent - (this.showLessItems ? 3 : 5));
    },
    getJumpNextPage() {
      return Math.min(
        calculatePage(undefined, this.$data, this.$props),
        this.stateCurrent + (this.showLessItems ? 3 : 5),
      );
    },
    getItemIcon(icon) {
      const { prefixCls } = this.$props;
      const iconNode = getComponentFromProp(this, icon, this.$props) || (
        <a class={`${prefixCls}-item-link`} />
      );
      return iconNode;
    },
    getValidValue(e) {
      const inputValue = e.target.value;
      const { stateCurrentInputValue } = this.$data;
      let value;
      if (inputValue === '') {
        value = inputValue;
      } else if (isNaN(Number(inputValue))) {
        value = stateCurrentInputValue;
      } else {
        value = Number(inputValue);
      }
      return value;
    },
    isValid(page) {
      return isInteger(page) && page >= 1 && page !== this.stateCurrent;
    },
    shouldDisplayQuickJumper() {
      const { showQuickJumper, pageSize, total } = this.$props;
      if (total <= pageSize) {
        return false;
      }
      return showQuickJumper;
    },
    // calculatePage (p) {
    //   let pageSize = p
    //   if (typeof pageSize === 'undefined') {
    //     pageSize = this.statePageSize
    //   }
    //   return Math.floor((this.total - 1) / pageSize) + 1
    // },
    handleKeyDown(event) {
      if (event.keyCode === KEYCODE.ARROW_UP || event.keyCode === KEYCODE.ARROW_DOWN) {
        event.preventDefault();
      }
    },
    handleKeyUp(e) {
      const value = this.getValidValue(e);
      const stateCurrentInputValue = this.stateCurrentInputValue;

      if (value !== stateCurrentInputValue) {
        this.setState({
          stateCurrentInputValue: value,
        });
      }

      if (e.keyCode === KEYCODE.ENTER) {
        this.handleChange(value);
      } else if (e.keyCode === KEYCODE.ARROW_UP) {
        this.handleChange(value - 1);
      } else if (e.keyCode === KEYCODE.ARROW_DOWN) {
        this.handleChange(value + 1);
      }
    },
    changePageSize(size) {
      let current = this.stateCurrent;
      const preCurrent = current;
      const newCurrent = calculatePage(size, this.$data, this.$props);
      current = current > newCurrent ? newCurrent : current;
      // fix the issue:
      // Once 'total' is 0, 'current' in 'onShowSizeChange' is 0, which is not correct.
      if (newCurrent === 0) {
        current = this.stateCurrent;
      }
      if (typeof size === 'number') {
        if (!hasProp(this, 'pageSize')) {
          this.setState({
            statePageSize: size,
          });
        }
        if (!hasProp(this, 'current')) {
          this.setState({
            stateCurrent: current,
            stateCurrentInputValue: current,
          });
        }
      }
      this.$emit('update:pageSize', size);
      this.$emit('showSizeChange', current, size);
      if (current !== preCurrent) {
        this.$emit('change.current', current, size);
      }
    },
    handleChange(p) {
      const { disabled } = this.$props;
      let page = p;
      if (this.isValid(page) && !disabled) {
        const currentPage = calculatePage(undefined, this.$data, this.$props);
        if (page > currentPage) {
          page = currentPage;
        }
        if (!hasProp(this, 'current')) {
          this.setState({
            stateCurrent: page,
            stateCurrentInputValue: page,
          });
        }
        // this.$emit('input', page)
        this.$emit('change', page, this.statePageSize);
        this.$emit('change.current', page, this.statePageSize);
        return page;
      }
      return this.stateCurrent;
    },
    prev() {
      if (this.hasPrev()) {
        this.handleChange(this.stateCurrent - 1);
      }
    },
    next() {
      if (this.hasNext()) {
        this.handleChange(this.stateCurrent + 1);
      }
    },
    jumpPrev() {
      this.handleChange(this.getJumpPrevPage());
    },
    jumpNext() {
      this.handleChange(this.getJumpNextPage());
    },
    hasPrev() {
      return this.stateCurrent > 1;
    },
    hasNext() {
      return this.stateCurrent < calculatePage(undefined, this.$data, this.$props);
    },
    runIfEnter(event, callback, ...restParams) {
      if (event.key === 'Enter' || event.charCode === 13) {
        callback(...restParams);
      }
    },
    runIfEnterPrev(event) {
      this.runIfEnter(event, this.prev);
    },
    runIfEnterNext(event) {
      this.runIfEnter(event, this.next);
    },
    runIfEnterJumpPrev(event) {
      this.runIfEnter(event, this.jumpPrev);
    },
    runIfEnterJumpNext(event) {
      this.runIfEnter(event, this.jumpNext);
    },
    handleGoTO(event) {
      if (event.keyCode === KEYCODE.ENTER || event.type === 'click') {
        this.handleChange(this.stateCurrentInputValue);
      }
    },
  },
  render() {
    const { prefixCls, disabled } = this.$props;

    // When hideOnSinglePage is true and there is only 1 page, hide the pager
    if (this.hideOnSinglePage === true && this.total <= this.statePageSize) {
      return null;
    }
    const props = this.$props;
    const locale = this.locale;

    const allPages = calculatePage(undefined, this.$data, this.$props);
    const pagerList = [];
    let jumpPrev = null;
    let jumpNext = null;
    let firstPager = null;
    let lastPager = null;
    let gotoButton = null;
    const goButton = this.showQuickJumper && this.showQuickJumper.goButton;
    const pageBufferSize = this.showLessItems ? 1 : 2;
    const { stateCurrent, statePageSize } = this;
    const prevPage = stateCurrent - 1 > 0 ? stateCurrent - 1 : 0;
    const nextPage = stateCurrent + 1 < allPages ? stateCurrent + 1 : allPages;

    if (this.simple) {
      if (goButton) {
        if (typeof goButton === 'boolean') {
          gotoButton = (
            <button type="button" onClick={this.handleGoTO} onKeyup={this.handleGoTO}>
              {locale.jump_to_confirm}
            </button>
          );
        } else {
          gotoButton = (
            <span onClick={this.handleGoTO} onKeyup={this.handleGoTO}>
              {goButton}
            </span>
          );
        }
        gotoButton = (
          <li
            title={this.showTitle ? `${locale.jump_to}${this.stateCurrent}/${allPages}` : null}
            class={`${prefixCls}-simple-pager`}
          >
            {gotoButton}
          </li>
        );
      }
      const hasPrev = this.hasPrev();
      const hasNext = this.hasNext();
      return (
        <ul class={`${prefixCls} ${prefixCls}-simple`}>
          <li
            title={this.showTitle ? locale.prev_page : null}
            onClick={this.prev}
            tabIndex={hasPrev ? 0 : null}
            onKeypress={this.runIfEnterPrev}
            class={`${hasPrev ? '' : `${prefixCls}-disabled`} ${prefixCls}-prev`}
            aria-disabled={!this.hasPrev()}
          >
            {this.itemRender(prevPage, 'prev', this.getItemIcon('prevIcon'))}
          </li>
          <li
            title={this.showTitle ? `${stateCurrent}/${allPages}` : null}
            class={`${prefixCls}-simple-pager`}
          >
            <input
              type="text"
              value={this.stateCurrentInputValue}
              onKeydown={this.handleKeyDown}
              onKeyup={this.handleKeyUp}
              onInput={this.handleKeyUp}
              size="3"
            />
            <span class={`${prefixCls}-slash`}>／</span>
            {allPages}
          </li>
          <li
            title={this.showTitle ? locale.next_page : null}
            onClick={this.next}
            tabIndex={this.hasNext ? 0 : null}
            onKeypress={this.runIfEnterNext}
            class={`${hasNext ? '' : `${prefixCls}-disabled`} ${prefixCls}-next`}
            aria-disabled={!this.hasNext()}
          >
            {this.itemRender(nextPage, 'next', this.getItemIcon('nextIcon'))}
          </li>
          {gotoButton}
        </ul>
      );
    }
    if (allPages <= 5 + pageBufferSize * 2) {
      const pagerProps = {
        props: {
          locale,
          rootPrefixCls: prefixCls,
          showTitle: props.showTitle,
          itemRender: props.itemRender,
        },
        on: {
          click: this.handleChange,
          keypress: this.runIfEnter,
        },
      };
      if (!allPages) {
        pagerList.push(
          <Pager {...pagerProps} key="noPager" page={allPages} class={`${prefixCls}-disabled`} />,
        );
      }
      for (let i = 1; i <= allPages; i++) {
        const active = stateCurrent === i;
        pagerList.push(<Pager {...pagerProps} key={i} page={i} active={active} />);
      }
    } else {
      const prevItemTitle = this.showLessItems ? locale.prev_3 : locale.prev_5;
      const nextItemTitle = this.showLessItems ? locale.next_3 : locale.next_5;
      if (this.showPrevNextJumpers) {
        let jumpPrevClassString = `${prefixCls}-jump-prev`;
        if (props.jumpPrevIcon) {
          jumpPrevClassString += ` ${prefixCls}-jump-prev-custom-icon`;
        }
        jumpPrev = (
          <li
            title={this.showTitle ? prevItemTitle : null}
            key="prev"
            onClick={this.jumpPrev}
            tabIndex="0"
            onKeypress={this.runIfEnterJumpPrev}
            class={jumpPrevClassString}
          >
            {this.itemRender(this.getJumpPrevPage(), 'jump-prev', this.getItemIcon('jumpPrevIcon'))}
          </li>
        );
        let jumpNextClassString = `${prefixCls}-jump-next`;
        if (props.jumpNextIcon) {
          jumpNextClassString += ` ${prefixCls}-jump-next-custom-icon`;
        }
        jumpNext = (
          <li
            title={this.showTitle ? nextItemTitle : null}
            key="next"
            tabIndex="0"
            onClick={this.jumpNext}
            onKeypress={this.runIfEnterJumpNext}
            class={jumpNextClassString}
          >
            {this.itemRender(this.getJumpNextPage(), 'jump-next', this.getItemIcon('jumpNextIcon'))}
          </li>
        );
      }

      lastPager = (
        <Pager
          locale={locale}
          last
          rootPrefixCls={prefixCls}
          onClick={this.handleChange}
          onKeypress={this.runIfEnter}
          key={allPages}
          page={allPages}
          active={false}
          showTitle={this.showTitle}
          itemRender={this.itemRender}
        />
      );
      firstPager = (
        <Pager
          locale={locale}
          rootPrefixCls={prefixCls}
          onClick={this.handleChange}
          onKeypress={this.runIfEnter}
          key={1}
          page={1}
          active={false}
          showTitle={this.showTitle}
          itemRender={this.itemRender}
        />
      );

      let left = Math.max(1, stateCurrent - pageBufferSize);
      let right = Math.min(stateCurrent + pageBufferSize, allPages);

      if (stateCurrent - 1 <= pageBufferSize) {
        right = 1 + pageBufferSize * 2;
      }

      if (allPages - stateCurrent <= pageBufferSize) {
        left = allPages - pageBufferSize * 2;
      }

      for (let i = left; i <= right; i++) {
        const active = stateCurrent === i;
        pagerList.push(
          <Pager
            locale={locale}
            rootPrefixCls={prefixCls}
            onClick={this.handleChange}
            onKeypress={this.runIfEnter}
            key={i}
            page={i}
            active={active}
            showTitle={this.showTitle}
            itemRender={this.itemRender}
          />,
        );
      }

      if (stateCurrent - 1 >= pageBufferSize * 2 && stateCurrent !== 1 + 2) {
        pagerList[0] = (
          <Pager
            locale={locale}
            rootPrefixCls={prefixCls}
            onClick={this.handleChange}
            onKeypress={this.runIfEnter}
            key={left}
            page={left}
            class={`${prefixCls}-item-after-jump-prev`}
            active={false}
            showTitle={this.showTitle}
            itemRender={this.itemRender}
          />
        );
        pagerList.unshift(jumpPrev);
      }
      if (allPages - stateCurrent >= pageBufferSize * 2 && stateCurrent !== allPages - 2) {
        pagerList[pagerList.length - 1] = (
          <Pager
            locale={locale}
            rootPrefixCls={prefixCls}
            onClick={this.handleChange}
            onKeypress={this.runIfEnter}
            key={right}
            page={right}
            class={`${prefixCls}-item-before-jump-next`}
            active={false}
            showTitle={this.showTitle}
            itemRender={this.itemRender}
          />
        );
        pagerList.push(jumpNext);
      }

      if (left !== 1) {
        pagerList.unshift(firstPager);
      }
      if (right !== allPages) {
        pagerList.push(lastPager);
      }
    }

    let totalText = null;

    if (this.showTotal) {
      totalText = (
        <li class={`${prefixCls}-total-text`}>
          {this.showTotal(this.total, [
            this.total === 0 ? 0 : (stateCurrent - 1) * statePageSize + 1,
            stateCurrent * statePageSize > this.total ? this.total : stateCurrent * statePageSize,
          ])}
        </li>
      );
    }
    const prevDisabled = !this.hasPrev() || !allPages;
    const nextDisabled = !this.hasNext() || !allPages;
    const buildOptionText = this.buildOptionText || this.$scopedSlots.buildOptionText;
    return (
      <ul
        class={{ [`${prefixCls}`]: true, [`${prefixCls}-disabled`]: disabled }}
        unselectable="unselectable"
        ref="paginationNode"
      >
        {totalText}
        <li
          title={this.showTitle ? locale.prev_page : null}
          onClick={this.prev}
          tabIndex={prevDisabled ? null : 0}
          onKeypress={this.runIfEnterPrev}
          class={`${!prevDisabled ? '' : `${prefixCls}-disabled`} ${prefixCls}-prev`}
          aria-disabled={prevDisabled}
        >
          {this.itemRender(prevPage, 'prev', this.getItemIcon('prevIcon'))}
        </li>
        {pagerList}
        <li
          title={this.showTitle ? locale.next_page : null}
          onClick={this.next}
          tabIndex={nextDisabled ? null : 0}
          onKeypress={this.runIfEnterNext}
          class={`${!nextDisabled ? '' : `${prefixCls}-disabled`} ${prefixCls}-next`}
          aria-disabled={nextDisabled}
        >
          {this.itemRender(nextPage, 'next', this.getItemIcon('nextIcon'))}
        </li>
        <Options
          disabled={disabled}
          locale={locale}
          rootPrefixCls={prefixCls}
          selectComponentClass={this.selectComponentClass}
          selectPrefixCls={this.selectPrefixCls}
          changeSize={this.showSizeChanger ? this.changePageSize : null}
          current={stateCurrent}
          pageSize={statePageSize}
          pageSizeOptions={this.pageSizeOptions}
          buildOptionText={buildOptionText || null}
          quickGo={this.shouldDisplayQuickJumper() ? this.handleChange : null}
          goButton={goButton}
        />
      </ul>
    );
  },
};