<template>
  <view class="uni-pagination">
    <!-- #ifndef MP -->
    <picker
      v-if="showPageSize === true || showPageSize === 'true'"
      class="select-picker"
      mode="selector"
      :value="pageSizeIndex"
      :range="pageSizeRange"
      @change="pickerChange"
      @cancel="pickerClick"
      @click.native="pickerClick">
      <button type="default" size="mini" :plain="true">
        <text>{{ pageSizeRange[pageSizeIndex] }} {{ piecePerPage }}</text>
        <uni-icons
          class="select-picker-icon"
          type="arrowdown"
          size="12"
          color="#999"></uni-icons>
      </button>
    </picker>
    <!-- #endif -->
    <!-- #ifndef APP-NVUE -->
    <view class="uni-pagination__total is-phone-hide">共 {{ total }} 条</view>
    <!-- #endif -->
    <view
      class="uni-pagination__btn"
      :class="
        currentIndex === 1
          ? 'uni-pagination--disabled'
          : 'uni-pagination--enabled'
      "
      :hover-class="currentIndex === 1 ? '' : 'uni-pagination--hover'"
      :hover-start-time="20"
      :hover-stay-time="70"
      @click="clickLeft">
      <template v-if="showIcon === true || showIcon === 'true'">
        <uni-icons color="#666" size="16" type="left" />
      </template>
      <template v-else>
        <text class="uni-pagination__child-btn">{{ prevPageText }}</text>
      </template>
    </view>
    <view class="uni-pagination__num uni-pagination__num-flex-none">
      <view class="uni-pagination__num-current">
        <text
          class="uni-pagination__num-current-text is-pc-hide current-index-text">
          {{ currentIndex }}
        </text>
        <text class="uni-pagination__num-current-text is-pc-hide">
          /{{ maxPage || 0 }}
        </text>
        <!-- #ifndef APP-NVUE -->
        <view
          v-for="(item, index) in paper"
          :key="index"
          :class="{ 'page--active': item === currentIndex }"
          class="uni-pagination__num-tag tag--active is-phone-hide"
          @click.top="selectPage(item, index)">
          <text>{{ item }}</text>
        </view>
        <!-- #endif -->
      </view>
    </view>
    <view
      class="uni-pagination__btn"
      :class="
        currentIndex >= maxPage
          ? 'uni-pagination--disabled'
          : 'uni-pagination--enabled'
      "
      :hover-class="currentIndex === maxPage ? '' : 'uni-pagination--hover'"
      :hover-start-time="20"
      :hover-stay-time="70"
      @click="clickRight">
      <template v-if="showIcon === true || showIcon === 'true'">
        <uni-icons color="#666" size="16" type="right" />
      </template>
      <template v-else>
        <text class="uni-pagination__child-btn">{{ nextPageText }}</text>
      </template>
    </view>
  </view>
</template>

<script>
/**
 * Pagination 分页器
 * @description 分页器组件，用于展示页码、请求数据等
 * @tutorial https://ext.dcloud.net.cn/plugin?id=32
 * @property {String} prevText 左侧按钮文字
 * @property {String} nextText 右侧按钮文字
 * @property {String} piecePerPageText 条/页文字
 * @property {Number} current 当前页
 * @property {Number} total 数据总量
 * @property {Number} pageSize 每页数据量
 * @property {Boolean} showIcon = [true|false] 是否以 icon 形式展示按钮
 * @property {Boolean} showPageSize = [true|false] 是否展示每页条数
 * @property {Array} pageSizeRange = [20, 50, 100, 500] 每页条数选框
 * @event {Function} change 点击页码按钮时触发 ,e={type,current} current为当前页，type值为：next/prev，表示点击的是上一页还是下一个
 * * @event {Function} pageSizeChange 当前每页条数改变时触发 ,e={pageSize} pageSize 为当前所选的每页条数
 */

import { initVueI18n } from "@dcloudio/uni-i18n";
import messages from "./i18n/index.js";
const { t } = initVueI18n(messages);
export default {
  name: "UniPagination",
  emits: ["update:modelValue", "input", "change", "pageSizeChange"],
  props: {
    value: {
      type: [Number, String],
      default: 1,
    },
    modelValue: {
      type: [Number, String],
      default: 1,
    },
    prevText: {
      type: String,
    },
    nextText: {
      type: String,
    },
    piecePerPageText: {
      type: String,
    },
    current: {
      type: [Number, String],
      default: 1,
    },
    total: {
      // 数据总量
      type: [Number, String],
      default: 0,
    },
    pageSize: {
      // 每页数据量
      type: [Number, String],
      default: 10,
    },
    showIcon: {
      // 是否以 icon 形式展示按钮
      type: [Boolean, String],
      default: false,
    },
    showPageSize: {
      // 是否以 icon 形式展示按钮
      type: [Boolean, String],
      default: false,
    },
    pagerCount: {
      type: Number,
      default: 7,
    },
    pageSizeRange: {
      type: Array,
      default: () => [20, 50, 100, 500],
    },
  },
  data() {
    return {
      pageSizeIndex: 0,
      currentIndex: 1,
      paperData: [],
      pickerShow: false,
    };
  },
  computed: {
    piecePerPage() {
      return this.piecePerPageText || t("uni-pagination.piecePerPage");
    },
    prevPageText() {
      return this.prevText || t("uni-pagination.prevText");
    },
    nextPageText() {
      return this.nextText || t("uni-pagination.nextText");
    },
    maxPage() {
      let maxPage = 1;
      let total = Number(this.total);
      let pageSize = Number(this.pageSize);
      if (total && pageSize) {
        maxPage = Math.ceil(total / pageSize);
      }
      return maxPage;
    },
    paper() {
      const num = this.currentIndex;
      // TODO 最大页数
      const pagerCount = this.pagerCount;
      // const total = 181
      const total = this.total;
      const pageSize = this.pageSize;
      let totalArr = [];
      let showPagerArr = [];
      let pagerNum = Math.ceil(total / pageSize);
      for (let i = 0; i < pagerNum; i++) {
        totalArr.push(i + 1);
      }
      showPagerArr.push(1);
      const totalNum = totalArr[totalArr.length - (pagerCount + 1) / 2];
      totalArr.forEach((item, index) => {
        if ((pagerCount + 1) / 2 >= num) {
          if (item < pagerCount + 1 && item > 1) {
            showPagerArr.push(item);
          }
        } else if (num + 2 <= totalNum) {
          if (
            item > num - (pagerCount + 1) / 2 &&
            item < num + (pagerCount + 1) / 2
          ) {
            showPagerArr.push(item);
          }
        } else {
          if (
            (item > num - (pagerCount + 1) / 2 ||
              pagerNum - pagerCount < item) &&
            item < totalArr[totalArr.length - 1]
          ) {
            showPagerArr.push(item);
          }
        }
      });
      if (pagerNum > pagerCount) {
        if ((pagerCount + 1) / 2 >= num) {
          showPagerArr[showPagerArr.length - 1] = "...";
        } else if (num + 2 <= totalNum) {
          showPagerArr[1] = "...";
          showPagerArr[showPagerArr.length - 1] = "...";
        } else {
          showPagerArr[1] = "...";
        }
        showPagerArr.push(totalArr[totalArr.length - 1]);
      } else {
        if ((pagerCount + 1) / 2 >= num) {
        } else if (num + 2 <= totalNum) {
        } else {
          showPagerArr.shift();
          showPagerArr.push(totalArr[totalArr.length - 1]);
        }
      }

      return showPagerArr;
    },
  },
  watch: {
    current: {
      immediate: true,
      handler(val, old) {
        if (val < 1) {
          this.currentIndex = 1;
        } else {
          this.currentIndex = val;
        }
      },
    },
    value: {
      immediate: true,
      handler(val) {
        if (Number(this.current) !== 1) return;
        if (val < 1) {
          this.currentIndex = 1;
        } else {
          this.currentIndex = val;
        }
      },
    },
    pageSizeIndex(val) {
      this.$emit("pageSizeChange", this.pageSizeRange[val]);
    },
  },
  methods: {
    pickerChange(e) {
      this.pageSizeIndex = e.detail.value;
      this.pickerClick();
    },
    pickerClick() {
      // #ifdef H5
      const body = document.querySelector("body");
      if (!body) return;

      const className = "uni-pagination-picker-show";
      this.pickerShow = !this.pickerShow;

      if (this.pickerShow) {
        body.classList.add(className);
      } else {
        setTimeout(() => body.classList.remove(className), 300);
      }
      // #endif
    },
    // 选择标签
    selectPage(e, index) {
      if (parseInt(e)) {
        this.currentIndex = e;
        this.change("current");
      } else {
        let pagerNum = Math.ceil(this.total / this.pageSize);
        // let pagerNum = Math.ceil(181 / this.pageSize)
        // 上一页
        if (index <= 1) {
          if (this.currentIndex - 5 > 1) {
            this.currentIndex -= 5;
          } else {
            this.currentIndex = 1;
          }
          return;
        }
        // 下一页
        if (index >= 6) {
          if (this.currentIndex + 5 > pagerNum) {
            this.currentIndex = pagerNum;
          } else {
            this.currentIndex += 5;
          }
          return;
        }
      }
    },
    clickLeft() {
      if (Number(this.currentIndex) === 1) {
        return;
      }
      this.currentIndex -= 1;
      this.change("prev");
    },
    clickRight() {
      if (Number(this.currentIndex) >= this.maxPage) {
        return;
      }
      this.currentIndex += 1;
      this.change("next");
    },
    change(e) {
      this.$emit("input", this.currentIndex);
      this.$emit("update:modelValue", this.currentIndex);
      this.$emit("change", {
        type: e,
        current: this.currentIndex,
      });
    },
  },
};
</script>

<style lang="scss" scoped>
$uni-primary: #2979ff !default;
.uni-pagination {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  position: relative;
  overflow: hidden;
  flex-direction: row;
  justify-content: center;
  align-items: center;
}

.uni-pagination__total {
  font-size: 14px;
  color: #999;
  margin-right: 15px;
}

.uni-pagination__btn {
  /* #ifndef APP-NVUE */
  display: flex;
  cursor: pointer;
  /* #endif */
  padding: 0 8px;
  line-height: 30px;
  font-size: 12px;
  position: relative;
  background-color: #f0f0f0;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  text-align: center;
  border-radius: 5px;
  // border-width: 1px;
  // border-style: solid;
  // border-color: $uni-border-color;
}

.uni-pagination__child-btn {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  font-size: 12px;
  position: relative;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  text-align: center;
  color: #666;
  font-size: 12px;
}

.uni-pagination__num {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex: 1;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  height: 30px;
  line-height: 30px;
  font-size: 12px;
  color: #666;
  margin: 0 5px;
}

.uni-pagination__num-tag {
  /* #ifdef H5 */
  cursor: pointer;
  min-width: 30px;
  /* #endif */
  margin: 0 5px;
  height: 30px;
  text-align: center;
  line-height: 30px;
  // border: 1px red solid;
  color: #999;
  border-radius: 4px;
  // border-width: 1px;
  // border-style: solid;
  // border-color: $uni-border-color;
}

.uni-pagination__num-current {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex-direction: row;
}

.uni-pagination__num-current-text {
  font-size: 15px;
}

.current-index-text {
  color: $uni-primary;
}

.uni-pagination--enabled {
  color: #333333;
  opacity: 1;
}

.uni-pagination--disabled {
  opacity: 0.5;
  /* #ifdef H5 */
  cursor: default;
  /* #endif */
}

.uni-pagination--hover {
  color: rgba(0, 0, 0, 0.6);
  background-color: #eee;
}

.tag--active:hover {
  color: $uni-primary;
}

.page--active {
  color: #fff;
  background-color: $uni-primary;
}

.page--active:hover {
  color: #fff;
}

/* #ifndef APP-NVUE */
.is-pc-hide {
  display: block;
}

.is-phone-hide {
  display: none;
}

// @media screen and (min-width: 450px) {
//   .is-pc-hide {
//     display: none;
//   }

//   .is-phone-hide {
//     display: block;
//   }

//   .uni-pagination__num-flex-none {
//     flex: none;
//   }
// }

/* #endif */
</style>