<template>
  <input
    type="number"
    :value="displayValue"
    @input="handleInput"
    @blur="handleBlur"
	class="filter_input"
    :class="inputClass"
  />
</template>

<script>
export default {
  name: "NumberInput",
  props: {
    value: [Number, String],
    inputClass: {
      type: String,
      default: ''
    },
    // 输入模式：integer(纯整数), decimal(纯小数), mixed(混合)
    mode: {
      type: String,
      default: "mixed",
      validator: (v) => ["integer", "decimal", "mixed"].includes(v),
    },
    // 小数位数限制
    decimalLength: {
      type: Number,
      default: 2,
    },
    // 最小值
    min: {
      type: Number,
      default: 0,
    },
    // 最大值
    max: {
      type: Number,
      default: Infinity,
    },
  },
  data() {
    return {
      displayValue: this.value?.toString() || "",
    };
  },
  watch: {
    value(newVal) {
      this.displayValue = newVal?.toString() || "";
    },
  },
  methods: {
    handleInput(e) {
      let value = e.detail.value;
      
      // 1. 过滤非法字符
      let filtered = value.replace(/[^\d.]/g, "");
      
      // 2. 处理多余的小数点
      if (this.mode === "integer") {
        filtered = filtered.replace(/\./g, ""); // 整数模式删除所有小数点
      } else {
        const firstDotIndex = filtered.indexOf(".");
        if (firstDotIndex !== -1) {
          // 只保留第一个小数点
          filtered =
            filtered.substring(0, firstDotIndex + 1) +
            filtered.substring(firstDotIndex + 1).replace(/\./g, "");
        }
      }
      
      // 3. 处理前导0
      if (filtered.startsWith("0") && filtered.length > 1 && !filtered.startsWith("0.")) {
        filtered = filtered.replace(/^0+/, "0").replace(/^0([^.])/, "$1");
      }
      
      // 4. 处理开头的小数点
      if (filtered.startsWith(".")) {
        if (this.mode === "integer") {
          filtered = "";
        } else {
          filtered = "0" + filtered;
        }
      }
      
      this.displayValue = filtered;
    },
    
    handleBlur() {
      let value = this.displayValue;
      
      // 空值处理
      if (value === "" || value === ".") {
        this.$emit("input", "");
        return;
      }
      
      // 处理结尾的小数点
      if (value.endsWith(".")) {
        value = value.slice(0, -1);
      }
      
      // 转换为数字
      const numValue = Number(value);
      
      // 小数位数处理
      let processedValue = value;
      if (this.mode !== "integer" && value.includes(".")) {
        const parts = value.split(".");
        if (parts[1].length > this.decimalLength) {
          processedValue = `${parts[0]}.${parts[1].slice(0, this.decimalLength)}`;
        }
      }
      
      // 范围校验
      let finalNum = Number(processedValue);
      if (finalNum < this.min) finalNum = this.min;
      if (finalNum > this.max) finalNum = this.max;
      
      // 更新值
      this.displayValue = finalNum.toString();
      this.$emit("input", finalNum);
    },
  },
};
</script>

<style scoped>
.number-input {
  border: 1px solid #ddd;
  padding: 8px 12px;
  border-radius: 4px;
  font-size: 14px;
}
</style>
