<script>
import axios from "axios";
export default {
  name: "calculator",
  mounted() {
    this.$nextTick(function () {
      this.getHistory();
    });
  },
  methods: {
    clickHandler(e) {
      let that = this;
      let target = e.target;
      if (target.nodeName == "SPAN") {
        target = e.target.parentNode;
        target.blur();
      }
      let button_text = target.id;
      console.log(target.id);
      // impl
      if (that.isNum(button_text)) {
        if (!that.noPrev) that.remake();
        if (button_text === "0" && that.isEmpty()) return;
        if (that.changeOp) that.changeOp = false;
        that.new_exp += button_text;
        try {
          that.currentVal = eval(this.new_exp);
        } catch (error) {
          this.errorHandler(error);
          return;
        }
      } else if (that.isSym(button_text)) {
        if (that.dot && that.new_exp.slice(-1) == ".") that.new_exp = "0";
        if (that.changeOp) {
          that.old_exp = that.old_exp.substring(0, that.old_exp.length - 1);
          that.old_exp += button_text;
        } else if (!that.noPrev) {
          that.noPrev = true;
          that.changeOp = true;
          that.new_exp = "";
          that.old_exp = that.currentVal.toString() + button_text;
        } else {
          if (that.isEmpty()) that.old_exp = "0";
          else that.old_exp += that.new_exp;
          that.new_exp = "";
          if (!this.bracket)
            try {
              that.lastVal = that.currentVal;
              that.currentVal = eval(that.old_exp);
            } catch (error) {
              this.errorHandler("等式错误");
              return;
            }
          that.old_exp += button_text;
          that.changeOp = true;
        }
      } else if (button_text === "=") {
        if (that.bracket != 0) this.errorHandler("括号不匹配");
        if (!that.noPrev) {
          that.old_exp = that.currentVal.toString();
          that.old_exp += that.holdVal;
          try {
            that.currentVal = eval(that.old_exp);
          } catch (error) {
            this.errorHandler("等式错误");
            return;
          }
          that.old_exp += "=";
        } else if (that.changeOp) {
          that.changeOp = false;
          that.noPrev = false;
          that.holdVal += that.old_exp.slice(-1);
          that.old_exp += that.currentVal.toString();
          try {
            that.currentVal = eval(that.old_exp);
          } catch (error) {
            this.errorHandler("等式错误");
            return;
          }
          that.holdVal += that.currentVal.toString();
          that.old_exp += "=";
        } else {
          that.noPrev = false;
          if (that.old_exp != "") {
            that.holdVal = that.old_exp.slice(-1) + that.new_exp;
            that.old_exp += that.new_exp;
          } else {
            that.holdVal = "";
            that.old_exp = that.new_exp;
            if (that.isEmpty()) that.old_exp = "0";
          }
          try {
            that.currentVal = eval(that.old_exp);
          } catch (error) {
            this.errorHandler(error);
            return;
          }
          that.old_exp += "=";
        }
        that.setHistory(that.old_exp + that.currentVal);
      } else if (button_text == "inv" && that.currentVal != 0) {
        that.currentVal = -that.currentVal;
        if (that.inv == false) {
          that.new_exp = "-" + that.new_exp;
          that.inv = true;
        } else {
          that.new_exp = that.new_exp.substring(1);
          that.inv = false;
        }
      } else if (button_text == ".") {
        if (!that.dot) {
          if (that.currentVal == 0) that.new_exp = "0";
          that.dot = true;
          that.new_exp += ".";
          that.currentVal = that.new_exp;
        }
      } else if (target.className === "el-button func el-button--default") {
        that.funcHandler(button_text);
      }
    },
    getAns() {
      let that = this;
      let pattern = /(?<==)[0-9.-]+/;
      if (that.tableData.length > 0) {
        that.currentVal = eval(that.tableData[0].exps.match(pattern)[0]);
        that.inv = that.currentVal < 0;
        that.new_exp = that.currentVal.toString();
      }
    },
    funcHandler(button_text) {
        ...
      // 和clickHandler一样，非常长，就不放进去了
    },
    errorHandler(e) {
      this.currentVal = "错误：" + e;
      this.isDisabled = true;
    },
    onShiftClick() {
      this.shift = !this.shift;
    },
    setHistory(history) {
      axios
        .post("/api/cal/setHistory", { exps: history })
        .then((response) => {
          console.log(response);
          this.getHistory();
        })
        .catch((error) => {
          console.error("Set history error", error);
        });
    },
    getHistory() {
      axios
        .get("/api/cal/getHistory")
        .then((response) => {
          this.tableData = response.data.data;
        })
        .catch((error) => {
          console.error("Get history error", error);
        });
    },
    remake() {
      let that = this;
      that.old_exp = "";
      that.new_exp = "";
      that.holdVal = "";
      that.currentVal = 0;
      that.lastVal = 0;
      that.dot = false;
      that.changeOp = false;
      that.inv = false;
      that.noPrev = true;
      that.bracket = 0;
      that.isDisabled = false;
    },
    isNum(val) {
      let pattern = /^[0-9]*$/;
      return pattern.test(val);
    },
    isSym(val) {
      return ["+", "-", "*", "/", "%"].indexOf(val) != -1;
    },
    isEmpty() {
      return this.currentVal === 0 && this.new_exp === "";
    },
    degToRad(deg) {
      return Math.PI * 2 * (deg / 360);
    },
  },
  data() {
    return {
      ...
    };
  },
};
</script>