import { IVProgParser } from "../ast/ivprogParser";
import * as Expressions from "../ast/expressions";
import { Types } from "../typeSystem/types";

const TYPES = {
  VARIABLE: "var",
  CONST: "const",
  FUNCTION: "function",
  RELATIONAL: "relational",
  LOGIC: "logic",
  ARITHMETIC: "arithmetic",
};

function translateOp (type, op) {
  switch (type) {
    case TYPES.ARITHMETIC:
      return op.value;
    case TYPES.RELATIONAL:
      return op.value;
    case TYPES.LOGIC: {
      if (op.ord === 11) {
        return "and";
      } else if (op.ord === 12) {
        return "or";
      } else {
        return "not";
      }
    }
  }
}

function getOpType (op) {
  switch (op.ord) {
    case 0:
    case 1:
    case 2:
    case 3:
    case 4:
      return TYPES.ARITHMETIC;
    case 5:
    case 6:
    case 7:
    case 8:
    case 9:
    case 10:
      return TYPES.RELATIONAL;
    default:
      return TYPES.LOGIC;
  }
}

function expressionWalker (expression) {
  let result;
  if (expression instanceof Expressions.VariableLiteral) {
    result = [
      { instance: "expression", type: TYPES.VARIABLE, value: expression.id },
    ];
  } else if (expression instanceof Expressions.FunctionCall) {
    const funcObj = {
      instance: "expression",
      type: TYPES.FUNCTION,
      value: expression.id,
    };
    const paramsList = expression.actualParameters.map((e) =>
      expressionWalker(e)
    );
    //const params = Array.prototype.concat.apply([], paramsList);
    funcObj.params = paramsList;
    result = [funcObj];
  } else if (expression instanceof Expressions.InfixApp) {
    const left = expressionWalker(expression.left);
    const right = expressionWalker(expression.right);
    const opType = getOpType(expression.op);
    const opValue = translateOp(opType, expression.op);
    result = [
      ...left,
      { instance: "operator", type: opType, value: opValue },
      ...right,
    ];
  } else if (expression instanceof Expressions.UnaryApp) {
    const left = expressionWalker(expression.left);
    const opType = getOpType(expression.op);
    const opValue = translateOp(opType, expression.op);
    result = [{ instance: "operator", type: opType, value: opValue }, ...left];
  } else if (expression instanceof Expressions.ArrayAccess) {
    const line = expressionWalker(expression.line);
    let arrayClass = "vector";
    let column = null;
    if (expression.column) {
      arrayClass = "matrix";
      column = expressionWalker(expression.column);
    }
    result = [
      {
        instance: "expression",
        type: TYPES.VARIABLE,
        class: arrayClass,
        column: column,
        line: line,
        value: expression.id,
      },
    ];
  } else {
    let value = expression.value;
    if (expression.value.toNumber) {
      if (
        Types.REAL.isCompatible(expression.type) &&
        expression.value.decimalPlaces() == 0
      ) {
        value = expression.value.toFixed(2);
      } else {
        value = expression.value.toNumber();
      }
    }
    result = [
      {
        instance: "expression",
        class: "simple",
        type: TYPES.CONST,
        value: value,
      },
    ];
  }
  if (expression.parenthesis) return ["(", ...result, ")"];
  else return result;
}

export function parseExpression (text) {
  const parser = IVProgParser.createParser(text);
  const expressionAST = parser.parseExpressionOR();
  return expressionWalker(expressionAST);
}