package simplify
import "fmt"
import "hw1/expr"

// Depth should return the simplified expresion
func Simplify(e expr.Expr, env expr.Env) expr.Expr {
    //TODO implement the simplify

    // Case 1: Any Var should be replaced with its value
    v, ok := e.(expr.Var)
    if ok == true {
        v = v
        if e.Eval(env) == 0 {
            return e
        }
        ans := fmt.Sprintf("%f", e.Eval(env))
        tp, ok := expr.Parse(ans)
        if ok == nil {
            return tp
        }
    }

    // Case 2: Any Unary with Literal should be replaced with Literal
    u, ok := e.(expr.Unary)
    if ok == true {
            temp := Simplify(u.X, env)
            if temp == u.X {
                return e
            }
            l, ok3 := temp.(expr.Literal)
            if ok3 == true {
                l = l
                if u.Op == '-' {
                    l = -1 * l
                }
                return l
            }
        }


    b, ok := e.(expr.Binary)
    if ok == true {


        // Case 4: Any Binary with addition of 0 should reduce
        l0, ok := b.X.(expr.Literal)
        if ok == true {
            l0 = l0
            if l0 == 0 {
                return b.Y
            }
        }
        l2, ok2 := b.Y.(expr.Literal)
        if ok2 == true {
            l2 = l2
            if l2 == 0 {
                return b.X
            }
        }

      // Case 3: Any Binary with both Literals return Literals
        l, ok2 := b.X.(expr.Literal)
        // Own Case: Binary with Var
        v, okk2 := b.X.(expr.Var)
        // Own case: One child is Binary, one is Var
        bl, bok := b.X.(expr.Binary)
        //TODO: put it HERE!!!!
        v = v
        if ok2 == true || okk2 == true || bok == true{
            if okk2 == true {
                temp := Simplify(b.X, env)
                if b.X != temp {
                    tpl, okkk := temp.(expr.Literal)
                    okkk = okkk
                    l = tpl
                } else if bok == true {
                    bl = bl
                    if bok == true {
                        fmt.Printf("f\n")
                        bltp := Simplify(bl, env)
                        l = bltp.(expr.Literal)
                    } else {
                        return e
                    }
                }
            }
            l2, ok3 := b.Y.(expr.Literal)
            v2, okk3 := b.Y.(expr.Var)
            v2 = v2
            if ok3 == true || okk3 == true {
                if okk3 == true {
                    temp := Simplify(b.Y, env)
                    if b.Y != temp {
                        tpl2, okkk2 := temp.(expr.Literal)
                        okkk2 = okkk2
                        l2 = tpl2
                    } else {
                        return e
                    }
                }
                l = l
                l2 = l2
                if b.Op == '+' {
                    l += l2
                } else if b.Op == '-' {
                    l -= l2
                } else if b.Op == '*' {
                    l *= l2
                } else if b.Op == '/' {
                    l /= l2
                }
                return l
            }
        }



    }



    panic("TODO: implement this!")
}