package service

import (
	"go/ast"
	"strings"
)

func handleExpr(expr ast.Expr) string {
	code := ""
	switch e := expr.(type) {
	case *ast.BasicLit:
		code += handleBasicLit(e)
	case *ast.UnaryExpr:
		code += handleUnaryExpr(e)
	case *ast.BinaryExpr:
		code += handleBinaryExpr(e)
	case *ast.CallExpr:
		code += handleCallExpr(e)
	case *ast.Ident:
		code += handleIdentExpr(e)
	case *ast.ParenExpr:
		code += handleParenExpr(e)
	case *ast.SelectorExpr:
		code += handleSelectorExpr(e)
	case *ast.StructType:
		code += handleStructType(e)
	}
	return code
}

func handleBasicLit(bl *ast.BasicLit) string {
	return bl.Value
}

func handleUnaryExpr(expr *ast.UnaryExpr) (code string) {
	cl, ok := expr.X.(*ast.CompositeLit)
	if ok {
		code += "new "
		code += handleIdentExpr(cl.Type)
		code += "()"
	} else {
		code += expr.Op.String()
		code += handleExpr(expr.X)
	}
	return
}

func handleBinaryExpr(expr ast.Expr) string {
	be := expr.(*ast.BinaryExpr)
	code := handleExpr(be.X)
	code += be.Op.String()
	code += handleExpr(be.Y)
	return code
}

func handleCallExpr(expr *ast.CallExpr) string {
	code := handleExpr(expr.Fun)
	code += "("
	args := make([]string, 0)
	for _, arg := range expr.Args {
		args = append(args, handleExpr(arg))
	}
	code += strings.Join(args, ",")
	code += ")"
	return code
}

func handleIdentExpr(expr ast.Expr) string {
	ident := expr.(*ast.Ident)
	code := ""
	switch ident.Name {
	case "nil":
		code += "NULL"
	case "uint32":
		code += "unsigned long"
	case "uint64":
		code += "unsigned long long"
	case "string":
		code += "std::string"
	default:
		code += ident.Name
	}
	return code
}

func handleParenExpr(stmt *ast.ParenExpr) string {
	code := ""
	code += handleExpr(stmt.X)
	return code
}

func handleSelectorExpr(expr ast.Expr) string {
	s := expr.(*ast.SelectorExpr)
	code := ""
	switch x := s.X.(type) {
	case *ast.Ident:
		if isInMethod {
			if x.Name == currentReceiverName {
				code += "this"
			} else {
				code += handleIdentExpr(x)
			}
			code += "->"
		} else {
			code += handleIdentExpr(x)
			code += "."
		}
	}
	code += handleIdentExpr(s.Sel)
	if val, ok := mapping[code]; ok {
		code = val
	}
	return code
}

func handleStarExpr(s *ast.StarExpr) (code string) {
	switch x := s.X.(type) {
	case *ast.Ident:
		code += handleIdentExpr(x)
	}
	return
}