package main

import (
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"os"
)

func main() {
	fileset := token.NewFileSet()
	files, err := parser.ParseDir(fileset, "./testfiles", filterNothing, 0)
	if err != nil {
		panic(err)
	}

	for filename, astPackage := range files {
		fmt.Printf("directory: %+v\n", filename)
		fmt.Printf("package: %+v\n", astPackage.Name)

		for filename, file := range astPackage.Files {
			fmt.Printf("file: %s\n", filename)
			for _, dec := range file.Decls {
				parseDec(dec)
			}
		}
	}
}

func parseDec(dec ast.Decl) {
	switch decType := dec.(type) {
	case *ast.GenDecl:
		parseGenDecl(dec)
	case *ast.FuncDecl:
		parseFuncDecl(dec)
	default:
		panic(fmt.Sprintf("unsupported decType %s", decType))
	}
}

func parseFuncDecl(dec ast.Decl) {
	funcDec := dec.(*ast.FuncDecl)
	fmt.Printf("function definition for %s\n", funcDec.Name)
}

func parseGenDecl(dec ast.Decl) {
	typeDec := dec.(*ast.GenDecl)

	fmt.Printf("Token: %s\n", typeDec.Tok)
	switch typeDec.Tok {
	case token.TYPE:
		fmt.Println("typedef")
		for _, spec := range typeDec.Specs {
			typeSpec := spec.(*ast.TypeSpec)
			fmt.Printf("%+v", typeSpec)
		}
	case token.VAR:
		fmt.Println("variable")
	case token.CONST:
		fmt.Println("constant")
	default:
		panic("unsupported type " + typeDec.Tok.String())
	}
}

func filterNothing(info os.FileInfo) bool {
	return true
}