package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"path"
	pcl "pcl/interp"
)

func main() {
	var (
		interp *pcl.Interp
		f      *os.File
		r      *bufio.Reader
		c      rune
		node   *pcl.Cnode_t
		v      pcl.Value_t

		err error
	)

	if len(os.Args) != 2 {
		fmt.Printf("Usage: %s filename\n", path.Base(os.Args[0]))
		goto oops
	}

	interp, err = pcl.NewInterp(1000, true)
	if err != nil {
		fmt.Printf("Error %s\n", err.Error())
		goto oops
	}

	f, err = os.Open(os.Args[1])
	if err != nil {
		fmt.Printf("Error %s\n", err.Error())
		goto oops
	}

	interp.BeginFeed()

	r = bufio.NewReader(f)
	for {
		c, _, err = r.ReadRune()
		if err != nil {
			if err == io.EOF {
				break
			}
			fmt.Printf("Error in ReadRune - %s\n", err.Error())
			goto oops
		}

		err = interp.FeedRune(c)
		if err != nil {
			fmt.Printf("Error in FeedRune - %s\n", err.Error())
			goto oops
		}
	}
	node, err = interp.EndFeed()
	if err != nil {
		fmt.Printf("Error in EndFeed %s\n", err.Error())
		goto oops
	}

	interp.Dump(node)
	fmt.Printf("------------- Executing ----------------\n")
	v, err = interp.Execute(node)
	if err != nil {
		fmt.Printf("Error in Execute - %s\n", err.Error())
		goto oops
	}

	if v == nil {
		panic("return value mut not be nil")
	}
	fmt.Printf("RETURN VALUE = [%s]\n", *v.(*string))

	interp.Close()
	f.Close()
	os.Exit(0)

oops:
	if interp != nil {
		interp.Close()

	}
	if f != nil {
		f.Close()
	}
	os.Exit(1)
}