package main

import "unsafe"

//export write
func cWrite(fd int32, buf unsafe.Pointer, count uint32) (n int32)

//export mxc_readfile
func cReadfile(path unsafe.Pointer, pathLen int32, buf unsafe.Pointer, bufCap int32) (n int32)

//export mxc_filesize
func cFilesize(path unsafe.Pointer, pathLen int32) (n int32)

var nl = []byte{10}

func out(s string) {
	if len(s) > 0 {
		cWrite(1, unsafe.Pointer(&[]byte(s)[0]), uint32(len(s)))
	}
}

func outln(s string) {
	out(s)
	cWrite(1, unsafe.Pointer(&nl[0]), 1)
}

func fatal(s string) {
	if len(s) > 0 {
		cWrite(2, unsafe.Pointer(&[]byte(s)[0]), uint32(len(s)))
	}
	cWrite(2, unsafe.Pointer(&nl[0]), 1)
}

func readFile(path string) (data []byte, ok bool) {
	sz := cFilesize(unsafe.Pointer(&[]byte(path)[0]), int32(len(path)))
	if sz < 0 { return nil, false }
	buf := []byte{:sz+1}
	n := cReadfile(unsafe.Pointer(&[]byte(path)[0]), int32(len(path)), unsafe.Pointer(&buf[0]), sz+1)
	if n < 0 { return nil, false }
	return buf[:n], true
}

func getArgs() (ss []string) {
	buf := []byte{:4096}
	n := cReadfile(unsafe.Pointer(&[]byte("/proc/self/cmdline")[0]), 18, unsafe.Pointer(&buf[0]), 4096)
	if n <= 0 { return nil }
	var args []string
	start := int32(0)
	for i := int32(0); i < n; i++ {
		if buf[i] == 0 {
			if i > start { args = append(args, string(buf[start:i])) }
			start = i + 1
		}
	}
	return args
}

func main() {
	args := getArgs()
	if len(args) < 2 { fatal("usage: mxparse <file.mx>"); return }
	path := args[1]
	data, ok := readFile(path)
	if !ok { fatal("error: cannot read " | path); return }
	file := parseSource(path, data)
	if file == nil { fatal("parse failed"); return }
	outln("File " | path)
	if file.PkgName == nil {
		outln("PkgName: nil")
	} else {
		outln("Package " | file.PkgName.Value)
	}
	outln("Decls: " | ItoaU32(uint32(len(file.DeclList))))
	for i := int32(0); i < int32(len(file.DeclList)); i++ {
		d := file.DeclList[i]
		if fd, ok := d.(*FuncDecl); ok && fd != nil {
			r := ""
			if fd.Recv != nil { r = "(method) " }
			name := "_"
			if fd.Name != nil { name = fd.Name.Value }
			outln("Func " | r | name)
		} else if td, ok := d.(*TypeDecl); ok && td != nil {
			outln("Type " | td.Name.Value)
		} else if _, ok := d.(*VarDecl); ok {
			outln("Var")
		} else if _, ok := d.(*ConstDecl); ok {
			outln("Const")
		} else if id, ok := d.(*ImportDecl); ok && id != nil {
			p := ""
			if id.Path != nil { p = id.Path.Value }
			outln("Import " | p)
		} else {
			outln("Decl?")
		}
	}
}