package main

import (
	"fmt"
	"io"
	"os"
)

func main() {
	f, _ := os.OpenFile("test.sort.pb.go", os.O_WRONLY|os.O_CREATE, 0600)
	header(f, "main")
	syncLock(f, "godeplock")
	iterTop(f, "GoDep")
}

func header(w io.Writer, name string) {
	fmt.Fprintln(w, "package "+name)
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// this is becoming a standard format")
	fmt.Fprintln(w, "// todo: autogenerate this from the .proto file?")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "import (")
	fmt.Fprintln(w, "	\"fmt\"")
	fmt.Fprintln(w, "	\"os\"")
	fmt.Fprintln(w, "	\"sort\"")
	fmt.Fprintln(w, "	\"sync\"")
	fmt.Fprintln(w, ")")
	fmt.Fprintln(w, "")
}

func syncLock(w io.Writer, name string) {
	fmt.Fprintln(w, "// bad global lock until I figure out some other plan")
	fmt.Fprintln(w, "var "+name+" sync.RWMutex")
	fmt.Fprintln(w, "")
}

func iterTop(w io.Writer, name string) {
	fmt.Fprintln(w, "type "+name+"Iterator struct {")
	fmt.Fprintln(w, "	sync.RWMutex")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	packs []*"+name)
	fmt.Fprintln(w, "	index int")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// New"+name+"Iterator initializes a new iterator.")
	fmt.Fprintln(w, "func New"+name+"Iterator(packs []*"+name+") *"+name+"Iterator {")
	fmt.Fprintln(w, "	return &"+name+"Iterator{packs: packs}")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// Scan moves to the next element and returns false if there are no more packs.")
	fmt.Fprintln(w, "func (it *"+name+"Iterator) Scan() bool {")
	fmt.Fprintln(w, "	if it.index >= len(it.packs) {")
	fmt.Fprintln(w, "		return false")
	fmt.Fprintln(w, "	}")
	fmt.Fprintln(w, "	it.index++")
	fmt.Fprintln(w, "	return true")
	fmt.Fprintln(w, "}")
}