package main

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

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

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, "// Use Scan() in a loop, similar to a while loop")
	fmt.Fprintln(w, "//")
	fmt.Fprintln(w, "//	for iterator.Scan() ")
	fmt.Fprintln(w, "//		d := iterator.Next(")
	fmt.Fprintln(w, "//		fmt.Println(\"found UUID:\", d.Uuid")
	fmt.Fprintln(w, "//	}")
	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, "}")
	fmt.Fprintln(w, "")
}

func iterNext(w io.Writer, name string) {
	fmt.Fprintln(w, "// Next() returns the next thing in the array")
	fmt.Fprintln(w, "func (it *" + name + "Iterator) Next() *" + name + " {")
	fmt.Fprintln(w, "	if it.packs[it.index-1] == nil {")
	fmt.Fprintln(w, "		for i, d := range it.packs {")
	fmt.Fprintln(w, "			fmt.Println(\"i =\", i, d)")
	fmt.Fprintln(w, "		}")
	fmt.Fprintln(w, "		fmt.Println(\"protobuf autogenpb sort error len =\", len(it.packs))")
	fmt.Fprintln(w, "		fmt.Println(\"protobuf autogenpb sort error next == nil\", it.index, it.index-1)")
	fmt.Fprintln(w, "		os.Exit(-1)")
	fmt.Fprintln(w, "	}")
	fmt.Fprintln(w, "	return it.packs[it.index-1]")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
}

/*

func (r *Repos) All() *RepoIterator {
	repoPointers := r.selectAllRepo()

	iterator := NewRepoIterator(repoPointers)
	return iterator
}

func (r *Repos) SortByPath() *RepoIterator {
	packs := r.selectAllRepo()

	sort.Sort(RepoByPath(packs))

	iterator := NewRepoIterator(packs)
	return iterator
}

func (all *Repos) Len() int {
	repolock.RLock()
	defer repolock.RUnlock()

	return len(all.Repos)
}

type RepoByPath []*Repo

func (a RepoByPath) Len() int           { return len(a) }
func (a RepoByPath) Less(i, j int) bool { return a[i].GoPath < a[j].GoPath }
func (a RepoByPath) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// safely returns a slice of pointers to the Repo protobufs
func (all *Repos) selectAllRepo() []*Repo {
	repolock.RLock()
	defer repolock.RUnlock()

	// Create a new slice to hold pointers to each Repo
	var aRepos []*Repo
	aRepos = make([]*Repo, len(all.Repos))
	for i, p := range all.Repos {
		aRepos[i] = p // Copy pointers for safe iteration
	}

	return aRepos
}
*/