package main

import (
	"fmt"
	"io"
)

// only make one of these for each message in the protobuf file
func newIter(w io.Writer, FRUIT, APPLE, APPLES, COLOR, LOCK string) {
	fmt.Fprintln(w, "// DEFINE THE ITERATOR. is unique to the "+APPLE+" protobuf message")
	fmt.Fprintln(w, "// itializes a new iterator.")
	fmt.Fprintln(w, "func New"+APPLE+"Iterator(things []*"+APPLE+") *"+APPLE+"Iterator {")
	fmt.Fprintln(w, "	return &"+APPLE+"Iterator{things: things}")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// safely returns a slice of pointers to the FRUIT protobufs")
	fmt.Fprintln(w, "func (x *"+FRUIT+") all() []*"+APPLE+" {")
	fmt.Fprintln(w, "	"+LOCK+".RLock()")
	fmt.Fprintln(w, "	defer "+LOCK+".RUnlock()")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	// Create a new slice to hold pointers to each FRUIT")
	fmt.Fprintln(w, "	var tmp []*"+APPLE+"")
	fmt.Fprintln(w, "	tmp = make([]*"+APPLE+", len(x."+APPLES+"))")
	fmt.Fprintln(w, "	for i, p := range x."+APPLES+" {")
	fmt.Fprintln(w, "		tmp[i] = p // Copy pointers for safe iteration")
	fmt.Fprintln(w, "	}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	return tmp")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "type "+APPLE+"Iterator struct {")
	fmt.Fprintln(w, "	sync.RWMutex // this isn't getting used properly yet?")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	things []*"+APPLE+"")
	fmt.Fprintln(w, "	index  int")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "func (it *"+APPLE+"Iterator) Scan() bool {")
	fmt.Fprintln(w, "	if it.index >= len(it.things) {")
	fmt.Fprintln(w, "		return false")
	fmt.Fprintln(w, "	}")
	fmt.Fprintln(w, "	it.index++")
	fmt.Fprintln(w, "	return true")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// Next() returns the next thing in the array")
	fmt.Fprintln(w, "func (it *"+APPLE+"Iterator) Next() *"+APPLE+" {")
	fmt.Fprintln(w, "	if it.things[it.index-1] == nil {")
	fmt.Fprintln(w, "		fmt.Println(\"Next() error in "+APPLE+"Iterator\", it.index)")
	fmt.Fprintln(w, "	}")
	fmt.Fprintln(w, "	return it.things[it.index-1]")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// END DEFINE THE ITERATOR")
	fmt.Fprintln(w, "")
}

func newSortBy(w io.Writer, FRUIT, APPLE, COLOR string) {
	fmt.Fprintln(w, "// START sort by ", COLOR, "(this is all you need once the Iterator is defined)")
	fmt.Fprintln(w, "type "+APPLE+COLOR+" []*"+APPLE+"")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "func (a "+APPLE+COLOR+") Len() int           { return len(a) }")
	fmt.Fprintln(w, "func (a "+APPLE+COLOR+") Less(i, j int) bool { return a[i]."+COLOR+" < a[j]."+COLOR+" }")
	fmt.Fprintln(w, "func (a "+APPLE+COLOR+") Swap(i, j int)      { a[i], a[j] = a[j], a[i] }")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "func (x *"+FRUIT+") SortBy"+COLOR+"() *"+APPLE+"Iterator {")
	fmt.Fprintln(w, "	things := x.all()")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	sort.Sort("+APPLE+COLOR+"(things))")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	iterator := New"+APPLE+"Iterator(things)")
	fmt.Fprintln(w, "	return iterator")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "// END sort by", COLOR)
}