package main

import (
	"fmt"
	"io"
)

func (msg *MsgName) newIterAll(w io.Writer, FRUIT, APPLE, APPLES, LOCKold string) string {
	LOCK := msg.getLockname("x")

	funcdef := "func (x *" + FRUIT + ") all" + APPLES + "() []*" + APPLE + " {"

	fmt.Fprintln(w, "// safely returns a slice of pointers to the FRUIT protobufs")
	fmt.Fprintln(w, funcdef)
	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, "")

	return funcdef
}

// only make one of these for each message in the protobuf file
func newIter(w io.Writer, msg *MsgName) string {
	if !msg.NeedIter {
		return "iter already done for " + msg.Name
	}
	msg.NeedIter = false
	APPLE := msg.Name

	// should this be 'new' or 'New' ? Does it matter? I think it's totally internal here
	// in this file where it is "new or "New". I changed it to lower case 2025.01.12
	funcdef := "func new" + APPLE + "Iterator(things []*" + APPLE + ") *" + APPLE + "Iterator"

	fmt.Fprintln(w, "// DEFINE THE", APPLE, "ITERATOR.")
	fmt.Fprintln(w, "// itializes a new iterator.")
	fmt.Fprintln(w, funcdef, "{")
	fmt.Fprintln(w, "	return &"+APPLE+"Iterator{things: things}")
	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, "")

	return funcdef
}

// maybe there are better ways in GO now adays // that's fine though. this is easy to read
// TODO; figure out what types this actually works on
// TODO; add timestamppb compare
func (msg *MsgName) newSortType(w io.Writer, STRUCT, VARNAME string) string {

	// Can these be lower case? Should they be lower case? maybe sort.Sort() requires upper case?
	fmt.Fprintln(w, "// sort struct by", VARNAME)
	fmt.Fprintln(w, "type "+STRUCT+VARNAME+" []*"+STRUCT+"")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "func (a "+STRUCT+VARNAME+") Len() int           { return len(a) }")
	fmt.Fprintln(w, "func (a "+STRUCT+VARNAME+") Less(i, j int) bool { return a[i]."+VARNAME+" < a[j]."+VARNAME+" }")
	fmt.Fprintln(w, "func (a "+STRUCT+VARNAME+") Swap(i, j int)      { a[i], a[j] = a[j], a[i] }")
	fmt.Fprintln(w, "")

	return "type " + STRUCT + VARNAME + " []*" + STRUCT + "  // { return a[i]." + VARNAME + " < a[j]." + VARNAME + " }"
}

func (msg *MsgName) newSortBy(w io.Writer, STRUCT, ITER, SORTNAME, SORTBY, SELECT, VARNAME string) string {
	funcdef := "func (x *" + STRUCT + ") " + SORTBY + "() *" + ITER + "Iterator"

	fmt.Fprintln(w, funcdef, "{")
	fmt.Fprintln(w, "	// copy the pointers as fast as possible.")
	fmt.Fprintln(w, "	things := x."+SELECT+"()")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// todo: try slices.SortFunc() instead to see what happens")
	fmt.Fprintln(w, "	sort.Sort("+SORTNAME+"(things))")
	fmt.Fprintln(w, "//    slices.SortFunc(things, func(a, b *"+STRUCT+") bool {")
	fmt.Fprintln(w, "//        return a."+VARNAME+" < b."+VARNAME+" // Sort by ??. let the compiler work it out??")
	fmt.Fprintln(w, "//    })")
	// should this be 'new' or 'New' ? Does it matter? I think it's totally internal here
	// in this file where it is "new or "New". I changed it to lower case 2025.01.12
	fmt.Fprintln(w, "	return new"+ITER+"Iterator(things)")
	fmt.Fprintln(w, "}")

	return funcdef
}

func (msg *MsgName) addAllFunc(w io.Writer, FRUIT, APPLE, APPLES string) string {
	funcdef := "func (x *" + FRUIT + ") All() *" + APPLE + "Iterator {"

	fmt.Fprintln(w, funcdef)
	fmt.Fprintln(w, "	"+APPLE+"Pointers := x.selectAll"+APPLES+"()")
	fmt.Fprintln(w, "")
	// should this be 'new' or 'New' ? Does it matter? I think it's totally internal here. I think there are only 3 places
	// in this file where it is "new or "New". I changed it to lower case 2025.01.12
	fmt.Fprintln(w, "	iterator := new"+APPLE+"Iterator("+APPLE+"Pointers)")
	fmt.Fprintln(w, "	return iterator")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")

	return funcdef
}

func (msg *MsgName) addLenFunc(w io.Writer, FRUIT, APPLES, LOCKold string) string {
	LOCK := msg.getLockname("x")

	funcdef := "func (x *" + FRUIT + ") Len() int {"
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, funcdef)
	fmt.Fprintln(w, "	"+LOCK+".RLock()")
	fmt.Fprintln(w, "	defer "+LOCK+".RUnlock()")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "	return len(x."+APPLES+")")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")

	return funcdef
}

func (msg *MsgName) addSelectAll(w io.Writer, FRUIT, APPLE, APPLES, LOCKold string) string {
	LOCK := msg.getLockname("x")

	funcdef := "func (x *" + FRUIT + ") selectAll" + APPLES + "() []*" + APPLE
	fmt.Fprintln(w, "// safely returns a slice of pointers to the "+APPLE+" protobufs")
	fmt.Fprintln(w, funcdef, "{")
	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 "+APPLE+"")
	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, "}")

	return funcdef
}