// Copyright (c) 2026 Charles KWON OhJun (charleskwonohjun@gmail.com)
// All rights reserved.

// RDD-related RTL functions: EOF(), BOF(), Found(), RecNo(), RecCount(), Deleted().
// Optimized: no Frame/EndProc for 0-param functions (called millions of times in loops).
package hbrtl

import (
	"five/hbrt"
	"five/hbrdd"
)

func rtlEOF(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			t.PushBool(area.EOF())
			t.RetValue()
			return
		}
	}
	t.PushBool(true)
	t.RetValue()
}

func rtlBOF(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			t.PushBool(area.BOF())
			t.RetValue()
			return
		}
	}
	t.PushBool(true)
	t.RetValue()
}

func rtlFound(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			t.PushBool(area.Found())
			t.RetValue()
			return
		}
	}
	t.PushBool(false)
	t.RetValue()
}

func rtlRecNo(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			t.RetInt(int64(area.RecNo()))
			return
		}
	}
	t.RetInt(0)
}

func rtlRecCount(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			rc, _ := area.RecCount()
			t.RetInt(int64(rc))
			return
		}
	}
	t.RetInt(0)
}

func rtlDeleted(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			t.PushBool(area.Deleted())
			t.RetValue()
			return
		}
	}
	t.PushBool(false)
	t.RetValue()
}

func rtlFieldGet(t *hbrt.Thread) {
	t.Frame(1, 0)
	defer t.EndProcFast()
	n := int(t.Local(1).AsNumInt())
	if wa := getWA(t); wa != nil {
		if area := wa.Current(); area != nil {
			val, err := area.GetValue(n - 1) // 1-based → 0-based
			if err == nil {
				t.PushValue(val)
				t.RetValue()
				return
			}
		}
	}
	t.PushNil()
	t.RetValue()
}

// getWA resolves the WorkAreaManager attached to this thread.
//
// The previous version cached the last-seen interface→*WAM pair in
// a process-global struct to skip the type assertion. That cache
// was the worst-of-both-worlds under multi-pgserver-connection
// load: each connection's thread has its own WAM, so the cache
// missed on every call and immediately re-wrote two shared
// `interface{}` fields. Go's interface is a two-word value, so a
// concurrent write+read produced torn pointers — different
// goroutines saw the WRONG WAM as their own, leading to the
// FieldPosCache + WAM.aliases "concurrent map writes" panics.
//
// The type assertion itself is fast (~ns). Drop the cache; if the
// micro-bench matters again, replace with a sync/atomic.Pointer
// or sync.Map keyed by thread, not a single global slot.
func getWA(t *hbrt.Thread) *hbrdd.WorkAreaManager {
	if t.WA == nil {
		return nil
	}
	wa, _ := t.WA.(*hbrdd.WorkAreaManager)
	return wa
}