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

// RDD-related RTL functions: EOF(), BOF(), Found(), RecNo(), RecCount(), Deleted().
// These read the current workarea state from Thread.WA.
package hbrtl

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

func rtlEOF(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProc()
	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.EndProc()
	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.EndProc()
	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.EndProc()
	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.EndProc()
	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.EndProc()
	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) {
	// FIELD->name is handled by gengo codegen, not this function.
	// This is for FieldGet(n) function call.
	t.Frame(1, 0)
	defer t.EndProc()
	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 to 0-based
			if err == nil {
				t.PushValue(val)
				t.RetValue()
				return
			}
		}
	}
	t.PushNil()
	t.RetValue()
}

func getWA(t *hbrt.Thread) *hbrdd.WorkAreaManager {
	if t.WA == nil {
		return nil
	}
	wa, ok := t.WA.(*hbrdd.WorkAreaManager)
	if !ok {
		return nil
	}
	return wa
}