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

// Missing RTL functions needed by FiveSql2 and other Harbour programs.
package hbrtl

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

// hb_FileExists(cFile) → lExists
func HbFileExists(t *hbrt.Thread) {
	t.Frame(1, 0)
	defer t.EndProcFast()
	fname := t.Local(1).AsString()
	_, err := os.Stat(fname)
	t.PushBool(err == nil)
	t.RetValue()
}

// hb_Second(dTimestamp) → nSeconds (seconds portion of timestamp)
func HbSecond(t *hbrt.Thread) {
	t.Frame(1, 0)
	defer t.EndProcFast()
	v := t.Local(1)
	if v.IsTimestamp() {
		ms := v.AsTimeMs()
		secs := int64(ms/1000) % 60
		t.RetInt(secs)
	} else {
		t.RetInt(0)
	}
}

// hb_ATokens(cString [, cDelim]) → aTokens
// Splits string by delimiter (default: space/tab/newline)
func HbATokens(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProcFast()

	s := t.Local(1).AsString()
	delim := " "
	if nParams >= 2 && !t.Local(2).IsNil() {
		delim = t.Local(2).AsString()
	}

	var parts []string
	if delim == " " {
		parts = strings.Fields(s)
	} else {
		parts = strings.Split(s, delim)
	}

	items := make([]hbrt.Value, len(parts))
	for i, p := range parts {
		items[i] = hbrt.MakeString(p)
	}
	t.PushValue(hbrt.MakeArrayFrom(items))
	t.RetValue()
}

// hb_cdpSelect([cCodepage]) → cPrevCodepage
// Stub: Five uses UTF-8 internally, codepage selection is a no-op.
func HbCdpSelect(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProcFast()
	t.RetString("")
}

// Used() → lUsed — checks if current workarea is in use
func Used(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProcFast()
	wam := getWA(t)
	if wam == nil {
		t.RetBool(false)
		return
	}
	t.RetBool(wam.Current() != nil)
}

// DBSETINDEX — SET INDEX TO <file> (adds index to current workarea).
// Previously a no-op; the generated code path for the SET INDEX TO
// command bypasses this RTL, but SqlAttachTableIndexes (TSqlDDL.prg)
// needs a runtime call so auto-attaching PK / UNIQUE indexes at
// SqlExecOpenTable can happen without parser help. Missing file is
// swallowed — matches Harbour's soft-fail semantics and keeps
// pre-index tables silent.
func rtlDbSetIndex(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProcFast()
	if nParams < 1 {
		t.RetNil()
		return
	}
	path := t.Local(1).AsString()
	if path == "" {
		t.RetNil()
		return
	}
	wam, ok := t.WA.(*hbrdd.WorkAreaManager)
	if !ok || wam == nil {
		t.RetNil()
		return
	}
	area := wam.Current()
	if area == nil {
		t.RetNil()
		return
	}
	// OrderListAdd lives on the optional Indexer interface — DBFNTX /
	// DBFCDX implement it, MEMRDD does not. Type-assert and silently
	// no-op on drivers without index support.
	if idx, ok := area.(hbrdd.Indexer); ok {
		_ = idx.OrderListAdd(path)
	}
	t.RetNil()
}