// Copyright (c) 2026 Charles KWON OhJun. All rights reserved.
// Extended file/directory RTL functions.

package hbrtl

import (
	"five/hbrt"
	"io"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"syscall"
	"time"
)

// HB_FSIZE(cFile) → nBytes
func HbFSize(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	info, err := os.Stat(t.Local(1).AsString())
	if err != nil { t.RetInt(0); return }
	t.RetInt(info.Size())
}

// HB_FCOPY(cSrc, cDst) → nError (0=ok, -1=fail)
func HbFCopy(t *hbrt.Thread) {
	t.Frame(2, 0); defer t.EndProc()
	src, err := os.Open(t.Local(1).AsString())
	if err != nil { t.RetInt(-1); return }
	defer src.Close()
	dst, err := os.Create(t.Local(2).AsString())
	if err != nil { t.RetInt(-1); return }
	defer dst.Close()
	if _, err := io.Copy(dst, src); err != nil { t.RetInt(-1); return }
	t.RetInt(0)
}

// HB_FEOF(nHandle) → lEOF
func HbFEof(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	h := t.Local(1).AsInt()
	f, ok := getHandle(h)
	if !ok { t.RetBool(true); return }
	cur, _ := f.Seek(0, io.SeekCurrent)
	end, _ := f.Seek(0, io.SeekEnd)
	f.Seek(cur, io.SeekStart)
	t.RetBool(cur >= end)
}

// HB_FCOMMIT(nHandle) → NIL
func HbFCommit(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	if f, ok := getHandle(t.Local(1).AsInt()); ok { f.Sync() }
	t.RetNil()
}

// HB_FREADLEN(nHandle, nLen) → cData
func HbFReadLen(t *hbrt.Thread) {
	t.Frame(2, 0); defer t.EndProc()
	f, ok := getHandle(t.Local(1).AsInt())
	if !ok { t.RetString(""); return }
	buf := make([]byte, t.Local(2).AsInt())
	n, _ := f.Read(buf)
	t.RetString(string(buf[:n]))
}

// HB_FGETATTR(cFile) → nAttr (Unix mode bits)
func HbFGetAttr(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	info, err := os.Stat(t.Local(1).AsString())
	if err != nil { t.RetInt(-1); return }
	t.RetInt(int64(info.Mode().Perm()))
}

// HB_FSETATTR(cFile, nAttr) → nError
func HbFSetAttr(t *hbrt.Thread) {
	t.Frame(2, 0); defer t.EndProc()
	err := os.Chmod(t.Local(1).AsString(), os.FileMode(t.Local(2).AsInt()))
	if err != nil { t.RetInt(-1) } else { t.RetInt(0) }
}

// HB_FGETDATETIME(cFile) → tTimestamp
func HbFGetDateTime(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	info, err := os.Stat(t.Local(1).AsString())
	if err != nil { t.RetNil(); return }
	mt := info.ModTime()
	t.RetVal(goTimeToTimestamp(mt))
}

// HB_FSETDATETIME(cFile, dDate [, cTime]) → nError
func HbFSetDateTime(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0); defer t.EndProc()
	path := t.Local(1).AsString()
	// Simple: set to current time if no date given, else use date
	mt := time.Now()
	if nParams >= 2 && !t.Local(2).IsNil() {
		mt = julianToGoTime(t.Local(2).AsJulian())
	}
	err := os.Chtimes(path, mt, mt)
	if err != nil { t.RetInt(-1) } else { t.RetInt(0) }
}

// HB_FLOCK(nHandle [, nOffset, nLength]) → lSuccess (stub — always true on non-Windows)
func HbFLock(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0); defer t.EndProc()
	t.RetBool(true) // stub
}

// HB_FUNLOCK(nHandle [, nOffset, nLength]) → lSuccess
func HbFUnlock(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0); defer t.EndProc()
	t.RetBool(true) // stub
}

// HB_FILEDELETE(cMask) → lSuccess
func HbFileDelete(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	matches, err := filepath.Glob(t.Local(1).AsString())
	if err != nil || len(matches) == 0 { t.RetBool(false); return }
	ok := true
	for _, m := range matches { if os.Remove(m) != nil { ok = false } }
	t.RetBool(ok)
}

// HB_FILEMATCH(cFile, cMask) → lMatch
func HbFileMatch(t *hbrt.Thread) {
	t.Frame(2, 0); defer t.EndProc()
	matched, _ := filepath.Match(t.Local(2).AsString(), filepath.Base(t.Local(1).AsString()))
	t.RetBool(matched)
}

// HB_FNAMEEXISTS(cFile) → lExists
func HbFNameExists(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	_, err := os.Stat(t.Local(1).AsString())
	t.RetBool(err == nil)
}

// HB_FNAMEEXTSET(cFile, cNewExt) → cNewFile
func HbFNameExtSet(t *hbrt.Thread) {
	t.Frame(2, 0); defer t.EndProc()
	f := t.Local(1).AsString()
	ext := t.Local(2).AsString()
	base := strings.TrimSuffix(f, filepath.Ext(f))
	if ext != "" && !strings.HasPrefix(ext, ".") { ext = "." + ext }
	t.RetString(base + ext)
}

// HB_FNAMENAMEEXT(cFile) → cNameExt (filename + ext, no path)
func HbFNameNameExt(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	t.RetString(filepath.Base(t.Local(1).AsString()))
}

// HB_MEMOREAD(cFile) → cContents (alias for MEMOREAD)
func HbMemoRead(t *hbrt.Thread) {
	t.Frame(1, 0); defer t.EndProc()
	data, err := os.ReadFile(t.Local(1).AsString())
	if err != nil { t.RetString(""); return }
	t.RetString(string(data))
}

// HB_MEMOWRIT(cFile, cData [, lAddEOF]) → lSuccess (alias for MEMOWRIT)
func HbMemoWrit(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0); defer t.EndProc()
	err := os.WriteFile(t.Local(1).AsString(), []byte(t.Local(2).AsString()), 0644)
	t.RetBool(err == nil)
}

// HB_DIRTEMP() → cTempDir
func HbDirTemp(t *hbrt.Thread) {
	t.Frame(0, 0); defer t.EndProc()
	t.RetString(os.TempDir())
}

// HB_DISKSPACE(cDrive [, nType]) → nFreeBytes
func HbDiskSpace(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0); defer t.EndProc()
	path := "/"
	if nParams >= 1 && !t.Local(1).IsNil() {
		path = t.Local(1).AsString()
	}
	if path == "" { path = "/" }
	if runtime.GOOS == "windows" {
		t.RetInt(0) // unsupported
		return
	}
	var stat syscall.Statfs_t
	if syscall.Statfs(path, &stat) != nil { t.RetInt(0); return }
	t.RetInt(int64(stat.Bavail) * int64(stat.Bsize))
}

// DISKSPACE([nDrive]) → nFreeBytes (Clipper-compatible)
func DiskSpaceFunc(t *hbrt.Thread) { HbDiskSpace(t) }

// --- helpers ---

func goTimeToTimestamp(gt time.Time) hbrt.Value {
	y, m, d := gt.Date()
	julian := dateToJulian(y, int(m), d)
	ms := int32(gt.Hour()*3600000 + gt.Minute()*60000 + gt.Second()*1000 + gt.Nanosecond()/1000000)
	return hbrt.MakeTimestamp(julian, ms)
}

func julianToGoTime(j int64) time.Time {
	y, m, d := julianToDate(j)
	return time.Date(y, time.Month(m), d, 0, 0, 0, 0, time.Local)
}

// dateToJulian and julianToDate are in datetime.go