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

// Error handling functions: ERRORBLOCK, ERRORNEW, DOSERROR, FERROR
// Harbour error system: Error object + ErrorBlock callback chain.

package hbrtl

import (
	"five/hbrt"
)

var (
	errorBlock hbrt.Value // current error handler block
	lastDosErr int        // last OS error code
	lastFErr   int        // last file error code
)

// ERRORBLOCK([bNewBlock]) → bOldBlock
// Gets/sets the error handler code block.
func ErrorBlock(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProc()

	old := errorBlock
	if old.IsNil() {
		old = hbrt.MakeNil()
	}

	if nParams >= 1 && !t.Local(1).IsNil() {
		errorBlock = t.Local(1)
	}

	t.RetVal(old)
}

// ERRORNEW() → oError
// Creates a new Error object as a hash with standard Harbour error properties.
func ErrorNew(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProc()

	keys := []hbrt.Value{
		hbrt.MakeString("ARGS"), hbrt.MakeString("CANDEFAULT"),
		hbrt.MakeString("CANRETRY"), hbrt.MakeString("CANSUBSTITUTE"),
		hbrt.MakeString("CARGO"), hbrt.MakeString("DESCRIPTION"),
		hbrt.MakeString("FILENAME"), hbrt.MakeString("GENCODE"),
		hbrt.MakeString("OPERATION"), hbrt.MakeString("OSCODE"),
		hbrt.MakeString("SEVERITY"), hbrt.MakeString("SUBCODE"),
		hbrt.MakeString("SUBSYSTEM"), hbrt.MakeString("TRIES"),
	}
	vals := []hbrt.Value{
		hbrt.MakeNil(), hbrt.MakeBool(false),
		hbrt.MakeBool(false), hbrt.MakeBool(false),
		hbrt.MakeNil(), hbrt.MakeString(""),
		hbrt.MakeString(""), hbrt.MakeInt(0),
		hbrt.MakeString(""), hbrt.MakeInt(0),
		hbrt.MakeInt(2), hbrt.MakeInt(0),
		hbrt.MakeString(""), hbrt.MakeInt(0),
	}

	h := &hbrt.HbHash{Keys: keys, Values: vals}
	order := make([]int, len(keys))
	for i := range order {
		order[i] = i
	}
	h.Order = order

	t.RetVal(hbrt.MakeHashFrom(h))
}

// DOSERROR([nNewCode]) → nOldCode
func DosError(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProc()

	old := lastDosErr
	if nParams >= 1 && !t.Local(1).IsNil() {
		lastDosErr = t.Local(1).AsInt()
	}
	t.RetInt(int64(old))
}

// FERROR() → nLastFileError
func FError(t *hbrt.Thread) {
	t.Frame(0, 0)
	defer t.EndProc()
	t.RetInt(int64(lastFErr))
}

// SetFError sets the file error code (called internally by file I/O functions).
func SetFError(code int) {
	lastFErr = code
}