// Fenrir console screen reader.
// Copyright (c) 2026 Storm Dragon
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

//go:build linux && cgo

package terminal

/*
#include "native.h"
*/
import "C"

import (
	"fmt"
	"unsafe"

	"git.stormux.org/storm/fenrir/internal/clipboard"
)

// Queue_paste belongs to the app loop. The existing nonblocking PTY relay
// drains it, preserving byte order and the child application's paste mode.
func (s *Session) Queue_paste(text string) error {
	if err := clipboard.Validate_text(text); err != nil {
		return err
	}
	if !s.active || s.eof || s.closed {
		return fmt.Errorf("clipboard paste: terminal inactive")
	}
	if len(s.pending)+len(text) > clipboard.MaxBytes {
		return fmt.Errorf("clipboard paste queue full")
	}
	if s.pasteEnd > 0 {
		return fmt.Errorf("clipboard paste already queued")
	}
	s.pasteStart = len(s.pending)
	s.pasteGeneration = uint64(C.terminal_generation(s.vt.native))
	var bytes [32]byte
	C.vterm_keyboard_start_paste(s.vt.native)
	n := C.vterm_output_read(s.vt.native, (*C.char)(unsafe.Pointer(&bytes[0])), C.size_t(len(bytes)))
	s.pending = append(s.pending, bytes[:int(n)]...)
	s.pending = append(s.pending, text...)
	C.vterm_keyboard_end_paste(s.vt.native)
	n = C.vterm_output_read(s.vt.native, (*C.char)(unsafe.Pointer(&bytes[0])), C.size_t(len(bytes)))
	s.pending = append(s.pending, bytes[:int(n)]...)
	s.pasteEnd = len(s.pending)
	s.arm_watch()
	return nil
}

func (s *Session) retire_paste() {
	if s.pasteEnd == 0 {
		return
	}
	if s.active && s.pasteGeneration == uint64(C.terminal_generation(s.vt.native)) {
		return
	}
	copy(s.pending[s.pasteStart:], s.pending[s.pasteEnd:])
	s.pending = s.pending[:len(s.pending)-(s.pasteEnd-s.pasteStart)]
	s.pasteStart, s.pasteEnd = 0, 0
}