// Cthulhu screen reader.
// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
//
// 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>.

package review

import (
	"context"
	"errors"
	"time"
)

// WarmDocument captures and syncs the currently focused document in the
// background so the first navigation key does not pay for a cold capture.
// Best-effort: a full queue or a focus outside web content is ignored by
// the worker, and no result is delivered.
func (worker *Worker) WarmDocument() {
	select {
	case worker.requests <- request{documentEpoch: worker.documentEpoch.Load(), documentLoadEpoch: worker.documentLoadEpoch.Load(), warmDocument: true, queuedAt: time.Now()}:
	default:
	}
}

func (worker *Worker) MoveDocumentCaret(command DocumentCaretCommand) error {
	if !command.valid() {
		return ErrInvalidDirection
	}
	select {
	case worker.requests <- request{documentEpoch: worker.documentEpoch.Load(), documentLoadEpoch: worker.documentLoadEpoch.Load(), caretCommand: command, queuedAt: time.Now()}:
		return nil
	default:
		return ErrRequestQueueFull
	}
}

func (worker *Worker) ActivateDocumentCaret() error {
	select {
	case worker.requests <- request{documentEpoch: worker.documentEpoch.Load(), documentLoadEpoch: worker.documentLoadEpoch.Load(), activate: true, queuedAt: time.Now()}:
		return nil
	default:
		return ErrRequestQueueFull
	}
}

func (worker *Worker) ReadAll(ctx context.Context) error {
	if ctx == nil {
		return errors.New("read all: nil context")
	}
	select {
	case worker.requests <- request{documentEpoch: worker.documentEpoch.Load(), documentLoadEpoch: worker.documentLoadEpoch.Load(), readAll: ctx, queuedAt: time.Now()}:
		return nil
	default:
		return ErrRequestQueueFull
	}
}

func (worker *Worker) JumpToDocumentFragment(fragment string) error {
	if fragment == "" {
		return ErrInvalidDirection
	}
	select {
	case worker.requests <- request{documentEpoch: worker.documentEpoch.Load(), documentLoadEpoch: worker.documentLoadEpoch.Load(), fragment: fragment, queuedAt: time.Now()}:
		return nil
	default:
		return ErrRequestQueueFull
	}
}