// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package speech

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

// SpeakAndWait uses SSIP BEGIN/END/CANCEL events, not the SPEAK queue
// acknowledgement, to pace continuous reading and report its current position.
// Protocol: https://github.com/brailcom/speechd/blob/master/doc/ssip.texi
func (client *Client) SpeakAndWait(ctx context.Context, text string, began func()) (result error) {
	client.mutex.Lock()
	defer client.mutex.Unlock()
	if client.conn == nil {
		return errors.New("speech client is not connected")
	}
	if err := client.sendCommand(ctx, []string{"SET", "SELF", "NOTIFICATION", "ALL", "on"}); err != nil {
		return err
	}
	defer func() {
		if client.conn != nil {
			cleanup, cancel := context.WithTimeout(context.Background(), client.ioTimeout)
			defer cancel()
			if err := client.sendCommand(cleanup, []string{"SET", "SELF", "NOTIFICATION", "ALL", "off"}); err != nil {
				result = errors.Join(result, err)
				_ = client.conn.Close()
				client.conn, client.reader = nil, nil
			}
		}
	}()
	if err := client.speak(ctx, text); err != nil {
		return err
	}
	conn := client.conn
	// A spoken line may take much longer than the command I/O timeout.
	if err := conn.SetDeadline(time.Time{}); err != nil {
		return err
	}
	done := make(chan struct{})
	stop := context.AfterFunc(ctx, func() {
		defer close(done)
		cleanup, cancel := context.WithTimeout(context.Background(), client.ioTimeout)
		defer cancel()
		_ = client.Cancel(cleanup)
		// Allow the final cancellation notification to be drained, preserving
		// the speaking connection for subsequent focus announcements.
		_ = conn.SetReadDeadline(time.Now().Add(client.ioTimeout))
	})
	defer func() {
		if !stop() {
			<-done
		}
	}()
	started := false
	for {
		event, err := readReply(client.reader)
		if err != nil {
			_ = conn.Close()
			client.conn, client.reader = nil, nil
			return errors.Join(ctx.Err(), err)
		}
		switch event.code {
		case 701:
			if !started && ctx.Err() == nil && began != nil {
				began()
			}
			started = true
		case 702:
			return ctx.Err()
		case 703:
			return context.Canceled
		}
	}
}