<?php

namespace Tests\Unit;

use App\Services\WhisperTranscriptionStream;
use PHPUnit\Framework\TestCase;

class WhisperTranscriptionStreamTest extends TestCase
{
    private WhisperTranscriptionStream $stream;

    protected function setUp(): void
    {
        parent::setUp();

        $this->stream = new WhisperTranscriptionStream;
    }

    public function test_extracts_sse_data_payloads_from_buffer(): void
    {
        $buffer = "data: {\"type\":\"transcript.text.delta\",\"delta\":\"Hello\"}\n\npartial";

        $payloads = $this->stream->extractPayloads($buffer);

        $this->assertSame(['{"type":"transcript.text.delta","delta":"Hello"}'], $payloads);
        $this->assertSame('partial', $buffer);
    }

    public function test_parses_openai_delta_and_done_events(): void
    {
        $delta = $this->stream->parseEvent('{"type":"transcript.text.delta","delta":"Hello "}');
        $done = $this->stream->parseEvent('{"type":"transcript.text.done","text":"Hello world"}');

        $this->assertSame('Hello ', $delta['append']);
        $this->assertFalse($delta['done']);
        $this->assertSame('Hello world', $done['replace']);
        $this->assertTrue($done['done']);
    }

    public function test_parses_legacy_segment_events(): void
    {
        $event = $this->stream->parseEvent('{"text":"First segment","start":0,"end":12.5}');

        $this->assertTrue($event['legacy']);
        $this->assertSame('First segment', $event['append']);
        $this->assertSame(12.5, $event['end']);
    }

    public function test_applies_delta_then_done_replace(): void
    {
        $delta = $this->stream->parseEvent('{"type":"transcript.text.delta","delta":"Hel"}');
        $text = $this->stream->applyEvent('', $delta);
        $delta2 = $this->stream->parseEvent('{"type":"transcript.text.delta","delta":"lo"}');
        $text = $this->stream->applyEvent($text, $delta2);
        $done = $this->stream->parseEvent('{"type":"transcript.text.done","text":"Hello world"}');
        $text = $this->stream->applyEvent($text, $done);

        $this->assertSame('Hello world', $text);
    }

    public function test_joins_legacy_segments_with_spaces(): void
    {
        $first = $this->stream->parseEvent('{"text":"Hello from","end":10}');
        $second = $this->stream->parseEvent('{"text":"whisper.","end":20}');

        $text = $this->stream->applyEvent('', $first);
        $text = $this->stream->applyEvent($text, $second);

        $this->assertSame('Hello from whisper.', $text);
    }

    public function test_ignores_done_sentinel_and_non_json(): void
    {
        $buffer = "data: [DONE]\n\ndata: not-json\n\n";

        $payloads = $this->stream->extractPayloads($buffer);

        $this->assertSame(['not-json'], $payloads);
        $this->assertNull($this->stream->parseEvent('not-json'));
    }

    public function test_flush_buffer_emits_trailing_frame(): void
    {
        $buffer = 'data: {"text":"Last"}';

        $payloads = $this->stream->flushBuffer($buffer);

        $this->assertSame(['{"text":"Last"}'], $payloads);
        $this->assertSame('', $buffer);
    }
}