<?php

declare(strict_types=1);

require dirname(__DIR__) . '/vendor/autoload.php';

use app\common\service\DifyChatService;

function difyStreamExpect(bool $condition, string $message): void
{
    if (!$condition) {
        fwrite(STDERR, "FAIL: {$message}\n");
        exit(1);
    }
}

/** @return mixed */
function callDifyStreamPrivate(string $method, array $arguments)
{
    return (new ReflectionClass(DifyChatService::class))->getMethod($method)->invokeArgs(null, $arguments);
}

$generic = callDifyStreamPrivate('buildRequestSpecs', [
    'https://ai.example.test/v1',
    'model-safe',
    ['case' => 'redacted'],
    'safe query',
    'admin-safe',
    true,
]);
difyStreamExpect(count($generic) === 2, 'generic /v1 keeps Dify then OpenAI fallback order');
difyStreamExpect($generic[0]['protocol'] === 'dify', 'Dify remains the first generic protocol');
difyStreamExpect(
    $generic[0]['payload']['response_mode'] === 'streaming',
    'Dify stream request uses response_mode=streaming'
);
difyStreamExpect($generic[1]['protocol'] === 'openai', 'OpenAI remains the fallback protocol');
difyStreamExpect($generic[1]['payload']['stream'] === true, 'OpenAI stream request uses stream=true');
difyStreamExpect(
    $generic[0]['payload']['inputs'] === ['case' => 'redacted']
        && $generic[0]['payload']['query'] === 'safe query'
        && $generic[0]['payload']['user'] === 'admin-safe',
    'Dify streaming preserves structured inputs, query and user'
);

$blocking = callDifyStreamPrivate('buildRequestSpecs', [
    'https://ai.example.test/v1',
    'model-safe',
    [],
    'safe query',
    'admin-safe',
]);
difyStreamExpect(
    $blocking[0]['payload']['response_mode'] === 'blocking',
    'legacy Dify blocking request remains unchanged'
);
difyStreamExpect(
    !array_key_exists('stream', $blocking[1]['payload']),
    'legacy OpenAI blocking request does not gain a stream field'
);

$explicitDify = callDifyStreamPrivate('buildRequestSpecs', [
    'https://ai.example.test/v1/chat-messages', 'model-safe', [], 'query', 'user', true,
]);
$explicitOpenAi = callDifyStreamPrivate('buildRequestSpecs', [
    'https://ai.example.test/v1/chat/completions', 'model-safe', [], 'query', 'user', true,
]);
difyStreamExpect(count($explicitDify) === 1 && $explicitDify[0]['protocol'] === 'dify', 'explicit Dify endpoint never changes protocol');
difyStreamExpect(count($explicitOpenAi) === 1 && $explicitOpenAi[0]['protocol'] === 'openai', 'explicit OpenAI endpoint never changes protocol');

$difyWire = ": ping\r\n\r\n"
    . "data: {\"event\":\"message\",\"answer\":\"你\",\"message_id\":\"msg-safe\"}\r\n\r\n"
    . "data: {\"event\":\"agent_message\",\"answer\":\"好\"}\r\n\r\n"
    . "data: {\"event\":\"ping\"}\r\n\r\n"
    . "data: {\"event\":\"message_end\",\"message_id\":\"msg-safe\"}\r\n\r\n";
$difyChunks = str_split($difyWire, 1);
$decodedDify = callDifyStreamPrivate('decodeStreamChunks', ['dify', $difyChunks]);
difyStreamExpect($decodedDify['content'] === '你好', 'Dify decoder handles every possible byte boundary, including UTF-8 bytes');
difyStreamExpect($decodedDify['deltas'] === ['你', '好'], 'Dify decoder emits only message text');
difyStreamExpect($decodedDify['message_id'] === 'msg-safe', 'Dify decoder retains the safe message id internally');
difyStreamExpect($decodedDify['finished'] === true, 'Dify message_end terminates parsing');

$openAiWire = "data: {\"id\":\"chat-safe\",\"choices\":[{\"delta\":{\"content\":\"A\"}}]}\n\n"
    . "data: {\"choices\":[{\"delta\":{\"content\":\"中\"}}]}\n\n"
    . "data: [DONE]";
$decodedOpenAi = callDifyStreamPrivate('decodeStreamChunks', ['openai', str_split($openAiWire, 2)]);
difyStreamExpect($decodedOpenAi['content'] === 'A中', 'OpenAI decoder handles arbitrary byte chunks and final frame without newline');
difyStreamExpect($decodedOpenAi['deltas'] === ['A', '中'], 'OpenAI decoder emits choices delta content only');
difyStreamExpect($decodedOpenAi['finished'] === true, 'OpenAI [DONE] terminates parsing');

$malformed = callDifyStreamPrivate('decodeStreamChunks', [
    'dify',
    ["data: not-json\n\n", "data: {\"event\":\"error\",\"message\":\"secret-upstream-body\"}\n\n"],
]);
difyStreamExpect($malformed['content'] === '', 'malformed and upstream error frames never become text');
difyStreamExpect($malformed['upstream_error'] === true, 'Dify error frame becomes an internal error flag');
difyStreamExpect(!str_contains(json_encode($malformed), 'secret-upstream-body'), 'upstream error body is not retained');

$safeError = callDifyStreamPrivate('formatStreamResponse', [[
    'errno' => 0,
    'http_code' => 200,
    'content' => '',
    'message_id' => '',
    'emitted' => false,
    'upstream_error' => true,
    'client_aborted' => false,
    'callback_error' => false,
    'finished' => false,
], microtime(true)]);
$encodedError = json_encode($safeError, JSON_UNESCAPED_UNICODE);
difyStreamExpect($safeError['error_code'] === 'UPSTREAM_REJECTED', 'upstream SSE errors map to a stable internal code');
difyStreamExpect(!str_contains($encodedError, 'secret'), 'formatted stream errors contain no upstream body, key or prompt');
$serviceSource = file_get_contents(dirname(__DIR__) . '/app/common/service/DifyChatService.php');
difyStreamExpect(
    is_string($serviceSource)
        && str_contains($serviceSource, '$responseCode < 200 || $responseCode >= 300')
        && str_contains($serviceSource, 'CURLOPT_HEADERFUNCTION => $header')
        && str_contains($serviceSource, "'Accept: text/event-stream'")
        && !str_contains($serviceSource, "config('ai')"),
    'streaming rejects HTTP error bodies before parsing and never mixes daily-diet AI configuration'
);

$timeoutError = callDifyStreamPrivate('formatStreamResponse', [[
    'errno' => CURLE_OPERATION_TIMEDOUT,
    'http_code' => 0,
    'content' => '',
    'message_id' => '',
    'emitted' => false,
    'upstream_error' => false,
    'client_aborted' => false,
    'callback_error' => false,
    'finished' => false,
], microtime(true)]);
$disconnectError = callDifyStreamPrivate('formatStreamResponse', [[
    'errno' => CURLE_ABORTED_BY_CALLBACK,
    'http_code' => 200,
    'content' => 'partial prompt must not appear',
    'message_id' => '',
    'emitted' => true,
    'upstream_error' => false,
    'client_aborted' => true,
    'callback_error' => false,
    'finished' => false,
], microtime(true)]);
difyStreamExpect($timeoutError['error_code'] === 'UPSTREAM_TIMEOUT', 'curl timeout maps to a stable timeout result');
difyStreamExpect($disconnectError['error_code'] === 'CLIENT_DISCONNECTED', 'client abort takes precedence over curl abort errno');
difyStreamExpect(!str_contains(json_encode($disconnectError), 'partial prompt'), 'disconnect result does not echo partial content');

$incompleteError = callDifyStreamPrivate('formatStreamResponse', [[
    'errno' => 0,
    'http_code' => 200,
    'content' => 'partial answer',
    'message_id' => '',
    'emitted' => true,
    'upstream_error' => false,
    'client_aborted' => false,
    'callback_error' => false,
    'finished' => false,
], microtime(true)]);
difyStreamExpect($incompleteError['error_code'] === 'INCOMPLETE_RESPONSE', 'missing [DONE]/message_end cannot become a successful done');
difyStreamExpect(!str_contains(json_encode($incompleteError), 'partial answer'), 'incomplete response error does not echo partial content');

echo "Dify chat stream contract: OK\n";