<?php

namespace app\service;

use think\facade\Cache;

class CosyVoiceService
{
    private const MODES = ['sft', 'instruct', 'zero_shot', 'cross_lingual', 'instruct2'];
    private const FALLBACK_VOICES = [
        'alloy', 'ash', 'ballad', 'coral', 'echo', 'fable', 'nova',
        'onyx', 'sage', 'shimmer', 'verse', 'marin', 'cedar',
    ];

    public static function getPersona(): array
    {
        $defaults = [
            'enabled'            => (bool) config('cosyvoice.enabled', true),
            'name'               => '小暖',
            'greeting'           => '您好，我是 AI 客服小暖，请问有什么可以帮您？',
            'role_prompt'        => '温暖、专业、耐心，像经验丰富的真人客服一样理解用户的真实诉求。',
            'base_url'           => (string) config('cosyvoice.base_url', 'http://127.0.0.1:50000'),
            'mode'               => (string) config('cosyvoice.mode', 'sft'),
            'speaker'            => (string) config('cosyvoice.speaker', '中文女'),
            'instruct_text'      => (string) config('cosyvoice.instruct_text', ''),
            'prompt_text'        => (string) config('cosyvoice.prompt_text', ''),
            'prompt_wav'         => (string) config('cosyvoice.prompt_wav', ''),
            'prompt_wav_name'    => '',
            'sample_rate'        => (int) config('cosyvoice.sample_rate', 22050),
            'fallback_voice'     => 'marin',
            'connect_timeout_ms' => (int) config('cosyvoice.connect_timeout_ms', 800),
            'timeout_seconds'    => (int) config('cosyvoice.timeout_seconds', 8),
            'failure_ttl'        => (int) config('cosyvoice.failure_ttl', 20),
        ];
        $stored = SettingsService::get('voice_persona', []);

        return array_merge($defaults, is_array($stored) ? $stored : []);
    }

    public static function publicPersona(): array
    {
        $persona = self::getPersona();
        return [
            'name'     => $persona['name'],
            'greeting' => $persona['greeting'],
        ];
    }

    public static function normalizePersona(array $input, ?array $current = null): array
    {
        $current ??= self::getPersona();
        $mode = trim((string) ($input['mode'] ?? $current['mode'] ?? 'sft'));
        if (!in_array($mode, self::MODES, true)) {
            $mode = 'sft';
        }

        $baseUrl = rtrim(trim((string) ($input['base_url'] ?? $current['base_url'] ?? '')), '/');
        if ($baseUrl !== '' && !preg_match('#^https?://#i', $baseUrl)) {
            $baseUrl = (string) ($current['base_url'] ?? '');
        }

        $fallbackVoice = trim((string) ($input['fallback_voice'] ?? $current['fallback_voice'] ?? 'marin'));
        if (!in_array($fallbackVoice, self::FALLBACK_VOICES, true)) {
            $fallbackVoice = 'marin';
        }

        $promptWav = self::safePromptPath((string) ($input['prompt_wav'] ?? $current['prompt_wav'] ?? ''));
        $sampleRate = (int) ($input['sample_rate'] ?? $current['sample_rate'] ?? 22050);
        if (!in_array($sampleRate, [16000, 22050, 24000, 44100, 48000], true)) {
            $sampleRate = 22050;
        }

        return [
            'enabled'            => filter_var($input['enabled'] ?? $current['enabled'] ?? true, FILTER_VALIDATE_BOOLEAN),
            'name'               => self::limitedText($input['name'] ?? $current['name'] ?? '小暖', 40),
            'greeting'           => self::limitedText($input['greeting'] ?? $current['greeting'] ?? '', 200),
            'role_prompt'        => self::limitedText($input['role_prompt'] ?? $current['role_prompt'] ?? '', 2000),
            'base_url'           => $baseUrl,
            'mode'               => $mode,
            'speaker'            => self::limitedText($input['speaker'] ?? $current['speaker'] ?? '中文女', 80),
            'instruct_text'      => self::limitedText($input['instruct_text'] ?? $current['instruct_text'] ?? '', 1000),
            'prompt_text'        => self::limitedText($input['prompt_text'] ?? $current['prompt_text'] ?? '', 1500),
            'prompt_wav'         => $promptWav,
            'prompt_wav_name'    => self::limitedText($input['prompt_wav_name'] ?? $current['prompt_wav_name'] ?? '', 180),
            'sample_rate'        => $sampleRate,
            'fallback_voice'     => $fallbackVoice,
            'connect_timeout_ms' => max(200, min(5000, (int) ($input['connect_timeout_ms'] ?? 800))),
            'timeout_seconds'    => max(2, min(60, (int) ($input['timeout_seconds'] ?? 8))),
            'failure_ttl'        => max(5, min(300, (int) ($input['failure_ttl'] ?? 20))),
        ];
    }

    public static function isEnabled(): bool
    {
        $persona = self::getPersona();
        return !empty($persona['enabled']) && trim((string) $persona['base_url']) !== '';
    }

    public static function canAttempt(): bool
    {
        if (!self::isEnabled()) {
            return false;
        }

        return !Cache::get(self::failureCacheKey(self::getPersona()), false);
    }

    public static function clearFailure(?array $persona = null): void
    {
        Cache::delete(self::failureCacheKey($persona ?? self::getPersona()));
    }

    /**
     * 调用官方 FastAPI 服务。上游返回裸 PCM16 流，这里封装为浏览器可播放的 WAV。
     *
     * @return array{audio: string, content_type: string, provider: string}
     */
    public static function speech(string $text): array
    {
        $persona = self::getPersona();
        if (empty($persona['enabled']) || trim((string) $persona['base_url']) === '') {
            throw new \RuntimeException('CosyVoice 未启用');
        }

        $mode = trim((string) $persona['mode']);
        if (!in_array($mode, self::MODES, true)) {
            throw new \RuntimeException('CosyVoice 模式无效: ' . $mode);
        }

        $fields = self::requestFields($mode, $text, $persona);
        $url = rtrim((string) $persona['base_url'], '/') . '/inference_' . $mode;
        $headers = ['Accept: application/octet-stream'];
        $apiKey = trim((string) config('cosyvoice.api_key', ''));
        if ($apiKey !== '') {
            $headers[] = 'Authorization: Bearer ' . $apiKey;
        }

        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_POST              => true,
            CURLOPT_POSTFIELDS        => $fields,
            CURLOPT_HTTPHEADER        => $headers,
            CURLOPT_RETURNTRANSFER    => true,
            CURLOPT_CONNECTTIMEOUT_MS => (int) $persona['connect_timeout_ms'],
            CURLOPT_TIMEOUT           => (int) $persona['timeout_seconds'],
            CURLOPT_SSL_VERIFYPEER    => false,
        ]);

        $pcm = curl_exec($ch);
        $httpCode = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $contentType = strtolower((string) (curl_getinfo($ch, CURLINFO_CONTENT_TYPE) ?: ''));
        $curlError = curl_error($ch);
        curl_close($ch);

        if ($pcm === false) {
            self::rememberFailure($persona);
            throw new \RuntimeException('CosyVoice 连接失败: ' . ($curlError ?: '网络不可达'));
        }
        if ($httpCode < 200 || $httpCode >= 300) {
            self::rememberFailure($persona);
            $detail = self::errorDetail($pcm);
            throw new \RuntimeException('CosyVoice 返回 HTTP ' . $httpCode . ($detail ? ': ' . $detail : ''));
        }
        if (str_contains($contentType, 'json')) {
            self::rememberFailure($persona);
            throw new \RuntimeException('CosyVoice 返回了错误响应: ' . (self::errorDetail($pcm) ?: '未知错误'));
        }
        if (strlen($pcm) < 2) {
            self::rememberFailure($persona);
            throw new \RuntimeException('CosyVoice 返回了空音频');
        }

        // PCM16 每个采样占两个字节；丢弃异常的尾部半个采样。
        if (strlen($pcm) % 2 !== 0) {
            $pcm = substr($pcm, 0, -1);
        }

        Cache::delete(self::failureCacheKey($persona));
        return [
            'audio'        => self::pcm16ToWav($pcm, (int) $persona['sample_rate']),
            'content_type' => 'audio/wav',
            'provider'     => 'cosyvoice',
        ];
    }

    /**
     * 将 CosyVoice 上游产生的 PCM16 数据块原样向下游推送，避免等待整段音频生成完成。
     *
     * @return array{bytes: int, sample_rate: int, provider: string, aborted: bool}
     */
    public static function streamSpeech(string $text, callable $onChunk, string $requestId = ''): array
    {
        $persona = self::getPersona();
        if (empty($persona['enabled']) || trim((string) $persona['base_url']) === '') {
            throw new \RuntimeException('CosyVoice 未启用');
        }

        $mode = trim((string) $persona['mode']);
        if (!in_array($mode, self::MODES, true)) {
            throw new \RuntimeException('CosyVoice 模式无效: ' . $mode);
        }

        $fields = self::requestFields($mode, $text, $persona);
        if ($requestId !== '') {
            $fields['request_id'] = $requestId;
        }
        $url = rtrim((string) $persona['base_url'], '/') . '/inference_' . $mode;
        $headers = ['Accept: application/octet-stream'];
        $apiKey = trim((string) config('cosyvoice.api_key', ''));
        if ($apiKey !== '') {
            $headers[] = 'Authorization: Bearer ' . $apiKey;
        }

        $httpCode = 0;
        $contentType = '';
        $errorBody = '';
        $bytes = 0;
        $aborted = false;

        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_POST              => true,
            CURLOPT_POSTFIELDS        => $fields,
            CURLOPT_HTTPHEADER        => $headers,
            CURLOPT_RETURNTRANSFER    => false,
            CURLOPT_HEADERFUNCTION    => function ($ch, string $header) use (&$httpCode, &$contentType): int {
                if (preg_match('/^HTTP\/\d+(?:\.\d+)?\s+(\d+)/i', trim($header), $matches)) {
                    $httpCode = (int) $matches[1];
                } elseif (stripos($header, 'Content-Type:') === 0) {
                    $contentType = strtolower(trim(substr($header, strlen('Content-Type:'))));
                }
                return strlen($header);
            },
            CURLOPT_WRITEFUNCTION => function ($ch, string $chunk) use (
                &$httpCode,
                &$contentType,
                &$errorBody,
                &$bytes,
                &$aborted,
                $onChunk
            ): int {
                if ($httpCode < 200 || $httpCode >= 300 || str_contains($contentType, 'json')) {
                    $errorBody .= $chunk;
                    return strlen($chunk);
                }
                if (connection_aborted()) {
                    $aborted = true;
                    return 0;
                }

                $bytes += strlen($chunk);
                $onChunk($chunk);
                return strlen($chunk);
            },
            CURLOPT_CONNECTTIMEOUT_MS => (int) $persona['connect_timeout_ms'],
            CURLOPT_TIMEOUT           => (int) $persona['timeout_seconds'],
            CURLOPT_SSL_VERIFYPEER    => false,
        ]);

        $result = curl_exec($ch);
        $curlError = curl_error($ch);
        $curlErrno = curl_errno($ch);
        if ($httpCode === 0) {
            $httpCode = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        }
        curl_close($ch);

        if ($aborted || ($result === false && $curlErrno === CURLE_WRITE_ERROR && connection_aborted())) {
            return [
                'bytes'       => $bytes,
                'sample_rate' => (int) $persona['sample_rate'],
                'provider'    => 'cosyvoice',
                'aborted'     => true,
            ];
        }
        if ($result === false) {
            self::rememberFailure($persona);
            throw new \RuntimeException('CosyVoice 流连接失败: ' . ($curlError ?: '网络不可达'));
        }
        if ($httpCode < 200 || $httpCode >= 300) {
            self::rememberFailure($persona);
            $detail = self::errorDetail($errorBody);
            throw new \RuntimeException('CosyVoice 返回 HTTP ' . $httpCode . ($detail ? ': ' . $detail : ''));
        }
        if (str_contains($contentType, 'json')) {
            self::rememberFailure($persona);
            throw new \RuntimeException('CosyVoice 返回了错误响应: ' . (self::errorDetail($errorBody) ?: '未知错误'));
        }
        if ($bytes < 2) {
            self::rememberFailure($persona);
            throw new \RuntimeException('CosyVoice 返回了空音频');
        }

        Cache::delete(self::failureCacheKey($persona));
        return [
            'bytes'       => $bytes,
            'sample_rate' => (int) $persona['sample_rate'],
            'provider'    => 'cosyvoice',
            'aborted'     => false,
        ];
    }

    public static function cancelSpeech(string $requestId): bool
    {
        $persona = self::getPersona();
        $requestId = trim($requestId);
        if ($requestId === '' || empty($persona['enabled']) || trim((string) $persona['base_url']) === '') {
            return false;
        }

        $url = rtrim((string) $persona['base_url'], '/') . '/cancel/' . rawurlencode($requestId);
        $headers = ['Accept: application/json'];
        $apiKey = trim((string) config('cosyvoice.api_key', ''));
        if ($apiKey !== '') {
            $headers[] = 'Authorization: Bearer ' . $apiKey;
        }

        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_POST              => true,
            CURLOPT_POSTFIELDS        => '',
            CURLOPT_HTTPHEADER        => $headers,
            CURLOPT_RETURNTRANSFER    => true,
            CURLOPT_CONNECTTIMEOUT_MS => min(800, (int) $persona['connect_timeout_ms']),
            CURLOPT_TIMEOUT_MS        => 1500,
            CURLOPT_SSL_VERIFYPEER    => false,
        ]);
        $body = curl_exec($ch);
        $httpCode = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($body === false || $httpCode < 200 || $httpCode >= 300) {
            return false;
        }

        $payload = json_decode($body, true);
        return is_array($payload) && !empty($payload['cancelled']);
    }

    private static function requestFields(string $mode, string $text, array $persona): array
    {
        $fields = ['tts_text' => $text];
        $speaker = trim((string) $persona['speaker']);
        $instruct = trim((string) $persona['instruct_text']);

        if (in_array($mode, ['sft', 'instruct'], true)) {
            $fields['spk_id'] = $speaker;
        }
        if (in_array($mode, ['instruct', 'instruct2'], true)) {
            $fields['instruct_text'] = $instruct;
        }
        if (in_array($mode, ['zero_shot', 'instruct2'], true)) {
            $fields['prompt_text'] = trim((string) $persona['prompt_text']);
        }
        if (in_array($mode, ['zero_shot', 'cross_lingual', 'instruct2'], true)) {
            $promptWav = trim((string) $persona['prompt_wav']);
            if ($promptWav === '' || !is_file($promptWav)) {
                throw new \RuntimeException('CosyVoice 音色样本不存在: ' . $promptWav);
            }
            $fields['prompt_wav'] = new \CURLFile($promptWav, 'audio/wav', basename($promptWav));
        }

        return $fields;
    }

    private static function pcm16ToWav(string $pcm, int $sampleRate): string
    {
        $channels = 1;
        $bitsPerSample = 16;
        $dataSize = strlen($pcm);
        $blockAlign = (int) ($channels * $bitsPerSample / 8);
        $byteRate = $sampleRate * $blockAlign;

        return 'RIFF'
            . pack('V', 36 + $dataSize)
            . 'WAVEfmt '
            . pack('VvvVVvv', 16, 1, $channels, $sampleRate, $byteRate, $blockAlign, $bitsPerSample)
            . 'data'
            . pack('V', $dataSize)
            . $pcm;
    }

    private static function errorDetail(string $body): string
    {
        $data = json_decode($body, true);
        if (is_array($data)) {
            $detail = $data['detail'] ?? $data['message'] ?? $data['error'] ?? '';
            if (is_array($detail)) {
                return json_encode($detail, JSON_UNESCAPED_UNICODE) ?: '';
            }
            return trim((string) $detail);
        }

        return mb_substr(trim(strip_tags($body)), 0, 240);
    }

    private static function rememberFailure(array $persona): void
    {
        Cache::set(
            self::failureCacheKey($persona),
            true,
            (int) $persona['failure_ttl']
        );
    }

    private static function failureCacheKey(array $persona): string
    {
        return 'cosyvoice_unavailable_' . md5((string) $persona['base_url']);
    }

    private static function limitedText(mixed $value, int $maxLength): string
    {
        return mb_substr(trim((string) $value), 0, $maxLength);
    }

    private static function safePromptPath(string $path): string
    {
        $path = trim($path);
        if ($path === '') {
            return '';
        }

        $realPath = realpath($path);
        $allowedRoot = realpath(root_path() . 'storage' . DIRECTORY_SEPARATOR . 'cosyvoice');
        if (!$realPath || !$allowedRoot || !is_file($realPath)) {
            return '';
        }

        $normalizedPath = strtolower(str_replace('\\', '/', $realPath));
        $normalizedRoot = rtrim(strtolower(str_replace('\\', '/', $allowedRoot)), '/') . '/';
        return str_starts_with($normalizedPath, $normalizedRoot) ? $realPath : '';
    }
}