<?php

namespace app\api\logic\tcm;

use app\common\model\tcm\BloodRecord;
use app\common\model\tcm\Diagnosis;
use app\common\service\AiChatService;
use think\facade\Cache;

/**
 * 日常护理 - AI 饮食建议（基于霍大夫升糖指数）
 */
class DailyDietAiLogic
{
    private const CACHE_TTL = 86400;

    /** 单次 AI 请求超时（秒），避免接口长时间挂起 */
    private const AI_TIMEOUT_SEC = 12;

    /** 流式 AI 请求超时（秒） */
    private const AI_STREAM_TIMEOUT_SEC = 18;

    /**
     * 今日推荐饮食（按诊单+日期缓存）
     *
     * @return array{ok:bool,error?:string,data?:array}
     */
    public static function getDailyRecommend(int $diagnosisId, bool $refresh = false): array
    {
        if ($diagnosisId <= 0) {
            return ['ok' => false, 'error' => '缺少就诊卡'];
        }

        $context = self::buildPatientContext($diagnosisId);
        if (!$context['ok']) {
            return ['ok' => false, 'error' => $context['error'] ?? '获取档案失败'];
        }
        $analysis = self::buildAnalysisPayload($context['data']);
        $exercise = self::buildExercisePayload($context['data']);

        $cacheKey = self::recommendCacheKey($diagnosisId);
        if (!$refresh) {
            $cached = Cache::get($cacheKey);
            if (is_array($cached) && !empty($cached['breakfast'])) {
                $cached['cached']   = true;
                $cached['analysis'] = $analysis;
                $cached['exercise'] = $exercise;
                return ['ok' => true, 'data' => $cached];
            }
        }

        $data = null;
        if (AiChatService::isEnabled()) {
            $raw = self::aiDailyRecommend($context['data'], $refresh);
            if (is_array($raw) && !empty($raw['breakfast'])) {
                $data = self::finalizeAiRecommendPlan($raw);
            }
        }
        if (!$data) {
            $tplIdx = self::resolveFallbackTemplateIndex($diagnosisId, $refresh);
            $data   = GiKnowledge::fallbackDailyMeals($diagnosisId, $tplIdx);
            $data['disclaimer'] = '按升糖指数与农家饭硬性规则推荐（午餐≥2样蛋白、淀粉不重复）。';
        }

        $data['date']   = date('Y-m-d');
        $data['cached'] = false;
        Cache::set($cacheKey, $data, self::CACHE_TTL);
        $data['analysis'] = $analysis;
        $data['exercise'] = $exercise;

        return ['ok' => true, 'data' => $data];
    }

    /**
     * 询问某食物能不能吃
     *
     * @return array{ok:bool,error?:string,data?:array}
     */
    public static function askFood(int $diagnosisId, string $question): array
    {
        $question = trim($question);
        if ($question === '') {
            return ['ok' => false, 'error' => '请输入想咨询的食物'];
        }
        if (mb_strlen($question) > 80) {
            return ['ok' => false, 'error' => '问题过长，请简短描述'];
        }

        $cacheKey = 'daily_diet_ai_ask:' . md5($diagnosisId . ':' . mb_strtolower($question));
        $cached   = Cache::get($cacheKey);
        if (is_array($cached) && !empty($cached['advice'])) {
            $cached['cached'] = true;
            return ['ok' => true, 'data' => $cached];
        }

        $context = self::buildPatientContext($diagnosisId);
        $data    = null;

        if (AiChatService::isEnabled()) {
            $data = self::aiAskFood($context['data'] ?? [], $question);
        }
        if (!$data) {
            $data = GiKnowledge::fallbackAsk($question);
        }

        $data['question']   = $question;
        $data['disclaimer'] = '仅供参考，不能替代医嘱。';
        $data['cached']     = false;
        Cache::set($cacheKey, $data, 3600);

        return ['ok' => true, 'data' => $data];
    }

    /**
     * 流式：今日饮食推荐（SSE delta + done）
     *
     * @param callable(string, array<string, mixed>):void $emit event: delta|done|error
     */
    public static function streamDailyRecommend(int $diagnosisId, bool $refresh, callable $emit): void
    {
        if ($diagnosisId <= 0) {
            $emit('error', ['message' => '缺少就诊卡']);
            return;
        }

        $context = self::buildPatientContext($diagnosisId);
        if (!$context['ok']) {
            $emit('error', ['message' => $context['error'] ?? '获取档案失败']);
            return;
        }
        $analysis = self::buildAnalysisPayload($context['data']);
        $exercise = self::buildExercisePayload($context['data']);
        // 先把「分析依据」「运动建议」推给前端，提升首屏感知
        $emit('analysis', ['analysis' => $analysis]);
        $emit('exercise', ['exercise' => $exercise]);

        $cacheKey = self::recommendCacheKey($diagnosisId);
        if (!$refresh) {
            $cached = Cache::get($cacheKey);
            if (is_array($cached) && !empty($cached['breakfast'])) {
                $cached['cached']   = true;
                $cached['analysis'] = $analysis;
                $cached['exercise'] = $exercise;
                $emit('done', $cached);
                return;
            }
        }

        $data     = null;
        $fullText = '';

        if (AiChatService::isEnabled()) {
            [$system, $user] = self::buildRecommendStreamPrompts($context['data'], $refresh);
            $streamRes = AiChatService::streamChat([
                ['role' => 'system', 'content' => $system],
                ['role' => 'user', 'content' => $user],
            ], static function (string $delta) use (&$fullText, $emit): void {
                $fullText .= $delta;
                $emit('delta', ['text' => $delta, 'buffer' => $fullText]);
            }, [
                'temperature' => $refresh ? 0.78 : 0.35,
                'max_tokens'  => 400,
                'timeout'     => self::AI_STREAM_TIMEOUT_SEC,
            ]);

            if ($streamRes['ok'] && $fullText !== '') {
                $parsed = self::parseRecommendPlainText($fullText);
                if ($parsed && !empty($parsed['breakfast'])) {
                    $data = self::finalizeAiRecommendPlan($parsed);
                }
            }
        }

        if (!$data) {
            $tplIdx = self::resolveFallbackTemplateIndex($diagnosisId, $refresh);
            $data   = GiKnowledge::fallbackDailyMeals($diagnosisId, $tplIdx);
            $data['source'] = 'rule';
            $data['disclaimer'] = '按升糖指数与农家饭硬性规则推荐（午餐≥2样蛋白、淀粉不重复）。';
        }

        $data['date']   = date('Y-m-d');
        $data['cached'] = false;
        Cache::set($cacheKey, $data, self::CACHE_TTL);
        $data['analysis'] = $analysis;
        $data['exercise'] = $exercise;
        $emit('done', $data);
    }

    /**
     * 流式：能不能吃（SSE delta + done）
     *
     * @param callable(string, array<string, mixed>):void $emit event: delta|done|error
     */
    public static function streamAskFood(int $diagnosisId, string $question, callable $emit): void
    {
        $question = trim($question);
        if ($question === '') {
            $emit('error', ['message' => '请输入想咨询的食物']);
            return;
        }
        if (mb_strlen($question) > 80) {
            $emit('error', ['message' => '问题过长，请简短描述']);
            return;
        }

        $cacheKey = 'daily_diet_ai_ask:' . md5($diagnosisId . ':' . mb_strtolower($question));
        $cached   = Cache::get($cacheKey);
        if (is_array($cached) && !empty($cached['advice'])) {
            $cached['cached'] = true;
            $emit('done', $cached);
            return;
        }

        $context  = self::buildPatientContext($diagnosisId);

        $data     = null;
        $fullText = '';

        if (AiChatService::isEnabled()) {
            [$system, $user] = self::buildAskStreamPrompts($context['data'] ?? [], $question);
            $streamRes = AiChatService::streamChat([
                ['role' => 'system', 'content' => $system],
                ['role' => 'user', 'content' => $user],
            ], static function (string $delta) use (&$fullText, $emit): void {
                $fullText .= $delta;
                $emit('delta', ['text' => $delta, 'advice' => $fullText]);
            }, [
                'temperature' => 0.3,
                'max_tokens'  => 200,
                'timeout'     => self::AI_STREAM_TIMEOUT_SEC,
            ]);

            if ($streamRes['ok'] && trim($fullText) !== '') {
                $data = self::finalizeAskFromText($context['data'] ?? [], $question, trim($fullText));
            }
        }

        if (!$data) {
            $data = GiKnowledge::fallbackAsk($question);
        }

        $data['question']   = $question;
        $data['disclaimer'] = '仅供参考，不能替代医嘱。';
        $data['cached']     = false;
        Cache::set($cacheKey, $data, 3600);
        $emit('done', $data);
    }

    private static function recommendCacheKey(int $diagnosisId): string
    {
        return 'daily_diet_ai_rec_v2:' . $diagnosisId . ':' . date('Y-m-d');
    }

    /** 换一换时轮换规则模板下标（与 GiKnowledge::$mealTemplates 数量一致） */
    private static function resolveFallbackTemplateIndex(int $diagnosisId, bool $refresh): int
    {
        $count      = 6;
        $cacheKey   = 'daily_diet_ai_tpl_idx:' . $diagnosisId . ':' . date('Y-m-d');
        $defaultIdx = abs(crc32(date('Y-m-d') . ':' . $diagnosisId)) % $count;

        if (!$refresh) {
            Cache::set($cacheKey, $defaultIdx, self::CACHE_TTL);
            return $defaultIdx;
        }

        $last = Cache::get($cacheKey);
        if ($last === null || $last === false) {
            $last = $defaultIdx;
        }
        $idx = (((int) $last) + 1) % $count;
        Cache::set($cacheKey, $idx, self::CACHE_TTL);

        return $idx;
    }

    /**
     * @return array{ok:bool,error?:string,data?:array}
     */
    private static function buildPatientContext(int $diagnosisId): array
    {
        $diagnosis = Diagnosis::where('id', $diagnosisId)->where('delete_time', null)->find();
        if (!$diagnosis) {
            return ['ok' => false, 'error' => '就诊卡不存在'];
        }

        $row = $diagnosis->toArray();
        $gender = (int) ($row['gender'] ?? 0);
        $genderText = $gender === 1 ? '男' : ($gender === 0 ? '女' : '未知');
        $age = (int) ($row['age'] ?? 0);

        // 拉取近 30 天血糖（涵盖近 7 天），统一计算 7/30 天统计
        $since30 = strtotime('-30 days 00:00:00');
        $bloodList = BloodRecord::where('diagnosis_id', $diagnosisId)
            ->where('record_date', '>=', $since30)
            ->where('delete_time', null)
            ->order('record_date', 'desc')
            ->field('record_date,fasting_blood_sugar,postprandial_blood_sugar,other_blood_sugar')
            ->select()
            ->toArray();

        $since7 = strtotime('-7 days 00:00:00');
        $list7  = array_values(array_filter($bloodList, static function ($b) use ($since7) {
            return (int) ($b['record_date'] ?? 0) >= $since7;
        }));

        // 近 7 天逐日明细（喂给 AI 的细节）
        $bloodSummary = [];
        foreach (array_slice($list7, 0, 7) as $b) {
            $date  = !empty($b['record_date']) ? date('Y-m-d', (int) $b['record_date']) : '';
            $parts = [];
            if ($b['fasting_blood_sugar'] !== null && $b['fasting_blood_sugar'] !== '') {
                $parts[] = '空腹' . $b['fasting_blood_sugar'];
            }
            if ($b['postprandial_blood_sugar'] !== null && $b['postprandial_blood_sugar'] !== '') {
                $parts[] = '餐后' . $b['postprandial_blood_sugar'];
            }
            if ($b['other_blood_sugar'] !== null && $b['other_blood_sugar'] !== '') {
                $parts[] = '其他' . $b['other_blood_sugar'];
            }
            if ($date && $parts) {
                $bloodSummary[] = $date . '：' . implode('，', $parts) . ' mmol/L';
            }
        }

        $stats7  = self::aggregateBloodStats($list7, $age, '近7天');
        $stats30 = self::aggregateBloodStats($bloodList, $age, '近30天');

        return [
            'ok'   => true,
            'data' => [
                'patient_name'  => (string) ($row['patient_name'] ?? ''),
                'age'           => $age,
                'gender_text'   => $genderText,
                'blood_recent'  => $bloodSummary,
                'stats_7d'      => $stats7,
                'stats_30d'     => $stats30,
                'today'         => date('Y-m-d'),
            ],
        ];
    }

    /**
     * 根据年龄返回血糖偏高阈值（与前端 getBloodSugarThresholds 保持一致）
     *
     * @return array{fasting:float,postprandial:float}|null
     */
    private static function bloodThresholds(int $age): array
    {
        // 年龄未知时用通用糖尿病控制目标兜底，避免「无阈值=全部达标」
        if ($age <= 0) {
            return ['fasting' => 7.0, 'postprandial' => 10.0];
        }
        return $age < 50
            ? ['fasting' => 7.0, 'postprandial' => 9.0]
            : ['fasting' => 8.0, 'postprandial' => 10.0];
    }

    /**
     * 汇总一段时间内的血糖统计：有记录天数、偏高天数、达标率、均值
     *
     * @param array<int,array<string,mixed>> $rows
     * @return array<string,mixed>
     */
    private static function aggregateBloodStats(array $rows, int $age, string $label): array
    {
        $thresholds = self::bloodThresholds($age);

        $byDate       = [];
        $fastingSum   = 0.0;
        $fastingCnt   = 0;
        $postSum      = 0.0;
        $postCnt      = 0;

        foreach ($rows as $b) {
            $ts = (int) ($b['record_date'] ?? 0);
            if ($ts <= 0) {
                continue;
            }
            $date    = date('Y-m-d', $ts);
            $fasting = ($b['fasting_blood_sugar'] !== null && $b['fasting_blood_sugar'] !== '') ? (float) $b['fasting_blood_sugar'] : null;
            $post    = ($b['postprandial_blood_sugar'] !== null && $b['postprandial_blood_sugar'] !== '') ? (float) $b['postprandial_blood_sugar'] : null;
            if ($fasting === null && $post === null) {
                continue;
            }

            if (!isset($byDate[$date])) {
                $byDate[$date] = ['high' => false];
            }
            if ($fasting !== null) {
                $fastingSum += $fasting;
                $fastingCnt++;
                if ($thresholds && $fasting >= $thresholds['fasting']) {
                    $byDate[$date]['high'] = true;
                }
            }
            if ($post !== null) {
                $postSum += $post;
                $postCnt++;
                if ($thresholds && $post >= $thresholds['postprandial']) {
                    $byDate[$date]['high'] = true;
                }
            }
        }

        $recordDays = count($byDate);
        $highDays   = 0;
        foreach ($byDate as $d) {
            if ($d['high']) {
                $highDays++;
            }
        }
        $normalDays = max(0, $recordDays - $highDays);
        $compliance = $recordDays > 0 ? (int) round($normalDays / $recordDays * 100) : 0;

        return [
            'label'             => $label,
            'record_days'       => $recordDays,
            'high_days'         => $highDays,
            'normal_days'       => $normalDays,
            'compliance'        => $compliance,
            'fasting_avg'       => $fastingCnt > 0 ? round($fastingSum / $fastingCnt, 1) : null,
            'postprandial_avg'  => $postCnt > 0 ? round($postSum / $postCnt, 1) : null,
        ];
    }

    /**
     * 把统计数据拼成喂给 AI 的一行人类可读文本
     *
     * @param array<string,mixed> $stats
     */
    private static function statsToLine(array $stats): string
    {
        if (($stats['record_days'] ?? 0) <= 0) {
            return $stats['label'] . '无血糖记录';
        }
        $segs = [
            $stats['label'] . "有记录{$stats['record_days']}天",
            "偏高{$stats['high_days']}天",
            "达标率{$stats['compliance']}%",
        ];
        if ($stats['fasting_avg'] !== null) {
            $segs[] = "空腹均值{$stats['fasting_avg']}";
        }
        if ($stats['postprandial_avg'] !== null) {
            $segs[] = "餐后均值{$stats['postprandial_avg']}";
        }
        return implode('，', $segs);
    }

    /**
     * 给前端展示的「分析依据」结构（近7天 + 近30天）
     *
     * @param array<string,mixed> $context
     * @return array<int,array<string,mixed>>
     */
    private static function buildAnalysisPayload(array $context): array
    {
        $out = [];
        foreach (['stats_7d', 'stats_30d'] as $key) {
            $s = $context[$key] ?? null;
            if (is_array($s)) {
                $out[] = $s;
            }
        }
        return $out;
    }

    /**
     * 给前端展示的「运动降糖」建议（按血糖统计调整强度）
     *
     * @param array<string,mixed> $context
     * @return array<string,mixed>
     */
    private static function buildExercisePayload(array $context): array
    {
        return GiKnowledge::exercisePlan(
            is_array($context['stats_7d'] ?? null) ? $context['stats_7d'] : [],
            is_array($context['stats_30d'] ?? null) ? $context['stats_30d'] : []
        );
    }

    /**
     * @return array{0:string,1:string}
     */
    private static function buildRecommendPrompts(array $context, bool $refresh = false): array
    {
        $bloodLine = empty($context['blood_recent'])
            ? '近7日无血糖记录'
            : implode('；', $context['blood_recent']);
        $stat7Line  = self::statsToLine($context['stats_7d'] ?? ['label' => '近7天', 'record_days' => 0]);
        $stat30Line = self::statsToLine($context['stats_30d'] ?? ['label' => '近30天', 'record_days' => 0]);

        $system = <<<SYS
你是村里懂糖尿病饮食的大夫助手，依据「霍大夫升糖指数（GI）」给农村老人推荐一日三餐。输出必须严格可执行。

硬性规则（违反即不合格）：
1. 午餐至少 2 样蛋白质（鱼/鸡鸭/瘦肉/蛋/豆腐/豆干），且午餐蛋白种类数 > 早餐 > 晚餐。
2. 淀粉定义：粥/饭/面/饼/窝头/薯/南瓜。每餐最多 1 种淀粉；早中晚 3 种淀粉必须互不相同。
3. 严禁：白馒头、油条、粘豆包、糯米饭、西瓜、含糖饮料、白稀饭（杂面窝头、玉米碴粥除外）。
4. 低 GI 优先；农村家常；禁止轻食/沙拉/藜麦等词。
5. lunch 字段写法：蛋白菜放前面，淀粉（如有）放最后且注明「小半碗/一个」。
6. 早餐必须包含「驼奶粉」（温水冲服，适量），可与粥、蛋、菜并列写。
7. drinks 单独写全天喝什么：温开水为主；可写驼奶粉冲饮时间；严禁含糖饮料、果汁、酒。
8. 只输出 JSON：
{"breakfast":"...","drinks":"...","lunch":"...","dinner":"...","tips":"...","avoid":["...","..."]}
SYS;

        $user = sprintf(
            "患者：%s，%s，%s岁。日期：%s。\n近7日逐日血糖：%s。\n血糖统计：%s；%s。\n（若近期偏高天数多或达标率低，请收紧主食与高GI食物，多安排蛋白与绿叶菜；若控制平稳可正常推荐。）\n\nGI知识：\n%s\n\n农家饭参考：\n%s\n\n请输出严格符合硬性规则的三餐 JSON。",
            $context['patient_name'] ?: '大爷大妈',
            $context['gender_text'] ?? '',
            $context['age'] ?? 0,
            $context['today'] ?? date('Y-m-d'),
            $bloodLine,
            $stat7Line,
            $stat30Line,
            GiKnowledge::summaryText(),
            GiKnowledge::ruralMealHints()
        );

        if ($refresh) {
            $user .= "\n\n用户点了「换一换」，请给一套完全不同的农家三餐，编号" . substr(md5((string) microtime(true)), 0, 8) . '。';
        }

        return [$system, $user];
    }

    /**
     * 流式三餐推荐：纯文本格式，便于逐字输出
     *
     * @return array{0:string,1:string}
     */
    private static function buildRecommendStreamPrompts(array $context, bool $refresh = false): array
    {
        $bloodLine = empty($context['blood_recent'])
            ? '近7日无血糖记录'
            : implode('；', $context['blood_recent']);
        $stat7Line  = self::statsToLine($context['stats_7d'] ?? ['label' => '近7天', 'record_days' => 0]);
        $stat30Line = self::statsToLine($context['stats_30d'] ?? ['label' => '近30天', 'record_days' => 0]);

        $system = <<<SYS
你是村里懂糖尿病饮食的大夫助手，依据「霍大夫升糖指数（GI）」给农村老人推荐一日三餐。

硬性规则：
1. 午餐至少 2 样蛋白质（鱼/鸡鸭/瘦肉/蛋/豆腐/豆干），且午餐蛋白 > 早餐 > 晚餐。
2. 淀粉（粥/饭/面/饼/窝头/薯/南瓜）每餐最多 1 种，早中晚互不相同。
3. 严禁白馒头、油条、粘豆包、糯米饭、西瓜、含糖饮料。
4. 农村家常饭，禁止轻食/沙拉/藜麦。
5. 早餐必须含驼奶粉（温水冲服）；喝的单独一行。

严格按下面 6 行格式输出，不要 JSON、不要 markdown、不要多余解释：
早餐：（具体食物，须含驼奶粉）
喝的：（温开水、驼奶粉冲饮安排等，忌甜饮）
午餐：（具体食物，蛋白放前）
晚餐：（具体食物）
提示：（一句土话提醒）
少碰：（用顿号隔开，如：白馒头、油条）
SYS;

        $user = sprintf(
            "患者：%s，%s，%s岁。日期：%s。\n近7日逐日血糖：%s。\n血糖统计：%s；%s。\n（偏高多或达标率低则收紧主食、多蛋白绿叶菜；平稳则正常推荐。）\n\nGI摘要：\n%s",
            $context['patient_name'] ?: '大爷大妈',
            $context['gender_text'] ?? '',
            $context['age'] ?? 0,
            $context['today'] ?? date('Y-m-d'),
            $bloodLine,
            $stat7Line,
            $stat30Line,
            mb_substr(GiKnowledge::summaryText(), 0, 320)
        );

        if ($refresh) {
            $user .= "\n\n用户点了「换一换」，请重新给一套完全不同的农家三餐，编号" . substr(md5((string) microtime(true)), 0, 8) . '，别跟常见模板重复。';
        }

        return [$system, $user];
    }

    /**
     * 解析流式三餐纯文本（兼容 JSON 回退）
     *
     * @return array<string, mixed>|null
     */
    private static function parseRecommendPlainText(string $text): ?array
    {
        $text = trim($text);
        if ($text === '') {
            return null;
        }

        if ($text[0] === '{') {
            $json = self::parseJsonObject($text);
            if (is_array($json)) {
                return $json;
            }
        }

        $map = [
            'breakfast' => null,
            'drinks'    => null,
            'lunch'     => null,
            'dinner'    => null,
            'tips'      => null,
            'avoid'     => null,
        ];

        if (preg_match('/早餐[：:]\s*(.+)$/mu', $text, $m)) {
            $map['breakfast'] = trim(preg_split('/\R/u', $m[1])[0] ?? $m[1]);
        }
        if (preg_match('/喝的[：:]\s*(.+)$/mu', $text, $m)) {
            $map['drinks'] = trim(preg_split('/\R/u', $m[1])[0] ?? $m[1]);
        }
        if (preg_match('/午餐[：:]\s*(.+)$/mu', $text, $m)) {
            $map['lunch'] = trim(preg_split('/\R/u', $m[1])[0] ?? $m[1]);
        }
        if (preg_match('/晚餐[：:]\s*(.+)$/mu', $text, $m)) {
            $map['dinner'] = trim(preg_split('/\R/u', $m[1])[0] ?? $m[1]);
        }
        if (preg_match('/提示[：:]\s*(.+)$/mu', $text, $m)) {
            $map['tips'] = trim(preg_split('/\R/u', $m[1])[0] ?? $m[1]);
        }
        if (preg_match('/少碰[：:]\s*(.+)$/mu', $text, $m)) {
            $avoidLine = trim(preg_split('/\R/u', $m[1])[0] ?? $m[1]);
            $parts     = preg_split('/[、,，;；\s]+/u', $avoidLine) ?: [];
            $map['avoid'] = array_values(array_filter(array_map('trim', $parts)));
        }

        if (empty($map['breakfast'])) {
            return null;
        }

        $out = [
            'breakfast' => (string) $map['breakfast'],
            'drinks'    => (string) ($map['drinks'] ?? ''),
            'lunch'     => (string) ($map['lunch'] ?? ''),
            'dinner'    => (string) ($map['dinner'] ?? ''),
            'tips'      => (string) ($map['tips'] ?? ''),
            'avoid'     => is_array($map['avoid']) ? $map['avoid'] : [],
        ];

        return $out;
    }

    /**
     * 产品要求：早餐含驼奶粉，并单独给出「喝的」
     *
     * @param array<string, mixed> $plan
     * @return array<string, mixed>
     */
    private static function applyDietProductDefaults(array $plan): array
    {
        $breakfast = trim((string) ($plan['breakfast'] ?? ''));
        if ($breakfast !== '' && mb_strpos($breakfast, '驼奶粉') === false && mb_strpos($breakfast, '驼奶') === false) {
            $plan['breakfast'] = '驼奶粉（温水冲服）、' . $breakfast;
        }

        $drinks = trim((string) ($plan['drinks'] ?? ''));
        if ($drinks === '') {
            $plan['drinks'] = '白天多喝温开水；早餐按量冲驼奶粉，别喝甜饮料、果汁。';
        } elseif (mb_strpos($drinks, '驼奶') === false) {
            $plan['drinks'] = $drinks . '；早餐已安排驼奶粉';
        }

        return $plan;
    }

    /**
     * 规范化 AI 三餐方案；校验未过也保留 AI 文案（避免流式展示后被规则模板覆盖）
     *
     * @param array<string, mixed> $parsed
     * @return array<string, mixed>
     */
    private static function finalizeAiRecommendPlan(array $parsed): array
    {
        $parsed  = self::applyDietProductDefaults($parsed);
        $checked = DietMealValidator::validateAndNormalize($parsed);
        $data    = $checked['plan'];
        $data['source'] = 'ai';
        $data['rules_summary'] = DietMealValidator::metaSummary($checked['meta']);
        if ($checked['ok']) {
            $data['disclaimer'] = 'AI 建议已通过规则校验，仍请结合医嘱与血糖监测。';
        } else {
            $data['validation_warnings'] = $checked['errors'];
            $data['disclaimer'] = 'AI 建议供参考，仍请结合医嘱与血糖监测。';
        }

        return $data;
    }

    /**
     * @return array{0:string,1:string}
     */
    private static function buildAskStreamPrompts(array $context, string $question): array
    {
        $food = GiKnowledge::extractFoodName($question);
        $hit  = GiKnowledge::lookupFood($food);
        $kbHint = $hit
            ? "知识库命中：{$hit['food']} → {$hit['level_label']}（{$hit['category']}）"
            : '知识库未命中，按 GI 原则用农村常识回答';

        $system = <<<SYS
你是村里糖尿病饮食顾问，用升糖指数（GI）回答农村老人「能不能吃某东西」。
用一两句土话直接回答，40字以内，先说能不能吃、再说咋吃/吃多少。不要 JSON、不要 markdown、不要列表。
SYS;

        $user = sprintf(
            "老人%s，%s。问：%s\n%s\n\nGI摘要：\n%s",
            $context['patient_name'] ?? '',
            $context['gender_text'] ?? '',
            $question,
            $kbHint,
            GiKnowledge::summaryText()
        );

        return [$system, $user];
    }

    /**
     * @return array<string, mixed>
     */
    private static function finalizeAskFromText(array $context, string $question, string $text): array
    {
        $food = GiKnowledge::extractFoodName($question);
        $hit  = GiKnowledge::lookupFood($food);

        $data = [
            'food'   => $food,
            'advice' => $text,
            'source' => 'ai',
        ];

        if ($hit) {
            $data['food']        = $hit['food'];
            $data['level']       = $hit['level'];
            $data['level_label'] = $hit['level_label'];
            $data['portion']     = $hit['level'] === GiKnowledge::LEVEL_HIGH
                ? '尽量别吃'
                : ($hit['level'] === GiKnowledge::LEVEL_MEDIUM ? '少量' : '适量');
        } else {
            $data['level']       = GiKnowledge::LEVEL_MEDIUM;
            $data['level_label'] = '中升糖';
            $data['portion']     = '少量';
        }

        return $data;
    }

    private static function aiDailyRecommend(array $context, bool $refresh = false): ?array
    {
        [$system, $user] = self::buildRecommendPrompts($context, $refresh);

        $res = AiChatService::chat([
            ['role' => 'system', 'content' => $system],
            ['role' => 'user', 'content' => $user],
        ], [
            'temperature'     => $refresh ? 0.78 : 0.35,
            'max_tokens'      => 900,
            'timeout'         => self::AI_TIMEOUT_SEC,
            'response_format' => ['type' => 'json_object'],
        ]);

        if (!$res['ok']) {
            return null;
        }

        $parsed = self::parseJsonObject((string) $res['content']);
        if (!$parsed || empty($parsed['breakfast'])) {
            return null;
        }

        $parsed['avoid'] = is_array($parsed['avoid'] ?? null) ? $parsed['avoid'] : [];

        return $parsed;
    }

    /**
     * @param array $context
     * @return array|null
     */
    private static function aiAskFood(array $context, string $question): ?array
    {
        $food = GiKnowledge::extractFoodName($question);
        $hit  = GiKnowledge::lookupFood($food);

        $system = <<<SYS
你是村里糖尿病饮食顾问，用升糖指数（GI）回答农村老人「能不能吃某东西」。
只输出 JSON：{"food":"食物名","level":"low|medium|high","level_label":"低升糖|中升糖|高升糖","advice":"40字内土话建议","portion":"咋吃、吃多少"}
level：low≤55，medium 56-69，high≥70。advice 要口语化，别文绉绉。
SYS;

        $kbHint = $hit
            ? "知识库命中：{$hit['food']} → {$hit['level_label']}（{$hit['category']}）"
            : '知识库未命中，按 GI 原则用农村常识回答';

        $user = sprintf(
            "老人%s，%s。问：%s\n%s\n\nGI摘要：\n%s\n\n农家饭原则：\n%s",
            $context['patient_name'] ?? '',
            $context['gender_text'] ?? '',
            $question,
            $kbHint,
            GiKnowledge::summaryText(),
            GiKnowledge::ruralMealHints()
        );

        $res = AiChatService::chat([
            ['role' => 'system', 'content' => $system],
            ['role' => 'user', 'content' => $user],
        ], [
            'temperature'     => 0.3,
            'max_tokens'      => 400,
            'timeout'           => self::AI_TIMEOUT_SEC,
            'response_format' => ['type' => 'json_object'],
        ]);

        if (!$res['ok']) {
            return null;
        }

        $parsed = self::parseJsonObject((string) $res['content']);
        if (!$parsed || empty($parsed['advice'])) {
            return null;
        }

        if ($hit) {
            $parsed['food']        = $hit['food'];
            $parsed['level']       = $hit['level'];
            $parsed['level_label'] = $hit['level_label'];
            if (empty($parsed['portion'])) {
                $parsed['portion'] = $hit['level'] === GiKnowledge::LEVEL_HIGH ? '尽量别吃' : ($hit['level'] === GiKnowledge::LEVEL_MEDIUM ? '少量' : '适量');
            }
        }

        $parsed['source'] = 'ai';
        if (empty($parsed['food'])) {
            $parsed['food'] = $food;
        }

        return $parsed;
    }

    /**
     * @return array<string, mixed>|null
     */
    private static function parseJsonObject(string $content): ?array
    {
        $content = trim($content);
        if ($content === '') {
            return null;
        }
        if ($content[0] !== '{') {
            if (preg_match('/\{[\s\S]*\}/', $content, $m)) {
                $content = $m[0];
            }
        }
        $decoded = json_decode($content, true);
        return is_array($decoded) ? $decoded : null;
    }
}