<?php

declare(strict_types=1);

namespace app\common\service\followupaudio;

use DateTimeImmutable;
use DateTimeZone;
use DomainException;

/** Pure conservative normalization. Model text is data, never a write instruction. */
final class FollowupAudioPolicy
{
    public const PERIODS = ['凌晨', '早晨', '上午', '中午', '下午', '晚上', '睡前'];

    public static function canonical(array $value): string
    {
        $sort = static function ($item) use (&$sort) {
            if (!is_array($item)) { return $item; }
            if (!array_is_list($item)) { ksort($item, SORT_STRING); }
            foreach ($item as $key => $child) { $item[$key] = $sort($child); }
            return $item;
        };
        return json_encode($sort($value), JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRESERVE_ZERO_FRACTION | JSON_THROW_ON_ERROR);
    }

    public static function hash(array $value): string { return hash('sha256', self::canonical($value)); }

    public static function strictDate($value): string
    {
        if (!is_string($value) || !preg_match('/^\d{4}-\d{2}-\d{2}$/D', $value)) {
            throw new DomainException('FOLLOWUP_AUDIO_DATE_INVALID');
        }
        $date = DateTimeImmutable::createFromFormat('!Y-m-d', $value, new DateTimeZone('Asia/Shanghai'));
        if (!$date || $date->format('Y-m-d') !== $value || $value < '1900-01-01') {
            throw new DomainException('FOLLOWUP_AUDIO_DATE_INVALID');
        }
        return $value;
    }

    public static function strictRecordedAt(string $value): string
    {
        $date = DateTimeImmutable::createFromFormat('!Y-m-d H:i:s', $value, new DateTimeZone('Asia/Shanghai'));
        if (!$date || $date->format('Y-m-d H:i:s') !== $value || $value < '1900-01-01 00:00:00' || $date->getTimestamp() > time() + 300) {
            throw new DomainException('FOLLOWUP_AUDIO_RECORDED_AT_INVALID');
        }
        return $value;
    }

    public static function dayTimestamp(string $date): int
    {
        return (new DateTimeImmutable(self::strictDate($date) . ' 00:00:00', new DateTimeZone('Asia/Shanghai')))->getTimestamp();
    }

    public static function strictTime($value): ?string
    {
        if ($value === null || $value === '') { return null; }
        if (!is_string($value) || !preg_match('/^(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d)?$/D', $value)) {
            throw new DomainException('FOLLOWUP_AUDIO_TIME_INVALID');
        }
        return substr($value, 0, 5);
    }

    public static function normalizeExtraction(array $result, string $recordedAt): array
    {
        self::strictRecordedAt($recordedAt);
        if (!is_string($result['transcript'] ?? null) || trim($result['transcript']) === '' || strlen($result['transcript']) > 2000000
            || !is_string($result['summary'] ?? null) || strlen($result['summary']) > 60000 || !is_array($result['items'] ?? null)
            || count($result['items']) > 500 || !is_array($result['uncertainties'] ?? [])) {
            throw new DomainException('FOLLOWUP_AUDIO_EXTRACTION_INVALID');
        }
        $uncertainties = [];
        foreach (($result['uncertainties'] ?? []) as $uncertainty) {
            if (is_string($uncertainty) && count($uncertainties) < 200) { $uncertainties[] = mb_substr($uncertainty, 0, 1000); }
        }
        $items = [];
        $seenEvents = [];
        $segments = array_key_exists('transcript_segments', $result) ? self::segments($result['transcript_segments']) : null;
        $segmentIndex = $segments === null ? [] : array_column($segments, null, 'id');
        $channelMode = $segments !== null && array_key_exists('channel', $segments[0]);
        foreach ($result['items'] as $index => $raw) {
            try {
                if (!is_array($raw) || !is_string($raw['kind'] ?? null) || !is_array($raw['values'] ?? null)) {
                    throw new DomainException('FOLLOWUP_AUDIO_ITEM_INVALID');
                }
                $kind = $raw['kind'];
                $values = FollowupAudioFields::validateValues($kind, $raw['values']);
                $evidence = self::evidence($raw['evidence'] ?? []);
                $quoted = $evidence !== [];
                foreach ($evidence as $quote) {
                    if (!str_contains($result['transcript'], $quote['text'])) { $quoted = false; }
                    if ($segments !== null) {
                        $segment = $segmentIndex[$quote['segment_id'] ?? ''] ?? null;
                        if ($segment === null || !str_contains($segment['text'], $quote['text'])
                            || ($quote['position_type'] ?? '') !== 'segment'
                            || ($quote['start_ms'] ?? null) !== $segment['start_ms']
                            || ($quote['end_ms'] ?? null) !== $segment['end_ms']
                            || array_key_exists('channel', $quote) !== array_key_exists('channel', $segment)
                            || (array_key_exists('channel', $segment) && $quote['channel'] !== $segment['channel'])) {
                            throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_SEGMENT_INVALID');
                        }
                    } elseif (isset($quote['segment_id'])) {
                        throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_SEGMENT_INVALID');
                    }
                }
                $dateText = self::shortText($raw['date_text'] ?? '');
                $timeText = self::shortText($raw['time_text'] ?? '');
                [$date, $dateText, $dateReview] = self::evidenceDate($raw['record_date'] ?? null, $dateText,
                    $recordedAt, $result['transcript'], $quoted ? $evidence : [], $segments !== null, $segmentIndex);
                $time = self::strictTime($raw['record_time'] ?? null);
                $period = self::period($raw['time_period'] ?? $timeText);
                // Approved default clocks are estimates, never claims of an exact spoken measurement time.
                $estimated = ($time === null && $kind !== 'diagnosis') || !empty($raw['time_estimated']);
                if ($time === null && $kind !== 'diagnosis') { $time = self::estimatedTime($period); }
                $needsReview = $channelMode || !empty($raw['needs_review']) || !$quoted || $dateReview
                    || FollowupAudioFields::requiresClinicalReview($kind, $values)
                    || self::riskyEvidenceContext($result['transcript'], $evidence)
                    || ($kind !== 'diagnosis' && ($date === null || $estimated));
                if ($date !== null && ($date > substr($recordedAt, 0, 10) || ($kind === 'diagnosis' && $date < substr($recordedAt, 0, 10)))) { $needsReview = true; }
                $item = [
                    'id' => '', 'kind' => $kind, 'values' => $values, 'record_date' => $date, 'record_time' => $time,
                    'time_period' => $period, 'time_estimated' => $estimated, 'time_text' => $timeText, 'date_text' => $dateText,
                    'evidence' => $evidence, 'needs_review' => $needsReview, 'selected' => false, 'target_id' => null,
                    'current_values' => [], 'expected_hash' => '', 'conflict' => false, 'possible_duplicate' => false,
                ];
                // Equal measurements/default times are NOT enough to collapse different utterances.
                $identity = ['kind' => $kind, 'values' => $values, 'date' => $date, 'time' => $time, 'period' => $period, 'evidence' => $evidence];
                $eventHash = self::hash($identity);
                if ($evidence !== [] && isset($seenEvents[$eventHash])) { continue; }
                $seenEvents[$eventHash] = true;
                $item['id'] = 'i_' . substr(self::hash([$identity, 'index' => $index]), 0, 32);
                $items[] = $item;
            } catch (DomainException $exception) {
                // Retain transcript for a human; do not silently turn unknown/invalid values into "normal".
                $uncertainties[] = '第' . ($index + 1) . '项未进入可写字段：' . $exception->getMessage();
            }
        }
        $normalized = ['summary' => trim($result['summary']), 'transcript' => $result['transcript'],
            'uncertainties' => array_slice($uncertainties, 0, 200), 'items' => $items];
        if ($segments !== null) { $normalized['transcript_segments'] = $segments; }
        return $normalized;
    }

    /**
     * Conservative review gate, NOT a semantic classifier. A substring proves neither
     * speaker identity nor negation/current-vs-historical meaning. Look around every
     * occurrence so a shortened quote cannot hide an adjacent question or family cue.
     */
    private static function riskyEvidenceContext(string $transcript, array $evidence): bool
    {
        $pattern = '/(?:家属|家人|父亲|母亲|爸爸|妈妈|父母|儿子|女儿|丈夫|妻子|老伴|爱人|爷爷|奶奶|姥姥|姥爷|'
            . '哥哥|姐姐|弟弟|妹妹|兄弟|姐妹|孩子|他们|她们|他(?:的|在|测|用)|她(?:的|在|测|用)|'
            . '客服|工作人员|销售|推测|可能是|请问|问[：:]|[?？]|是否|有没有|是不是|多少|吗|呢|否认|没有|没|未|不是|不|'
            . '更正|纠正|说错|口误|改成|其实|好像|可能|大概|大约|差不多|估计|似乎|左右|记不清|忘记|以前|曾经|过去|之前|上次|去年|前年|往年|当时|停药|停用|'
            . '\b(?:family|father|mother|wife|husband|son|daughter|no|not|never|denied|maybe|uncertain|previously|stopped|correction)\b)/iu';
        foreach ($evidence as $quote) {
            $offset = 0;
            $occurrences = 0;
            $length = mb_strlen($quote['text'], 'UTF-8');
            while (($position = mb_strpos($transcript, $quote['text'], $offset, 'UTF-8')) !== false) {
                // Excessively repeated fragments cannot establish a unique reliable context.
                if (++$occurrences > 20) { return true; }
                $start = max(0, $position - 160);
                $context = mb_substr($transcript, $start, $position - $start + $length + 160, 'UTF-8');
                if (preg_match($pattern, $context)) { return true; }
                $offset = $position + max(1, $length);
            }
        }
        return false;
    }

    public static function period($value): ?string
    {
        if ($value === null || $value === '') { return null; }
        if (!is_string($value)) { throw new DomainException('FOLLOWUP_AUDIO_PERIOD_INVALID'); }
        $aliases = ['morning' => '上午', 'noon' => '中午', 'afternoon' => '下午', 'evening' => '晚上',
            'night' => '晚上', 'bedtime' => '睡前', '早上' => '早晨', '清晨' => '早晨', '傍晚' => '晚上'];
        $value = $aliases[$value] ?? $value;
        foreach (self::PERIODS as $period) {
            if (str_contains($value, $period)) { return $period; }
        }
        return null;
    }

    public static function estimatedTime(?string $period): ?string
    {
        return ['早晨' => '08:00', '上午' => '08:00', '中午' => '12:00', '下午' => '15:00',
            '晚上' => '20:00', '睡前' => '22:00'][$period ?? ''] ?? null;
    }

    private static function resolveDate($explicit, string $text, string $recordedAt): ?string
    {
        // A model-supplied calendar date cannot resolve an explicitly ambiguous spoken range.
        if (preg_match('/(?:或|至|到|最近|这几天|前几天|近几天|上周|上星期|上个月|不记得|记不清|大概|左右|between|around)/iu', $text)) { return null; }
        $base = new DateTimeImmutable(substr($recordedAt, 0, 10), new DateTimeZone('Asia/Shanghai'));
        $relative = null;
        foreach (['前天' => '-2 days', '昨天' => '-1 day', '昨日' => '-1 day', '今天' => '+0 days', '今日' => '+0 days',
            'yesterday' => '-1 day', 'today' => '+0 days'] as $word => $offset) {
            if ($text === $word || str_starts_with($text, $word)) { $relative = $base->modify($offset)->format('Y-m-d'); break; }
        }
        if ($explicit !== null && $explicit !== '') {
            $date = self::strictDate($explicit);
            // A relative phrase and supplied date disagree: leave unresolved instead of trusting one silently.
            return $relative !== null && $relative !== $date ? null : $date;
        }
        if ($relative !== null) { return $relative; }
        if (preg_match('/^\d{4}-\d{2}-\d{2}$/D', $text)) { return self::strictDate($text); }
        if (preg_match('/^(\d{4})年(\d{1,2})月(\d{1,2})日$/Du', $text, $match)) {
            return self::strictDate(sprintf('%04d-%02d-%02d', $match[1], $match[2], $match[3]));
        }
        return null;
    }

    /** A model may omit or mislabel date_text; the cited words still constrain its date. */
    private static function evidenceDate($explicit, string $text, string $recordedAt, string $transcript,
        array $evidence, bool $requiresGrounding, array $segmentIndex): array
    {
        // Preserve invalid-date rejection and the established conflicting-date => null behavior.
        $supplied = $explicit === null || $explicit === '' ? null : self::strictDate($explicit);
        // A server-owned citation is a broad window, not an event/date binding. Preserve a
        // model's abstention, including on repeated normalization of a cleared conflict.
        // An explicit calendar without its spoken date label is equally unbound.
        if ($requiresGrounding && ($supplied === null || $text === '')) { return [null, $text, true]; }
        $dates = [];
        $phrases = [];
        $ambiguous = false;
        $directlyGrounded = false;
        $spokenRange = '';
        foreach ($evidence as $quote) {
            // A repeated fragment in another chunk is not evidence for this chunk's date.
            $source = $segmentIndex[$quote['segment_id'] ?? '']['text'] ?? $transcript;
            $contexts = [$quote['text']];
            [$directDates, , $directAmbiguous] = self::dateCues($quote['text'], $recordedAt);
            $directlyGrounded = $directlyGrounded || $directDates !== [];
            if ($spokenRange === '' && ($directAmbiguous || count(array_unique($directDates)) > 1)) { $spokenRange = $quote['text']; }
            if ($directDates === [] && !$directAmbiguous) {
                // Recover an omitted date prefix only within the same sentence, never another event.
                $contexts = [];
                $offset = 0;
                while (($position = mb_strpos($source, $quote['text'], $offset, 'UTF-8')) !== false) {
                    if (count($contexts) >= 20) { $ambiguous = true; break; }
                    $start = max(0, $position - 160);
                    $before = mb_substr($source, $start, $position - $start, 'UTF-8');
                    $after = mb_substr($source, $position + mb_strlen($quote['text'], 'UTF-8'), 160, 'UTF-8');
                    $prefix = preg_split('/[。！？!?；;\r\n]/u', $before);
                    $suffix = preg_split('/[。！？!?；;\r\n]/u', $after);
                    $contexts[] = end($prefix) . $quote['text'] . ($suffix[0] ?? '');
                    $offset = $position + max(1, mb_strlen($quote['text'], 'UTF-8'));
                }
            }
            foreach ($contexts as $context) {
                [$found, $words, $vague] = self::dateCues($context, $recordedAt);
                $dates = array_merge($dates, $found);
                $phrases = array_merge($phrases, $words);
                $ambiguous = $ambiguous || $vague;
            }
        }
        $dates = array_values(array_unique($dates));
        [$claimedDates, , $claimedAmbiguous] = self::dateCues($text, $recordedAt);
        $claimedDates = array_values(array_unique($claimedDates));
        if ($text === '' && $phrases !== [] && ($directlyGrounded || $ambiguous)) {
            $text = mb_substr($spokenRange !== '' ? $spokenRange : implode('；', array_unique($phrases)), 0, 255, 'UTF-8');
        }
        if ($ambiguous || $claimedAmbiguous || count($dates) > 1 || count($claimedDates) > 1) {
            return [null, $text, true];
        }
        if ($dates !== []) {
            $grounded = $dates[0];
            if (($supplied !== null && $supplied !== $grounded)
                || ($claimedDates !== [] && $claimedDates[0] !== $grounded)) {
                return [null, $text, true];
            }
            // Neighbor words can invalidate a conflicting date, but do not prove this event's date.
            // Legacy transcripts may concatenate independent utterances without sentence boundaries.
            if (!$directlyGrounded) {
                return $requiresGrounding ? [null, $text, true] : [self::resolveDate($explicit, $text, $recordedAt), $text, false];
            }
            // An ambiguous model date label is not silently replaced by an exact evidence date.
            if (self::resolveDate(null, $text, $recordedAt) === null && preg_match('/(?:或|至|到|大概|左右|around|between)/iu', $text)) {
                return [null, $text, true];
            }
            return [$grounded, $text, false];
        }
        // A strict transcript pipeline cannot invent a calendar day when none was spoken.
        if ($requiresGrounding) { return [null, $text, true]; }
        return [self::resolveDate($explicit, $text, $recordedAt), $text, false];
    }

    /** Literal temporal cues only, not a general natural-language or speaker classifier. */
    private static function dateCues(string $text, string $recordedAt): array
    {
        $base = new DateTimeImmutable(substr($recordedAt, 0, 10), new DateTimeZone('Asia/Shanghai'));
        $offsets = ['大前天' => -3, '前天' => -2, '昨天' => -1, '昨日' => -1, '今天' => 0, '今日' => 0,
            '明天' => 1, '明日' => 1, '后天' => 2, 'day before yesterday' => -2, 'yesterday' => -1, 'today' => 0, 'tomorrow' => 1];
        $dates = [];
        $phrases = [];
        preg_match_all('/大前天|前天|昨天|昨日|今天|今日|明天|明日|后天|\b(?:day before yesterday|yesterday|today|tomorrow)\b/iu', $text, $matches);
        foreach ($matches[0] as $word) {
            $dates[] = $base->modify(sprintf('%+d days', $offsets[strtolower($word)]))->format('Y-m-d');
            $phrases[] = $word;
        }
        preg_match_all('/(?<!\d)(\d{4})[-年](\d{1,2})[-月](\d{1,2})(?:日|号)?(?!\d)/u', $text, $matches, PREG_SET_ORDER);
        foreach ($matches as $match) {
            $dates[] = self::strictDate(sprintf('%04d-%02d-%02d', $match[1], $match[2], $match[3]));
            $phrases[] = $match[0];
        }
        preg_match_all('/最近(?:几天|一周|一个月)?|这几天|前几天|近几天|前两天|前段时间|这段时间|上周|上星期|上个月|去年|前年|今年|往年|\d{4}年(?!\d{1,2}月)|不记得哪天|记不清哪天|\blast (?:week|month|year)\b|\brecently\b/iu', $text, $vague);
        // Numeric uncertainty (e.g. 昨天读数大概120左右) does not erase an unambiguous date.
        $ambiguous = $vague[0] !== [] || preg_match('/(?:大概|可能|不确定是|记不清是)(?:大前天|前天|昨天|今天)|(?:大前天|前天|昨天|今天)(?:左右|前后)/u', $text) === 1;
        preg_match_all('/(?:星期|周|礼拜)([一二三四五六日天])/u', $text, $weekdays, PREG_SET_ORDER);
        $weekdayNumbers = ['一' => 1, '二' => 2, '三' => 3, '四' => 4, '五' => 5, '六' => 6, '日' => 7, '天' => 7];
        foreach ($weekdays as $weekday) {
            $phrases[] = $weekday[0];
            if ($dates === []) { $ambiguous = true; }
            foreach ($dates as $date) {
                if ((int) (new DateTimeImmutable($date, new DateTimeZone('Asia/Shanghai')))->format('N') !== $weekdayNumbers[$weekday[1]]) {
                    $ambiguous = true;
                }
            }
        }
        return [$dates, array_merge($phrases, $vague[0]), $ambiguous];
    }

    private static function segments($raw): array
    {
        if (!is_array($raw)) { throw new DomainException('FOLLOWUP_AUDIO_SEGMENTS_INVALID'); }
        FollowupAudioTranscriptPrompt::validateSegments($raw);
        return $raw;
    }

    private static function shortText($value): string
    {
        if (!is_string($value) || mb_strlen($value) > 255) { throw new DomainException('FOLLOWUP_AUDIO_TEXT_INVALID'); }
        return trim($value);
    }

    private static function evidence($raw): array
    {
        if (!is_array($raw) || count($raw) > 30) { throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_INVALID'); }
        $evidence = [];
        foreach ($raw as $entry) {
            if (!is_array($entry) || !is_string($entry['text'] ?? null) || trim($entry['text']) === '' || mb_strlen($entry['text']) > 5000) {
                throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_INVALID');
            }
            $quote = [];
            if (array_key_exists('segment_id', $entry)) {
                if (!is_string($entry['segment_id']) || !preg_match('/^[A-Za-z0-9_-]{1,128}$/D', $entry['segment_id'])
                    || ($entry['position_type'] ?? '') !== 'segment' || !isset($entry['start_ms'], $entry['end_ms'])) {
                    throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_SEGMENT_INVALID');
                }
                $quote['segment_id'] = $entry['segment_id'];
            }
            $quote['text'] = isset($entry['segment_id']) ? $entry['text'] : trim($entry['text']);
            foreach (['start_ms', 'end_ms'] as $key) {
                if (isset($entry[$key])) {
                    if (!is_int($entry[$key]) || $entry[$key] < 0 || $entry[$key] > 3600000) {
                        throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_TIME_INVALID');
                    }
                    $quote[$key] = $entry[$key];
                }
            }
            if (isset($quote['start_ms'], $quote['end_ms']) && $quote['end_ms'] < $quote['start_ms']) {
                throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_TIME_INVALID');
            }
            if (array_key_exists('position_type', $entry)) {
                if ($entry['position_type'] !== 'segment' || !isset($quote['segment_id'])) {
                    throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_SEGMENT_INVALID');
                }
                $quote['position_type'] = 'segment';
            }
            if (array_key_exists('channel', $entry)) {
                if (!is_int($entry['channel']) || !in_array($entry['channel'], [0, 1], true)
                    || !isset($quote['segment_id']) || ($quote['position_type'] ?? '') !== 'segment') {
                    throw new DomainException('FOLLOWUP_AUDIO_EVIDENCE_SEGMENT_INVALID');
                }
                $quote['channel'] = $entry['channel'];
            }
            $evidence[] = $quote;
        }
        return $evidence;
    }
}