<?php

declare(strict_types=1);

namespace app\common\service\prescriptionai;

/** Minimal display projection of the immutable prescription; never reads live records. */
final class PrescriptionAiDoctorSnapshot
{
    public static function project(array $prescription): array
    {
        $patient = self::scalars($prescription, ['gender', 'age']);
        $patient['name'] = self::text($prescription['patient_name'] ?? null);
        $gender = self::text($patient['gender'] ?? null);
        $patient['gender_label'] = in_array($gender, ['1', '男'], true) ? '男'
            : (in_array($gender, ['0', '2', '女'], true) ? '女' : '未知');
        $rx = self::scalars($prescription, [
            'prescription_name', 'prescription_type', 'dosage_unit', 'dose_unit', 'dose_basis',
            'dose_count', 'usage_instruction', 'usage_days', 'times_per_day', 'usage_time',
            'usage_way', 'usage_notes', 'dietary_taboo', 'dosage_amount', 'dosage_bag_count',
            'need_decoction', 'bags_per_dose',
        ]);
        $auxUsage = self::scalars(PrescriptionAiPolicy::decode($prescription['aux_usage'] ?? []), [
            'prescription_name', 'dosage_amount', 'dosage_bag_count', 'need_decoction',
            'bags_per_dose', 'times_per_day', 'usage_days',
        ]);
        if ($auxUsage !== []) {
            // Auxiliary formula instructions belong to that formula, never the main usage.
            $rx['aux_usage'] = $auxUsage;
        }
        $rx['herbs'] = [];
        foreach (PrescriptionAiPolicy::decode($prescription['herbs'] ?? []) as $herb) {
            if (!is_array($herb)) {
                continue;
            }
            // Preserve saved row order and duplicates, without costs, stock, IDs or attachments.
            $rx['herbs'][] = self::scalars($herb, [
                'name', 'dosage', 'unit', 'dose_basis', 'formula_type', 'processing',
                'special_usage', 'instructions', 'usage', 'remark',
            ]);
        }
        return [
            'patient' => $patient,
            // The source has one combined clinical diagnosis. Do not invent a Western/TCM split
            // or expose case_record, which may contain other encounters and contact details.
            'diagnosis' => ['clinical_diagnosis' => self::text($prescription['clinical_diagnosis'] ?? null)],
            'prescription' => $rx,
        ];
    }

    private static function scalars(array $row, array $fields): array
    {
        return array_filter(array_intersect_key($row, array_flip($fields)),
            static fn ($value): bool => is_string($value) || is_int($value) || is_float($value));
    }

    private static function text($value): string
    {
        return is_string($value) || is_numeric($value) ? trim((string) $value) : '';
    }
}