<?php

namespace App\Services\Reports;

use App\Domain\Reports\ValueObjects\MetrikaConfig;
use App\Models\Department;
use App\Models\DutyReportMetricResult;
use App\Models\DutyUnwantedEvent;
use App\Models\ReportDuty;
use App\Models\ReportDutyPatient;
use App\Models\ReportNurse;
use App\Models\ReportNursePatient;
use App\Services\DateRange;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use InvalidArgumentException;

/**
 * Реестр источников данных для отчётов. Каждый источник умеет вернуть набор строк
 * по отделению и периоду — на этих же источниках строятся и встроенные отчёты
 * (дежурный врач / старшая медсестра), и пользовательские шаблоны из конструктора.
 */
class ReportSourceRegistry
{
    private const URGENCY_OPTIONS = [1 => 'Планово', 2 => 'Экстренно'];

    /** @var array<string,ReportSource> */
    private array $sources;

    public function __construct()
    {
        $this->sources = [
            'duty_metrics' => $this->dutyMetricsSource(),
            'duty_patients' => $this->dutyPatientsSource(),
            'nurse_patients' => $this->nursePatientsSource(),
            'unwanted_events' => $this->unwantedEventsSource(),
            'observable_patients' => $this->observablePatientsSource(),
        ];
    }

    /** @return array<string,ReportSource> */
    public function all(): array
    {
        return $this->sources;
    }

    public function get(string $key): ReportSource
    {
        if (! isset($this->sources[$key])) {
            throw new InvalidArgumentException("Неизвестный источник отчёта: {$key}");
        }

        return $this->sources[$key];
    }

    /**
     * Сданные дежурные отчёты отделения, пересекающиеся с периодом.
     */
    public function dutyReports(Department $department, DateRange $dateRange): Collection
    {
        return ReportDuty::where('rf_department_id', $department->department_id)
            ->withinPeriod($dateRange->startSql(), $dateRange->endSql())
            ->onlySubmitted()
            ->orderBy('period_end')
            ->get();
    }

    /**
     * Сданные отчёты (журналы) медсестры отделения, пересекающиеся с периодом.
     */
    public function nurseReports(Department $department, DateRange $dateRange): Collection
    {
        return ReportNurse::where('rf_department_id', $department->department_id)
            ->where('status_id', 2)
            ->where('period_end', '>=', $dateRange->startSql())
            ->where('period_start', '<=', $dateRange->endSql())
            ->orderBy('period_end')
            ->get();
    }

    private function dutyMetricsSource(): ReportSource
    {
        $columns = [
            'period' => 'Период',
            'beds' => 'Коек',
            'recipient_plan' => 'Поступило плановых',
            'recipient_emergency' => 'Поступило экстренных',
            'discharged' => 'Выписано',
            'transferred' => 'Переведено',
            'deceased' => 'Умерло',
            'occupancy_percent' => 'Занятость, %',
            'avg_bed_days' => 'Ср. койко-день',
            'lethality_percent' => 'Летальность, %',
            'surgery_plan' => 'Операции плановые',
            'surgery_emergency' => 'Операции экстренные',
            'staff_count' => 'Мед. персонал',
        ];

        $metricMap = [
            'beds' => MetrikaConfig::BEDS,
            'recipient_plan' => MetrikaConfig::PLAN,
            'recipient_emergency' => MetrikaConfig::EMERGENCY,
            'discharged' => MetrikaConfig::DISCHARGED,
            'transferred' => MetrikaConfig::TRANSFERRED,
            'deceased' => MetrikaConfig::DECEASED,
            'occupancy_percent' => MetrikaConfig::DEPARTMENT_LOADED,
            'avg_bed_days' => MetrikaConfig::AVERAGE_BED_DAYS,
            'lethality_percent' => MetrikaConfig::LETHALITY,
            'surgery_plan' => MetrikaConfig::PLAN_SURGERY,
            'surgery_emergency' => MetrikaConfig::EMERGENCY_SURGERY,
            'staff_count' => MetrikaConfig::STAFF_COUNT,
        ];

        $resolver = function (Department $department, DateRange $dateRange, array $columns) use ($metricMap) {
            $reports = $this->dutyReports($department, $dateRange);

            if ($reports->isEmpty()) {
                return [];
            }

            $values = DutyReportMetricResult::whereIn('rf_report_id', $reports->pluck('id'))
                ->get(['rf_report_id', 'rf_metrika_item_id', 'value'])
                ->groupBy('rf_report_id');

            $rows = [];
            foreach ($reports as $report) {
                $byMetric = ($values->get($report->id) ?? collect())->pluck('value', 'rf_metrika_item_id');

                $row = [];
                foreach ($columns as $key) {
                    if ($key === 'period') {
                        $row[$key] = $report->period_start?->format('d.m.Y H:i').' — '.$report->period_end?->format('d.m.Y H:i');

                        continue;
                    }

                    $metricId = $metricMap[$key] ?? null;
                    $row[$key] = $metricId !== null ? ($byMetric->get($metricId) ?? 0) : null;
                }

                $rows[] = $row;
            }

            return $rows;
        };

        return new ReportSource('duty_metrics', 'Показатели смены (дежурный врач)', $columns, [], $resolver);
    }

    private function patientColumns(): array
    {
        return [
            'full_name' => 'ФИО',
            'birth_date' => 'Дата рождения',
            'medical_card_number' => '№ карты',
            'recipient_date' => 'Дата поступления',
            'extract_date' => 'Дата выбытия',
            'diagnosis_code' => 'Код диагноза',
            'diagnosis_name' => 'Диагноз',
            'urgency' => 'Срочность',
            'outcome' => 'Исход',
        ];
    }

    private function patientFilterableFields(): array
    {
        return [
            'urgency_id' => ['label' => 'Срочность', 'options' => self::URGENCY_OPTIONS],
            'visit_result_id' => ['label' => 'Код исхода', 'options' => null],
        ];
    }

    private function dutyPatientsSource(): ReportSource
    {
        $columns = $this->patientColumns();
        $filterable = $this->patientFilterableFields();

        $resolver = function (Department $department, DateRange $dateRange, array $columns, array $filters) {
            $reportIds = $this->dutyReports($department, $dateRange)->pluck('id');

            if ($reportIds->isEmpty()) {
                return [];
            }

            $query = ReportDutyPatient::whereIn('report_duty_id', $reportIds)->with('latestMigration');
            $this->applyEqualityFilters($query, $filters, ['urgency_id', 'visit_result_id']);

            return $query->get()->map(fn ($patient) => $this->mapPatientRow($patient, $columns))->all();
        };

        return new ReportSource('duty_patients', 'Пациенты (дежурный врач)', $columns, $filterable, $resolver);
    }

    private function nursePatientsSource(): ReportSource
    {
        $columns = $this->patientColumns();
        $filterable = $this->patientFilterableFields();

        $resolver = function (Department $department, DateRange $dateRange, array $columns, array $filters) {
            $reportIds = $this->nurseReports($department, $dateRange)->pluck('id');

            if ($reportIds->isEmpty()) {
                return [];
            }

            $query = ReportNursePatient::whereIn('report_nurse_id', $reportIds)->with('latestMigration');
            $this->applyEqualityFilters($query, $filters, ['urgency_id', 'visit_result_id']);

            return $query->get()->map(fn ($patient) => $this->mapPatientRow($patient, $columns))->all();
        };

        return new ReportSource('nurse_patients', 'Журнал пациентов (старшая медсестра)', $columns, $filterable, $resolver);
    }

    private function unwantedEventsSource(): ReportSource
    {
        $columns = [
            'title' => 'Событие',
            'comment' => 'Комментарий',
            'created_at' => 'Дата',
        ];

        $resolver = function (Department $department, DateRange $dateRange) {
            $reportIds = $this->dutyReports($department, $dateRange)->pluck('id');

            if ($reportIds->isEmpty()) {
                return [];
            }

            return DutyUnwantedEvent::whereIn('report_duty_id', $reportIds)->get()
                ->map(fn ($event) => [
                    'title' => $event->title,
                    'comment' => $event->comment,
                    'created_at' => $event->created_at?->format('d.m.Y H:i'),
                ])->all();
        };

        return new ReportSource('unwanted_events', 'Нежелательные события', $columns, [], $resolver);
    }

    private function observablePatientsSource(): ReportSource
    {
        $columns = [
            'full_name' => 'ФИО',
            'birth_date' => 'Дата рождения',
            'observable_in' => 'Начало наблюдения',
            'observable_out' => 'Конец наблюдения',
            'observable_reason' => 'Причина',
        ];

        $resolver = function (Department $department, DateRange $dateRange) {
            $reportIds = $this->dutyReports($department, $dateRange)->pluck('id');

            if ($reportIds->isEmpty()) {
                return [];
            }

            return DB::table('observable_medical_histories as omh')
                ->join('report_duty_patients as rdp', 'rdp.original_id', '=', 'omh.original_id')
                ->whereIn('rdp.report_duty_id', $reportIds)
                ->where('omh.observable_in', '>=', $dateRange->startSql())
                ->where('omh.observable_in', '<=', $dateRange->endSql())
                ->select('omh.full_name', 'omh.birth_date', 'omh.observable_in', 'omh.observable_out', 'omh.observable_reason')
                ->distinct()
                ->get()
                ->map(fn ($row) => [
                    'full_name' => $row->full_name,
                    'birth_date' => $this->formatDate($row->birth_date, 'd.m.Y'),
                    'observable_in' => $this->formatDate($row->observable_in, 'd.m.Y H:i'),
                    'observable_out' => $this->formatDate($row->observable_out, 'd.m.Y H:i'),
                    'observable_reason' => $row->observable_reason,
                ])->all();
        };

        return new ReportSource('observable_patients', 'Пациенты на контроле', $columns, [], $resolver);
    }

    private function mapPatientRow(ReportDutyPatient|ReportNursePatient $patient, array $columns): array
    {
        $migration = $patient->latestMigration;

        $row = [];
        foreach ($columns as $key) {
            $row[$key] = match ($key) {
                'full_name' => $patient->full_name,
                'birth_date' => $patient->birth_date?->format('d.m.Y'),
                'medical_card_number' => $patient->medical_card_number,
                'recipient_date' => $patient->recipient_date?->format('d.m.Y H:i'),
                'extract_date' => $patient->extract_date?->format('d.m.Y H:i'),
                'diagnosis_code' => $migration?->diagnosis_code,
                'diagnosis_name' => $migration?->diagnosis_name,
                'urgency' => self::URGENCY_OPTIONS[(int) $patient->urgency_id] ?? '—',
                'outcome' => $this->outcomeLabel($patient),
                default => null,
            };
        }

        return $row;
    }

    private function outcomeLabel(ReportDutyPatient|ReportNursePatient $patient): string
    {
        if ($patient->death_date) {
            return 'Умер';
        }

        if (in_array((int) $patient->visit_result_id, [4, 14], true)) {
            return 'Переведён';
        }

        if ($patient->extract_date) {
            return 'Выписан';
        }

        return 'В отделении';
    }

    /**
     * @param  array<int,array{field:string,value:mixed}>  $filters
     * @param  array<int,string>  $allowedFields  allow-list полей источника — защита от произвольных имён колонок
     */
    private function applyEqualityFilters(Builder $query, array $filters, array $allowedFields): void
    {
        foreach ($filters as $filter) {
            $field = $filter['field'] ?? null;
            $value = $filter['value'] ?? null;

            if ($field === null || $value === null || $value === '' || ! in_array($field, $allowedFields, true)) {
                continue;
            }

            $query->where($field, $value);
        }
    }

    private function formatDate(?string $value, string $format): ?string
    {
        return $value ? Carbon::parse($value)->format($format) : null;
    }
}