<?php
declare(strict_types=1);

namespace app\smt\service;

use DateInterval;
use DateTimeImmutable;
use DateTimeInterface;
use DateTimeZone;

final class Support
{
    public const DATE_LAYOUT = 'Y-m-d';
    public const DATETIME_LAYOUT = 'Y-m-d H:i:s';

    public static function tz(): DateTimeZone
    {
        return new DateTimeZone((string) config('app.default_timezone', 'Asia/Shanghai'));
    }

    public static function now(): DateTimeImmutable
    {
        return new DateTimeImmutable('now', self::tz());
    }

    public static function dateOnly($value = null): DateTimeImmutable
    {
        $dt = self::toDateTime($value);
        return $dt->setTime(0, 0, 0);
    }

    public static function parseDate(?string $value, string $field = 'date'): ?DateTimeImmutable
    {
        $text = trim((string) $value);
        if ($text === '') {
            return null;
        }

        $dt = DateTimeImmutable::createFromFormat(self::DATE_LAYOUT, $text, self::tz());
        if (!$dt || $dt->format(self::DATE_LAYOUT) !== $text) {
            throw new \RuntimeException(sprintf('%s 格式错误，应为 YYYY-MM-DD', $field), 400);
        }

        return $dt->setTime(0, 0, 0);
    }

    public static function parseDateTime(?string $value, string $field = 'datetime'): ?DateTimeImmutable
    {
        $text = trim((string) $value);
        if ($text === '') {
            return null;
        }

        $dt = DateTimeImmutable::createFromFormat(self::DATETIME_LAYOUT, $text, self::tz());
        if ($dt && $dt->format(self::DATETIME_LAYOUT) === $text) {
            return $dt;
        }

        try {
            return (new DateTimeImmutable($text))->setTimezone(self::tz());
        } catch (\Throwable $e) {
            throw new \RuntimeException(sprintf('%s 格式错误，应为 YYYY-MM-DD HH:MM:SS 或 RFC3339', $field), 400);
        }
    }

    public static function toDateTime($value): DateTimeImmutable
    {
        if ($value instanceof DateTimeImmutable) {
            return $value->setTimezone(self::tz());
        }

        if ($value instanceof DateTimeInterface) {
            return (new DateTimeImmutable($value->format(DateTimeInterface::ATOM)))->setTimezone(self::tz());
        }

        if (is_int($value)) {
            return (new DateTimeImmutable('@' . $value))->setTimezone(self::tz());
        }

        if (is_numeric($value) && (string) (int) $value === (string) $value) {
            return (new DateTimeImmutable('@' . (int) $value))->setTimezone(self::tz());
        }

        $text = trim((string) $value);
        if ($text === '') {
            return self::now();
        }

        if (preg_match('/^\d{4}-\d{2}-\d{2}$/', $text)) {
            return new DateTimeImmutable($text . ' 00:00:00', self::tz());
        }

        return (new DateTimeImmutable($text, self::tz()))->setTimezone(self::tz());
    }

    public static function toDbDate($value): ?string
    {
        if ($value === null || trim((string) $value) === '') {
            return null;
        }

        return self::dateOnly($value)->format(self::DATE_LAYOUT);
    }

    public static function toDbDateTime($value): ?string
    {
        if ($value === null || trim((string) $value) === '') {
            return null;
        }

        return self::toDateTime($value)->format(self::DATETIME_LAYOUT);
    }

    public static function formatRfc3339($value): string
    {
        if ($value === null || trim((string) $value) === '') {
            return '';
        }

        return self::toDateTime($value)->format(DateTimeInterface::RFC3339);
    }

    public static function formatClock($value): string
    {
        if ($value === null || trim((string) $value) === '') {
            return '';
        }

        return self::toDateTime($value)->format('H:i');
    }

    public static function parseHHMM(string $value): int
    {
        $text = trim($value);
        if (!preg_match('/^\d{2}:\d{2}$/', $text)) {
            throw new \RuntimeException('作息时间格式错误，应为 HH:MM', 400);
        }

        [$hour, $minute] = array_map('intval', explode(':', $text));
        if ($hour < 0 || $hour > 23 || $minute < 0 || $minute > 59) {
            throw new \RuntimeException('作息时间格式错误，应为 HH:MM', 400);
        }

        return $hour * 60 + $minute;
    }

    public static function awakeMinutes(string $wakeUpTime, string $sleepTime): int
    {
        $wake = trim($wakeUpTime);
        $sleep = trim($sleepTime);
        if ($wake === '' || $sleep === '') {
            return 16 * 60;
        }

        $wakeMin = self::parseHHMM($wake);
        $sleepMin = self::parseHHMM($sleep);
        if ($wakeMin === $sleepMin) {
            return 24 * 60;
        }

        if ($sleepMin > $wakeMin) {
            return $sleepMin - $wakeMin;
        }

        return (24 * 60 - $wakeMin) + $sleepMin;
    }

    public static function baselineIntervalMinutes(int $awakeMinutes, int $baselineCigsPerDay): int
    {
        if ($awakeMinutes <= 0 || $baselineCigsPerDay <= 0) {
            return 0;
        }

        return max(1, intdiv($awakeMinutes, $baselineCigsPerDay));
    }

    public static function normalizedMode(?string $mode): string
    {
        $value = trim((string) $mode);
        return $value === 'quit' ? 'quit' : 'record';
    }

    public static function jsonArray($value): array
    {
        if (is_array($value)) {
            return array_values(array_filter(array_map(function ($item) {
                return trim((string) $item);
            }, $value), static function ($item) {
                return $item !== '';
            }));
        }

        if ($value === null || $value === '') {
            return [];
        }

        $decoded = json_decode((string) $value, true);
        return is_array($decoded) ? self::jsonArray($decoded) : [];
    }

    public static function jsonEncodeArray(array $items): string
    {
        return json_encode(self::jsonArray($items), JSON_UNESCAPED_UNICODE);
    }

    public static function formatLog(array $row): array
    {
        return [
            'id' => (int) ($row['id'] ?? 0),
            'smoke_time' => self::formatRfc3339($row['smoke_time'] ?? null),
            'smoke_at' => self::formatRfc3339($row['smoke_at'] ?? null),
            'remark' => (string) ($row['remark'] ?? ''),
            'reason_tags' => self::jsonArray($row['reason_tags'] ?? []),
            'createtime' => isset($row['createtime']) ? (int) $row['createtime'] : 0,
            'updatetime' => isset($row['updatetime']) ? (int) $row['updatetime'] : 0,
            'deletetime' => isset($row['deletetime']) && $row['deletetime'] !== null ? (int) $row['deletetime'] : null,
            'level' => (int) ($row['level'] ?? 1),
            'num' => (int) ($row['num'] ?? 1),
        ];
    }

    public static function logEventAt(array $row): ?DateTimeImmutable
    {
        if (!empty($row['smoke_at'])) {
            return self::toDateTime($row['smoke_at']);
        }

        if (!empty($row['createtime'])) {
            return self::toDateTime((int) $row['createtime']);
        }

        if (!empty($row['smoke_time'])) {
            return self::dateOnly($row['smoke_time']);
        }

        return null;
    }

    public static function weekRange(DateTimeImmutable $anchor): array
    {
        $weekday = (int) $anchor->format('N');
        $start = self::dateOnly($anchor)->sub(new DateInterval('P' . ($weekday - 1) . 'D'));
        return [$start, $start->add(new DateInterval('P6D'))];
    }

    public static function daysBetweenInclusive(DateTimeImmutable $start, DateTimeImmutable $end): int
    {
        $start = self::dateOnly($start);
        $end = self::dateOnly($end);
        if ($end < $start) {
            return 0;
        }

        return (int) $start->diff($end)->days + 1;
    }

    public static function maskNickname(string $value): string
    {
        $text = trim($value);
        if ($text === '') {
            return '戒烟用户';
        }

        $length = mb_strlen($text);
        if ($length <= 1) {
            return '戒烟用户';
        }
        if ($length === 2) {
            return mb_substr($text, 0, 1) . '*';
        }

        return mb_substr($text, 0, 1) . str_repeat('*', $length - 2) . mb_substr($text, -1);
    }

    public static function deriveUserSegment(int $baselineCigsPerDay, float $smokingYears): string
    {
        if ($baselineCigsPerDay >= 20 || $smokingYears >= 10) {
            return 'heavy';
        }
        if ($baselineCigsPerDay >= 10 || $smokingYears >= 3) {
            return 'moderate';
        }

        return 'newbie';
    }

    public static function truncate(string $value, int $max): string
    {
        if ($max <= 0 || mb_strlen($value) <= $max) {
            return $value;
        }

        return mb_substr($value, 0, $max);
    }
}