<?php

namespace App\Models;

use Carbon\Carbon;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class ActivityDay extends Model
{
    protected $fillable = [
        'activity_id',
        'session_name',
        'activity_date',
        'day_quota',
        'booked_count',
        'opens_at',
        'closes_at',
        'session_start_at',
        'session_end_at',
        'booking_deadline_at',
    ];

    protected $casts = [
        'activity_date' => 'date',
        'opens_at' => 'datetime',
        'closes_at' => 'datetime',
        'session_start_at' => 'datetime',
        'session_end_at' => 'datetime',
        'booking_deadline_at' => 'datetime',
        'day_quota' => 'integer',
        'booked_count' => 'integer',
    ];

    /** 管理端/接口序列化时附带，与 H5 中 `time_range_text` 一致 */
    protected $appends = ['time_range_text'];

    public function getTimeRangeTextAttribute(): string
    {
        return $this->formatSessionTimeRangeZh();
    }

    protected static function booted(): void
    {
        static::saving(function (ActivityDay $day) {
            if ($day->session_start_at) {
                $tz = (string) config('app.timezone');
                $day->activity_date = $day->session_start_at->copy()->timezone($tz)->format('Y-m-d');
            }
        });
    }

    public function activity(): BelongsTo
    {
        return $this->belongsTo(Activity::class);
    }

    /**
     * 场次时间段展示：同日则「Y年m月d日 H:i-H:i」。
     */
    public function formatSessionTimeRangeZh(): string
    {
        if (!$this->session_start_at || !$this->session_end_at) {
            return $this->activity_date?->format('Y年m月d日') ?? '';
        }
        $tz = (string) config('app.timezone');
        $s = $this->session_start_at->copy()->timezone($tz);
        $e = $this->session_end_at->copy()->timezone($tz);
        if ($s->toDateString() === $e->toDateString()) {
            return $s->format('Y年m月d日 H:i') . '-' . $e->format('H:i');
        }

        return $s->format('Y年m月d日 H:i') . ' ~ ' . $e->format('Y年m月d日 H:i');
    }

    public function isSessionMode(): bool
    {
        return $this->session_start_at !== null
            && $this->session_end_at !== null
            && $this->booking_deadline_at !== null;
    }

    /**
     * 当前时刻是否可预约：截止前、有余量、未重复预约等由业务层与 H5 数组字段共同约束。
     * 这里仅表示「未过预约截止且有余量」（legacy 为原 opens/closes 窗口逻辑）。
     */
    public function isCurrentlyBookable(): bool
    {
        $available = max(0, (int) $this->day_quota - (int) $this->booked_count);
        if ($available <= 0) {
            return false;
        }

        if ($this->isSessionMode()) {
            return now()->lte($this->booking_deadline_at);
        }

        $closesAt = $this->closes_at ?: $this->opens_at?->copy()->endOfDay();
        $now = now();
        if (!$this->opens_at || !$closesAt) {
            return false;
        }
        $isOpenWindow = $this->opens_at->lte($now) && $closesAt->gte($now);

        return $isOpenWindow;
    }

    /**
     * H5 预约页/活动详情：单场次展示与可约态。
     *
     * @return array<string, mixed>
     */
    public function toH5BookingDayArray(bool $alreadyReserved = false): array
    {
        $available = max(0, (int) $this->day_quota - (int) $this->booked_count);
        $now = now();
        $enrolledCountText = '已报名数：' . (int) $this->booked_count;
        $bookedPeopleText = '已约' . (int) $this->booked_count . '人';

        if ($this->isSessionMode()) {
            $deadline = $this->booking_deadline_at;
            $unavailableReason = null;
            $isBookable = false;
            if ($alreadyReserved) {
                $unavailableReason = 'already_reserved';
                $actionHeadline = '已预约';
                $statusText = '已约';
                $statusKind = 'reserved';
            } elseif (! $deadline) {
                $unavailableReason = 'closed';
                $actionHeadline = '预约已结束';
                $statusText = '预约已结束';
                $statusKind = 'closed';
            } elseif ($now->gt($deadline)) {
                $unavailableReason = 'deadline_passed';
                $actionHeadline = '预约已结束';
                $statusText = '已约' . (int) $this->booked_count . '人';
                $statusKind = 'booked_info';
            } elseif ($available <= 0) {
                $unavailableReason = 'sold_out';
                $actionHeadline = '预约已满';
                $statusText = '预约已满';
                $statusKind = 'full';
            } else {
                $isBookable = true;
                $unavailableReason = null;
                $actionHeadline = '立即预约';
                $statusText = '已约' . (int) $this->booked_count . '人';
                $statusKind = 'open';
            }
            $timeDisplay = $this->formatSessionTimeRangeZh();
        } else {
            // legacy：无场次字段时沿用原预约窗口
            $timeDisplay = $this->activity_date?->format('Y年m月d日') ?? '';
            if ($alreadyReserved) {
                $unavailableReason = 'already_reserved';
                $actionHeadline = '已预约';
                $statusText = '已约';
                $statusKind = 'reserved';
            } elseif ($available <= 0) {
                $unavailableReason = 'sold_out';
                $actionHeadline = '预约已满';
                $statusText = '预约已满';
                $statusKind = 'full';
            } else {
                $closesAt = $this->closes_at ?: $this->opens_at?->copy()->endOfDay();
                if ($this->opens_at && $this->opens_at->gt($now)) {
                    $unavailableReason = 'not_started';
                    $actionHeadline = '未开放';
                    $statusText = '未开放';
                    $statusKind = 'closed';
                } elseif ($closesAt && $closesAt->lt($now)) {
                    $unavailableReason = 'closed';
                    $actionHeadline = '预约已结束';
                    $statusText = '不可预约';
                    $statusKind = 'closed';
                } else {
                    $unavailableReason = null;
                    $actionHeadline = '立即预约';
                    $statusText = '已约' . (int) $this->booked_count . '人';
                    $statusKind = 'open';
                }
            }
            $isBookable = $this->isCurrentlyBookable() && ! $alreadyReserved;
        }

        if ($alreadyReserved) {
            $isBookable = false;
        }

        $closesAtLegacy = $this->closes_at ?: $this->opens_at?->copy()->endOfDay();
        $isOpenWindow = $this->opens_at && $closesAtLegacy
            ? ($this->opens_at->lte($now) && $closesAtLegacy->gte($now))
            : false;

        return [
            'id' => $this->id,
            'session_name' => (string) ($this->session_name ?? ''),
            'session_start_at' => $this->session_start_at?->format('Y-m-d H:i:s'),
            'session_end_at' => $this->session_end_at?->format('Y-m-d H:i:s'),
            'booking_deadline_at' => $this->booking_deadline_at?->format('Y-m-d H:i:s'),
            'time_display' => $timeDisplay,
            'activity_date' => $this->activity_date?->format('Y-m-d'),
            'opens_at' => $this->opens_at?->format('Y-m-d H:i:s'),
            'closes_at' => $closesAtLegacy?->format('Y-m-d H:i:s'),
            'day_quota' => (int) $this->day_quota,
            'booked_count' => (int) $this->booked_count,
            'available_count' => $available,
            'is_open' => $isOpenWindow,
            'is_bookable' => $isBookable,
            'unavailable_reason' => $unavailableReason,
            'status_text' => $statusText,
            'status_kind' => $statusKind,
            'already_reserved' => $alreadyReserved,
            'action_headline' => $actionHeadline,
            'enrolled_count_text' => $enrolledCountText,
            'booked_people_text' => $bookedPeopleText,
        ];
    }
}