<?php

namespace App\Services;

use Illuminate\Support\Facades\DB;

/**
 * 号源计划服务类
 * 处理号源查询、可用号源查找等业务逻辑
 */
class PlanService
{
    /**
     * 查询医嘱的共同资源ID数组
     *
     * @param array $examApplicationIds 医嘱ID数组
     * @return array 共同资源ID数组，没有共同资源返回空数组
     */
    public function getCommonResourceIds(array $examApplicationIds): array
    {
        // 1. 查询医嘱的检查项目代码
        $itemCodes = DB::table('exam_application')
            ->whereIn('id', $examApplicationIds)
            ->where('deleted', 0)
            ->pluck('examination_item_code')
            ->unique()
            ->toArray();

        if (empty($itemCodes)) {
            return [];
        }

        // 2. 查询检查项目ID
        $examItemIds = DB::table('exam_item')
            ->whereIn('code', $itemCodes)
            ->where('deleted', 0)
            ->pluck('id')
            ->toArray();

        if (empty($examItemIds)) {
            return [];
        }

        // 3. 查询项目-资源关联
        $itemResources = DB::table('exam_item_resource')
            ->whereIn('item_id', $examItemIds)
            ->where('deleted', 0)
            ->select('item_id', 'resource_id')
            ->get();

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

        // 4. 按 item_id 分组资源
        $resourcesByItem = [];
        foreach ($itemResources as $ir) {
            $resourcesByItem[$ir->item_id][] = $ir->resource_id;
        }

        // 5. 计算所有项目的资源交集
        if (count($resourcesByItem) === 1) {
            return reset($resourcesByItem);
        } else {
            return array_values(call_user_func_array('array_intersect', array_values($resourcesByItem)));
        }
    }

    /**
     * 计算医嘱的总占位数
     *
     * @param array $examApplicationIds 医嘱ID数组
     * @return int 总占位数
     */
    public function calculateTotalSeats(array $examApplicationIds): int
    {
        $itemCodes = DB::table('exam_application')
            ->whereIn('id', $examApplicationIds)
            ->where('deleted', 0)
            ->pluck('examination_item_code')
            ->unique()
            ->toArray();

        if (empty($itemCodes)) {
            return 0;
        }

        $useSeatsByItemCode = DB::table('exam_item')
            ->whereIn('code', $itemCodes)
            ->where('deleted', 0)
            ->pluck('use_seats', 'code')
            ->toArray();

        $applications = DB::table('exam_application')
            ->whereIn('id', $examApplicationIds)
            ->where('deleted', 0)
            ->select('examination_item_code')
            ->get();

        $totalSeats = 0;
        foreach ($applications as $app) {
            $useSeats = $useSeatsByItemCode[$app->examination_item_code] ?? 1;
            $totalSeats += $useSeats;
        }

        return $totalSeats;
    }

    /**
     * 查询号源批次数据（GetEnablePlan、GetPlanCalendar 和 findEarliestAvailableSlot 的公共逻辑）
     *
     * @param array $examApplicationIds 医嘱ID数组
     * @param int $channelId 渠道ID
     * @param string $startDate 开始日期
     * @param int $days 查询天数
     * @param array|null $dates 指定日期数组，传入时忽略 startDate 和 days
     * @return array
     * @throws \Exception
     */
    public function queryPlanBatchesData(array $examApplicationIds, int $channelId, string $startDate, int $days = 15, ?array $dates = null): array
    {
        // 1. 查询医嘱信息
        $examApplications = DB::table('exam_application')
            ->whereIn('id', $examApplicationIds)
            ->select('id', 'patient_id', 'patient_type', 'examination_item_code', 'examination_item_name')
            ->get();

        if ($examApplications->isEmpty()) {
            throw new \Exception('医嘱不存在');
        }

        // 2. 获取所有检查项目代码
        $itemCodes = $examApplications->pluck('examination_item_code')->unique()->toArray();

        // 3. 查询检查项目
        $examItems = DB::table('exam_item')
            ->whereIn('code', $itemCodes)
            ->where('deleted', 0)
            ->select('id', 'code', 'name', 'use_seats')
            ->get();

        if ($examItems->isEmpty()) {
            throw new \Exception('检查项目不存在');
        }

        $examItemIds = $examItems->pluck('id')->toArray();

        // 4. 建立 use_seats 映射
        $useSeatsByItemCode = [];
        foreach ($examItems as $item) {
            $useSeatsByItemCode[$item->code] = $item->use_seats ?? 1;
        }

        // 5. 计算所有项目的总占位数
        $totalUseSeats = 0;
        foreach ($examApplications as $app) {
            $useSeats = $useSeatsByItemCode[$app->examination_item_code] ?? 1;
            $totalUseSeats += $useSeats;
        }

        // 6. 查询项目-资源关联
        $itemResources = DB::table('exam_item_resource')
            ->whereIn('item_id', $examItemIds)
            ->where('deleted', 0)
            ->select('item_id', 'resource_id')
            ->get();

        if ($itemResources->isEmpty()) {
            throw new \Exception('检查项目未关联资源');
        }

        // 7. 按 item_id 分组资源
        $resourcesByItem = [];
        foreach ($itemResources as $ir) {
            $resourcesByItem[$ir->item_id][] = $ir->resource_id;
        }

        // 8. 计算所有项目的资源交集
        if (count($resourcesByItem) === 1) {
            $commonResourceIds = reset($resourcesByItem);
        } else {
            $commonResourceIds = array_values(call_user_func_array('array_intersect', array_values($resourcesByItem)));
        }

        if (empty($commonResourceIds)) {
            throw new \Exception('这些医嘱项目没有共同可用的资源');
        }

        // 9. 计算 patient_type 交集（位掩码 AND）
        $patientTypes = $examApplications->pluck('patient_type')->unique()->toArray();
        $commonPatientTypeMask = array_reduce($patientTypes, function ($carry, $type) {
            return $carry === null ? $type : ($carry & $type);
        }, null);

        if ($commonPatientTypeMask === 0) {
            throw new \Exception('医嘱患者类型无共同支持的号源类型');
        }

        // 10. 生成日期范围
        if ($dates === null) {
            $dates = [];
            for ($i = 0; $i < $days; $i++) {
                $dates[] = date('Y-m-d', strtotime($startDate . ' +' . $i . ' days'));
            }
        }

        // 11. 查询符合条件的号源批次
        $planBatches = DB::table('plan_batch')
            ->leftJoin('department_resource', 'plan_batch.resource_id', '=', 'department_resource.id')
            ->whereIn('plan_batch.resource_id', $commonResourceIds)
            ->whereIn('plan_batch.plan_date', $dates)
            ->where('plan_batch.deleted', 0)
            ->where('plan_batch.status', 1)
            ->where(function ($query) use ($commonPatientTypeMask) {
                $query->whereNull('plan_batch.patient_type_mask')
                    ->orWhereRaw('(plan_batch.patient_type_mask & ?) != 0', [$commonPatientTypeMask]);
            })
            ->select(
                'plan_batch.id as batch_id',
                'plan_batch.resource_id',
                'department_resource.name as resource_name',
                'department_resource.slot_mode',
                'plan_batch.plan_date',
                'plan_batch.start_time',
                'plan_batch.end_time',
                'plan_batch.cutoff_time',
                'plan_batch.total_quota',
                'plan_batch.used_quota',
                'plan_batch.slot_mode',
                'plan_batch.enable_channel_quota'
            )
            ->orderBy('plan_batch.plan_date')
            ->orderBy('plan_batch.start_time')
            ->get();

        if ($planBatches->isEmpty()) {
            return [
                'planBatches' => $planBatches,
                'quotaByBatch' => [],
                'totalUseSeats' => $totalUseSeats,
                'commonResourceIds' => $commonResourceIds,
                'commonPatientTypeMask' => $commonPatientTypeMask
            ];
        }

        // 12. 批量预加载渠道配额
        $allBatchIds = $planBatches->pluck('batch_id')->toArray();
        $channelQuotaRecords = DB::table('plan_batch_channel_quota')
            ->whereIn('batch_id', $allBatchIds)
            ->whereIn('channel_id', [$channelId, -1])
            ->where(['deleted' => 0, 'status' => 1])
            ->select('batch_id', 'channel_id', 'total_quota', 'used_quota', 'locked_quota', 'allow_overuse_public_pool')
            ->get();

        $quotaByBatch = [];
        foreach ($channelQuotaRecords as $record) {
            if (!isset($quotaByBatch[$record->batch_id])) {
                $quotaByBatch[$record->batch_id] = ['public' => null, 'channel' => null];
            }
            if ($record->channel_id == -1) {
                $quotaByBatch[$record->batch_id]['public'] = $record;
            } elseif ($record->channel_id == $channelId) {
                $quotaByBatch[$record->batch_id]['channel'] = $record;
            }
        }

        return [
            'planBatches' => $planBatches,
            'quotaByBatch' => $quotaByBatch,
            'totalUseSeats' => $totalUseSeats,
            'commonResourceIds' => $commonResourceIds,
            'commonPatientTypeMask' => $commonPatientTypeMask
        ];
    }

    /**
     * 从批次数组中查找最早的可用号源
     *
     * @param \Illuminate\Support\Collection $planBatches 号源批次数组
     * @param array $quotaByBatch 批次配额映射
     * @param int $requiredSeats 需要的占位数
     * @param int $channelId 渠道ID
     * @return array|null 最早可用号源信息
     */
    public function findEarliestSlot($planBatches, array $quotaByBatch, int $requiredSeats, int $channelId): ?array
    {
        $now = now();
        $currentDate = $now->format('Y-m-d');

        foreach ($planBatches as $batch) {
            // 跳过今天之前的日期
            if ($batch->plan_date < $currentDate) {
                continue;
            }

            // 判断是否超过截止时间
            $isPastCutoff = ($batch->plan_date === $currentDate) &&
                $now->gt(\Carbon\Carbon::createFromFormat('Y-m-d H:i:s', $batch->plan_date . ' ' . $batch->cutoff_time));

            if ($isPastCutoff) {
                continue;
            }

            // 获取配额信息
            $quotas = $quotaByBatch[$batch->batch_id] ?? ['public' => null, 'channel' => null];
            $publicQuota = $quotas['public'];
            $channelQuota = $quotas['channel'];
            $slotMode = $batch->slot_mode;

            // 检查配额
            $remainingQuota = $this->calculateRemainingQuota($batch, $channelId, $channelQuota, $publicQuota, $requiredSeats);

            if ($remainingQuota >= $requiredSeats) {
                // 配额充足，查询 plan 记录
                $planRecord = null;

                if ($slotMode == 1) {
                    // 时间段模式：只有1条 plan 记录
                    $planRecord = DB::table('plan')
                        ->where('batch_id', $batch->batch_id)
                        ->where('deleted', 0)
                        ->select('id', 'start_time', 'total_quota', 'used_quota')
                        ->first();
                } else {
                    // 时间点模式：找最早的时间点
                    $planRecord = DB::table('plan')
                        ->where('batch_id', $batch->batch_id)
                        ->where('status', 1)
                        ->where('deleted', 0)
                        ->orderBy('start_time')
                        ->select('id', 'start_time', 'total_quota', 'used_quota')
                        ->first();

                    // 时间点模式需要额外检查时间点是否过期
                    if ($planRecord && $batch->plan_date === $currentDate) {
                        $tpStartTime = \Carbon\Carbon::createFromFormat('Y-m-d H:i:s', $batch->plan_date . ' ' . $planRecord->start_time);
                        $isTimeExpired = $now->gt($tpStartTime);
                        if ($isTimeExpired) {
                            continue;
                        }
                    }
                }

                if ($planRecord) {
                    return [
                        'plan_id' => $planRecord->id,
                        'batch_id' => $batch->batch_id,
                        'resource_id' => $batch->resource_id,
                        'resource_name' => $batch->resource_name,
                        'plan_date' => $batch->plan_date,
                        'start_time' => $planRecord->start_time ?? $batch->start_time,
                        'end_time' => $batch->end_time,
                        'slot_mode' => $slotMode,
                        'total_quota' => $batch->total_quota,
                        'remaining_quota' => $remainingQuota,
                        'required_seats' => $requiredSeats
                    ];
                }
            }
        }

        return null;
    }

    /**
     * 查找指定医嘱的最早可用号源（封装方法）
     *
     * @param array $examApplicationIds 医嘱ID数组
     * @param int $channelId 渠道ID
     * @param string $startDate 开始日期
     * @param int $days 查询天数
     * @return array|null 最早可用号源信息，无可用号源返回null
     */
    public function findEarliestAvailableSlot(array $examApplicationIds, int $channelId, string $startDate, int $days = 15): ?array
    {
        try {
            $data = $this->queryPlanBatchesData($examApplicationIds, $channelId, $startDate, $days);
            return $this->findEarliestSlot($data['planBatches'], $data['quotaByBatch'], $data['totalUseSeats'], $channelId);
        } catch (\Exception $e) {
            return null;
        }
    }

    /**
     * 计算批次的剩余配额
     *
     * @param object $batch 批次对象
     * @param int $channelId 渠道ID
     * @param object|null $channelQuota 渠道配额
     * @param object|null $publicQuota 公共配额
     * @param int $requiredSeats 需要的占位数
     * @return int 剩余配额
     */
    public function calculateRemainingQuota($batch, int $channelId, $channelQuota, $publicQuota, int $requiredSeats): int
    {
        $enableChannelQuota = ($batch->enable_channel_quota ?? 0) == 1;

        if ($enableChannelQuota) {
            if (!$channelQuota) {
                return 0;
            }
            $effectiveQuota = $channelQuota;
            $allowOveruse = $channelQuota->allow_overuse_public_pool ?? 0;
        } else {
            if (!$publicQuota) {
                return 0;
            }
            $effectiveQuota = $publicQuota;
            $allowOveruse = 0;
        }

        $totalQuota = $effectiveQuota->total_quota;
        $usedQuota = $effectiveQuota->used_quota;
        $lockedQuota = $effectiveQuota->locked_quota ?? 0;

        if ($allowOveruse && $publicQuota && $enableChannelQuota) {
            $totalQuota += $publicQuota->total_quota;
            $usedQuota += $publicQuota->used_quota;
            $lockedQuota += $publicQuota->locked_quota ?? 0;
        }

        return max(0, $totalQuota - $usedQuota - $lockedQuota);
    }
}