<?php

namespace App\Support;

use App\Models\Business\CourierOnboarding;
use App\Models\Business\CourierQuoteChange;
use App\Models\Business\CourierQuoteChangeEvent;
use App\Models\Business\CourierQuoteVersion;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

/**
 * 已入驻快递的后台变价：我方在入驻同款报价页里改价格或计费方式，
 * 提交成报价变更单 → 审核通过生成新版本 → 按入驻资料推送给快递 e签宝签署 → 签完回传归档。
 * 同一家快递始终只有一条入驻记录，报价按版本往后接。
 */
final class CourierRequoteService
{
    public const CHANGE_PRICE = '变价';

    public const CHANGE_STRUCTURE = '重新报价';

    /** 单项涨跌超过 30% 在审核页提醒。 */
    public const LARGE_CHANGE = 0.3;

    /** 报价管理里的报价类型：区分入驻首版和后续变价。 */
    public static function quoteTypeFor(string $changeType): string
    {
        return $changeType === self::CHANGE_STRUCTURE ? '快递重新报价' : '快递变价报价';
    }

    public function __construct(private readonly CourierOnboardingService $onboardings)
    {
    }

    /** 报价版本属于哪家已入驻快递（按系统快递名称对应）。 */
    public function onboardingForCourier(?string $courierName): ?CourierOnboarding
    {
        if (blank($courierName)) {
            return null;
        }

        return CourierOnboarding::query()
            ->where('courier_name', $courierName)
            ->whereIn('status', [CourierOnboarding::STATUS_APPROVED, CourierOnboarding::STATUS_ACTIVATED])
            ->latest('id')
            ->first();
    }

    /**
     * 已入驻快递的系统名称 => 入驻 id，报价管理列表一次取出。
     *
     * @return array<string,int>
     */
    public function onboardedCourierIds(): array
    {
        return CourierOnboarding::query()
            ->whereIn('status', [CourierOnboarding::STATUS_APPROVED, CourierOnboarding::STATUS_ACTIVATED])
            ->whereNotNull('courier_name')
            ->orderBy('id')
            ->pluck('id', 'courier_name')
            ->all();
    }

    /** 这家快递最新的报价版本（含待签署的）。 */
    public function latestVersion(CourierOnboarding $onboarding): ?CourierQuoteVersion
    {
        return CourierQuoteVersion::query()
            ->with('signature')
            ->where('company_name', $onboarding->courier_name)
            ->whereNull('courier_expcode')
            ->where('status', 'approved')
            ->latest('id')
            ->first();
    }

    /** @return \Illuminate\Support\Collection<int,CourierQuoteVersion> */
    public function versions(CourierOnboarding $onboarding): \Illuminate\Support\Collection
    {
        return CourierQuoteVersion::query()
            ->with('signature')
            ->where('company_name', $onboarding->courier_name)
            ->whereNull('courier_expcode')
            ->where('status', 'approved')
            ->latest('id')
            ->get();
    }

    /** 还没审核完的变价单（待审核或已退回），同一时间只允许一张。 */
    public function openChange(CourierOnboarding $onboarding): ?CourierQuoteChange
    {
        return CourierQuoteChange::query()
            ->where('carrier_name', $onboarding->courier_name)
            ->whereIn('status', [CourierQuoteChange::STATUS_PENDING_REVIEW, CourierQuoteChange::STATUS_RETURNED, CourierQuoteChange::STATUS_DRAFT])
            ->whereNotNull('quote_payload')
            ->where('change_type', '!=', '存量报价')
            ->latest('id')
            ->first();
    }

    /**
     * 当前生效（最新）版本的报价结构，作为变价底稿。
     *
     * @return array<string,mixed>
     */
    public function currentPayload(CourierOnboarding $onboarding): array
    {
        // 以最新的长期报价为底稿：临时变价到期就作废，不该成为下一次变价的起点。
        $version = $this->versions($onboarding)->first(static fn (CourierQuoteVersion $item): bool => ! $item->isTemporary())
            ?? $this->latestVersion($onboarding);
        $change = $version?->source_change_id ? CourierQuoteChange::query()->find($version->source_change_id) : null;

        return $change?->hasQuotePayload() ? $change->quote_payload : $this->onboardings->quotePayload($onboarding);
    }

    /** 用报价结构生成一份临时的入驻对象，复用入驻的报价列、规则文字和报价矩阵。 */
    public function draftModel(CourierOnboarding $onboarding, array $payload): CourierOnboarding
    {
        $model = $onboarding->replicate();
        $model->id = $onboarding->id;
        foreach (CourierOnboardingService::QUOTE_FIELDS as $field) {
            $model->setAttribute($field, $payload[$field] ?? null);
        }
        $model->setRelation('files', collect());

        return $model;
    }

    /**
     * 提交变价单（新建或更新已退回的那张），进入待审核。
     *
     * @param array<string,mixed> $data
     */
    public function submit(CourierOnboarding $onboarding, array $data, int $userId): CourierQuoteChange
    {
        if ($onboarding->status !== CourierOnboarding::STATUS_ACTIVATED) {
            throw ValidationException::withMessages(['status' => '快递开通后才能发起变价。']);
        }

        $attributes = $this->onboardings->quoteAttributes($data);
        $structure = $attributes['quote_structure'];
        if (($structure['mode'] ?? '') === 'other') {
            throw ValidationException::withMessages(['quote_mode' => '后台变价请选择具体的计费方式。']);
        }
        $errors = CourierQuoteStructure::validate($structure, $attributes['quote_rows']);
        if (blank($attributes['quote_effective_date'])) {
            $errors['quote_effective_date'] = '请填写新报价的执行日期。';
        }
        // 结束日期选填：填了就是短期（临时）变价，到期后自动回到原来的长期报价。
        $endDate = filled($data['quote_end_date'] ?? null) ? Carbon::parse((string) $data['quote_end_date'])->startOfDay() : null;
        if ($endDate !== null && filled($attributes['quote_effective_date']) && $endDate->lt(Carbon::parse($attributes['quote_effective_date'])->startOfDay())) {
            $errors['quote_end_date'] = '结束日期不能早于执行日期。';
        }
        if ($errors !== []) {
            throw ValidationException::withMessages($errors);
        }

        $payload = [];
        foreach (CourierOnboardingService::QUOTE_FIELDS as $field) {
            $payload[$field] = $attributes[$field] ?? null;
        }
        $current = $this->currentPayload($onboarding);
        if ($this->comparable($payload) === $this->comparable($current)) {
            throw ValidationException::withMessages(['quote_rows' => '报价和当前版本完全一样，没有需要变更的内容。']);
        }

        $open = $this->openChange($onboarding);
        if ($open !== null && $open->status === CourierQuoteChange::STATUS_PENDING_REVIEW) {
            throw ValidationException::withMessages(['status' => "已有待审核的变价单 {$open->number}，审核完成后再发起新的变价。"]);
        }

        $version = $this->latestVersion($onboarding);
        $effectiveDate = Carbon::parse($payload['quote_effective_date'])->startOfDay();
        $draft = $this->draftModel($onboarding, $payload);
        $values = $this->onboardings->quoteMatrix($draft, $draft->quoteRowList(), $effectiveDate);
        $type = $this->sameStructure($payload, $current) ? self::CHANGE_PRICE : self::CHANGE_STRUCTURE;

        return DB::transaction(function () use ($onboarding, $data, $userId, $payload, $values, $version, $effectiveDate, $endDate, $type, $open): CourierQuoteChange {
            $attributes = [
                'source_quote_id' => $version?->version_code ?? ('RZ-' . $onboarding->id),
                'source_sheet_name' => $version?->sheet_name ?? ($onboarding->courier_name . '报价'),
                'carrier_name' => $onboarding->courier_name,
                'quote_type' => $version?->quote_type ?? '快递报价',
                'change_type' => $type,
                'status' => CourierQuoteChange::STATUS_PENDING_REVIEW,
                'effective_date' => $effectiveDate,
                'end_date' => $endDate,
                'is_retrospective' => $effectiveDate->lt(today()),
                'recalculation_status' => CourierQuoteChange::RECALCULATION_NOT_REQUIRED,
                'summary' => trim((string) $data['summary']),
                'submitted_by' => $userId,
                'submitted_at' => now(),
                'quote_payload' => $payload,
                'proposed_values_json' => json_encode($values, JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR),
            ];

            if ($open !== null) {
                $from = $open->status;
                $open->update($attributes);
                $change = $open;
            } else {
                $from = null;
                $change = CourierQuoteChange::create([
                    'company_id' => company_id(),
                    'number' => $this->nextChangeNumber(),
                    'created_by' => $userId,
                    ...$attributes,
                ]);
            }

            CourierQuoteChangeEvent::create([
                'company_id' => company_id(),
                'quote_change_id' => $change->id,
                'event_type' => 'submitted',
                'from_status' => $from,
                'to_status' => CourierQuoteChange::STATUS_PENDING_REVIEW,
                'note' => "后台{$type}：{$onboarding->courier_name}，自 {$effectiveDate->toDateString()} 起执行。",
                'created_by' => $userId,
            ]);

            return $change->fresh();
        });
    }

    /**
     * 新旧报价对比：同一计费方式时逐格列出变动；计费方式变了则说明结构变化。
     *
     * @return array{same_structure:bool,old_mode:string,new_mode:string,old_columns:list<string>,new_columns:list<string>,cells:list<array{region:string,label:string,old:?float,new:?float}>,added:list<string>,removed:list<string>,rules:list<array{old:string,new:string}>}
     */
    public function diff(CourierOnboarding $onboarding, array $old, array $new): array
    {
        $oldModel = $this->draftModel($onboarding, $old);
        $newModel = $this->draftModel($onboarding, $new);
        $oldColumns = $oldModel->quoteColumns();
        $newColumns = $newModel->quoteColumns();
        $oldRows = collect($oldModel->quoteRowList())->keyBy('region');
        $newRows = collect($newModel->quoteRowList())->keyBy('region');
        $same = $this->sameStructure($new, $old);

        $cells = [];
        if ($same) {
            foreach ($newRows as $region => $row) {
                if (! $oldRows->has($region)) {
                    continue;
                }
                $before = CourierQuoteStructure::rowValues($oldRows->get($region), $oldColumns);
                $after = CourierQuoteStructure::rowValues($row, $newColumns);
                foreach ($newColumns as $index => $column) {
                    if (round((float) ($before[$index] ?? 0), 4) !== round((float) ($after[$index] ?? 0), 4) || ($before[$index] === null) !== ($after[$index] === null)) {
                        $cells[] = ['region' => (string) $region, 'label' => $column['label'], 'old' => $before[$index], 'new' => $after[$index]];
                    }
                }
            }
        }

        $oldRules = $oldModel->quoteRuleLines();
        $newRules = $newModel->quoteRuleLines();
        $rules = [];
        foreach (array_unique([...array_keys($oldRules), ...array_keys($newRules)]) as $index) {
            if (($oldRules[$index] ?? '') !== ($newRules[$index] ?? '')) {
                $rules[] = ['old' => (string) ($oldRules[$index] ?? '—'), 'new' => (string) ($newRules[$index] ?? '—')];
            }
        }
        if (($old['quote_note'] ?? null) !== ($new['quote_note'] ?? null)) {
            $rules[] = ['old' => '备注：' . ($old['quote_note'] ?: '无'), 'new' => '备注：' . ($new['quote_note'] ?: '无')];
        }

        return [
            'same_structure' => $same,
            'old_mode' => CourierQuoteStructure::describe($oldModel->quoteStructure()),
            'new_mode' => CourierQuoteStructure::describe($newModel->quoteStructure()),
            'old_columns' => array_column($oldColumns, 'label'),
            'new_columns' => array_column($newColumns, 'label'),
            'cells' => $cells,
            'added' => $newRows->keys()->diff($oldRows->keys())->values()->all(),
            'removed' => $oldRows->keys()->diff($newRows->keys())->values()->all(),
            'rules' => $rules,
        ];
    }

    /** 变价单对应的底稿（变价前的版本）报价结构。 */
    public function basePayload(CourierOnboarding $onboarding, CourierQuoteChange $change): array
    {
        $source = CourierQuoteVersion::query()->where('version_code', $change->source_quote_id)->first();
        $sourceChange = $source?->source_change_id ? CourierQuoteChange::query()->find($source->source_change_id) : null;

        return $sourceChange?->hasQuotePayload() ? $sourceChange->quote_payload : $this->onboardings->quotePayload($onboarding);
    }

    /**
     * 作废发错的报价版本。还没签完的同时撤回 e签宝 签署任务；已签完的只做内部作废（原件、回签单保留），
     * 需另发一版正确报价让快递重新签。
     *
     * @return string 给操作人看的结果说明
     */
    public function voidVersion(CourierQuoteVersion $version, string $reason, int $userId): string
    {
        if ($version->isVoided()) {
            throw ValidationException::withMessages(['void_reason' => "{$version->version_code} 已经作废。"]);
        }

        $signature = $version->signature()->first();
        $signed = $signature !== null && in_array($signature->status, [
            \App\Models\Business\CourierQuoteSignature::STATUS_ARCHIVED,
            \App\Models\Business\CourierQuoteSignature::STATUS_COMPLETED,
        ], true);
        $note = '';

        if ($signature !== null && ! $signed && filled($signature->esign_sign_flow_id)
            && $signature->status === \App\Models\Business\CourierQuoteSignature::STATUS_SIGNING) {
            try {
                app(\App\Services\Esign\EsignClient::class)->revokeSignFlow((string) $signature->esign_sign_flow_id, '报价发错作废：' . $reason);
            } catch (\Throwable $exception) {
                throw ValidationException::withMessages(['void_reason' => '撤回 e签宝 签署任务失败：' . mb_substr($exception->getMessage(), 0, 200) . '。可先点「同步签署状态」确认快递是否已签。']);
            }
            $signature->update(['status' => \App\Models\Business\CourierQuoteSignature::STATUS_REVOKED, 'updated_by' => $userId]);
            $note = '已撤回快递 e签宝 里的待签任务。';
        } elseif ($signed) {
            $note = '快递已签署，回签单保留；请另发一版正确报价让快递重新签署。';
        }

        DB::transaction(function () use ($version, $reason, $userId, $signature, $signed, $note): void {
            $version->update([
                'status' => CourierQuoteVersion::STATUS_VOIDED,
                'signature_status' => $signed ? $version->signature_status : ($signature !== null ? '已撤销' : $version->signature_status),
                'void_reason' => $reason,
                'voided_at' => now(),
                'voided_by' => $userId,
            ]);

            if ($version->source_change_id) {
                CourierQuoteChangeEvent::create([
                    'company_id' => $version->company_id,
                    'quote_change_id' => $version->source_change_id,
                    'event_type' => 'voided',
                    'from_status' => null,
                    'to_status' => null,
                    'note' => "报价版本 {$version->version_code} 已作废：{$reason}。{$note}",
                    'created_by' => $userId,
                ]);
            }
        });

        return "{$version->version_code} 已作废，不再参与生效。" . $note;
    }

    /** 这家快递当前生效的版本：已签署、未作废、执行日期已到中最新的一版。 */
    /**
     * 某一天（默认今天）执行的报价版本：已签署、未作废、执行期间覆盖这一天，取开始日期最晚的一版。
     * 短期变价期间用临时价，到期后自动回到原来的长期报价。
     */
    public function effectiveVersion(string $courierName, ?\DateTimeInterface $date = null): ?CourierQuoteVersion
    {
        $versions = CourierQuoteVersion::query()
            ->with('signature')
            ->where('company_name', $courierName)
            ->whereNull('courier_expcode')
            ->where('status', CourierQuoteVersion::STATUS_APPROVED)
            ->get();

        return self::resolveAt($versions, $date ?? today());
    }

    /**
     * @param \Illuminate\Support\Collection<int,CourierQuoteVersion> $versions 同一家快递的版本
     * @param bool $includeTemporary false 时只看长期报价（算「临时价到期后回到哪一版」）
     */
    public static function resolveAt(\Illuminate\Support\Collection $versions, \DateTimeInterface $date, bool $includeTemporary = true): ?CourierQuoteVersion
    {
        return $versions
            ->filter(static fn (CourierQuoteVersion $version): bool => ! $version->isVoided()
                && self::isSignedVersion($version)
                && ($includeTemporary || ! $version->isTemporary())
                && $version->coversDate($date))
            ->sortBy([
                static fn ($a, $b) => $b->effective_date <=> $a->effective_date,
                static fn ($a, $b) => $b->id <=> $a->id,
            ])
            ->first();
    }

    public static function isSignedVersion(CourierQuoteVersion $version): bool
    {
        return in_array($version->signature_status, ['已签署并归档', '历史签署资料已归档'], true)
            || $version->signature?->status === \App\Models\Business\CourierQuoteSignature::STATUS_ARCHIVED;
    }

    /**
     * 审核提醒：倒签、价格为 0、涨跌幅过大。
     *
     * @param array<string,mixed>|null $diff
     * @return list<string>
     */
    public function reviewWarnings(CourierQuoteChange $change, ?array $diff): array
    {
        $warnings = [];
        $current = $this->effectiveVersion((string) $change->carrier_name);
        if ($current !== null && $change->effective_date->lt($current->effective_date)) {
            $warnings[] = "执行日期 {$change->effective_date->toDateString()} 早于当前生效版本 {$current->version_code}（{$current->effective_date->toDateString()} 起），属于倒签，会改动已发生运单的运费。";
        } elseif ($change->effective_date->lt(today())) {
            $warnings[] = "执行日期 {$change->effective_date->toDateString()} 早于今天，属于倒签，会改动已发生运单的运费。";
        }

        if ($change->end_date !== null) {
            $others = CourierQuoteVersion::query()
                ->where('company_name', (string) $change->carrier_name)
                ->where('status', CourierQuoteVersion::STATUS_APPROVED)
                ->where(static fn ($query) => $query->whereNull('source_change_id')->orWhere('source_change_id', '!=', $change->id))
                ->get();
            $base = self::resolveAt($others, $change->end_date->copy()->addDay(), false);
            $warnings[] = $base !== null
                ? "这是短期变价：{$change->effective_date->toDateString()} 至 {$change->end_date->toDateString()} 执行，{$change->end_date->copy()->addDay()->toDateString()} 起自动恢复 {$base->version_code}（{$base->periodLabel()}）。"
                : "这是短期变价，但到期后（{$change->end_date->copy()->addDay()->toDateString()} 起）没有可以恢复的已签署长期报价，到期后这家快递将没有生效报价。";
            $overlap = $others->filter(static fn (CourierQuoteVersion $version): bool => ! $version->isVoided() && $version->isTemporary()
                && $version->effective_date->lte($change->end_date) && $version->end_date->gte($change->effective_date));
            if ($overlap->isNotEmpty()) {
                $warnings[] = '和已有的短期变价执行期间重叠：' . $overlap->map(static fn (CourierQuoteVersion $version): string => $version->version_code . '（' . $version->periodLabel() . '）')->implode('、') . '，重叠的日期以开始日期较晚的一份为准。';
            }
        }

        $big = [];
        foreach ($diff['cells'] ?? [] as $cell) {
            $old = $cell['old'];
            $new = $cell['new'];
            if ($old !== null && $new !== null && (float) $old > 0 && abs((float) $new - (float) $old) / (float) $old > self::LARGE_CHANGE) {
                $big[] = $cell['region'] . ' ' . $cell['label'] . ' ' . CourierQuoteStructure::kg((float) $old) . '→' . CourierQuoteStructure::kg((float) $new);
            }
        }
        if ($big !== []) {
            $warnings[] = '涨跌超过 ' . (int) (self::LARGE_CHANGE * 100) . '%：' . implode('；', array_slice($big, 0, 8)) . (count($big) > 8 ? ' 等 ' . count($big) . ' 处' : '') . '，请核对是否多打或少打了位数。';
        }

        $zeros = [];
        $table = \App\Http\Controllers\Business\CourierQuoteSignatures::quoteTable(json_decode((string) $change->proposed_values_json, true) ?: []);
        foreach (array_slice($table, 1) as $row) {
            foreach (array_slice($row, 1, null, true) as $index => $value) {
                if (is_numeric($value) && (float) $value === 0.0) {
                    $zeros[] = $row[0] . ' ' . ($table[0][$index] ?? '');
                }
            }
        }
        if ($zeros !== []) {
            $warnings[] = '价格为 0：' . implode('、', array_slice($zeros, 0, 8)) . (count($zeros) > 8 ? ' 等 ' . count($zeros) . ' 处' : '') . '。';
        }

        return $warnings;
    }

    private function sameStructure(array $a, array $b): bool
    {
        $shape = static fn (array $payload): array => CourierQuoteStructure::columns(
            is_array($payload['quote_structure'] ?? null) ? $payload['quote_structure'] : []
        );

        return $shape($a) === $shape($b);
    }

    private function comparable(array $payload): string
    {
        $rows = array_map(static fn (array $row): array => [
            'region' => $row['region'] ?? '',
            'flat' => array_map(static fn ($v) => $v === null ? null : round((float) $v, 4), (array) ($row['flat'] ?? [])),
            'base' => isset($row['base']) ? round((float) $row['base'], 4) : null,
            'rates' => array_map(static fn ($v) => $v === null ? null : round((float) $v, 4), (array) ($row['rates'] ?? [])),
        ], array_values(array_filter((array) ($payload['quote_rows'] ?? []), 'is_array')));
        $copy = $payload;
        $copy['quote_rows'] = $rows;
        unset($copy['quote_effective_date']);
        foreach (['min_weight', 'per_ticket_surcharge'] as $key) {
            $copy[$key] = isset($copy[$key]) ? round((float) $copy[$key], 4) : null;
        }
        $copy['volumetric_divisor'] = isset($copy['volumetric_divisor']) ? (int) $copy['volumetric_divisor'] : null;
        ksort($copy);

        return json_encode($copy, JSON_UNESCAPED_UNICODE);
    }

    private function nextChangeNumber(): string
    {
        $prefix = 'BG-' . now()->format('Ymd') . '-';
        $last = CourierQuoteChange::withTrashed()->where('number', 'like', $prefix . '%')->lockForUpdate()->max('number');
        $sequence = $last ? ((int) substr((string) $last, -3)) + 1 : 1;

        return $prefix . str_pad((string) $sequence, 3, '0', STR_PAD_LEFT);
    }
}