<?php

namespace App\Services\Config;

use App\Models\PlayType;
use App\Models\AdminUser;
use Illuminate\Http\Request;
use App\Services\AuditLogger;
use App\Models\PlayConfigItem;
use App\Models\PlayConfigVersion;
use Illuminate\Support\Facades\DB;
use App\Lottery\ConfigVersionStatus;
use Illuminate\Validation\ValidationException;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;

/** 后台：玩法配置版本（{@see play_config_versions} / {@see play_config_items}） */
final class PlayConfigStreamService
{
    /** @return LengthAwarePaginator<int, PlayConfigVersion> */
    public function paginate(?string $status, int $perPage, int $page = 1): LengthAwarePaginator
    {
        $q = PlayConfigVersion::query()->orderByDesc('id');
        if ($status !== null && $status !== '') {
            $q->where('status', $status);
        }

        return $q->paginate($perPage, ['*'], 'page', max(1, $page));
    }

    public function createDraft(AdminUser $admin, ?string $reason, ?int $cloneFromVersionId): PlayConfigVersion
    {
        $nextNo = (int) (PlayConfigVersion::query()->max('version_no') ?? 0) + 1;

        return DB::transaction(function () use ($admin, $reason, $cloneFromVersionId, $nextNo): PlayConfigVersion {
            $draft = PlayConfigVersion::query()->create([
                'version_no' => $nextNo,
                'status' => ConfigVersionStatus::Draft->value,
                'effective_at' => null,
                'updated_by' => $admin->id,
                'reason' => $reason,
            ]);

            $source = null;
            if ($cloneFromVersionId !== null) {
                $source = PlayConfigVersion::query()->whereKey($cloneFromVersionId)->firstOrFail();
            } else {
                $source = PlayConfigVersion::query()
                    ->where('status', ConfigVersionStatus::Active->value)
                    ->first();
            }

            if ($source !== null) {
                foreach ($source->items()->orderBy('play_code')->get() as $row) {
                    PlayConfigItem::query()->create([
                        'version_id' => $draft->id,
                        'play_code' => $row->play_code,
                        'is_enabled' => $row->is_enabled,
                        'min_bet_amount' => $row->min_bet_amount,
                        'max_bet_amount' => $row->max_bet_amount,
                        'display_order' => $row->display_order,
                        'rule_text_zh' => $row->rule_text_zh,
                        'rule_text_en' => $row->rule_text_en,
                        'rule_text_ne' => $row->rule_text_ne,
                        'extra_config_json' => $row->extra_config_json,
                    ]);
                }
            } else {
                foreach (PlayType::query()->orderBy('sort_order')->orderBy('play_code')->get() as $pt) {
                    PlayConfigItem::query()->create([
                        'version_id' => $draft->id,
                        'play_code' => $pt->play_code,
                        'is_enabled' => (bool) $pt->is_enabled,
                        'min_bet_amount' => 100,
                        'max_bet_amount' => 500_000_000,
                        'display_order' => (int) $pt->sort_order,
                        'rule_text_zh' => null,
                        'rule_text_en' => null,
                        'rule_text_ne' => null,
                        'extra_config_json' => null,
                    ]);
                }
            }

            return $draft->fresh(['items']);
        });
    }

    /**
     * @param  array<int, array<string, mixed>>  $items
     */
    public function replaceItems(PlayConfigVersion $draft, array $items, AdminUser $admin): void
    {
        DB::transaction(function () use ($draft, $items, $admin): void {
            PlayConfigItem::query()->where('version_id', $draft->id)->delete();

            foreach ($items as $row) {
                PlayConfigItem::query()->create([
                    'version_id' => $draft->id,
                    'play_code' => (string) $row['play_code'],
                    'is_enabled' => (bool) ($row['is_enabled'] ?? true),
                    'min_bet_amount' => (int) ($row['min_bet_amount'] ?? 0),
                    'max_bet_amount' => (int) ($row['max_bet_amount'] ?? 0),
                    'display_order' => (int) ($row['display_order'] ?? 0),
                    'rule_text_zh' => isset($row['rule_text_zh']) ? (string) $row['rule_text_zh'] : null,
                    'rule_text_en' => isset($row['rule_text_en']) ? (string) $row['rule_text_en'] : null,
                    'rule_text_ne' => isset($row['rule_text_ne']) ? (string) $row['rule_text_ne'] : null,
                    'extra_config_json' => $row['extra_config_json'] ?? null,
                ]);
            }

            $draft->forceFill(['updated_by' => $admin->id])->save();
        });
    }

    public function publish(PlayConfigVersion $draft, AdminUser $admin, ?Request $request = null): void
    {
        $this->validatePublishableDraft($draft);
        $before = $this->snapshotVersion($draft);

        DB::transaction(function () use ($draft, $admin): void {
            /** @var PlayConfigVersion|null $current */
            $current = PlayConfigVersion::query()
                ->where('status', ConfigVersionStatus::Active->value)
                ->lockForUpdate()
                ->first();

            if ($current !== null) {
                $current->forceFill(['status' => ConfigVersionStatus::Archived->value])->save();
            }

            $draft->forceFill([
                'status' => ConfigVersionStatus::Active->value,
                'effective_at' => now(),
                'updated_by' => $admin->id,
            ])->save();
        });

        $after = $this->snapshotVersion($draft->fresh(['items']));

        AuditLogger::recordForAdmin(
            $admin,
            $request,
            moduleCode: 'play_config',
            actionCode: 'publish',
            targetType: 'play_config_version',
            targetId: (string) $draft->id,
            beforeJson: $before,
            afterJson: $after,
        );
    }

    public function deleteVersion(PlayConfigVersion $version, AdminUser $admin, ?Request $request = null): void
    {
        $before = $this->snapshotVersion($version);

        DB::transaction(function () use ($version): void {
            $version->delete();
        });

        AuditLogger::recordForAdmin(
            $admin,
            $request,
            moduleCode: 'play_config',
            actionCode: 'delete',
            targetType: 'play_config_version',
            targetId: (string) $version->id,
            beforeJson: $before,
            afterJson: null,
        );
    }

    /** @return array<string, mixed> */
    private function snapshotVersion(PlayConfigVersion $v): array
    {
        return [
            'id' => $v->id,
            'version_no' => $v->version_no,
            'status' => $v->status,
            'effective_at' => $v->effective_at?->toIso8601String(),
            'items_count' => $v->items()->count(),
        ];
    }

    private function validatePublishableDraft(PlayConfigVersion $draft): void
    {
        $items = $draft->items()->orderBy('play_code')->get();
        $allowedPlayCodes = array_fill_keys(
            PlayType::query()->pluck('play_code')->all(),
            true,
        );

        $errors = [];
        $seenPlayCodes = [];

        if ($items->isEmpty()) {
            $errors['items'][] = '草稿至少需要一条玩法配置';
        }

        foreach ($items as $index => $row) {
            $playCode = (string) $row->play_code;
            $minBet = (int) $row->min_bet_amount;
            $maxBet = (int) $row->max_bet_amount;

            if (! isset($allowedPlayCodes[$playCode])) {
                $errors["items.$index.play_code"][] = '玩法不存在';
            }

            if (isset($seenPlayCodes[$playCode])) {
                $errors["items.$index.play_code"][] = '玩法重复';
            }
            $seenPlayCodes[$playCode] = true;

            if ($minBet < 0) {
                $errors["items.$index.min_bet_amount"][] = '最小下注额不能小于 0';
            }

            if ($maxBet < 0) {
                $errors["items.$index.max_bet_amount"][] = '最大下注额不能小于 0';
            }

            if ($maxBet < $minBet) {
                $errors["items.$index.max_bet_amount"][] = '最大下注额不能小于最小下注额';
            }
        }

        if ($errors !== []) {
            throw ValidationException::withMessages($errors);
        }
    }
}