<?php

namespace App\Services\Customer;

use App\Enums\Portal;
use App\Models\Company;
use App\Models\User;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Session;

class CustomerCompanyContext
{
    public const SessionKey = 'customer_company_context_id';

    /**
     * @return Collection<int, Company>
     */
    public function companiesFor(User $user): Collection
    {
        $linkedCompanies = $user->companies()
            ->withoutGlobalScopes()
            ->select(['companies.id', 'companies.name', 'companies.portal', 'companies.owner_user_id'])
            ->withPivot('role')
            ->get();

        $ownedCompanies = $user->ownedCompanies()
            ->withoutGlobalScopes()
            ->whereNotIn('id', $linkedCompanies->pluck('id'))
            ->get(['id', 'name', 'portal', 'owner_user_id']);

        return $linkedCompanies
            ->concat($ownedCompanies)
            ->sortBy('name', SORT_NATURAL | SORT_FLAG_CASE)
            ->values();
    }

    public function selectedCompanyId(User $user): ?int
    {
        $companyId = session(self::SessionKey);

        if (! is_numeric($companyId)) {
            return null;
        }

        $companyId = (int) $companyId;

        if (! $this->userCanAccessCompany($user, $companyId)) {
            $this->clear();

            return null;
        }

        return $companyId;
    }

    public function selectedCompany(User $user): ?Company
    {
        $companyId = $this->selectedCompanyId($user);

        if ($companyId === null) {
            return null;
        }

        return $this->findFor($user, $companyId);
    }

    /**
     * @return Collection<int, Company>
     */
    public function latestCompaniesFor(User $user, int $limit = 10): Collection
    {
        return $this->accessibleCompanyQuery($user)
            ->select(['companies.id', 'companies.name', 'companies.portal', 'companies.owner_user_id', 'companies.created_at'])
            ->latest('companies.created_at')
            ->latest('companies.id')
            ->limit($limit)
            ->get();
    }

    /**
     * @return Collection<int, Company>
     */
    public function searchCompaniesFor(User $user, string $term = '', ?int $selectedCompanyId = null, int $limit = 10): Collection
    {
        $term = Portal::stripTrailingAbbreviation($term);
        $limit = max(1, $limit);

        if ($term === '') {
            return $this->companyOptionsWithSelected($user, $selectedCompanyId, $limit);
        }

        return $this->companyOptionQuery($user)
            ->where(function (Builder $query) use ($term): void {
                $query->where('companies.name', 'like', '%'.$term.'%')
                    ->orWhere('companies.slug', 'like', '%'.$term.'%')
                    ->orWhere('companies.email', 'like', '%'.$term.'%');
            })
            ->orderBy('companies.name')
            ->orderBy('companies.id')
            ->limit($limit)
            ->get();
    }

    public function companyCountFor(User $user): int
    {
        return $this->accessibleCompanyQuery($user)->count();
    }

    /**
     * @return Collection<int, Company>
     */
    public function switcherCompaniesFor(User $user, ?int $selectedCompanyId = null, int $limit = 50): Collection
    {
        $companies = $this->switcherCompanyQuery($user)
            ->latest('companies.created_at')
            ->latest('companies.id')
            ->limit($limit)
            ->get();

        if ($selectedCompanyId === null || $companies->contains('id', $selectedCompanyId)) {
            return $companies;
        }

        $selectedCompany = $this->switcherCompanyQuery($user)
            ->whereKey($selectedCompanyId)
            ->first();

        if (! $selectedCompany) {
            return $companies;
        }

        return $companies
            ->prepend($selectedCompany)
            ->unique('id')
            ->values();
    }

    /**
     * @return Builder<Company>
     */
    public function accessibleCompanyQuery(User $user): Builder
    {
        return Company::query()
            ->withoutGlobalScopes()
            ->where(function ($query) use ($user): void {
                $query->where('owner_user_id', $user->id)
                    ->orWhereHas('users', fn ($userQuery) => $userQuery->whereKey($user->id));
            });
    }

    public function findFor(User $user, int $companyId): ?Company
    {
        return $this->accessibleCompanyQuery($user)
            ->whereKey($companyId)
            ->first();
    }

    public function select(User $user, ?int $companyId): void
    {
        if ($companyId === null) {
            $this->clear();

            return;
        }

        if (! $this->userCanAccessCompany($user, $companyId)) {
            return;
        }

        session([self::SessionKey => $companyId]);
    }

    public function clear(): void
    {
        Session::forget(self::SessionKey);
    }

    public function roleLabelFor(Company $company, User $user): string
    {
        $role = $company->owner_user_id === $user->id
            ? 'owner'
            : ($company->getAttribute('current_user_role') ?? $company->pivot?->role ?? 'member');

        return match ($role) {
            'owner' => __('Owner'),
            'responsible' => __('Verantwortlich'),
            default => __('Mitglied'),
        };
    }

    /**
     * @return Builder<Company>
     */
    private function switcherCompanyQuery(User $user): Builder
    {
        return $this->accessibleCompanyQuery($user)
            ->select(['companies.id', 'companies.name', 'companies.portal', 'companies.owner_user_id', 'companies.created_at'])
            ->addSelect([
                'current_user_role' => DB::table('company_user')
                    ->select('role')
                    ->whereColumn('company_user.company_id', 'companies.id')
                    ->where('company_user.user_id', $user->id)
                    ->limit(1),
            ]);
    }

    /**
     * @return Builder<Company>
     */
    private function companyOptionQuery(User $user): Builder
    {
        return $this->accessibleCompanyQuery($user)
            ->select(['companies.id', 'companies.name', 'companies.portal', 'companies.owner_user_id', 'companies.created_at']);
    }

    /**
     * @return Collection<int, Company>
     */
    private function companyOptionsWithSelected(User $user, ?int $selectedCompanyId, int $limit): Collection
    {
        $selectedCompany = $selectedCompanyId
            ? $this->companyOptionQuery($user)->whereKey($selectedCompanyId)->first()
            : null;

        $companies = $this->companyOptionQuery($user)
            ->when($selectedCompany, fn (Builder $query): Builder => $query->whereKeyNot($selectedCompany->id))
            ->latest('companies.created_at')
            ->latest('companies.id')
            ->limit($selectedCompany ? max(0, $limit - 1) : $limit)
            ->get();

        if (! $selectedCompany) {
            return $companies;
        }

        return $companies
            ->prepend($selectedCompany)
            ->unique('id')
            ->values();
    }

    private function userCanAccessCompany(User $user, int $companyId): bool
    {
        return $this->accessibleCompanyQuery($user)
            ->whereKey($companyId)
            ->exists();
    }
}