<?php
namespace App\Services;

use App\Models\ProgramAclRule;
use App\Models\User;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Facades\Schema;

class ProgramAclService
{
    /** @return array<string, array<string, mixed>> */
    public function catalog(): array
    {
        $programs = config('program_acl.programs', []);

        return is_array($programs) ? $programs : [];
    }

    /** @return array<string, string> */
    public function programOptions(): array
    {
        $options = [];

        foreach ($this->catalog() as $key => $definition) {
            $label         = trim((string) ($definition['label'] ?? $key));
            $description   = trim((string) ($definition['description'] ?? ''));
            $options[$key] = $description !== '' ? ($label . ' - ' . $description) : $label;
        }

        return $options;
    }

    /** @return array<int, string> */
    public function manageableRolesFor(User $actor): array
    {
        if ($actor->hasRole('super-admin')) {
            return ['admin', 'amministratore', 'collaboratore', 'fornitore', 'condomino', 'inquilino', 'proprietario'];
        }

        if ($actor->hasRole('admin')) {
            return ['amministratore', 'collaboratore', 'fornitore', 'condomino', 'inquilino', 'proprietario'];
        }

        if ($actor->hasRole('amministratore')) {
            return ['collaboratore'];
        }

        return [];
    }

    public function canManageRole(User $actor, string $role): bool
    {
        return in_array($role, $this->manageableRolesFor($actor), true);
    }

    public function manageableUsersQuery(User $actor): Builder
    {
        $query = User::query()->with('roles')->orderBy('name');

        if ($actor->hasAnyRole(['super-admin', 'admin'])) {
            return $query;
        }

        if (! $actor->hasRole('amministratore')) {
            return $query->whereRaw('1 = 0');
        }

        if (! Schema::hasColumn('users', 'amministratore_id')) {
            return $query->whereRaw('1 = 0');
        }

        $amministratoreId = (int) ($actor->amministratore?->id ?? 0);
        if ($amministratoreId <= 0) {
            return $query->whereRaw('1 = 0');
        }

        return $query
            ->where('amministratore_id', $amministratoreId)
            ->whereHas('roles', static function (Builder $roleQuery): void {
                $roleQuery->where('name', 'collaboratore');
            });
    }

    /** @return array<int, string> */
    public function manageableUserOptions(User $actor): array
    {
        return $this->manageableUsersQuery($actor)
            ->get(['id', 'name', 'email'])
            ->mapWithKeys(static function (User $user): array {
                $label = trim((string) $user->name);
                $email = trim((string) $user->email);

                if ($label === '') {
                    $label = $email !== '' ? $email : ('Utente #' . (string) $user->id);
                } elseif ($email !== '') {
                    $label .= ' <' . $email . '>';
                }

                return [(int) $user->id => $label];
            })
            ->all();
    }

    public function canManageUser(User $actor, User $target): bool
    {
        if ($actor->hasAnyRole(['super-admin', 'admin'])) {
            return true;
        }

        if (! $actor->hasRole('amministratore')) {
            return false;
        }

        if (! $target->hasRole('collaboratore') || ! Schema::hasColumn('users', 'amministratore_id')) {
            return false;
        }

        return (int) $target->amministratore_id === (int) ($actor->amministratore?->id ?? 0);
    }

    /** @return array{allow: array<int, string>, deny: array<int, string>} */
    public function roleRules(string $role): array
    {
        if (! $this->hasRulesTable()) {
            return ['allow' => [], 'deny' => []];
        }

        $rules = ProgramAclRule::query()
            ->forRole($role)
            ->get(['program_key', 'is_allowed']);

        return [
            'allow' => $rules->where('is_allowed', true)->pluck('program_key')->values()->all(),
            'deny'  => $rules->where('is_allowed', false)->pluck('program_key')->values()->all(),
        ];
    }

    /** @return array{allow: array<int, string>, deny: array<int, string>} */
    public function userRules(int $userId): array
    {
        if (! $this->hasRulesTable()) {
            return ['allow' => [], 'deny' => []];
        }

        $rules = ProgramAclRule::query()
            ->forUser($userId)
            ->get(['program_key', 'is_allowed']);

        return [
            'allow' => $rules->where('is_allowed', true)->pluck('program_key')->values()->all(),
            'deny'  => $rules->where('is_allowed', false)->pluck('program_key')->values()->all(),
        ];
    }

    /** @param array<int, string> $allow
     *  @param array<int, string> $deny */
    public function replaceRoleRules(string $role, array $allow, array $deny): void
    {
        if (! $this->hasRulesTable()) {
            return;
        }

        ProgramAclRule::query()->forRole($role)->delete();
        $this->insertRules('role', $role, $allow, $deny);
    }

    /** @param array<int, string> $allow
     *  @param array<int, string> $deny */
    public function replaceUserRules(int $userId, array $allow, array $deny): void
    {
        if (! $this->hasRulesTable()) {
            return;
        }

        ProgramAclRule::query()->forUser($userId)->delete();
        $this->insertRules('user', (string) $userId, $allow, $deny);
    }

    public function canAccessProgram(?User $user, string $programKey): bool
    {
        $catalog = $this->catalog();
        if (! isset($catalog[$programKey]) || ! $user instanceof User) {
            return false;
        }

        if ($user->hasRole('super-admin')) {
            return true;
        }

        $roleNames = $user->getRoleNames()->values()->all();

        if ($this->hasRulesTable()) {
            $userRule = ProgramAclRule::query()
                ->forUser((int) $user->id)
                ->where('program_key', $programKey)
                ->first();

            if ($userRule instanceof ProgramAclRule) {
                return (bool) $userRule->is_allowed;
            }

            if ($roleNames !== []) {
                $roleRules = ProgramAclRule::query()
                    ->where('scope_type', 'role')
                    ->whereIn('scope_key', $roleNames)
                    ->where('program_key', $programKey)
                    ->get(['is_allowed']);

                if ($roleRules->contains(static fn(ProgramAclRule $rule): bool => $rule->is_allowed === false)) {
                    return false;
                }

                if ($roleRules->contains(static fn(ProgramAclRule $rule): bool => $rule->is_allowed === true)) {
                    return true;
                }
            }
        }

        $defaultRoles = $catalog[$programKey]['default_roles'] ?? [];
        if (! is_array($defaultRoles)) {
            return false;
        }

        foreach ($roleNames as $roleName) {
            if (in_array($roleName, $defaultRoles, true)) {
                return true;
            }
        }

        return false;
    }

    /** @param array<int, string> $allow
     *  @param array<int, string> $deny */
    private function insertRules(string $scopeType, string $scopeKey, array $allow, array $deny): void
    {
        if (! $this->hasRulesTable()) {
            return;
        }

        $catalogKeys = array_keys($this->catalog());
        $allow       = array_values(array_unique(array_intersect($catalogKeys, $allow)));
        $deny        = array_values(array_unique(array_diff(array_intersect($catalogKeys, $deny), $allow)));

        $rows = [];
        foreach ($allow as $programKey) {
            $rows[] = [
                'scope_type'  => $scopeType,
                'scope_key'   => $scopeKey,
                'program_key' => $programKey,
                'is_allowed'  => true,
                'created_at'  => now(),
                'updated_at'  => now(),
            ];
        }

        foreach ($deny as $programKey) {
            $rows[] = [
                'scope_type'  => $scopeType,
                'scope_key'   => $scopeKey,
                'program_key' => $programKey,
                'is_allowed'  => false,
                'created_at'  => now(),
                'updated_at'  => now(),
            ];
        }

        if ($rows !== []) {
            ProgramAclRule::query()->insert($rows);
        }
    }

    private function hasRulesTable(): bool
    {
        return Schema::hasTable('program_acl_rules');
    }
}