<?php

namespace KTXC\Stores;

use KTXC\Db\DataStore;
use KTXF\Utile\UUID;

class UserAccountsStore
{

    public function __construct(protected DataStore $store)
    { }

    // =========================================================================
    // User Operations (Full User Object)
    // =========================================================================

    /**
     * List all users for a tenant with optional filters
     */
    public function listUsers(string $tenant, array $filters = []): array
    {
        // Build filter
        $filter = ['tid' => $tenant];
        
        if (isset($filters['enabled'])) {
            $filter['enabled'] = (bool)$filters['enabled'];
        }
        
        if (isset($filters['role'])) {
            $filter['roles'] = $filters['role'];
        }
        
        // Fetch users with aggregated role data
        $pipeline = [
            ['$match' => $filter],
            [
                '$lookup' => [
                    'from' => 'user_roles',
                    'localField' => 'roles',
                    'foreignField' => 'rid',
                    'as' => 'role_details'
                ]
            ],
            [
                '$addFields' => [
                    'permissions' => [
                        '$reduce' => [
                            'input' => [
                                '$map' => [
                                    'input' => '$role_details',
                                    'as' => 'r',
                                    'in' => ['$ifNull' => ['$$r.permissions', []]]
                                ]
                            ],
                            'initialValue' => [],
                            'in' => ['$setUnion' => ['$$value', '$$this']]
                        ]
                    ]
                ]
            ],
            ['$unset' => 'role_details'],
            ['$sort' => ['label' => 1]]
        ];
        
        $cursor = $this->store->selectCollection('user_accounts')->aggregate($pipeline);
        
        $users = [];
        foreach ($cursor as $entry) {
            $users[] = (array)$entry;
        }
        
        return $users;
    }

    public function fetchByIdentity(string $tenant, string $identity): array | null
    {

        $pipeline = [
            [
                '$match' => [
                    'tid' => $tenant,
                    'identity' => $identity
                ]
            ],
            [
                '$lookup' => [
                    'from' => 'user_roles',
                    'localField' => 'roles',         // Array field in `users`
                    'foreignField' => 'rid',         // Scalar field in `user_roles`
                    'as' => 'role_details'
                ]
            ],
            // Add flattened, deduplicated permissions while preserving all original user fields
            [
                '$addFields' => [
                    'permissions' => [
                        '$reduce' => [
                            'input' => [
                                '$map' => [
                                    'input' => '$role_details',
                                    'as' => 'r',
                                    'in' => [ '$ifNull' => ['$$r.permissions', []] ]
                                ]
                            ],
                            'initialValue' => [],
                            'in' => [ '$setUnion' => ['$$value', '$$this'] ]
                        ]
                    ]
                ]
            ],
            // Optionally remove expanded role documents from output
            [ '$unset' => 'role_details' ]
        ];

        $entry = $this->store->selectCollection('user_accounts')->aggregate($pipeline)->toArray()[0] ?? null;
        if (!$entry) { return null; }
        return (array)$entry;
    }

    public function fetchByIdentifier(string $tenant, string $identifier): array | null
    {
        $pipeline = [
            [
                '$match' => [
                    'tid' => $tenant,
                    'uid' => $identifier
                ]
            ],
            [
                '$lookup' => [
                    'from' => 'user_roles',
                    'localField' => 'roles',
                    'foreignField' => 'rid',
                    'as' => 'role_details'
                ]
            ],
            [
                '$addFields' => [
                    'permissions' => [
                        '$reduce' => [
                            'input' => [
                                '$map' => [
                                    'input' => '$role_details',
                                    'as' => 'r',
                                    'in' => [ '$ifNull' => ['$$r.permissions', []] ]
                                ]
                            ],
                            'initialValue' => [],
                            'in' => [ '$setUnion' => ['$$value', '$$this'] ]
                        ]
                    ]
                ]
            ],
            [ '$unset' => 'role_details' ]
        ];

        $entry = $this->store->selectCollection('user_accounts')->aggregate($pipeline)->toArray()[0] ?? null;
        if (!$entry) { return null; }
        return (array)$entry;
    }

    public function fetchByProviderSubject(string $tenant, string $provider, string $subject): array | null
    {
        $entry = $this->store->selectCollection('user_accounts')->findOne([
            'tid' => $tenant,
            'provider' => $provider,
            'provider_subject' => $subject
        ]);
        if (!$entry) { return null; }
        return (array)$entry;
    }

    public function createUser(string $tenant, array $userData): array
    {
        $userData['tid'] = $tenant;
        $userData['uid'] = $userData['uid'] ?? UUID::v4();
        $userData['enabled'] = $userData['enabled'] ?? true;
        $userData['roles'] = $userData['roles'] ?? [];
        $userData['profile'] = $userData['profile'] ?? [];
        $userData['settings'] = $userData['settings'] ?? [];
        
        $this->store->selectCollection('user_accounts')->insertOne($userData);
        
        return $this->fetchByIdentifier($tenant, $userData['uid']);
    }

    public function updateUser(string $tenant, string $uid, array $updates): bool
    {
        $result = $this->store->selectCollection('user_accounts')->updateOne(
            ['tid' => $tenant, 'uid' => $uid],
            ['$set' => $updates]
        );
        
        return $result->getModifiedCount() > 0;
    }

    public function deleteUser(string $tenant, string $uid): bool
    {
        $result = $this->store->selectCollection('user_accounts')->deleteOne([
            'tid' => $tenant,
            'uid' => $uid
        ]);
        
        return $result->getDeletedCount() > 0;
    }

    // =========================================================================
    // Profile Operations
    // =========================================================================

    public function fetchProfile(string $tenant, string $uid): ?array
    {
        $user = $this->store->selectCollection('user_accounts')->findOne(
            ['tid' => $tenant, 'uid' => $uid],
            ['projection' => ['profile' => 1, 'provider_managed_fields' => 1]]
        );
        
        if (!$user) {
            return null;
        }

        return [
            'profile' => $user['profile'] ?? [],
            'provider_managed_fields' => $user['provider_managed_fields'] ?? [],
        ];
    }

    public function storeProfile(string $tenant, string $uid, array $profileFields): bool
    {
        if (empty($profileFields)) {
            return false;
        }

        $updates = [];
        foreach ($profileFields as $key => $value) {
            $updates["profile.{$key}"] = $value;
        }

        $result = $this->store->selectCollection('user_accounts')->updateOne(
            ['tid' => $tenant, 'uid' => $uid],
            ['$set' => $updates]
        );
        
        return $result->getModifiedCount() > 0;
    }

    // =========================================================================
    // Settings Operations
    // =========================================================================

    public function fetchSettings(string $tenant, string $uid, array $settings = []): ?array
    {
        // Only fetch the settings field from the database
        $user = $this->store->selectCollection('user_accounts')->findOne(
            ['tid' => $tenant, 'uid' => $uid],
            ['projection' => ['settings' => 1]]
        );
        
        if (!$user) {
            return null;
        }

        $userSettings = $user['settings'] ?? [];

        if (empty($settings)) {
            return $userSettings;
        }

        $result = [];
        foreach ($settings as $key) {
            $result[$key] = $userSettings[$key] ?? null;
        }
        return $result;
    }

    public function storeSettings(string $tenant, string $uid, array $settings): bool
    {
        if (empty($settings)) {
            return false;
        }

        $updates = [];
        foreach ($settings as $key => $value) {
            $updates["settings.{$key}"] = $value;
        }

        $result = $this->store->selectCollection('user_accounts')->updateOne(
            ['tid' => $tenant, 'uid' => $uid],
            ['$set' => $updates]
        );
        
        // Return true if document was matched (exists), even if not modified
        return $result->getMatchedCount() > 0;
    }

}