<?php

namespace classes;

use Exception;
use Throwable;

/**
 * Repository for the `api_keys` table.
 *
 * This is a thin procedural wrapper that uses the project's existing
 * `$db` global (mysqli) — no Eloquent, no ORM. The pattern matches
 * other repositories in this codebase (see `classes/orders_o.php`,
 * `classes/invoice_store.php`, etc.).
 *
 * Records are returned as associative arrays. The caller is expected
 * to interact with them as plain dicts; there is no dedicated model
 * class for api keys.
 */
class api_key_repository
{
    public const TABLE = 'api_keys';

    private static function db()
    {
        global $db;
        if (!isset($db) || !is_object($db)) {
            throw new Exception('Database connection ($db) is not available');
        }
        // Lazy-create the table on first use so callers don't have to
        // remember to call ensureTables().
        if (class_exists(api_key_schema_bootstrap::class)) {
            api_key_schema_bootstrap::ensureTables();
        }
        return $db;
    }

    /**
     * Validate the input data for create(). Exposed so test doubles
     * can exercise the same validation without touching a real DB.
     *
     * @param array<string, mixed> $data
     */
    public static function validate(array $data): void
    {
        $required = ['key_id', 'key_hash', 'name', 'role'];
        foreach ($required as $field) {
            if (!isset($data[$field]) || !is_string($data[$field]) || $data[$field] === '') {
                throw new \InvalidArgumentException("Missing required field: {$field}");
            }
        }
        $allowedRoles = ['superuser', 'admin', 'customer', 'subuser'];
        if (!in_array($data['role'], $allowedRoles, true)) {
            throw new \InvalidArgumentException("Invalid role: {$data['role']}");
        }
    }

    /**
     * @param array<string, mixed> $data
     * @return int inserted id
     */
    public static function create(array $data): int
    {
        self::validate($data);

        $db = self::db();
        $scopesJson = isset($data['scopes']) && $data['scopes'] !== null
            ? (is_string($data['scopes']) ? $data['scopes'] : json_encode($data['scopes'], JSON_UNESCAPED_SLASHES))
            : null;

        $stmt = $db->conn()->prepare(
            'INSERT INTO api_keys (key_id, key_hash, name, role, scopes, customer_id, created_by, expires_at)
             VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
        );
        if ($stmt === false) {
            throw new Exception('Failed to prepare insert: ' . $db->conn()->error);
        }

        $customerId = isset($data['customer_id']) ? (int)$data['customer_id'] : null;
        $createdBy = isset($data['created_by']) ? (int)$data['created_by'] : null;
        $expiresAt = isset($data['expires_at']) && $data['expires_at'] !== null
            ? (string)$data['expires_at']
            : null;

        $stmt->bind_param(
            'sssssiss',
            $data['key_id'],
            $data['key_hash'],
            $data['name'],
            $data['role'],
            $scopesJson,
            $customerId,
            $createdBy,
            $expiresAt
        );

        if (!$stmt->execute()) {
            $err = $stmt->error;
            $stmt->close();
            throw new Exception('Failed to insert api_key: ' . $err);
        }
        $id = $stmt->insert_id;
        $stmt->close();
        return (int)$id;
    }

    /**
     * Find a non-revoked key by its public key_id.
     *
     * @return array<string, mixed>|null
     */
    public static function findActiveByKeyId(string $keyId): ?array
    {
        if ($keyId === '') {
            return null;
        }
        $db = self::db();
        $stmt = $db->conn()->prepare(
            'SELECT * FROM api_keys WHERE key_id = ? AND revoked_at IS NULL LIMIT 1'
        );
        if ($stmt === false) {
            throw new Exception('Failed to prepare select: ' . $db->conn()->error);
        }
        $stmt->bind_param('s', $keyId);
        if (!$stmt->execute()) {
            $err = $stmt->error;
            $stmt->close();
            throw new Exception('Failed to execute select: ' . $err);
        }
        $result = $stmt->get_result();
        $row = $result ? $result->fetch_assoc() : null;
        $stmt->close();
        return $row ?: null;
    }

    /**
     * Find any key by id (including revoked).
     *
     * @return array<string, mixed>|null
     */
    public static function findById(int $id): ?array
    {
        $db = self::db();
        $stmt = $db->conn()->prepare('SELECT * FROM api_keys WHERE id = ? LIMIT 1');
        if ($stmt === false) {
            throw new Exception('Failed to prepare select: ' . $db->conn()->error);
        }
        $stmt->bind_param('i', $id);
        if (!$stmt->execute()) {
            $err = $stmt->error;
            $stmt->close();
            throw new Exception('Failed to execute select: ' . $err);
        }
        $result = $stmt->get_result();
        $row = $result ? $result->fetch_assoc() : null;
        $stmt->close();
        return $row ?: null;
    }

    /**
     * Revoke a key (sets revoked_at = NOW()). Returns true on success.
     */
    public static function revoke(int $id): bool
    {
        $db = self::db();
        $stmt = $db->conn()->prepare(
            'UPDATE api_keys SET revoked_at = CURRENT_TIMESTAMP WHERE id = ? AND revoked_at IS NULL'
        );
        if ($stmt === false) {
            throw new Exception('Failed to prepare revoke: ' . $db->conn()->error);
        }
        $stmt->bind_param('i', $id);
        $ok = $stmt->execute();
        $affected = $stmt->affected_rows;
        $stmt->close();
        return $ok && $affected > 0;
    }

    /**
     * Bump last_used_at for a key. Best-effort: failures are swallowed
     * because this is a hot-path observability hook and must not
     * break the request.
     */
    public static function touchLastUsed(int $id): void
    {
        try {
            $db = self::db();
            $stmt = $db->conn()->prepare(
                'UPDATE api_keys SET last_used_at = CURRENT_TIMESTAMP WHERE id = ?'
            );
            if ($stmt === false) {
                return;
            }
            $stmt->bind_param('i', $id);
            $stmt->execute();
            $stmt->close();
        } catch (Throwable) {
            // intentionally ignored
        }
    }

    /**
     * List keys for a customer, newest first.
     *
     * @return array<int, array<string, mixed>>
     */
    public static function listForCustomer(int $customerId, bool $includeRevoked = false): array
    {
        $db = self::db();
        $sql = 'SELECT * FROM api_keys WHERE customer_id = ?';
        if (!$includeRevoked) {
            $sql .= ' AND revoked_at IS NULL';
        }
        $sql .= ' ORDER BY id DESC';
        $stmt = $db->conn()->prepare($sql);
        if ($stmt === false) {
            throw new Exception('Failed to prepare list: ' . $db->conn()->error);
        }
        $stmt->bind_param('i', $customerId);
        if (!$stmt->execute()) {
            $err = $stmt->error;
            $stmt->close();
            throw new Exception('Failed to execute list: ' . $err);
        }
        $result = $stmt->get_result();
        $rows = $result ? $result->fetch_all(MYSQLI_ASSOC) : [];
        $stmt->close();
        return is_array($rows) ? $rows : [];
    }

    /**
     * Delete a key by id. Returns true if a row was removed.
     * Generally prefer `revoke()` over `delete()` so audit trails
     * stay intact.
     */
    public static function delete(int $id): bool
    {
        $db = self::db();
        $stmt = $db->conn()->prepare('DELETE FROM api_keys WHERE id = ?');
        if ($stmt === false) {
            throw new Exception('Failed to prepare delete: ' . $db->conn()->error);
        }
        $stmt->bind_param('i', $id);
        $ok = $stmt->execute();
        $affected = $stmt->affected_rows;
        $stmt->close();
        return $ok && $affected > 0;
    }
}