import SQLKit
import Vapor

struct UserToken: Decodable {
    let token: String

    static func create (connection: any SQLDatabase) async throws -> UserToken {
        return try await connection.raw ("""
            SELECT string_agg (substr (c, (random() * length (c) + 1)::integer, 1), '') AS "token"
              FROM (VALUES ('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789')) AS x(c),
                   generate_series (1, 32)
            """)
            .first (decoding: UserToken.self)!
    }

    struct Token: Content {
        let userId: UUID
        let email: String

        enum CodingKeys: String, CodingKey {
            case userId = "user_id"
            case email
        }
    }

    static func fetch (token: String, connection: any SQLDatabase) async throws -> Token? {
        return try await connection.raw ("""
            SELECT "user_id", "email"
              FROM "user_tokens"
              JOIN "users"
                ON "users"."id" = "user_tokens"."user_id"
             WHERE "token" = \(bind: token)
               AND "insert_time" >= CURRENT_TIMESTAMP - INTERVAL '1 HOUR'
            """)
            .first (decoding: Token.self)
    }

    static func delete (token: String, connection: any SQLDatabase) async throws {
        return try await connection.raw ("""
            DELETE FROM "user_tokens"
             WHERE "token" = \(bind: token)
            """)
            .run()
    }
}