import Vapor
import Leaf
import PostgresKit
import SwiftSMTPVapor

public struct AdminController<User: ManagedUser>: Sendable where User.SessionID == ExpiringUserId {
    public init() {}

    public func routes (_ router: any RoutesBuilder, api apiRouter: any RoutesBuilder) {
        let admin = router
            .grouped ("admin")
            .grouped (RoleMiddleware<User> (role: "admin"))
        let api = apiRouter
            .grouped ("admin")
            .grouped (RoleAPIMiddleware<User> (role: "admin"))

        admin.get (use: adminPage (request:))
        api.get (use: list (request:))
        api.get (":id", use: fetch (request:))
        api.put (use: invite (request:))
        api.post (":id", use: save(request:))
    }

    struct AdminContext: Encodable {
        let roles: [String]
        let section: String
    }

    @Sendable
    private func adminPage (request: Request) async throws -> View {
        let roles = try await request.db.withSQLConnection { connection in
            return try await UserRole.all (connection: connection)
        }
        return try await request.view.render ("admin", AdminContext (roles: roles.map (\.name), section: "useradmin"))
    }

    struct UserItem: Content {
        let id: UUID
        let email: String
        let fullName: String
        let isActive: Bool
        let roles: [String]

        init(user: User) {
            self.id = user.id
            self.email = user.email
            self.fullName = user.fullName
            self.isActive = user.isActive
            self.roles = user.roles
        }
    }

    @Sendable
    private func list (request: Request) async throws -> [UserItem] {
        return try await request.db.withSQLConnection { connection in
            let users = try await User.all(on: connection)
            return users.map { UserItem (user: $0) }
        }
    }

    @Sendable
    private func fetch (request: Request) async throws -> UserItem {
        guard let idString = request.parameters.get ("id"), let id = UUID (uuidString: idString) else {
            throw Abort (.badRequest)
        }
        return try await request.db.withSQLConnection { connection in
            guard let user = try await User.fetch (id, on: connection) else {
                throw Abort (.notFound)
            }

            return UserItem (user: user)
        }
    }

    struct Invitation: Decodable {
        let email: String
        let fullname: String
        let roles: [String]
    }

    @Sendable
    private func invite (request: Request) async throws -> Response {

        let invitation = try request.content.decode(Invitation.self)

        return try await request.db.withConnection { connection in
            try await connection.transaction { connection in
                let token = try await UserToken.create (connection: connection).token
                try await User.create (email: invitation.email, fullname: invitation.fullname, roles: invitation.roles, token: token, on: connection)
                let host = try Environment.baseURL.host() ?? ""
                let body = try await request.view.render ("email/invite", AuthenticationController<User>.TokenEmailContext (token: token, host: host, expiration: Calendar.current.date (byAdding: .day, value: 1, to: Date()) ?? Date()))
                    .data
                let message = Email (sender: Email.Contact (emailAddress: try Environment.emailSender),
                                     recipients: [Email.Contact(emailAddress: invitation.email)],
                                     subject: "Aktivera ditt konto på \(host)",
                                     body: .plain (String (buffer: body)))
                try await request.swiftSMTP.mailer.send(message)

                return Response (status: .created)
            }
        }
    }

    struct Save: Decodable {
        let email: String
        let fullname: String
        let roles: [String]
        let isActive: Bool
    }

    @Sendable
    private func save (request: Request) async throws -> Response {

        guard let userId = request.parameters.get("id", as: UUID.self) else {
            throw Abort (.badRequest)
        }
        let save = try request.content.decode(Save.self)

        return try await request.db.withSQLConnection (user: try request.auth.require (BasicUser.self)) { connection in
            guard (try await User.fetch (userId, on: connection)) != nil else {
                throw Abort (.notFound)
            }
            guard !save.email.isEmpty && !save.fullname.isEmpty else {
                throw Abort (.badRequest)
            }

            try await User.save (id: userId, email: save.email, fullname: save.fullname, roles: save.roles, isActive: save.isActive, on: connection)

            return Response (status: .ok)
        }
    }
}