package eu.eudat.handlers;

import eu.eudat.exceptions.security.UnauthorisedException;
import eu.eudat.models.security.Principal;
import eu.eudat.security.claims.ClaimedAuthorities;
import eu.eudat.services.operations.AuthenticationService;
import eu.eudat.services.operations.AuthenticationServiceImpl;
import eu.eudat.types.Authorities;
import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import java.lang.annotation.Annotation;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;
import java.util.UUID;


public final class PrincipalArgumentResolver implements HandlerMethodArgumentResolver {

    private AuthenticationService authenticationService;

    @Override
    public boolean supportsParameter(MethodParameter methodParameter) {
        return methodParameter.getParameterType().equals(Principal.class);
    }

    @Override
    public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
        String token = nativeWebRequest.getHeader("AuthToken");
        Optional<Annotation> claimsAnnotation = Arrays.stream(methodParameter.getParameterAnnotations()).filter(annotation -> annotation.annotationType().equals(ClaimedAuthorities.class)).findAny();
        List<Authorities> claimList = claimsAnnotation.map(annotation -> Arrays.asList(((ClaimedAuthorities) annotation).claims())).orElse(Authorities.all());
        if (token == null) throw new UnauthorisedException("Authentication Information Is Missing");
        UUID authToken;
        try {
            authToken = UUID.fromString(token);
        } catch (IllegalArgumentException ex) {
            throw new UnauthorisedException("Authentication Information Is Missing");
        }

        Principal principal = this.authenticationService.Touch(authToken);
        if (principal == null) throw new UnauthorisedException("Authentication Information Missing");
        if (!principal.isAuthorized(claimList))
            throw new UnauthorisedException("You are not Authorized For this Action");
        return principal;
    }

    public PrincipalArgumentResolver(AuthenticationService authenticationService) {
        this.authenticationService = authenticationService;
    }

}