package com.alttd.altitudeweb.config;

import com.alttd.altitudeweb.controllers.login.KeyPairService;
import com.alttd.altitudeweb.model.PermissionClaimDto;
import com.nimbusds.jose.jwk.JWK;
import com.nimbusds.jose.jwk.JWKSet;
import com.nimbusds.jose.jwk.RSAKey;
import com.nimbusds.jose.jwk.source.ImmutableJWKSet;
import com.nimbusds.jose.jwk.source.JWKSource;
import com.nimbusds.jose.proc.SecurityContext;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpMethod;
import org.springframework.security.config.Customizer;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.oauth2.jwt.JwtDecoder;
import org.springframework.security.oauth2.jwt.JwtEncoder;
import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
import org.springframework.security.oauth2.jwt.NimbusJwtEncoder;
import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationConverter;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.access.expression.WebExpressionAuthorizationManager;

import java.security.KeyPair;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.util.*;
import java.util.stream.Collectors;

@Slf4j
@Configuration
@EnableWebSecurity
@RequiredArgsConstructor
public class SecurityConfig {

    private final KeyPairService keyPairService;
    private final SecurityAuthFailureHandler securityAuthFailureHandler;

    @Value("${chat.allowed-ip}")
    private String allowedIp;

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
        WebExpressionAuthorizationManager allowedIpCheck = new WebExpressionAuthorizationManager(
                "hasIpAddress('%s')".formatted(allowedIp));
        return http
                .authorizeHttpRequests(
                        auth -> auth
                                .requestMatchers(HttpMethod.OPTIONS, "/**").permitAll()
                                .requestMatchers("/api/chat/send/**").access(allowedIpCheck)
                                .requestMatchers("/actuator/mappings").access(allowedIpCheck)
                                .requestMatchers("/api/form/**").authenticated()
                                .requestMatchers("/api/login/getUsername").authenticated()
                                .requestMatchers("/api/mail/**").authenticated()
                                .requestMatchers("/api/site/vote").authenticated()
                                .requestMatchers("/api/appeal").authenticated()
                                .requestMatchers("/api/chat/read/**").hasAnyAuthority(PermissionClaimDto.HEAD_MOD.getValue(), PermissionClaimDto.MOD.getValue())
                                .requestMatchers("/api/site/get-staff-playtime/**").hasAuthority(PermissionClaimDto.HEAD_MOD.getValue())
                                .requestMatchers("/api/head_mod/**").hasAuthority(PermissionClaimDto.HEAD_MOD.getValue())
                                .requestMatchers("/api/particles/**").hasAuthority(PermissionClaimDto.HEAD_MOD.getValue())
                                .requestMatchers("/api/files/save/**").hasAuthority(PermissionClaimDto.HEAD_MOD.getValue())
                                //TODO allow users access to their own folder
                                .requestMatchers("/api/files/download/**").hasAuthority(PermissionClaimDto.HEAD_MOD.getValue())
                                .requestMatchers("/api/history/admin/**").hasAuthority(PermissionClaimDto.HEAD_MOD.getValue())
                                .requestMatchers("/api/login/userLogin/**").permitAll()
                                .anyRequest().permitAll()
                )
                .csrf(AbstractHttpConfigurer::disable)
                .oauth2ResourceServer(
                        oauth2 -> oauth2
                                .jwt(jwt -> jwt.jwtAuthenticationConverter(jwtAuthenticationConverter()))
                                .authenticationEntryPoint(securityAuthFailureHandler)
                                .accessDeniedHandler(securityAuthFailureHandler)
                )
                .exceptionHandling(
                        ex -> ex
                                .authenticationEntryPoint(securityAuthFailureHandler)
                                .accessDeniedHandler(securityAuthFailureHandler)
                )
                .sessionManagement(
                        session -> session
                                .sessionCreationPolicy(SessionCreationPolicy.STATELESS)
                )
                .build();
    }

    @Bean
    public JwtEncoder jwtEncoder() {
        KeyPair keyPair = keyPairService.getJwtSigningKeyPair();
        JWK jwk = new RSAKey.Builder((RSAPublicKey) keyPair.getPublic())
                .privateKey((RSAPrivateKey) keyPair.getPrivate())
                .build();
        JWKSource<SecurityContext> jwkSource = new ImmutableJWKSet<>(new JWKSet(jwk));
        return new NimbusJwtEncoder(jwkSource);
    }

    @Bean
    public JwtDecoder jwtDecoder() {
        KeyPair keyPair = keyPairService.getJwtSigningKeyPair();
        return NimbusJwtDecoder.withPublicKey((RSAPublicKey) keyPair.getPublic()).build();
    }



    @Bean
    public JwtAuthenticationConverter jwtAuthenticationConverter() {
        JwtAuthenticationConverter converter = new JwtAuthenticationConverter();
        converter.setJwtGrantedAuthoritiesConverter(jwt -> {
            Map<String, Object> claims = jwt.getClaims();

            Object authoritiesClaim = claims.get("authorities");
            if (authoritiesClaim instanceof List<?> authorities) {
                Collection<GrantedAuthority> authorityList = authorities.stream()
                        .map(Object::toString)
                        .map(SimpleGrantedAuthority::new)
                        .collect(Collectors.toList());
                log.debug("Authorities found in authorities: {}", authorityList);
                return authorityList;
            }

            Object scopeClaim = claims.get("scope");
            if (scopeClaim instanceof String scopeString) {
                Collection<GrantedAuthority> authorityList = Arrays.stream(scopeString.split(" "))
                        .map(scope -> new SimpleGrantedAuthority("SCOPE_" + scope))
                        .collect(Collectors.toList());
                log.debug("Authorities found in authorities scope string: {}", authorityList);
                return authorityList;
            }

            if (scopeClaim instanceof List<?> scopeList) {
                Collection<GrantedAuthority> authorityList = scopeList.stream()
                        .map(Object::toString)
                        .map(scope -> new SimpleGrantedAuthority("SCOPE_" + scope))
                        .collect(Collectors.toList());
                log.debug("Authorities found in authorities scope list: {}", authorityList);
                return authorityList;
            }

            log.debug("No granted authorities found");
            return Collections.emptyList();
        });
        return converter;
    }
}