use tonic::{Request, Response, Status};

use crate::pb::core::token_service_server::TokenService as TokenServiceTrait;
use crate::pb::core::{
    GetSigningKeysRequest, GetSigningKeysResponse, IssueTokenRequest, IssueTokenResponse,
    RefreshTokenRequest, RefreshTokenResponse, RevokeTokenRequest, RevokeTokenResponse,
    SigningKey, TokenClaims as PbTokenClaims, VerifyTokenRequest, VerifyTokenResponse,
    revoke_token_request::Target,
};
use crate::service::internal_auth::TokenService;

pub struct TokenGrpcService {
    service: TokenService,
}

impl TokenGrpcService {
    pub fn new(service: TokenService) -> Self {
        Self { service }
    }
}

#[tonic::async_trait]
impl TokenServiceTrait for TokenGrpcService {
    async fn issue_token(
        &self,
        request: Request<IssueTokenRequest>,
    ) -> Result<Response<IssueTokenResponse>, Status> {
        let req = request.into_inner();

        if req.user_id.is_empty() {
            return Err(Status::invalid_argument("user_id is required"));
        }

        let ttl = if req.ttl_secs > 0 { req.ttl_secs } else { 3600 };

        let tokens = self
            .service
            .issue_token(
                &req.user_id,
                ttl,
                req.scopes,
                req.extra,
            )
            .await
            .map_err(|e| Status::internal(e.to_string()))?;

        Ok(Response::new(IssueTokenResponse {
            access_token: tokens.access_token,
            refresh_token: tokens.refresh_token,
            expires_at: tokens.expires_at,
            key_id: tokens.key_id,
        }))
    }

    async fn refresh_token(
        &self,
        request: Request<RefreshTokenRequest>,
    ) -> Result<Response<RefreshTokenResponse>, Status> {
        let req = request.into_inner();

        let tokens = self
            .service
            .refresh_token(&req.refresh_token, 3600)
            .await
            .map_err(|e| Status::unauthenticated(e.to_string()))?;

        Ok(Response::new(RefreshTokenResponse {
            access_token: tokens.access_token,
            refresh_token: tokens.refresh_token,
            expires_at: tokens.expires_at,
            key_id: tokens.key_id,
        }))
    }

    async fn revoke_token(
        &self,
        request: Request<RevokeTokenRequest>,
    ) -> Result<Response<RevokeTokenResponse>, Status> {
        let req = request.into_inner();

        match req.target {
            Some(Target::Jti(jti)) => {
                self.service
                    .revoke_by_jti(&jti, 86400)
                    .await
                    .map_err(|e| Status::internal(e.to_string()))?;
                Ok(Response::new(RevokeTokenResponse { revoked_count: 1 }))
            }
            Some(Target::UserId(user_id)) => {
                let count = self
                    .service
                    .revoke_user_tokens(&user_id)
                    .await
                    .map_err(|e| Status::internal(e.to_string()))?;
                Ok(Response::new(RevokeTokenResponse {
                    revoked_count: count as i32,
                }))
            }
            None => Err(Status::invalid_argument("target is required")),
        }
    }

    async fn verify_token(
        &self,
        request: Request<VerifyTokenRequest>,
    ) -> Result<Response<VerifyTokenResponse>, Status> {
        let req = request.into_inner();

        match self
            .service
            .verify_token(&req.token)
            .await
            .map_err(|e| Status::internal(e.to_string()))?
        {
            Ok(claims) => Ok(Response::new(VerifyTokenResponse {
                valid: true,
                claims: Some(PbTokenClaims {
                    sub: claims.sub,
                    iss: claims.iss,
                    iat: claims.iat,
                    exp: claims.exp,
                    jti: claims.jti,
                    scope: claims.scope,
                    extra: claims.extra,
                }),
                reason: String::new(),
            })),
            Err(reason) => Ok(Response::new(VerifyTokenResponse {
                valid: false,
                claims: None,
                reason,
            })),
        }
    }

    async fn get_signing_keys(
        &self,
        _request: Request<GetSigningKeysRequest>,
    ) -> Result<Response<GetSigningKeysResponse>, Status> {
        let (keys, next_rotation_at) = self
            .service
            .get_signing_keys()
            .await
            .map_err(|e| Status::internal(e.to_string()))?;

        Ok(Response::new(GetSigningKeysResponse {
            keys: keys
                .into_iter()
                .map(|k| SigningKey {
                    kid: k.kid,
                    algorithm: k.algorithm,
                    key_material: k.key_material,
                    issued_at: k.issued_at,
                    expires_at: k.expires_at,
                    active: k.active,
                })
                .collect(),
            next_rotation_at,
        }))
    }
}