// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

use crate::storage::Storable;
use crate::{FileAuthTag, FileCrypto, OwnerList};
use anyhow::{anyhow, Result};
use serde::{Deserialize, Serialize};
use std::prelude::v1::*;
use url::Url;
use uuid::Uuid;

const INPUT_FILE_PREFIX: &str = "input";
const OUTPUT_FILE_PREFIX: &str = "output";

fn create_uuid() -> Uuid {
    Uuid::new_v4()
}

#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct TeaclaveInputFile {
    pub url: Url,
    pub cmac: FileAuthTag,
    pub crypto_info: FileCrypto,
    pub owner: OwnerList,
    pub uuid: Uuid,
}

#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct TeaclaveOutputFile {
    pub url: Url,
    pub cmac: Option<FileAuthTag>,
    pub crypto_info: FileCrypto,
    pub owner: OwnerList,
    pub uuid: Uuid,
}

impl TeaclaveInputFile {
    pub fn new(
        url: Url,
        cmac: FileAuthTag,
        crypto_info: FileCrypto,
        owner: impl Into<OwnerList>,
    ) -> TeaclaveInputFile {
        TeaclaveInputFile {
            url,
            cmac,
            crypto_info,
            owner: owner.into(),
            uuid: create_uuid(),
        }
    }

    pub fn from_output(output: TeaclaveOutputFile) -> Result<TeaclaveInputFile> {
        let input = TeaclaveInputFile {
            url: output.url,
            cmac: output
                .cmac
                .ok_or_else(|| anyhow!("output is not finished"))?,
            crypto_info: output.crypto_info,
            owner: output.owner,
            uuid: output.uuid,
        };
        Ok(input)
    }
}

impl Storable for TeaclaveInputFile {
    fn key_prefix() -> &'static str {
        INPUT_FILE_PREFIX
    }

    fn uuid(&self) -> Uuid {
        self.uuid
    }
}

impl TeaclaveOutputFile {
    pub fn new(
        url: Url,
        crypto_info: FileCrypto,
        owner: impl Into<OwnerList>,
    ) -> TeaclaveOutputFile {
        TeaclaveOutputFile {
            url,
            cmac: None,
            crypto_info,
            owner: owner.into(),
            uuid: create_uuid(),
        }
    }

    pub fn assign_cmac(&mut self, cmac: &FileAuthTag) -> Result<()> {
        anyhow::ensure!(self.cmac.is_none(), "Cannot overwrite output file cmac");
        self.cmac = Some(cmac.to_owned());
        Ok(())
    }
}

impl Storable for TeaclaveOutputFile {
    fn key_prefix() -> &'static str {
        OUTPUT_FILE_PREFIX
    }

    fn uuid(&self) -> Uuid {
        self.uuid
    }
}