/*
 * Copyright (C) 2022 Huawei Device Co., Ltd.
 * Licensed 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::{
    ipc_binding, MsgParcel, RemoteObj, IRemoteObj,
    InterfaceToken, String16, IpcResult, IpcStatusCode,
    parse_status_code
};
use crate::parcel::{vec_to_string, allocate_vec_with_buffer};
use std::ffi::{CString, c_char, c_void};
use hilog_rust::{info, hilog, HiLogLabel, LogType};

const LOG_LABEL: HiLogLabel = HiLogLabel {
    log_type: LogType::LogCore,
    domain: 0xD0057CA,
    tag: "RustProcess"
};

/// Get proxy object of samgr
pub fn get_context_object() -> Option<RemoteObj>
{
    // SAFETY: If no SamgrContextManager object is available, the function might return nullptr,
    // causing the subsequent RemoteObj::from_raw call to fail.
    unsafe {
        let samgr = ipc_binding::GetContextManager();
        RemoteObj::from_raw(samgr)
    }
}

/// Add a service to samgr
pub fn add_service(service: &RemoteObj, said: i32) -> IpcResult<()>
{
    let samgr = get_context_object().expect("samgr is not null");
    let mut data = MsgParcel::new().expect("MsgParcel is not null");
    data.write(&InterfaceToken::new("ohos.samgr.accessToken"))?;
    data.write(&said)?;
    data.write(service)?;
    data.write(&false)?;
    data.write(&0)?;
    data.write(&String16::new(""))?;
    data.write(&String16::new(""))?;
    let reply = samgr.send_request(3, &data, false)?;
    let reply_value: i32 = reply.read()?;
    info!(LOG_LABEL, "register service result: {}", reply_value);
    if reply_value == 0 { Ok(())} else { Err(parse_status_code(reply_value)) }
}

/// Get a service proxy from samgr
pub fn get_service(said: i32) -> IpcResult<RemoteObj>
{
    let samgr = get_context_object().expect("samgr is not null");
    let mut data = MsgParcel::new().expect("MsgParcel is not null");
    data.write(&InterfaceToken::new("ohos.samgr.accessToken"))?;
    data.write(&said)?;
    let reply = samgr.send_request(2, &data, false)?;
    let remote: RemoteObj = reply.read()?;
    info!(LOG_LABEL, "get service success");
    Ok(remote)
}

/// Make current thread join to the IPC/RPC work thread pool
#[inline]
pub fn join_work_thread()
{
    // SAFETY:
    // It should only be called from a thread not already part of the pool.
    // The potential blocking nature of the function and its impact on other threads.
    unsafe {
        ipc_binding::JoinWorkThread();
    }
}

/// Exit current thread from IPC/RPC work thread pool
#[inline]
pub fn stop_work_thread()
{
    // SAFETY:
    // It should only be called from a thread belonging to the pool.
    // Prematurely exiting might leave pending requests unprocessed and cause unexpected behavior.
    unsafe {
        ipc_binding::StopWorkThread()
    }
}

/// Get calling token ID of caller
#[inline]
pub fn get_calling_token_id() -> u64
{
    // SAFETY:
    // Consider verifying it with additional security measures and context-based information when necessary.
    unsafe {
        ipc_binding::GetCallingTokenId()
    }
}

/// Get first calling token ID of caller
#[inline]
pub fn get_first_token_id() -> u64
{
    // SAFETY:
    // Consider verifying it with additional security measures and context-based information when necessary.
    unsafe {
        ipc_binding::GetFirstToekenId()
    }
}

/// Get self token id of current process
#[inline]
pub fn get_self_token_id() -> u64
{
    // SAFETY:
    // Minimize its exposure, restrict access to authorized parties within your application.
    unsafe {
        ipc_binding::GetSelfToekenId()
    }
}

/// Get calling process id of caller
#[inline]
pub fn get_calling_pid() -> u64
{
    // SAFETY:
    // The returned PID might be incorrect or invalid due to potential issues
    // with the IPC mechanism or malicious attempts to manipulate it.
    unsafe {
        ipc_binding::GetCallingPid()
    }
}

/// Get calling user id of caller
#[inline]
pub fn get_calling_uid() -> u64
{
    // SAFETY:
    // Minimize its exposure, restrict access to authorized parties,
    // and implement robust security measures to prevent unauthorized leaks or manipulation.
    unsafe {
        ipc_binding::GetCallingUid()
    }
}

/// Set the maximum number of threads
#[inline]
pub fn set_max_work_thread(max_thread_num: i32) -> bool
{
    // SAFETY:
    // Ensuring the provided value is valid and appropriate for the system resources and workload.
    unsafe {
        ipc_binding::SetMaxWorkThreadNum(max_thread_num)
    }
}

/// Determine whether it is a local call
#[inline]
pub fn is_local_calling() -> bool
{
    // SAFETY:
    // Ensure proper usage within the context of the IPC binding system and its intended behavior.
    unsafe {
        ipc_binding::IsLocalCalling()
    }
}

/// Set calling identity
#[inline]
pub fn set_calling_identity(identity: String) -> bool
{
    match CString::new(identity.as_str()) {
        Ok(name) => {
            // SAFETY:
            // Name is valid
            unsafe {
                ipc_binding::SetCallingIdentity(name.as_ptr())
            }
        },
        Err(_) => false,
    }
}

/// get local device id
#[inline]
pub fn get_local_device_id() -> IpcResult<String>
{
    let mut vec: Option<Vec<u8>> = None;
    // SAFETY:
    // it's important to ensure that the vec contains valid data and is not null.
    // The provided buffer size is sufficient to hold the returned data.
    let ok_status = unsafe {
        ipc_binding::GetLocalDeviceID(
            &mut vec as *mut _ as *mut c_void,
            allocate_vec_with_buffer::<u8>
        )
    };

    if ok_status {
        vec_to_string(vec)
    } else {
        Err(IpcStatusCode::Failed)
    }
}

/// get calling device id
#[inline]
pub fn get_calling_device_id() -> IpcResult<String>
{
    let mut vec: Option<Vec<u8>> = None;
    // SAFETY:
    // it's important to ensure that the vec contains valid data and is not null.
    // The provided buffer size is sufficient to hold the returned data.
    let ok_status = unsafe {
        ipc_binding::GetCallingDeviceID(
            &mut vec as *mut _ as *mut c_void,
            allocate_vec_with_buffer::<u8>
        )
    };

    if ok_status {
        vec_to_string(vec)
    } else {
        Err(IpcStatusCode::Failed)
    }
}

/// reset calling identity
#[inline]
pub fn reset_calling_identity() -> IpcResult<String>
{
    let mut vec: Option<Vec<u8>> = None;
    // SAFETY:
    // The provided buffer size is sufficient to hold the returned data.
    // The returned `String` is validated before using it.
    let ok_status = unsafe {
        ipc_binding::ResetCallingIdentity(
            &mut vec as *mut _ as *mut c_void,
            allocate_vec_with_buffer::<u8>
        )
    };

    if ok_status {
        vec_to_string(vec)
    } else {
        Err(IpcStatusCode::Failed)
    }
}

/// Determine whether the current thread is currently executing an incoming transaction.
#[inline]
pub fn is_handling_transaction() -> bool
{
    // SAFETY:
    // Ensure proper usage within the context of the IPC binding system and its intended behavior.
    unsafe {
        ipc_binding::IsHandlingTransaction()
    }
}