// system headers

#include <array>

#include <filesystem>

#include <thread>

#include <utility>

// local headers

#include <linuxdeploy/plugin/plugin_process_handler.h>

#include <linuxdeploy/subprocess/process.h>

#include <linuxdeploy/util/util.h>

#include <linuxdeploy/log/log.h>

#include <linuxdeploy/subprocess/pipe_reader.h>

namespace fs = std::filesystem;

namespace linuxdeploy {

namespace plugin {

using namespace log;

plugin_process_handler::plugin_process_handler(std::string name, fs::path path) : name_(std::move(name)),

path_(std::move(path)) {}

int plugin_process_handler::run(const fs::path& appDir) const {

// prepare arguments and environment variables

const std::initializer_list<std::string> args = {path_.string(), "--appdir", appDir.string()};

auto environmentVariables = subprocess::get_environment();

// add $LINUXDEPLOY, which points to the current binary

// we do not need to pass $APPIMAGE or alike, since while linuxdeploy is running, the path in the

// temporary mountpoint of its AppImage will be valid anyway

environmentVariables["LINUXDEPLOY"] = linuxdeploy::util::getOwnExecutablePath();

linuxdeploy::subprocess::process proc{args, environmentVariables};

// we want to insert a custom log prefix whenever a CR or LF is written into either buffer

// like in subprocess's check_output, we use pipe readers to read from the subprocess's stdout/stderr pipes

// however, we just dump everything we receive directly in the log, using our ĺogging framework

// we store an ldLog instance per stream so we can just send all data into those, which allows us to get away

// with relatively small buffers (we don't have to cache complete lines or alike)

class pipe_to_be_logged {

public:

pipe_reader reader_;

std::string stream_name_;

ldLog log_;

bool print_prefix_in_next_iteration_;

bool eof = false;

pipe_to_be_logged(int pipe_fd, std::string stream_name) : reader_(pipe_fd),

stream_name_(std::move(stream_name)),

log_(),

print_prefix_in_next_iteration_(true) {}

};

std::array<pipe_to_be_logged, 2> pipes_to_be_logged{

pipe_to_be_logged(proc.stdout_fd(), "stdout"),

pipe_to_be_logged(proc.stderr_fd(), "stderr"),

};

for (;;) {

for (auto& pipe_to_be_logged : pipes_to_be_logged) {

if (pipe_to_be_logged.eof) {

continue;

}

const auto log_prefix = "[" + name_ + "/" + pipe_to_be_logged.stream_name_ + "] ";

// since we have our own ldLog instance for every pipe, we can get away with this rather small read buffer

subprocess::subprocess_result_buffer_t intermediate_buffer(4096);

// (try to) read from pipe

switch (pipe_to_be_logged.reader_.read(intermediate_buffer)) {

case pipe_reader::result::SUCCESS: {

// all we have to do now is to look for CR or LF, send everything up to that location into the ldLog instance,

// write our prefix and then repeat

for (auto it = intermediate_buffer.begin(); it != intermediate_buffer.end(); ++it) {

if (pipe_to_be_logged.print_prefix_in_next_iteration_) {

pipe_to_be_logged.log_ << log_prefix;

}

const auto next_lf = std::find(it, intermediate_buffer.end(), '\n');

const auto next_cr = std::find(it, intermediate_buffer.end(), '\r');

// we don't care which one goes first -- we pick the closest one, write everything up to it into our ldLog,

// then print our prefix and repeat that until there's nothing left in our buffer

auto next_control_char = std::min({next_lf, next_cr});

// if there is a control char, we remember this for the next iteration, where we print our

// log prefix

// in any case, we can write the remaining buffer contents into the ldLog object

pipe_to_be_logged.print_prefix_in_next_iteration_ = (next_control_char !=

intermediate_buffer.end());

const auto distance_from_begin_to_it = std::distance(intermediate_buffer.begin(), it);

auto distance_from_it_to_next_cc = std::distance(it, next_control_char);

if (pipe_to_be_logged.print_prefix_in_next_iteration_) {

distance_from_it_to_next_cc++;

}

// need to make sure we include the control char in the write

pipe_to_be_logged.log_.write(

intermediate_buffer.data() + distance_from_begin_to_it,

distance_from_it_to_next_cc

);

it = next_control_char;

// TODO: should not be necessary, should be fixed in for loop

if (!pipe_to_be_logged.print_prefix_in_next_iteration_) {

break;

}

}

break;

}

case pipe_reader::result::END_OF_FILE: {

pipe_to_be_logged.eof = true;

break;

}

case pipe_reader::result::TIMEOUT:

break;

}

}

// once all buffers are EOF, we can stop reading

if (std::all_of(pipes_to_be_logged.begin(), pipes_to_be_logged.end(), [](const pipe_to_be_logged& pipe_state) {

return pipe_state.eof;

})) {

break;

}

}

return proc.close();

}

}

}