#include "trygvis/sensor.h"
#include "trygvis/sensor/io.h"
#include "apps.h"
#include <fstream>
#include <sys/stat.h>

namespace trygvis {
namespace apps {

using namespace std;
using namespace trygvis::apps;
using namespace trygvis::sensor;
using namespace trygvis::sensor::io;
namespace po = boost::program_options;

enum class time_resolution {
    SECONDS,
    MILLISECONDS,
};

std::ostream& operator<<(std::ostream& os, time_resolution const& type) {
    if (type == time_resolution::SECONDS) {
        os << "seconds";
    } else if(type == time_resolution::MILLISECONDS) {
        os << "milliseconds";
    }

    return os;
}

std::istream& operator>>(std::istream& is, time_resolution & type) {
    string s;

    is >> s;

    if(s == "seconds") {
        type = time_resolution::SECONDS;
    } else if(s == "milliseconds") {
        type = time_resolution::MILLISECONDS;
    }

    return is;
}

class TimestampFixingSampleOutputStream : public SampleOutputStream {

public:
    TimestampFixingSampleOutputStream(shared_ptr<SampleOutputStream> output, KeyDictionary &dict, string timestamp_name, string relative_name, time_resolution input_time_resolution, time_t start_time) :
            timestamp_key(dict.indexOf(timestamp_name)), relative_key(dict.indexOf(relative_name)), input_time_resolution_(input_time_resolution), start_time_(start_time), output_(output) {
    }

    virtual void write(SampleRecord const &sample) override {
        o<long> relative_time_o = sample.lexical_at<long>(relative_key);

        if (!relative_time_o) {
            return;
        }

        long relative_time = relative_time_o.get();

        long updated_time;
        if (input_time_resolution_ == time_resolution::SECONDS) {
            updated_time = start_time_ + relative_time;
        } else if (input_time_resolution_ == time_resolution::MILLISECONDS) {
            updated_time = start_time_ + relative_time / 1000;
        }

        string updated_value = std::to_string(updated_time);

        SampleRecord updated_sample(sample);

        updated_sample.set(timestamp_key, updated_value);

        output_->write(updated_sample);
    };

private:
    const SampleKey* relative_key, *timestamp_key;
    time_t start_time_;
    time_resolution input_time_resolution_;
    shared_ptr<SampleOutputStream> output_;
};

class sample_timestamp : public app {

private:
    string input_file, timestamp_name, relative_name;
    time_resolution relative_resolution;
    SampleKey* relative_key;

public:
    sample_timestamp() : input_file("") {
    }

    void add_options(po::options_description_easy_init &options) override {
        options
                ("help", "produce this help message")
                ("input", po::value<string>(&input_file)->required())
                ("relative-name", po::value<string>(&relative_name)->default_value("relative"))
                ("relative-resolution", po::value<time_resolution>(&relative_resolution)->default_value(time_resolution::SECONDS))
                ("timestamp-name", po::value<string>(&timestamp_name)->default_value("timestamp"));
    }

    int main(app_execution &execution) override {
        ifstream input(input_file, std::ifstream::in | std::ifstream::binary);

        if (input.fail()) {
            cerr << "Could not open file: " << input_file << endl;
            return EXIT_FAILURE;
        }

        const int buffer_size = 1024;

        input.seekg(-buffer_size, ios_base::end);

        struct stat buf;

        if (stat(input_file.c_str(), &buf)) {
            cerr << "stat failed" << endl;
            return EXIT_FAILURE;
        }

        KeyDictionary dict;

        relative_key = dict.indexOf(relative_name);

        auto sample_buffer = make_shared<VectorSampleOutputStream>();
        auto parser = open_sample_stream_parser(sample_buffer, dict);
        while (!input.fail()) {
            char buffer[buffer_size];
            input.read(buffer, buffer_size);
            auto count = (size_t) input.gcount();

            cerr << "eof? " << input.eof() << endl;
            mutable_buffers_1 b = boost::asio::buffer(buffer, count);
            parser->process(b);
        }

        if (sample_buffer->samples.empty()) {
            cerr << "Could not find any samples" << endl;
            return EXIT_FAILURE;
        }

        time_t end_time = buf.st_mtim.tv_sec;

        SampleRecord sample = *--sample_buffer->samples.end();

        o<string> s = sample.at(relative_key);
        if (!s) {
            cerr << "Missing key '" + relative_name + "'." << endl;
            cerr << "Found " << sample_buffer->samples.size() << " samples." << endl;
            cerr << "keys: " << sample.to_string() << endl;
            return EXIT_FAILURE;
        }

        long relative;
        try {
            relative = boost::lexical_cast<long>(s.get());
        } catch (const boost::bad_lexical_cast &e) {
            cerr << "Bad integer value '" + s.get() + "'." << endl;
            return EXIT_FAILURE;
        }

        if (relative_resolution == time_resolution::MILLISECONDS) {
            relative /= 1000;
        }

        time_t start_time = end_time - relative;
        cerr << "end_time   " << end_time << endl;
        cerr << "relative        " << relative << endl;
        cerr << "start_time " << start_time << endl;

        // Restart the reading of the input file and add the adjusted timestamp
        input.clear(ios::eofbit);
        input.seekg(0);
        if(input.fail()) {
            cerr << "Coult not seek input file" << endl;
            return EXIT_FAILURE;
        }

        vector<sample_output_stream_option*> options = {};
        unique_ptr<SampleOutputStream> unique_output_stream = open_sample_output_stream(shared_ptr<ostream>(&cout, noop_deleter), dict, parser->type(), options);
        shared_ptr<SampleOutputStream> output_stream{std::move(unique_output_stream)};
        shared_ptr<SampleOutputStream> p = make_shared<TimestampFixingSampleOutputStream>(output_stream, dict, timestamp_name, relative_name, relative_resolution, start_time);
        parser = open_sample_stream_parser(p, dict, parser->type());

        int recordCount = 0;

        while (!input.eof()) {
            char buffer[buffer_size];
            input.read(buffer, buffer_size);
            size_t gcount = (size_t)input.gcount();

            recordCount++;

            mutable_buffers_1 b = boost::asio::buffer(buffer, gcount);
            parser->process(b);
        }

        return EXIT_SUCCESS;
    };
};

}
}

using namespace trygvis::apps;

int main(int argc, char *argv[]) {
    sample_timestamp app;
    return launch_app(argc, argv, app);
}