//    This file is part of Motion Watch.

//    Motion Watch is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.

//    Motion Watch is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.

#include "common.h"

string cleanDir(const string &path)
{
    if (path[path.size() - 1] == '/')
    {
        return path.substr(0, path.size() - 1);
    }
    else
    {
        return path;
    }
}

bool createDir(const string &dir)
{
    auto ret = mkdir(dir.c_str(), 0777);

    if (ret == -1)
    {
        return errno == EEXIST;
    }
    else
    {
        return true;
    }
}

bool createDirTree(const string &full_path)
{
    size_t pos = 0;
    auto   ret = true;

    while (ret == true && pos != string::npos)
    {
        pos = full_path.find('/', pos + 1);
        ret = createDir(full_path.substr(0, pos));
    }

    return ret;
}

void cleanupEmptyDirs(const string &path)
{
    if (exists(path))
    {
        for (auto &entry : directory_iterator(path))
        {
            if (entry.is_directory())
            {
                try
                {
                    remove(entry.path());
                }
                catch (filesystem_error const &ex)
                {
                    // non-empty dir assumed when filesystem_error is raised.
                    cleanupEmptyDirs(path + "/" + entry.path().filename().string());
                }
            }
        }
    }
}

vector<string> lsFilesInDir(const string &path, const string &ext)
{
    vector<string> names;

    if (exists(path))
    {
        for (auto &entry : directory_iterator(path))
        {
            if (entry.is_regular_file())
            {
                auto name = entry.path().filename().string();

                if (ext.empty() || name.ends_with(ext))
                {
                    names.push_back(name);
                }
            }
        }
    }

    sort(names.begin(), names.end());

    return names;
}

vector<string> lsDirsInDir(const string &path)
{
    vector<string> names;

    if (exists(path))
    {
        for (auto &entry : directory_iterator(path))
        {
            if (entry.is_directory())
            {
                names.push_back(entry.path().filename().string());
            }
        }
    }

    sort(names.begin(), names.end());

    return names;
}

void cleanupStream(const string &plsPath)
{
    ifstream fileIn(plsPath);

    for (string line; getline(fileIn, line); )
    {
        if (line.starts_with("VIDEO_TS/"))
        {
            remove(line);
        }
    }
}

void enforceMaxEvents(shared_t *share)
{
    auto names = lsFilesInDir(".", ".m3u8");

    while (names.size() > share->maxEvents)
    {
        if (names[0] != "stream.m3u8")
        {
            // removes the playlist file extension.
            auto nameOnly = names[0].substr(0, names[0].size() - 5);
            auto imgFile  = nameOnly + ".jpg";
            auto webFile  = nameOnly + ".html";

            cleanupStream(names[0]);
            remove(names[0]);

            if (exists(imgFile)) remove(imgFile);
            if (exists(webFile)) remove(webFile);
        }

        names.erase(names.begin());
    }
}


string genTimeStr(const char *fmt)
{
    time_t rawtime;

    time(&rawtime);

    auto timeinfo = localtime(&rawtime);

    char ret[50];

    strftime(ret, 50, fmt, timeinfo);

    return string(ret);
}

string genDstFile(const string &dirOut, const char *fmt, const string &ext)
{
    createDirTree(cleanDir(dirOut));

    return cleanDir(dirOut) + string("/") + genTimeStr(fmt) + ext;
}

void rdLine(const string &param, const string &line, string *value)
{
    if (line.rfind(param.c_str(), 0) == 0)
    {
        *value = line.substr(param.size());
    }
}

void rdLine(const string &param, const string &line, int *value)
{
    if (line.rfind(param.c_str(), 0) == 0)
    {
        *value = strtol(line.substr(param.size()).c_str(), NULL, 10);
    }
}

bool rdConf(const string &filePath, shared_t *share)
{
    ifstream varFile(filePath.c_str());

    if (!varFile.is_open())
    {
        share->retCode = ENOENT;

        cerr << "err: config file: " << filePath << " does not exists or lack read permissions." << endl;
    }
    else
    {
        string line;

        do
        {
            getline(varFile, line);

            if (line.rfind("#", 0) != 0)
            {
                rdLine("cam_name = ",         line, &share->camName);
                rdLine("recording_stream = ", line, &share->recordUrl);
                rdLine("web_root = ",         line, &share->webRoot);
                rdLine("web_text = ",         line, &share->webTxt);
                rdLine("web_bg = ",           line, &share->webBg);
                rdLine("web_font = ",         line, &share->webFont);
                rdLine("sch_sec = ",          line, &share->schSec);
                rdLine("post_cmd = ",         line, &share->postCmd);
                rdLine("pix_thresh = ",       line, &share->pixThresh);
                rdLine("img_thresh = ",       line, &share->imgThresh);
                rdLine("max_days = ",         line, &share->maxDays);
                rdLine("max_events = ",       line, &share->maxEvents);
                rdLine("max_log_size = ",     line, &share->maxLogSize);
            }

        } while(!line.empty());
    }

    return share->retCode == 0;
}

bool rdConf(shared_t *share)
{
    share->recordUrl.clear();
    share->postCmd.clear();
    share->camName.clear();

    share->retCode    = 0;
    share->pixThresh  = 50;
    share->imgThresh  = 800;
    share->maxDays    = 15;
    share->maxEvents  = 20;
    share->maxLogSize = 50000;
    share->skipCmd    = false;
    share->schSec     = 60;
    share->webRoot    = "/var/www/html";
    share->webBg      = "#485564";
    share->webTxt     = "#dee5ee";
    share->webFont    = "courier";

    if (rdConf(share->conf, share))
    {
        if (share->camName.empty())
        {
            share->camName = path(share->conf).filename();
        }

        share->outDir = cleanDir(share->webRoot) + "/" + share->camName;

        error_code ec;

        createDirTree(share->outDir);
        current_path(share->outDir, ec);

        share->retCode = ec.value();

        if (share->retCode != 0)
        {
            cerr << "err: " << ec.message() << endl;
        }
    }

    return share->retCode == 0;
}

string parseForParam(const string &arg, int argc, char** argv, bool argOnly, int &offs)
{
    auto ret = string();

    for (; offs < argc; ++offs)
    {
        auto argInParams = string(argv[offs]);

        if (arg.compare(argInParams) == 0)
        {
            if (!argOnly)
            {
                offs++;
                // check ahead, make sure offs + 1 won't cause out-of-range exception
                if (offs <= (argc - 1))
                {
                    ret = string(argv[offs]);
                }
            }
            else
            {
                ret = string("true");
            }
        }
    }

    return ret;
}

string parseForParam(const string &arg, int argc, char** argv, bool argOnly)
{
    auto notUsed = 0;

    return parseForParam(arg, argc, argv, argOnly, notUsed);
}

string genEventPath(const string &tsPath)
{
    if (tsPath.size() > 14)
    {
        // removes 'VIDEO_TS/live/' from the front of the string.
        auto ret = tsPath.substr(14);

        return "VIDEO_TS/events/" + ret;
    }
    else
    {
        return string();
    }
}

string genVidNameFromLive(const string &tsPath)
{
    if (tsPath.size() > 17)
    {
        // removes 'VIDEO_TS/live/' from the front of the string.
        auto ret = tsPath.substr(14);
        auto ind = tsPath.find('/');
        // removes '.ts' from the end of the string.
        ret = ret.substr(0, ret.size() - 3);

        while (ind != string::npos)
        {
            // remove all '/'
            ret.erase(ind, 1);

            ind = ret.find('/');
        }

        return ret;
    }
    else
    {
        return string();
    }
}

uint64_t genEpoch()
{
    return duration_cast<seconds>(system_clock::now().time_since_epoch()).count();
}