/*
 Copyright (C) 2019 Fredrik Öhrström

 This program 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.

 This program 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.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include"config.h"
#include"meters.h"

#include<vector>
#include<string>

using namespace std;

pair<string,string> getNextKeyValue(vector<char> &buf, vector<char>::iterator &i)
{
    bool eof, err;
    string key, value;
    key = eatToSkipWhitespace(buf, i, '=', 64, &eof, &err);
    if (eof || err) goto nomore;
    value = eatToSkipWhitespace(buf, i, '\n', 4096, &eof, &err);
    if (err) goto nomore;

    return { key, value };

    nomore:

    return { "", "" };
}

void parseMeterConfig(CommandLine *c, vector<char> &buf, string file)
{
    auto i = buf.begin();
    string name;
    string type;
    string id;
    string key;

    for (;;) {
        auto p = getNextKeyValue(buf, i);

        if (p.first == "") break;

        if (p.first == "name") name = p.second;
        if (p.first == "type") type = p.second;
        if (p.first == "id") id = p.second;
        if (p.first == "key") key = p.second;
    }

    MeterType mt = toMeterType(type);
    if (mt == UNKNOWN_METER) error("Not a valid meter type \"%s\"\n", type.c_str());
    if (!isValidId(id)) error("Not a valid meter id \"%s\"\n", id.c_str());
    if (!isValidKey(key)) error("Not a valid meter key \"%s\"\n", key.c_str());

    c->meters.push_back(MeterInfo(name, type, id, key));

    return;

}

unique_ptr<CommandLine> loadConfiguration()
{
    CommandLine *c = new CommandLine;

    vector<char> global_conf;
    loadFile("/etc/wmbusmeters.conf", &global_conf);

    auto i = global_conf.begin();
    string loglevel;
    string device;
    string meterfiles_dir;

    for (;;) {
        auto p = getNextKeyValue(global_conf, i);

        if (p.first == "") break;

        if (p.first == "loglevel") loglevel = p.second;
        if (p.first == "device") device = p.second;
        if (p.first == "meterfilesdir") meterfiles_dir = p.second;
    }

    if (loglevel == "verbose") {
        c->verbose = true;
    } else
    if (loglevel == "debug") {
        c->debug = true;
    } else
    if (loglevel == "silent") {
        c->silence = true;
    } else
    if (loglevel == "normal") {
    } else
    {
        warning("No such log level: \"%s\"\n", loglevel.c_str());
    }
    // cmdline->logtelegrams

    c->meterfiles_dir = meterfiles_dir;
    if (!checkIfDirExists(c->meterfiles_dir.c_str())) {
        warning("Cannot write meter files into dir \"%s\"\n", c->meterfiles_dir.c_str());
    }

    c->usb_device = device;

    vector<string> meter_files;
    listFiles("/etc/wmbusmeters.d", &meter_files);

    for (auto& f : meter_files)
    {
        vector<char> meter_conf;
        string file = string("/etc/wmbusmeters.d/")+f;
        loadFile(file.c_str(), &meter_conf);
        parseMeterConfig(c, meter_conf, file);
    }

    return unique_ptr<CommandLine>(c);
}