// Copyright (C) 2021 xaizek <xaizek@posteo.net>
//
// This file is part of zograscope.
//
// zograscope is free software: you can redistribute it and/or modify
// it under the terms of version 3 of the GNU Affero General Public License as
// published by the Free Software Foundation.
//
// zograscope 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with zograscope.  If not, see <http://www.gnu.org/licenses/>.

#ifndef ZOGRASCOPE_TOOLING_CONFIG_HPP_
#define ZOGRASCOPE_TOOLING_CONFIG_HPP_

#include <boost/filesystem/path.hpp>

#include <string>
#include <utility>
#include <vector>

// Set of attribute for a path.
struct Attrs
{
    // Language to use, empty if unspecified.
    std::string lang;
    // Number of spaces in a full tabulation, -1 if unspecified.
    int tabWidth = -1;
};

// Encapsulates configuration information.
class Config
{
    class MatchExpr;

public:
    // Discovers configuration files and root by visiting parents of the
    // specified path.
    explicit Config(const boost::filesystem::path &currDir);

    // Destroys fields with full types.
    ~Config();

public:
    // Checks whether contents of specific directory should be looked at.
    bool shouldVisitDirectory(const std::string &path) const;
    // Checks whether specific file should be processed.
    bool shouldProcessFile(const std::string &path) const;

    // Retrieves attributes for a specific path.
    Attrs lookupAttrs(const std::string &path) const;

private:
    // Finds root directory (sets `rootDir`) and returns path to configuration
    // directory.  Both paths are empty if nothing was found.
    boost::filesystem::path discoverRoot();
    // Loads data from configuration directory.
    void loadConfigDir(const boost::filesystem::path &configDir);
    // Checks whether specific path should be processed.
    bool isAllowed(const std::string &path, bool isDir) const;

private:
    boost::filesystem::path rootDir; // Root for the configuration.
    boost::filesystem::path currDir; // Current directory for relative paths.

    // List of rules for file exclusion.
    std::vector<MatchExpr> excludeRules;
    // List of rules for attribute assignments.
    std::vector<std::pair<MatchExpr, Attrs>> attrRules;
};

#endif // ZOGRASCOPE_TOOLING_CONFIG_HPP_